bidding document - ashuganj power station company ltd. · bidding document demolition, disposal of...

Bidding Document

Demolition, Disposal of Existing Power Plants & Site Development

And

Specification

of

Ashuganj 400 MW Combined Cycle Power Plant Project (East)

VOLUME 2 OF 3 (Part-A)

Demolition & Disposal of Existing Power Plants and

Site Development

VOLUME 2 OF 3 (Part-B)

Technical Specifications of Power Plant

Ashuganj Power Station Company Ltd. (APSCL)

Ashuganj, Brahmanbaria-3402

Bangladesh

May, 2016

Volume-2 of 3 (Part-A) Page-i

Ashuganj 400 MW CCPP (East) Demolition & Disposal of Existing Power Plants

Demolition & Disposal of Existing Power Plants and Site Development (Part-A)

Table of Contents

Appendix 1 – Definitions .............................................................................................................................. 1

1. PREAMBLE ........................................................................................................................................... 2

2. GENERAL REQUIREMENTS ............................................................................................................... 2

2.1 Introduction ...................................................................................................................... 2

2.2 General Particulars .......................................................................................................... 3

2.2.1 Planning of Work ....................................................................................................... 3

2.2.2 Meetings .................................................................................................................... 3

2.2.3 Monthly Progress Report .......................................................................................... 3

2.2.4 Photographs .............................................................................................................. 4

2.2.5 Operational Requirements ........................................................................................ 4

2.2.6 Site Security .............................................................................................................. 4

2.2.7 Safety ........................................................................................................................ 4

2.2.8 Substance Abuse policy & Responsibility ................................................................. 5

2.2.9 Temporary Construction Facilities ............................................................................. 6

2.3 Quality Management ....................................................................................................... 6

2.3.1 Quality management requirements ........................................................................... 6

2.3.1.1 General ........................................................................................................................................... 6

2.3.1.2 Scope .............................................................................................................................................. 6

2.3.1.3 Definitions ...................................................................................................................................... 7

2.3.2 Contractor's Quality Management ............................................................................. 7

2.3.2.1 Quality Systems ............................................................................................................................ 7

2.3.2.2 Quality Planning ............................................................................................................................. 7

2.3.2.3 Quality Documentation .................................................................................................................. 7

2.3.3 Engineer’s Quality Control ........................................................................................ 7

2.3.3.1 Evaluation of Quality System ......................................................................................................... 7

2.3.3.2 Assessment of Effectiveness of Quality Control ............................................................................. 8

2.3.3.3 Surveillance .................................................................................................................................... 8

2.3.4 Procedural Requirements ......................................................................................... 8

2.3.4.1 Quality control Plans ...................................................................................................................... 8

2.3.4.2 Right of Access ............................................................................................................................... 8

2.3.4.3 Quality Control Records ................................................................................................................. 8

3. SCOPE OF WORK ............................................................................................................................... 8

4. List of Equipment and the Register ....................................................................................................... 9

5. THE REGISTER OF EXTERNAL SERVICE CONNECTIONS ........................................................... 10

5.1 Electrical Supplies ......................................................................................................... 10

5.2 Cooling Water Supply & Cooling Water Outfall ............................................................. 10

Page-ii Volume-2 of 3 (Part-A)

Demolition & Disposal of Existing Power Plants Ashuganj 400 MW CCPP (East)

5.3 Towns Water Supplies ................................................................................................... 10

5.4 Sewage .......................................................................................................................... 10

5.5 Waste Disposal .............................................................................................................. 10

5.6 Entrance and Exit Ways ................................................................................................ 11

5.7 Transmitting & Receiving Aerial Facilities from High Structures: Should be

followed .......................................................................................................................... 11

5.8 Site Licenses and Insurances ........................................................................................ 11

6. PLANT INSULATION ISSUES ............................................................................................................ 11

7. DETERMINING STRUCTURAL HAZARDS ........................................................................................ 12

8. HAZARD IDENTIFICATION STUDY AND PLANT ITEM CHECK LIST ............................................. 13

8.1 Health Hazards .............................................................................................................. 13

9. MANAGEMENT OF DEMOUTION - SITE DEMOLITION PROCEEDURE ........................................ 14

9.1 Scope ............................................................................................................................. 14

9.2 Definition ........................................................................................................................ 14

9.3 Planning- ...................................................................................................................... 14

9.4 The Strategy ................................................................................................................. 15

9.5 Practical Stages of Demolition...................................................................................... 15

9.6 Clearance of Plant/System Final Operation ................................................................ 15

9.7 Clearance of Plant/System Terminal Isolation............................................................... 15

9.8 Closure Report ............................................................................................................... 15

9.9 Nomination of Staff ..................................................................................................... 16

10. SITE DEMOLITION SUPPLIES.......................................................................................................... 16

11. POST CONSTRUCTION SECURITY ................................................................................................. 16

12. List of Equipments and Structure/Foundation (to demolished and disposed) ....................................... 17

12.1 GT-1 and its auxiliaries .................................................................................................. 17

12.2 GT-2 and its auxiliaries .................................................................................................. 18

12.3 Waste Heat Recovery Unit (WHRU), Steam Turbine (ST) and their auxiliaries ............ 19

12.4 Others ............................................................................................................................ 19

13. Annexure 1 .......................................................................................................................................... 20

Volume-2 of 3 (Part-B) Page-iii

Ashuganj 400 MW CCPP (East) Techical Specification of Plant

Technical Specifications of Power Plant (Part-B)

Table of Contents

1. PROJECT DESCRIPTION .................................................................................................................. 21

1.1 General .......................................................................................................................... 21

1.2 Summary Scope of Work of Contractor ........................................................................ 21

1.2.1 Scope of Works ....................................................................................................... 22

1.2.2 Scope of Supply ...................................................................................................... 22

1.3 Terminal Points and Interfaces ..................................................................................... 25

1.3.1 Natural Gas ............................................................................................................. 25

1.3.2 Water ....................................................................................................................... 25

1.3.2.1 Raw Water .................................................................................................................... 25

1.3.2.2 Potable Water .............................................................................................................. 25

1.3.3 Drainage .................................................................................................................. 26

1.3.3.1 Surface water ............................................................................................................... 26

1.3.3.2 Sanitary and Sewer Facilities ........................................................................................ 26

1.3.3.3 Oily and Chemical Drains .............................................................................................. 26

1.3.4 Electrical Connections ............................................................................................. 26

1.3.4.1 Characteristics of the System Load .............................................................................. 26

1.3.4.2 Present Network for Transmission of Power ............................................................... 26

1.3.4.3 400 kV GIS Sub-Station for power evacuation ............................................................. 26

1.3.5 Interface Summary Table ........................................................................................ 27

1.4 Site Description ............................................................................................................. 28

1.4.1 LOCATION .............................................................................................................. 28

1.4.2 Site Condition .......................................................................................................... 28

1.4.2.1 Topography .................................................................................................................. 28

1.4.2.2 Site investigation .......................................................................................................... 28

1.4.2.3 Soil conditions .............................................................................................................. 28

1.4.2.4 Seismic Conditions ....................................................................................................... 29

1.4.2.5 Meteorological Condition ............................................................................................. 29

1.4.2.6 Hydrological Conditions ............................................................................................... 29

1.4.2.7 Water Supply ................................................................................................................ 30

1.4.2.8 River Water Quality ...................................................................................................... 30

1.4.2.9 Air Temperature ........................................................................................................... 30

1.4.3 Existing Power Plants at the station ........................................................................ 31

2. PERFORMANCE, OPERATING AND MAINTENANCE REQUIREMENTS ....................................... 32

2.1 Plant Design Criteria ..................................................................................................... 32

Page-iv Volume-2 of 3 (Part-B)

Techical Specification of Plant Ashuganj 400 MW CCPP (East)

2.2 Fuel Gas Specification ................................................................................................... 32

2.3 Performance Guarantees and Operating Requirements ............................................... 33

2.3.1 Performance Guarantees ........................................................................................ 33

2.3.2 Plant Operation Conditions ...................................................................................... 35

2.3.2.1 Plant Operating Profile ................................................................................................ 35

2.3.2.2 The estimated number of starts per year is as follows: ............................................... 36

2.3.2.3 Availability and Reliability ............................................................................................ 36

2.3.2.4 Electrical Grid Requirements ....................................................................................... 37

2.3.2.5 Other Operating Conditions ........................................................................................ 37

2.4 Operability ...................................................................................................................... 38

2.5 Plant Dispatch ................................................................................................................ 38

2.6 Maintainability ................................................................................................................ 38

2.7 General Redundancy Requirements ............................................................................. 38

2.8 Plant Standardization ..................................................................................................... 40

3. GENERAL REQUIREMENTS ............................................................................................................. 41

3.1 Definition of Terms ......................................................................................................... 41

3.2 Codes and Standards .................................................................................................... 42

3.3 Design Life ..................................................................................................................... 44

3.4 Language and Units ....................................................................................................... 44

3.5 Site Regulations and Safety .......................................................................................... 44

3.6 Notices and Permits ....................................................................................................... 45

3.7 Verification of Dimensions ............................................................................................. 45

3.8 Site to be Kept Tidy ....................................................................................................... 45

3.9 Reinstatement ................................................................................................................ 45

3.10 Site Supervisors ............................................................................................................. 45

3.11 Occupational Health and Safety .................................................................................... 45

3.12 Packing and Transport Identification ............................................................................. 46

3.13 Identification Markings ................................................................................................... 46

3.14 Maintenance Tools and Appliances ............................................................................... 46

3.15 Disposal and Pollution ................................................................................................... 47

4. SITE CONDITIONS ............................................................................................................................. 48

4.1 General .......................................................................................................................... 48

4.2 Meteorology ................................................................................................................... 48

4.2.1 General Description of Climatic Conditions at Ashuganj ......................................... 48

4.2.2 Temperature and Humidity ...................................................................................... 48

4.2.3 Rainfall ..................................................................................................................... 49

4.2.4 Wind ......................................................................................................................... 49

4.2.4.1 Design Wind ................................................................................................................................. 50

4.2.5 Air Quality ................................................................................................................ 50

4.3 Hydrology ....................................................................................................................... 51

4.3.1 General Description of Meghna River Adjacent to the Ashuganj Site ..................... 51

4.3.2 River Water Temperature ........................................................................................ 51

4.3.3 River Water Flow and Velocity ................................................................................ 52

Volume-2 of 3 (Part-B) Page-v


4.3.4 Water Levels, Depths and Bathymetry .................................................................... 52

4.3.5 Extremes in Records Data ...................................................................................... 53

4.3.6 River Water Quality ................................................................................................. 53

4.3.7 Ground Water Quality (for information only) ........................................................... 54

4.3.8 Ground Water Level ................................................................................................ 55

4.3.9 Other Notes on the Meghna River .......................................................................... 55

4.3.10 Site Level ................................................................................................................. 55

4.4 Site Seismicity and Seismic Design Codes................................................................... 56

4.5 Geotechnical Investigation Requirements..................................................................... 56

4.6 Site Access .................................................................................................................... 57

4.7 Construction Facilities and Site Services ...................................................................... 57

4.7.1 Lay Down Area ........................................................................................................ 57

4.7.2 Staffing / Accommodation ....................................................................................... 57

4.7.3 Utilities ..................................................................................................................... 58

4.7.3.1 Construction Power ...................................................................................................... 58

4.7.3.2 Construction Water ...................................................................................................... 58

4.7.3.3 Gas for Commissioning ................................................................................................. 58

4.7.3.4 Electricity Feeding for Commissioning ......................................................................... 58

4.7.3.5 Electricity Produced after First Synchronization .......................................................... 58

5. CIVIL, STRUCTURAL AND ARCHITECTURAL WORKS .................................................................. 59

5.1 General Requirements .................................................................................................. 59

5.2 Site Development and Site Level .................................................................................. 59

5.2.1 General .................................................................................................................... 59

5.2.2 Earthwork ................................................................................................................ 59

5.2.2.1 General ......................................................................................................................... 59

5.2.2.2 Excavation .................................................................................................................... 59

5.2.2.3 Clearing and Grubbing .................................................................................................. 60

5.2.2.4 Stripping ....................................................................................................................... 60

5.2.2.5 Disposal of Unusable Materials .................................................................................... 60

5.2.2.6 Plant Grading ................................................................................................................ 60

5.2.2.7 Filling, Site Development and Compaction Requirements ........................................... 61

5.2.2.8 Backfilling ..................................................................................................................... 61

5.3 Site Drainage ................................................................................................................. 62

5.3.1 Description of Site Drainage System ...................................................................... 62

5.3.2 Storm Water Drainage Design and Construction .................................................... 62

5.3.3 Contaminated Storm water Runoff .......................................................................... 63

5.3.4 Sanitary Waste Water ............................................................................................. 63

5.4 Potable Water supply .................................................................................................... 63

5.5 Road and Paving Work ................................................................................................. 63

5.5.1 General .................................................................................................................... 63

Page-vi Volume-2 of 3 (Part-B)


5.5.2 Roadway Design ...................................................................................................... 64

5.5.3 Road Classifications ................................................................................................ 64

5.5.4 Road Geometry ....................................................................................................... 64

5.5.5 Sidewalks ................................................................................................................. 64

5.6 Structural Work .............................................................................................................. 64

5.6.1 General .................................................................................................................... 64

5.6.2 Design Loading ........................................................................................................ 65

5.6.2.1 General ........................................................................................................................ 65

5.6.2.2 Live Load ...................................................................................................................... 65

5.6.2.3 Dead Loads .................................................................................................................. 67

5.6.2.4 Piping, Conduit and Cable Tray Loads .......................................................................... 67

5.6.2.5 Wind Load .................................................................................................................... 67

5.6.2.6 Seismic Load ................................................................................................................ 67

5.6.2.7 Construction Live Loads ............................................................................................... 68

5.6.2.8 Equipment Loads ......................................................................................................... 68

5.6.2.9 Impact and Dynamic Loads .......................................................................................... 68

5.6.2.10 Monorail Loads ............................................................................................................ 69

5.6.2.11 Loads for Earth Retaining Structures ........................................................................... 69

5.6.2.12 General Stability Loads ................................................................................................ 69

5.6.2.13 Column Stability Loads................................................................................................. 69

5.6.3 Serviceability Limits ................................................................................................. 69

5.6.4 Loading and Load Combinations ............................................................................. 70

5.6.4.1 Loading Conditions ...................................................................................................... 70

5.6.4.2 Loads to be Considered ............................................................................................... 70

5.6.4.3 Load Combinations ...................................................................................................... 72

5.6.4.4 Load Combination (Allowable Stress Design) .............................................................. 72

5.6.4.4.1 Loading Combinations (Strength Design) ........................................................ 72

5.7 Piling .............................................................................................................................. 72

5.7.1 Pre-cast Piles ........................................................................................................... 73

5.7.2 Driving Piles ............................................................................................................. 73

5.7.3 In-Situ Piles .............................................................................................................. 74

5.7.4 Testing ..................................................................................................................... 75

5.7.5 Test Pile Load .......................................................................................................... 75

5.7.6 Settlement under Test Loads .................................................................................. 76

5.7.7 Installation Tolerances ............................................................................................. 76

5.7.8 Pile Layout ............................................................................................................... 76

5.7.9 Rejection of Piles ..................................................................................................... 76

5.8 Foundations ................................................................................................................... 76

5.8.1 General .................................................................................................................... 76

Volume-2 of 3 (Part-B) Page-vii


5.8.2 Equipment Foundations .......................................................................................... 77

5.8.3 Steam Turbine Foundation ...................................................................................... 77

5.8.4 HRSG and Chimney Foundation ............................................................................. 77

5.8.5 Building Foundations ............................................................................................... 78

5.8.6 Transformer Foundations ........................................................................................ 78

5.8.7 Switching Area Foundations ................................................................................... 78

5.8.8 Electrical Ducts and Manholes ................................................................................ 78

5.9 Buildings and Structures ............................................................................................... 79

5.9.1 General .................................................................................................................... 79

5.9.2 Glazed Ceramic Tiling ............................................................................................. 79

5.9.3 Suspended Ceiling .................................................................................................. 80

5.9.4 Gypsum Board Partitions ........................................................................................ 80

5.9.5 Air Conditioning System .......................................................................................... 80

5.9.6 Ventilation System ................................................................................................... 81

5.9.7 Plumbing and Sanitary Installation .......................................................................... 81

5.9.8 Lighting .................................................................................................................... 81

5.9.9 Fire Protection of Buildings ..................................................................................... 81

5.9.10 Lightning .................................................................................................................. 81

5.9.11 External Louvres ..................................................................................................... 81

5.9.12 Buildings .................................................................................................................. 82

5.9.12.1 GT/Steam Turbine Building .......................................................................................... 82

5.9.12.2 Control Room and Electrical Annex .............................................................................. 82

5.9.12.3 Warehouse Building ..................................................................................................... 82

5.9.12.4 Water and Wastewater Treatment Buildings ............................................................... 83

5.9.12.5 Fire Water Pump House ............................................................................................... 83

5.9.12.6 Additional Site Access Points and Security ................................................................... 83

5.9.12.7 Miscellaneous Buildings ............................................................................................... 83

5.9.12.8 Plant support Structures .............................................................................................. 83

5.10 River Water Intake and Outfall Structures ..................................................................... 83

5.10.1 Water Intake ............................................................................................................ 83

5.10.2 Outfall Structure ...................................................................................................... 84

5.11 Unloading Facilities ....................................................................................................... 84

5.12 Major Construction Materials ........................................................................................ 84

5.13 Concrete Work .............................................................................................................. 85

5.13.1 General .................................................................................................................... 85

5.13.2 Material .................................................................................................................... 85

5.13.3 Execution of Work ................................................................................................... 86

5.13.4 Minimum Cover ....................................................................................................... 86

5.13.5 Other Requirements ................................................................................................ 86

5.13.6 Tests ........................................................................................................................ 86

Page-viii Volume-2 of 3 (Part-B)


5.13.7 Cement .................................................................................................................... 87

5.13.8 Admixture ................................................................................................................. 87

5.13.9 Water ....................................................................................................................... 87

5.13.10 Aggregate ................................................................................................................ 87

5.13.11 Concrete Mixing ....................................................................................................... 88

5.13.12 Placing ..................................................................................................................... 88

5.13.13 Transportation .......................................................................................................... 89

5.13.14 Curing ...................................................................................................................... 89

5.13.15 Formwork and Timber .............................................................................................. 89

5.13.16 Water Stops and Expansion Joints .......................................................................... 89

5.13.17 Finish and Repair of Concrete ................................................................................. 90

5.13.17.1 General ........................................................................................................................ 90

5.13.17.2 Concrete Construction Tolerances .............................................................................. 90

5.13.17.3 Repair of concrete ....................................................................................................... 91

5.13.18 Reinforcing Bars ...................................................................................................... 91

5.13.19 Stop Ends ................................................................................................................ 92

5.14 Masonry Work ................................................................................................................ 92

5.14.1 Brick Walls ............................................................................................................... 93

5.15 Calking ........................................................................................................................... 93

5.16 Carpentry and Joinery ................................................................................................... 93

5.16.1 Timber ...................................................................................................................... 93

5.16.2 Preservative ............................................................................................................. 93

5.16.3 Joinery Fittings ......................................................................................................... 93

5.16.4 Faults ....................................................................................................................... 94

5.17 Doors and Windows ....................................................................................................... 94

5.18 Painting .......................................................................................................................... 94

5.18.1 Materials .................................................................................................................. 94

5.18.2 Surface Preparation ................................................................................................. 95

5.18.3 Workmanship ........................................................................................................... 95

5.18.4 Priming ..................................................................................................................... 95

5.18.5 Number of Coats ...................................................................................................... 95

5.19 Steelwork ....................................................................................................................... 95

5.19.1 General .................................................................................................................... 95

5.19.2 Paint ......................................................................................................................... 96

5.19.3 Connections ............................................................................................................. 96

5.19.3.1 General ........................................................................................................................ 96

5.19.3.2 Design .......................................................................................................................... 96

5.20 Perimeter Security Fencing and Gates .......................................................................... 97

5.21 Site Laboratory .............................................................................................................. 97

5.22 Records and Drawings .................................................................................................. 97

5.23 Samples, Testing and Inspection .................................................................................. 97

Volume-2 of 3 (Part-B) Page-ix


5.24 Landscaping .................................................................................................................. 98

5.25 Quality of local materials ............................................................................................... 98

6. GAS TURBINE .................................................................................................................................... 99

6.1 Gas Turbine Package .................................................................................................... 99

6.2 Compressor ................................................................................................................. 101

6.3 Fuel Supply System .................................................................................................... 101

6.4 Combustion System .................................................................................................... 102

6.5 Air Inlet Filtering and Silencing .................................................................................... 103

6.6 Exhaust System .......................................................................................................... 104

6.7 Starting Facilities ......................................................................................................... 105

6.8 Wash System .............................................................................................................. 105

6.9 Turning Gear ............................................................................................................... 105

6.10 Lubrication Oil System ................................................................................................ 105

6.10.1 Lube Oil Pumps ..................................................................................................... 106

6.10.2 Lube Oil Coolers .................................................................................................... 106

6.10.3 Lube Oil Filters ...................................................................................................... 106

6.10.4 Vapour Extractors .................................................................................................. 106

6.11 Fire and Gas Detection and Protection ....................................................................... 106

6.11.1 Fire Detection System ........................................................................................... 106

6.11.2 Fire Protection/Detection System Controls ........................................................... 107

6.12 Cooling System ........................................................................................................... 107

6.13 GT Package Enclosures and Insulation ...................................................................... 107

6.14 Controls and Supervisory Instrumentation .................................................................. 108

6.15 Trip and Alarm Functions ............................................................................................ 109

7. FUEL GAS SYSTEM ........................................................................................................................ 110

7.1 Scope .......................................................................................................................... 110

7.2 Standards .................................................................................................................... 111

7.3 Guarantees .................................................................................................................. 112

7.4 Gas Industry Relationships ......................................................................................... 112

7.5 Fuel Gas Composition ................................................................................................. 112

7.5.1 Regulating and Metering Station (RMS) ............................................................... 112

7.6 Fuel Gas Demand ....................................................................................................... 113

7.7 Gas Metering ............................................................................................................... 113

7.8 Branch Pipeline ........................................................................................................... 113

7.9 Gas Conditioning ......................................................................................................... 113

7.10 Gas Compressors ....................................................................................................... 114

7.11 Gas Venting and Purging ............................................................................................ 114

7.12 Filtration and Pressure Reduction Equipment............................................................. 115

7.13 Gas Piping ................................................................................................................... 115

7.14 Electrical Sub-Systems ............................................................................................... 116

7.15 Instruments and Controls ............................................................................................ 116

7.16 Civil Engineering ......................................................................................................... 116

7.17 Consumables .............................................................................................................. 116

7.18 Lube Oil / Condensate Removal ................................................................................. 116

Page-x Volume-2 of 3 (Part-B)


7.19 Noise Control ............................................................................................................... 116

7.20 Documentation ............................................................................................................. 117

8. HEAT RECOVERY STEAM GENERATOR ...................................................................................... 118

8.1 General Requirements ................................................................................................. 118

8.1.1 Applicable Codes ................................................................................................... 118

8.1.2 Specific Requirements ........................................................................................... 118

8.2 Casing and Refractory Materials ................................................................................. 120

8.3 Drums and Headers ..................................................................................................... 120

8.4 Heat Transfer Tubes .................................................................................................... 120

8.5 Blow down Equipment ................................................................................................. 121

8.6 Valves and Accessories ............................................................................................... 121

8.7 Exhaust Stack .............................................................................................................. 121

8.8 Water and Steam Sampling Analysis Systems ........................................................... 122

8.9 Chemical Feed Systems .............................................................................................. 122

8.10 Expansion joints ........................................................................................................... 122

8.11 Desuperheaters and Attemperators ............................................................................ 122

8.12 Drains ........................................................................................................................... 123

9. STEAM TURBINE AND AUXILIARIES ............................................................................................. 124


9.2 Turbine, Stop, Intercept and Throttle Valves ............................................................... 127

9.2.1 Multiple Steam Control Valves: ............................................................................. 128

9.3 Casing .......................................................................................................................... 128

9.4 Rotor, Blading, bearings and Couplings ...................................................................... 129

9.5 Gland Steam Sealing System ...................................................................................... 129

9.6 Turbine Turning Gear .................................................................................................. 129

9.7 Turbine Lube Oil System ............................................................................................. 130

9.7.1 Lubricating Oil Pumps ............................................................................................ 130

9.7.2 Lubricating Oil Coolers .......................................................................................... 131

9.7.3 Oil Purifier .............................................................................................................. 131

9.7.4 Oil Pipe work .......................................................................................................... 131

9.7.5 Hydraulic Oil System ............................................................................................. 131

9.8 Steam Strainers ........................................................................................................... 132

9.9 Exhaust Hood Sprays .................................................................................................. 132

9.10 Governing System ....................................................................................................... 132

9.10.1 Governor Speed and Reference Signals ............................................................... 132

9.10.2 Requirements for On-Load Governor Control ....................................................... 132

9.11 Emergency Trips .......................................................................................................... 133

9.11.1 Online Testing ........................................................................................................ 133

9.11.2 Integrity and Reliability ........................................................................................... 134

9.12 Steam Turbine Bypass System ................................................................................... 134

9.13 Packing Leakage Dump Valve .................................................................................... 135

9.14 Low Vacuum Tripping Device ...................................................................................... 135

9.15 Remote Trip ................................................................................................................. 135

Volume-2 of 3 (Part-B) Page-xi


9.16 Microprocessor Based Digital Electro Hydraulic Control System ............................... 135

9.17 Deaerator .................................................................................................................... 136

9.18 Boiler Feed Pumps ...................................................................................................... 136

10. HEAT REJECTION SYSTEM ........................................................................................................... 137

10.1 Condenser ................................................................................................................... 137

10.1.1 Design ................................................................................................................... 137

10.1.2 Steam Bypass System .......................................................................................... 138

10.1.3 Air Evacuation and Removal ................................................................................. 138

10.2 Condensate System .................................................................................................... 138

10.3 Circulating Water System ............................................................................................ 139

10.3.1 Main Cooling Water Pumps .................................................................................. 139

10.3.2 Ancillary Systems and Equipment ......................................................................... 140

10.3.3 Intake Screens ...................................................................................................... 140

10.4 Auxiliary Cooling Water System .................................................................................. 140

11. MECHANICAL BALANCE OF PLANT .............................................................................................. 142

11.1 River Water System .................................................................................................... 142

11.1.1 General .................................................................................................................. 142

11.1.2 Circulating Water Intake System ........................................................................... 142

11.1.3 Common raw water suction chamber .................................................................... 143

11.1.4 Lifting equipment ................................................................................................... 143

11.1.5 Raw Water Pumps ................................................................................................ 144

11.1.5.1 Submersible Option.................................................................................................................... 144

11.1.6 Pipe work ............................................................................................................... 144

11.2 Raw Water Treatment System .................................................................................... 144

11.3 Demineralised Water System ...................................................................................... 144

11.4 Potable/Drinking Water System .................................................................................. 145

11.5 Waste Water Treatment System ................................................................................. 145

11.6 Compressed Air System .............................................................................................. 146

11.6.1 Plant Compressed Air ........................................................................................... 146

11.6.2 Instrument Compressed Air .................................................................................. 146

11.7 Fire Detection and Protection System ......................................................................... 147

11.7.1 Fire Protection Master Plan and Design Basis ..................................................... 147

11.7.2 Codes and Standards............................................................................................ 148

11.7.3 Fire Protection Water Supply and Water Storage ................................................. 150

11.7.4 Fire Pumps ............................................................................................................ 150

11.7.5 Fire Detection Systems ......................................................................................... 150

11.7.6 Fire Protection and Detection Systems ................................................................. 151

11.7.7 Fire Protection Alarms and Controls ..................................................................... 154

11.7.8 Hydrant System ..................................................................................................... 154

11.7.9 Portable Extinguishers .......................................................................................... 154

11.8 Cranes and Lifting Equipment ..................................................................................... 154

11.9 Heating Ventilation and Air Conditioning ..................................................................... 155

Page-xii Volume-2 of 3 (Part-B)


11.9.1 Air Conditioning Systems....................................................................................... 156

11.9.2 Battery Room Exhaust ........................................................................................... 156

11.9.3 Design Parameters for HVAC ................................................................................ 157

11.9.4 HVAC Applicable Standards .................................................................................. 157

11.10 Chemical and Bottled Gas Storage ............................................................................. 158

11.11 Hydrogen Generation Plant (if necessary) .................................................................. 159

11.12 Emergency Diesel Generating Set (EDG) ................................................................... 159

11.13 Modernization of the existing workshop ...................................................................... 159

11.14 Chemical Laboratory Equipment ................................................................................. 160

11.15 Electrical workshop Equipment.................................................................................... 160

12. PLANT ELECTRICAL SYSTEMS AND EQUIPMENT ...................................................................... 162


12.2 Plant Start-up and House Load Operation .................................................................. 162

12.3 Generator ..................................................................................................................... 163

12.3.1 Type ....................................................................................................................... 163

12.3.2 Rating..................................................................................................................... 163

12.3.3 Generator Construction ......................................................................................... 163

12.3.4 Cooling ................................................................................................................... 164

12.3.5 Accessories ........................................................................................................... 164

12.3.6 Excitation and Voltage Regulation ......................................................................... 164

12.3.7 Turbine-Generator Starting System ....................................................................... 165

12.3.8 Generator Main Connections ................................................................................. 165

12.3.9 Neutral Earthing ..................................................................................................... 166

12.4 Generator Circuit Breaker ............................................................................................ 166

12.5 Isolated Phase Bus Ducts ............................................................................................ 166

12.6 Transformer ................................................................................................................. 166

12.6.1 General .................................................................................................................. 166

12.6.2 Technical Requirements for Oil-type Transformers ............................................... 167

12.6.3 Generator Step-Up Transformer ............................................................................ 171

12.6.3.1 230/6.6 KV, 32 MVA Grid Auxiliary Transformer ....................................................................... 171

12.6.3.2 11~22/6.6 KV, 32 MVA Unit Auxiliary Transformer ................................................................... 172

12.6.3.3 GSUT On-Load Tap Changer ...................................................................................................... 172

12.6.4 Auxiliary Power ...................................................................................................... 172

12.6.5 Auxiliary Transformers ........................................................................................... 172

12.6.6 400 KV GIS Equipment.......................................................................................... 173

12.6.6.1 GENERAL .................................................................................................................... 173

12.6.6.1.1 DESIGN EQUIPMENT ..................................................................................... 173

12.6.6.2 400 KV GIS EQUIPMENT ............................................................................................. 173

12.6.6.2.1 400 KV CIRCUIT BREAKERS ............................................................................ 173

12.6.6.2.3 400KV VOLTAGE TRANSFORMER .................................................................. 175

12.6.6.2.5 400 KV LIGHTNING ARRESTERS ..................................................................... 177

Volume-2 of 3 (Part-B) Page-xiii


12.6.6.3 STEEL STRUCTURE ...................................................................................................... 178

12.6.6.3.1 TYPE ............................................................................................................... 178

12.6.6.3.2 DESIGN CRITERIA ........................................................................................... 178

12.6.6.3.3 REQUIREMENTS FOR DESIGN AND CONSTRUCTION ............................. 179

12.6.6.3.4 DESIGN ITEMS ................................................................................................ 179

12.6.6.3.5 ACCESSORIES ................................................................................................. 179

12.6.6.4 INSULATORS AND WIRING MATERIALS ...................................................................... 180

12.6.6.4.1 INSULATORS ................................................................................................... 180

12.6.6.4.2 FITTING .......................................................................................................... 180

12.6.6.4.3 STANDARD CONDUCTORS FOR OVERHEAD LINE ........................................... 181

12.6.6.4.4 MISCELLANEOUS MATERIALS ........................................................................ 181

12.6.6.5 400 kV SWITCHGEAR CONTROL AND PROTECTION ................................................... 181

12.6.6.5.1 400 kV SWITCHGEAR EQUIPMENT PANEL ..................................................... 181

12.6.7 230 KV GIS Equipment ......................................................................................... 182

12.6.7.1 GENERAL ..................................................................................................................... 182

12.6.7.2 230 KV GIS EQUIPMENT ............................................................................................. 182

12.6.7.2.1 230 KV CIRCUIT BREAKERS ............................................................................. 182

12.6.7.2.2 230KV DISCONNECTING SWITCHES ............................................................... 184

12.6.7.2.3 230KV VOLTAGE TRANSFORMER ................................................................... 184

12.6.7.2.4 230KV CURRENT TRANSFORMERS ................................................................. 185

12.6.7.2.5 230 KV LIGHTNING ARRESTERS ...................................................................... 186

12.6.7.3 STEEL STRUCTURE ...................................................................................................... 187

12.6.7.3.1 TYPE ............................................................................................................... 187

12.6.7.3.2 DESIGN CRITERIA ........................................................................................... 187

12.6.7.3.3 REQUIREMENTS FOR DESIGN AND CONSTRUCTION ..................................... 188

12.6.7.3.4 DESIGN ITEMS ................................................................................................ 189

12.6.7.3.5 ACCESSORIES ................................................................................................. 189

12.6.7.4 INSULATORS AND WIRING MATERIALS ...................................................................... 189

12.6.7.4.1 INSULATORS ................................................................................................... 189

12.6.7.4.2 FITTING .......................................................................................................... 190

12.6.7.4.3 STANDARD CONDUCTORS FOR OVERHEAD LINE ........................................... 190

12.6.7.4.4 MISCELLANEOUS MATERIALS ........................................................................ 191

12.6.7.5 230 kV SWITCHGEAR CONTROL AND PROTECTION ................................................... 191

12.6.7.5.1 230 kV SWITCHGEAR EQUIPMENT PANEL ..................................................... 191

12.7 Medium Voltage Switchgear ....................................................................................... 191

12.8 Low Voltage Switchboards and Motor Control Centres .............................................. 192

12.9 Bus Ducts (as required) ............................................................................................... 193

12.9.1 Non-Segregated Phase Bus Duct ......................................................................... 193

Page-xiv Volume-2 of 3 (Part-B)


12.10 Electric Motors ............................................................................................................. 193

12.11 Protection Relays ......................................................................................................... 194

12.11.1 Generator Protection ............................................................................................. 195

12.11.2 Transformer Protection .......................................................................................... 195

12.11.3 400 KV Bus-bar Differential Protection .................................................................. 196

12.11.4 Circuit Breaker Fail Protection ............................................................................... 196

12.11.5 Medium Voltage Switchgear Protection ................................................................. 196

12.11.6 Low Voltage Switchboard Protection ..................................................................... 196

12.12 DC and UPS Systems ................................................................................................. 196

12.12.1 Battery Charger Performance ................................................................................ 197

12.12.2 UPS Performance .................................................................................................. 198

12.12.3 Batteries Performance ........................................................................................... 198

12.13 Power and Control Cabling .......................................................................................... 199

12.13.1 Conductors ............................................................................................................ 199

12.13.2 Conductor Screen .................................................................................................. 199

12.13.3 Cable Insulation ..................................................................................................... 199

12.13.4 Filler and Binder ..................................................................................................... 200

12.13.5 Insulation Screen ................................................................................................... 200

12.13.6 Metallic Screen ...................................................................................................... 200

12.13.7 Oversheath ............................................................................................................ 200

12.13.8 Sealing and Drumming .......................................................................................... 201

12.13.9 Accessories ........................................................................................................... 201

12.14 Earthing and Lightning Protection ............................................................................... 201

12.14.1 Earthing.................................................................................................................. 201

12.14.2 Lightning Protection ............................................................................................... 203

12.15 Lighting System and Power Outlets ............................................................................ 203

12.15.1 General Design Requirement ................................................................................ 203

12.15.2 Lighting Sources .................................................................................................... 203

12.15.3 Emergency Lighting ............................................................................................... 203

12.15.4 Outdoor Lighting .................................................................................................... 204

12.15.5 Power Outlet Sockets ............................................................................................ 204

12.16 Fire Detection System ................................................................................................. 204

12.17 Cathodic Protection ..................................................................................................... 205

12.18 Electrical Apparatus in Hazardous Areas .................................................................... 205

12.19 Power Evacuation ........................................................................................................ 206

12.19.1 Cable Construction ................................................................................................ 206

12.19.2 Insulation ............................................................................................................... 206

12.19.3 Manufacturing Process of Conductor Screen, Insulation and Insulation Screen .. 207

12.19.4 Bedding Tape ........................................................................................................ 207

12.19.5 Insulation Screen (Metallic) ................................................................................... 207

12.19.6 Longitudinal Water Blocking .................................................................................. 207

Volume-2 of 3 (Part-B) Page-xv


12.19.7 Metallic Sheath ...................................................................................................... 208

12.19.8 Short-Circuit .......................................................................................................... 208

12.19.9 Outer Sheath ......................................................................................................... 208

12.19.10 Testing and Inspection .......................................................................................... 208

12.19.11 Site Test Insulating Barrier of Joints ..................................................................... 208

12.19.12 Special Bonding Test ............................................................................................ 208

12.19.13 Impedance Measurements .................................................................................... 209

13. CONTROL AND INSTRUMENTATION ............................................................................................ 210

13.1 Description of Control Architecture ............................................................................. 210

13.2 Introduction .................................................................................................................. 210

13.3 Scope .......................................................................................................................... 210

13.4 ICMS Design Principles ............................................................................................... 210

13.4.1 General Design Principles ..................................................................................... 210

13.4.2 Codes and Standards............................................................................................ 212

13.5 ICMS Architecture ....................................................................................................... 214

13.5.1 Distributed Control System ................................................................................... 214

13.5.2 Data Communications Network ............................................................................. 214

13.5.3 Network Components ............................................................................................ 215

13.5.4 Field Bus ............................................................................................................... 215

13.6 ICMS Characteristics ................................................................................................... 215

13.7 ICMS Functionality ...................................................................................................... 216

13.8 Points of Monitoring and Control ................................................................................. 217

13.8.1 Locally at Auxiliary Equipment .............................................................................. 217

13.8.2 Process Stations ................................................................................................... 217

13.8.3 Central Control Room............................................................................................ 217

13.8.4 National Load Dispatch Centre (NLDC) ................................................................ 218

13.8.5 Engineer’s Workstation ......................................................................................... 220

13.8.6 Plant Manager’s Workstation ................................................................................ 221

13.8.7 Condition Monitoring Workstation ......................................................................... 221

13.8.8 Plant Performance Monitoring ............................................................................... 222

13.8.9 Security and Access Control ................................................................................. 223

13.9 Displays and Reports .................................................................................................. 223

13.9.1 Overview Display ................................................................................................... 223

13.9.2 Process Graphics Display ..................................................................................... 223

13.9.3 Operator Input Windows ....................................................................................... 224

13.9.4 Group Display ........................................................................................................ 224

13.9.5 Loop Display .......................................................................................................... 224

13.9.6 Alarm Summary Display ........................................................................................ 225

13.9.7 Trend Display ........................................................................................................ 225

13.9.8 Characteristic Curve .............................................................................................. 225

13.9.9 Logging .................................................................................................................. 226

Page-xvi Volume-2 of 3 (Part-B)


13.9.10 Alarm Display ......................................................................................................... 226

13.9.11 Sequence of Events Recording ............................................................................. 228

13.9.12 ICMS Configuration Summary ............................................................................... 228

13.9.13 Notepad Display .................................................................................................... 228

13.9.14 Building Services and Instrumented Protective System Displays ......................... 228

13.10 ICMS Performance and Capacity ................................................................................ 228

13.11 Instrumentation ............................................................................................................ 229

13.11.1 General .................................................................................................................. 229

13.11.2 Thermowells and Protecting Tubes ....................................................................... 229

13.11.3 Thermocouples and Resistance Temperature Detectors ...................................... 229

13.11.4 Transmitters ........................................................................................................... 229

13.11.5 Process Measurement Switches ........................................................................... 229

13.11.6 Local Indicators ...................................................................................................... 229

13.11.7 Solenoid Valves ..................................................................................................... 230

13.11.8 Actuators ................................................................................................................ 230

13.11.9 Earthling ................................................................................................................. 230

13.11.10 Calibration Test Bench / Console .......................................................................... 230

13.11.11 Test Instruments .................................................................................................... 233

13.12 Historian Server ........................................................................................................... 235

13.13 Station Facilities ........................................................................................................... 236

13.13.1 Emissions Monitoring ............................................................................................. 236

13.13.2 Station Clock System ............................................................................................. 237

13.13.3 Public Address System .......................................................................................... 238

13.13.4 Revenue Metering ................................................................................................. 238

13.14 Communications Systems ........................................................................................... 240

13.14.1 General .................................................................................................................. 240

13.14.2 Communication System Standards ....................................................................... 240

13.14.3 External Data Communications ............................................................................. 241

13.14.4 Optical Cable and Equipment ................................................................................ 241

13.14.5 Telephone System ................................................................................................. 242

13.14.5.1 Power Station ........................................................................................................................ 242

14. GENERAL TECHNICAL REQUIREMENTS ...................................................................................... 243

14.1 Pumps .......................................................................................................................... 243

14.2 Valves .......................................................................................................................... 244

14.2.1 Access ................................................................................................................... 244

14.2.2 Nameplates ............................................................................................................ 244

14.2.3 Requirements ........................................................................................................ 244

14.2.3.1 Wedge Gate Valves .................................................................................................... 245

14.2.3.2 Swing Check Valves .................................................................................................... 245

14.2.3.3 Wafer Type Check Valves ........................................................................................... 246

14.2.3.4 Ball Valves .................................................................................................................. 246

Volume-2 of 3 (Part-B) Page-xvii


14.2.3.5 Butterfly Valves .......................................................................................................... 246

14.2.3.6 Globe Valves ............................................................................................................... 247

14.2.3.7 Full Conduit Slab Gate Valve ...................................................................................... 247

14.2.4 Corrosion Protection.............................................................................................. 248

14.2.5 Repair of Defects ................................................................................................... 248

14.2.6 Drawings ............................................................................................................... 248

14.2.7 Steam .................................................................................................................... 248

14.2.8 Condensate Drains and Air Release ..................................................................... 249

14.2.9 Steam and Circulating Water ................................................................................ 249

14.2.10 Filters and Strainers .............................................................................................. 249

14.2.11 Steam Traps .......................................................................................................... 249

14.2.12 High Point Vents .................................................................................................... 249

14.2.13 Low Point Drain ..................................................................................................... 249

14.3 Actuators for Power Operated Valves ......................................................................... 250

14.3.1 General .................................................................................................................. 250

14.3.2 Modulating Valve Control ...................................................................................... 250

14.3.3 Electro Hydraulic Actuators ................................................................................... 251

14.3.4 Solenoid Actuators ................................................................................................ 251

14.3.5 Electric Actuators .................................................................................................. 251

14.3.5.1 General ....................................................................................................................... 251

14.3.5.2 Actuator Environmental Protection ........................................................................... 252

14.3.5.3 Actuator Local Manual Controls ................................................................................. 252

14.3.5.4 Torque and Travel Limiting ......................................................................................... 252

14.3.5.5 Actuator Analogue and Discrete Inputs/Outputs ....................................................... 253

14.3.5.6 Actuator Remote Control and Monitoring Facilities .................................................. 254

14.3.5.7 Actuator Controls, Data and Fault Communications .................................................. 254

14.3.5.8 Motor Power Supply .................................................................................................. 255

14.3.5.9 Seismic and Vibration Resistance ............................................................................... 255

14.3.5.10 Commissioning Aids ................................................................................................... 255

14.3.6 Pneumatically Operated Control Valves ............................................................... 255

14.3.6.1 Codes and Standards .................................................................................................. 255

14.3.6.2 Tagging and Name Plate ............................................................................................. 256

14.3.6.3 Valve Body .................................................................................................................. 256

14.3.6.4 Actuators .................................................................................................................... 257

14.3.6.5 Control Valve Ancillaries............................................................................................. 257

14.3.6.6 Technical Data Sheets ................................................................................................ 258

14.4 Welding........................................................................................................................ 258

14.4.1 General .................................................................................................................. 258

14.4.2 Welding Standards ................................................................................................ 258

Page-xviii Volume-2 of 3 (Part-B)


14.4.3 Welding Procedure Qualification ........................................................................... 259

14.4.4 Welder Qualification ............................................................................................... 259

14.4.5 Production Welding ................................................................................................ 259

14.4.6 Filler Materials and Controls .................................................................................. 261

14.4.7 Weld Joint Preparation .......................................................................................... 262

14.4.8 Thermal Treatment ................................................................................................ 262

14.4.9 Inspections, Tests and Repairs of Welds .............................................................. 263

14.4.10 Weld Repairs ......................................................................................................... 263

14.4.11 Welding Stainless Steel ......................................................................................... 264

14.5 Piping Systems ............................................................................................................ 265

14.5.1 Codes and Standards ............................................................................................ 265

14.5.2 Design .................................................................................................................... 265

14.5.3 Stress Analysis ...................................................................................................... 266

14.5.4 Material Selection .................................................................................................. 267

14.5.5 Materials ................................................................................................................ 267

14.5.6 Layout .................................................................................................................... 269

14.5.7 Handling and Storage ............................................................................................ 269

14.5.8 Fabrication, Assembly and Erection ...................................................................... 270

14.5.8.1 Pipe Bends ................................................................................................................. 270

14.5.8.2 Alignment of Welded Joint ........................................................................................ 271

14.5.8.3 Installation of Pipeline Components .......................................................................... 271

14.5.8.4 Installation and Alignment of Pipes and Pipe Supports ............................................. 272

14.5.8.5 Pipe Supports, Anchors and Guides ........................................................................... 273

14.5.9 Size Changes ........................................................................................................ 274

14.5.10 Flanges .................................................................................................................. 274

14.5.11 Jointing................................................................................................................... 275

14.5.12 Floor Collars, Wall Boxes and Weather Hoods ..................................................... 276

14.6 Thermal Insulation ....................................................................................................... 276

14.6.1 Design .................................................................................................................... 276

14.6.2 Materials ................................................................................................................ 277

14.6.3 Installation of Insulating Systems .......................................................................... 278

14.6.3.1 Application of Full Insulation on Piping ..................................................................... 278

14.6.3.2 Insulation Surrounding Control Valves ...................................................................... 279

14.7 Pressure Vessels, Tanks and Heat Exchangers ......................................................... 280

14.7.1 Pressure Vessels ................................................................................................... 280

14.7.2 Tanks ..................................................................................................................... 280

14.7.3 Heat Exchangers ................................................................................................... 281

14.8 Mechanical Plant Erection ........................................................................................... 281

14.8.1 General Requirements ........................................................................................... 281

14.8.2 Sub-Contractors ..................................................................................................... 282

Volume-2 of 3 (Part-B) Page-xix


14.8.3 Care of Plant Prior to Installation .......................................................................... 282

14.8.4 Craneage and Scaffolding ..................................................................................... 282

14.8.5 Cleanliness ............................................................................................................ 282

14.8.6 Piping Connections ............................................................................................... 282

14.8.7 Alignment and Leveling ......................................................................................... 283

14.8.8 Seal Packing ......................................................................................................... 283

14.8.9 Welding ................................................................................................................. 283

14.8.10 Motors ................................................................................................................... 283

14.8.11 Lubrication ............................................................................................................. 283

14.9 Electrical Construction and Installation ....................................................................... 284

14.9.1 General Requirements .......................................................................................... 284

14.9.2 Fixings and Supports............................................................................................. 284

14.9.3 Cable Trays ........................................................................................................... 285

14.9.4 Cable Conduits and Accessories .......................................................................... 285

14.9.5 Cabling .................................................................................................................. 286

14.9.5.1 General Requirements ............................................................................................... 286

14.9.5.2 Direct Buried .............................................................................................................. 287

14.9.5.3 6.6 kV and 400 V Power Cabling ................................................................................. 287

14.9.5.4 Control and Instrumentation Cabling ......................................................................... 288

14.9.5.5 Panel Wiring ............................................................................................................... 288

14.9.6 Fibre Optic Cabling ................................................................................................ 288

14.9.6.1 General Requirements ............................................................................................... 288

14.9.6.2 Fibre Optic Junction Boxes ......................................................................................... 289

14.9.6.3 Patch Panels ............................................................................................................... 289

14.9.6.4 Fibre Connectors ........................................................................................................ 290

14.9.7 Cable and Individual Core Labelling ..................................................................... 291

14.9.8 Junction and Cable through Boxes ....................................................................... 291

14.9.9 Terminals ............................................................................................................... 291

14.9.10 Labels .................................................................................................................... 292

14.9.11 Earthing Grids ....................................................................................................... 292

14.10 Instrument Valves and Tubing .................................................................................... 292

14.10.1 Instrument Valves .................................................................................................. 292

14.10.2 Instrument Tubing and Fittings .............................................................................. 293

14.10.3 Instrument Electric Supply Systems ...................................................................... 293

14.10.4 Field Instruments Miscellaneous Requirements ................................................... 294

14.10.5 Electronic Equipment ............................................................................................ 294

14.10.6 Instrument Cables and Wiring ............................................................................... 294

14.11 Health and Safety ........................................................................................................ 295

14.11.1 General Requirements .......................................................................................... 295

14.11.2 Health and Safety Management at Site ................................................................ 296

Page-xx Volume-2 of 3 (Part-B)


14.11.3 Staff and Labour Records ...................................................................................... 297

14.11.4 Health and Safety Equipment and Protective Devices .......................................... 297

14.11.5 Health and Safety Related Signs, Cordons and Training ...................................... 297

14.11.6 Health and Safety Responsibility ........................................................................... 297

14.11.7 Work in Confined Spaces ...................................................................................... 297

14.11.8 Health Records and Hazardous Substances......................................................... 297

14.11.9 Storage Facilities for Chemicals, Fuel, Oil and Grease ......................................... 297

14.11.10 Fit for Purpose of Construction and Maintenance Equipment, Instruments and Vehicles ................................................................................................................. 298

14.11.11 Labour Laws .......................................................................................................... 298

14.11.12 Working hours ........................................................................................................ 298

14.11.13 Facilities for Staff and Labour ................................................................................ 298

14.11.14 Wages and Employment Conditions ..................................................................... 298

14.11.15 Workers Camp and Temporary Construction Facilities ......................................... 298

14.11.16 Housekeeping ........................................................................................................ 299

14.11.17 Substance Abuse ................................................................................................... 299

14.11.18 General Fire Protection Requirements .................................................................. 300

14.11.19 Emergency Response Plan ................................................................................... 300

14.12 HAZOP ......................................................................................................................... 300

14.12.1 General .................................................................................................................. 300

14.12.2 Risk Assessment and Management ...................................................................... 300

14.13 Plant Identification and Labeling .................................................................................. 300

14.13.1 General .................................................................................................................. 300

14.13.2 Signs, Nameplates and Labels .............................................................................. 301

14.13.3 Instrument Identification and Labeling ................................................................... 301

14.14 Corrosion Protection and Surface Coatings ................................................................ 302

14.14.1 General .................................................................................................................. 302

14.14.2 Galvanising ............................................................................................................ 302

14.14.3 Schedule of Protective Coatings ........................................................................... 303

14.14.4 Painting and Protection.......................................................................................... 303

14.14.4.1 Surface Preparation and Inspections ......................................................................... 303

14.14.4.2 Application of Paint Systems ..................................................................................... 304

14.14.4.3 Structural Steel and Associated Items ....................................................................... 304

14.14.4.4 Painting Final Coat Colour Schedule .......................................................................... 304

14.15 Equipment Baseline Monitoring Surveys ..................................................................... 304

14.15.1 Vessel and Pipe Wall Thickness Survey ............................................................... 304

14.15.2 Rotating Equipment Vibration Spectrum Survey ................................................... 305

15. QUALITY ASSURANCE, INSPECTION AND TESTING .................................................................. 306

15.1 Quality Control, Inspection and Testing ....................................................................... 306

15.1.1 General .................................................................................................................. 306

15.1.2 Employer Review: .................................................................................................. 306

Volume-2 of 3 (Part-B) Page-xxi


15.1.2.1 Incorporation of Employer Review Comments .......................................................... 307

15.1.2.2 Design Review Meetings ............................................................................................ 307

15.1.2.3 Design Deficiencies ..................................................................................................... 307

15.1.2.4 Design Discrepancies .................................................................................................. 307

15.1.3 Extent of Work ....................................................................................................... 308

15.1.4 Document Submission .......................................................................................... 308

15.1.5 Inspection Notification and Right of Access .......................................................... 310

15.1.6 Inspection and Tests ............................................................................................. 310

15.1.7 Non-Conformances ............................................................................................... 311

15.1.8 Quality Control Records, Certificates and Certificates of Conformance ............... 312

15.2 Factory Tests ............................................................................................................... 313

15.2.1 Gas Turbine ........................................................................................................... 313

15.2.2 Steam Turbine ....................................................................................................... 314

15.2.3 HRSG .................................................................................................................... 315

15.2.4 Gas Booster Compressors .................................................................................... 315

15.2.4.1 Required Tests ............................................................................................................ 315

15.2.4.2 Compressor Tests to be Witnessed by the Employer................................................. 315

15.2.4.3 Technical Data to be Provided ................................................................................... 316

15.2.5 Generator .............................................................................................................. 316

15.2.6 Exciter ................................................................................................................... 316

15.2.7 Transformers ......................................................................................................... 316

15.2.8 Generator Circuit Breakers ................................................................................... 317

15.2.9 Disconnectors and Earth Switches ....................................................................... 317

15.2.10 Current Transformers ............................................................................................ 318

15.2.11 Voltage Transformers ............................................................................................ 318

15.2.12 Surge Arrestors ..................................................................................................... 318

15.2.13 Galvanizing ............................................................................................................ 318

15.2.14 Structures .............................................................................................................. 318

15.2.15 Control and Protection System ............................................................................. 318

15.2.16 ICMS System Test Requirements ......................................................................... 319

15.2.17 Piping Specific Requirements ............................................................................... 320

15.2.17.1 Test Certificates .......................................................................................................... 320

15.2.17.2 Identification Marks ................................................................................................... 320

15.2.17.3 Pipe Dimensional Tolerances ..................................................................................... 320

15.2.17.4 Manufacturing Inspection .......................................................................................... 320

15.2.18 Valve Specific Requirements ................................................................................ 321

15.2.18.1 Testing ........................................................................................................................ 321

15.2.18.2 Inspection and Non-Destructive Examination ............................................................ 322

15.2.19 Other Materials and Equipment ............................................................................ 324

Page-xxii Volume-2 of 3 (Part-B)


15.3 Tests at Site ................................................................................................................. 324

15.3.1 General .................................................................................................................. 324

15.3.2 Responsibility for Tests .......................................................................................... 324

15.3.3 Pre-commissioning ................................................................................................ 325

15.3.3.1 Inspection and Checking of Units .............................................................................. 325

15.3.3.2 Start-up and Trial Operation ...................................................................................... 325

15.3.3.3 Reliability Run ............................................................................................................ 327

15.3.4 Commissioning - Performance and Operational Acceptance Tests ...................... 327

15.3.4.1 General ...................................................................................................................... 327

15.3.4.2 Start-up Guarantee Tests ........................................................................................... 328

15.3.4.3 Performance Guarantee Tests ................................................................................... 328

15.3.5 Civil Inspections and Testing ................................................................................. 332

15.3.6 Field Inspections and Tests on Switchgear and Equipment .................................. 333

15.3.6.1 Protection, Control, Alarm, Measurement and Indication Equipment...................... 333

15.3.6.2 Current Transformer Magnetizing Tests .................................................................... 334

15.3.6.3 DC Operations ............................................................................................................ 334

15.3.6.4 On Load Tests ............................................................................................................ 334

15.3.6.5 Transformers ............................................................................................................. 335

15.4 Government and Third Party Inspections .................................................................... 335

16. Definitions and General References ................................................................................................. 336

16.1 Project Description ....................................................................................................... 337

16.2 Operating Regime ........................................................................................................ 338

17. SPARES ............................................................................................................................................ 339


17.2 Mandatory Spares ....................................................................................................... 339

17.3 Recommended Spares ................................................................................................ 340


17.4.1 Spares.................................................................................................................... 340

17.4.2 Logistics and Acceptance of Spares ..................................................................... 340

17.4.3 Long Term Availability of Spares ........................................................................... 341

17.4.4 Tools ...................................................................................................................... 341

17.5 Storage of Spare Parts ................................................................................................ 341

17.5.1 Locking Devices (Permit to Work) ......................................................................... 342

17.5.2 Packing Lists .......................................................................................................... 342

17.5.3 Gas Turbine Generator .......................................................................................... 342

17.5.4 Receipt and Storage .............................................................................................. 342

18. ENVIRONMENTAL............................................................................................................................ 344

18.1 General Introduction .................................................................................................... 344

18.2 Information ................................................................................................................... 344

18.3 General Environmental Requirements and Permit Compliance .................................. 344

18.4 Environmental Limits and Permit Compliance ............................................................. 345

Volume-2 of 3 (Part-B) Page-xxiii


18.4.1 Air Emissions ......................................................................................................... 345

18.4.2 Ambient Air Quality ................................................................................................ 345

18.4.3 Noise Level ............................................................................................................ 345

18.5 Effluent Discharge ....................................................................................................... 346

18.5.1 Sanitary - Domestic Wastewater ........................................................................... 347

18.5.2 Plant Wastewater .................................................................................................. 348

18.6 Solid Wastes ............................................................................................................... 348

18.7 River Water Temperature ............................................................................................ 348

18.7.1 Mitigation Measures .............................................................................................. 349

18.8 Environmental Monitoring............................................................................................ 349

18.9 Environmental Management Plan ............................................................................... 349

18.9.1 General Introduction .............................................................................................. 349

18.9.2 Work Plans and Schedules ................................................................................... 350

18.9.2.1 Air Quality Management ............................................................................................ 350

18.9.2.2 Water Quality Management ...................................................................................... 350

18.9.2.3 Solid Waste Management .......................................................................................... 351

18.9.2.4 Fuel Management ...................................................................................................... 351

18.9.2.5 Lubricating Materials and Chemicals Management ................................................... 351

18.9.2.6 Health and Safety Management ................................................................................ 351

18.9.3 Compensatory Measures and Emergencies ......................................................... 355

18.9.3.1 Resources, Implementation and Training .................................................................. 355

18.9.3.2 Compensatory Measures ........................................................................................... 356

18.9.3.3 Emergencies ............................................................................................................... 356

18.10 Environmental Monitoring Programme ........................................................................ 357

18.10.1 General .................................................................................................................. 357

18.10.2 Institutional Capability and Requirements ............................................................. 358

18.11 Environmental Monitoring Plan ................................................................................... 358

18.11.1 Parameters to be monitored .................................................................................. 358

18.11.2 Target Media and Monitoring Schedule ................................................................ 359

18.11.3 Reporting Procedures ........................................................................................... 360

19. DOCUMENTATION .......................................................................................................................... 370

19.1 General ........................................................................................................................ 370

19.1.1 Language .............................................................................................................. 370

19.1.2 Control ................................................................................................................... 370

19.1.3 Identification .......................................................................................................... 370

19.1.4 Organization of Documentation ............................................................................. 370

19.1.5 Quantity ................................................................................................................. 370

19.1.6 Quality ................................................................................................................... 370

19.1.7 Size........................................................................................................................ 371

19.1.8 Symbols ................................................................................................................. 371

Page-xxiv Volume-2 of 3 (Part-B)


19.1.9 Units and Scale Ratios .......................................................................................... 371

19.2 During Contract ............................................................................................................ 371

19.2.1 Documentation Schedule....................................................................................... 371

19.2.2 Calculations ........................................................................................................... 372

19.2.3 Construction Procurement Records ...................................................................... 373

19.2.4 Welding Procedures .............................................................................................. 374

19.2.5 Codes and Standards ............................................................................................ 374

19.2.6 Erection Procedure ................................................................................................ 374

19.2.7 Pre-Commissioning Procedures ............................................................................ 374

19.2.8 Commissioning ...................................................................................................... 375

19.3 Submission of Final Documentation ............................................................................ 375

19.3.1 Timing of Final Documentation .............................................................................. 375

19.3.2 Quality and Format ................................................................................................ 375

19.3.3 Storage at Site ....................................................................................................... 375

19.3.4 Hand-over .............................................................................................................. 376

19.3.5 Types of Manuals .................................................................................................. 376

19.4 Implementation Schedules .......................................................................................... 377

19.4.1 General .................................................................................................................. 377

19.4.2 EPC Contract Schedule ......................................................................................... 377

19.5 Progress Reports ......................................................................................................... 377

19.5.1 Progress Measurement ......................................................................................... 377

19.5.2 Progress Reporting ................................................................................................ 378

19.5.3 Photographs .......................................................................................................... 379

19.5.4 Data for Asset Management System ..................................................................... 379

20. END USER’S PLANT VISIT .............................................................................................................. 380

21. Annexure (Technical) ........................................................................................................................ 381

Annexure-1: Existing Ashuganj Power Station complex showing site for proposed 400 MW CCPP ........................................................................................................................... 381

Annexure-2: Single Line Diagram of 400KV and 230 KV Sub-station for Power Evacuation and Grid Auxiliary Power Supply for proposed 400 MW CCPP .................................. 382

Annexure-3: Basic Wind Speed Map of Bangladesh ........................................................................ 383

Annexure-4: Seismic Zoning Map of Bangladesh ............................................................................. 384

Volume-2 of 3 (Part-A) Page-1

Ashuganj 400 MW CCPP (East) Demolition and Disposal of the Exiting Plants

Appendix 1

Appendix 1 – Definitions

Works The demolition & disposal of existing plant and site development as defined in Section 2

Contractor The turn-key contractor appointed for the demolition & disposal of existing plant, site development and construction of the plant on the site

Demolition Area The area is the existing 146MW Power Plants (2x56MW GT and 1×34 MW ST) and its all auxiliaries including all structures within the Project Area of new Plant.

Demolition and Disposal Manager

The named individual who shall be employed by the Contractor and who shall be responsible for the supervision of the demolition of the Works

Site Manager The named individual who shall be employed by the Contractor and who shall have overall responsible for the complete development of the site and construction of the plant.

Demolition & disposal Procedure

A procedure prepared by the Contractor describing how the demolition & disposal of existing plant and site development will be carried out and containing Method statement.

Closure Report On completion of the works, the Contractor shall prepare a Closure Report. The acceptance of the Closure Report by the APSCL shall not release any further liabilities and responsibilities on the contractor in the area covered by the Closure Report.

Clearance of plant/ System Final Operation

Clearance issued by the APSCL to the Contractor confirming that identified plant and or systems have ceased operational duty and can be released for demolition.

Clearance of plant/ System Terminal Isolation

Clearance issue by the APSCL to the Contractor confirming that identified plant and/or systems have been securely terminally isolated from external services.

Hazard Identification Sheet

A list prepared by the Contractor of all elements which could constitute a risk or a hazard to the demolition and disposal procedure.

List of Plant and structures

A comprehensive list prepared by the APSCL of major items of plant and structures within the Demolition Area.

Register of External Connections

A comprehensive list prepared by the APSCL of all electrical, mechanical, Fuel, water, steam and structural connection between the Demolition Area and any external source.

Plant Item Check List

A comprehensive list prepared by the Contractor of all energy inputs to the Demolition Area.

Engineer or Consultant

"Engineer or Consultant" shall mean consulting firm for the time being or from time to time duly appointed by the Employer and whose authority shall be notified in writing to the Contractor by the Employer and who is acting on behalf of the Employer as Engineer for the purpose of the Contract and includes such other person (if any) to whom the Engineer's authority may have been lawfully delegated pursuant to the Contract.

Page-2 Volume-2 of 3 (Part-A)

Demolition and Disposal of the Exiting Plants Ashuganj 400 MW CCPP (East)

1. PREAMBLE

Two Gas Turbines and One Steam Turbine Power Plant exists at project site which are owned by

the Ashuganj Power Station Company Ltd. It consists of 1 (one) 56MW Gas Turbine-1, 1 (one)

56MW Gas Turbine-2 and 1 (one) 34MW Steam Turbine Power plant and all its associated facilities.

Already Gas Turbine-1 and Steam Turbine has retired from service. Gas Turbine-2 which is still in

operation and expected retired time in June 2016.

To enable a new 400 (5%) Combined Cycle Power Plant to be constructed in the area of the

existing 146MW Gas & Steam Turbine Power Plants is to be demolished and disposed to make the

land available for the new Plant.

This functional specification for the demolition & disposal of the existing 146MW Gas & Steam

Turbine Power Plants sets down a basic structure for carrying out the works. The Works will be set

to an “EPC Contractor” (The Contractor) and will cover the demolition & disposal works and the

EPC work for the new 400 (5%) CCPP, (the Works).

This Specification is based upon the recommendations of BS 6187 Code of Practice for demolition.

All proposals for decommissioning and demolition shall be in accordance with BS 6187 and related

British Standards and with the Bangladesh national Codes of Practice and Health and Safety

Regulations.

The Contractor will be given a clearance by the APSCL to operate within the Demolition Area. The

demolition activities will be contained within that demolition Area.

It is envisaged that Contractor may appoint a specialist sub-contractor (or an independent division

within his own organization) as stated in the Qualification of Bid document.

Embarking upon the demolition & disposal process requires that a responsible manager be

appointed by the Contractor, who has the accountability for achieving the demolition, disposal and

site preparation objectives.

The Contractor shall establish the demolition, disposal and site preparation objectives including

programme of demolition & disposal, a strategy plan and timetable for the next essential step. The

programme can only be formulated by reference to all of the information that is relevant to the site,

starting with what structures and plant are present and therefore requires to be demolished &

disposed, through to the risks that must be managed against specific health and safety

requirements and custody of the decommissioned site for the EPC work.

The contractor shall submit a progress report monthly on completion of the Demolition and disposal

(either in parts or in whole) with mentioning the date. Closure Report should be submitted by the

Contractor after completion of works.

2. GENERAL REQUIREMENTS

2.1 Introduction

The existing Gas turbine & Steam Turbine Power Plants at project site were constructed in the 1980s. It consists of 146 MW of plant (2x56MW GT Units and 1×34 MW ST Unit) housed individually in a steel framed sheet covered building. The Plant comprises the usual buildings such as control room, electrical rooms and water intake and outfall facilities, emergency diesel etc. It is also mentioned that there have another 7 Power plants adjacent the sites within the APSCL complex. Another Gas Engine Power plant (Precision Power Energy) is situated at the adjacent site.

The work under this Demolition specification is to demolish and remove from the area of 146 MW Power Plant and all its attendant facilities as further defined in the Scope of work below. It is estimated that the duration of the demolition programme is 6(six) months. All demolished material shall be the property of the Contractor with the exception of those items specifically listed by the APSCL (Annexure 1)

The Contractor will then be required to construct and set into commercial operation a 400

(5%) MW Combined Cycle Power Plant on the cleared site.



2.2 General Particulars

The Contractor will be responsible to the APSCL for all the works activities and scheduling.

The Contractor is responsible to ensure, follow and maintains the required, Health and Safety standards. The requirements to be ensured by the Contractor are as follows;

2.2.1 Planning of Work

Within 21 days from the date of signing of contract, the Contractor shall prepare a

detailed programme for the plant demolition and disposal and shall submit the

programme to the owner’s Engineer and the APSCL for comments and approval.

The sub-programme for the demolition of the works shall be incorporated into the

main network programme.

If at any time during the execution of the Contract it is found necessary to modify

the approved plan demolition and disposal programme, the Contractor shall inform

to the APSCL and submit a modified programme for his approval. The programme

shall be updated at monthly intervals and submitted to the APSCL no later than at

the middle of each calendar month. Provided that completion time of the whole

project will not be extended due to modify the plan.

Preference will be given to the use of modern programming systems such as

Primavera or equivalent

2.2.2 Meetings

During the course of the Contract periodical meetings to discuss project

management and site progress will be held between the APSCL, the Engineer and

the Contractor. The frequency must be considered as being monthly during the

course of the Contract. The APSCL & Engineer shall decide the location of the

meetings but are expected to be at the Site Offices.

2.2.3 Monthly Progress Report

The Contractor shall submit detailed progress reports at monthly intervals until the

completion of the works. The reports shall show clearly and accurately the position

of all activities associated with the demolition, disposal and site preparation work

with regard to the agreed Contract programme.

The demolition portion of the progress report shall be segregated into the main

items of work and the work shall be monitored giving the percentage completion

and the projected completion date of the work in accordance with the agreed

Contract programme.

The Contractor shall report in respect of the various items of the groups of the

works, the erection equipment in use or held in readiness, a return of labour and

supervisory staff and the details of any matters arising which may generally affect

the progress of the site work.

Any details regarding the disposal of the Plant should be highlighted, e.g. removal

from site by river or road, disposal to recognized disposal to areas for particular

items etc.

The Contractor shall give a summary of the detailed progress report giving

position with regard to the agreed Contract programme.

The progress reports shall be set out in a format to be agreed with the APSCL

within 10 days after signing of the Contract.

The progress report shall be forwarded promptly to the APSCL, so that on receipt

the information contained is as up to date as possible.

Ten copies of the report are to be distributed as follows:-



a) 6 copies to the APSCL

b) 4 copies to the Engineer

2.2.4 Photographs

As soon as the work commences on site the Contractor shall provide photographs

of the works from positions to be selected by the APSCL. Up to 15 photographs of

project site per month will be required in bound photographic albums. Each

photographic print shall not be less than 120 mm x 150 mm and shall bear printed

description, a serial number and the date taken. Inscriptions shall be in English.

Four copies of the photographic albums shall be furnished.

Soft copy of all photographs shall be numbered and handed over to the APSCL at

the completion of the demolition and disposal work.

The Contractor shall provide a number of selected photographs for submission

with each copy of the monthly progress report as required by the APSCL. The

Contractor shall also provide from time to time as and when required by the

APSCL, further photographs of the Contract works to record or illustrate specific

events.

2.2.5 Operational Requirements

It is to be noted that the Contract works are to take place on an operational power

station site area. The Contractor shall take account of the operational

requirements of the adjacent station plant when working.

2.2.6 Site Security

Entry to and exit from, operational sites and areas is subject to security restrictions

particularly with respect to vehicular access. The Contractor shall fully acquaint

himself with the applicable security regulations.

In accordance with the General Conditions of Contract, the Contractor shall

provide all security equipment and services necessary to protect the Facility. The

Work, the Site, the laydown areas and all property of APSCL or the Contractors

that is required for the project relating to the work and located at the Site or

laydown areas. The Contractor shall take all necessary precautions for the

security and safety of its sub-contractors, agents, employees and guests on the

Site and the laydown areas and shall comply with all applicable Laws relating to

health and safety. In an emergency situation jeopardizing the safety of life or

threatening damage or loss to the Site, the laydown areas, the work or the Facility,

Contractor, without special instruction or authorization from the APSCL, shall act

to prevent such threatened loss or injury.

2.2.7 Safety

The Contractor shall develop an appropriate safety management plan and take all

necessary safety and other precautions to protect property and persons from

damage, injury, or illness arising out of the performance of the work consistent

with the Facility Site access and Safety Procedures.

The Contractor shall be responsible for providing its employees agents and Sub-

contractors with a safe working environment. The Contractor shall inspect the

working environments where its employees, agents or Sub-contractors are or may

be present at the Site and shall promptly take action to correct conditions that

cause or may reasonably be expected to cause such working environments to

become an unsafe place of employment.



The Contractor shall have policies and rules of personal safety accountability.

Such rules shall apply to anyone working on the Site. As a minimum requirement,

these policies and rules shall cover the following:

Head and foot protection,

Eye protection,

Substance abuse,

Weapons,

Reporting of unsafe conditions,

Use of power tools

Other general rules of behavior at a construction site.

Prior to starting any field work on each job, the Contractor will conduct an initial

safety conference with an authorized representative of his Sub-contractor and

APSCL's safety representative, when available.

The Contractor shall have a written safety work procedure and/or standards to

cover the following types of activities, as well as a plan (i.e. training sessions,

weekly training sessions, etc.) to communicate all Site safety and loss prevention

requirements to its employees and sub-contractors. As a minimum, such

procedures and/or standards shall cover the following activities:

Excavation

Use of ladders and platforms

Work requiring protective clothing and equipment

Noise protection

Working at elevated locations

Burning and welding operations

Cleaning and working inside confined spaces

Cleaning lagging and working on equipment that has been energized

Protection from and safe handling of hazardous chemicals substances.

Use of motor vehicles on the site

Use of mobile cranes

Radiography

Electrical work on near energized circuits

Safe handling and storing of pressurized gas cylinders

Crisis management plan

Reporting of injuries and other safety and loss prevention incidents.

The APSCL is entitled to conduct safety audits for compliance with this

specification, at any time during the progress of the Work with or without notice to

Contractor. Safety shall be included as a topic for discussion by APSCL in any

regularly scheduled project meeting that is conducted.

2.2.8 Substance Abuse policy & Responsibility

The use possession, concealment, transportation, promotion, or sale of the

following substances and items by any contractor, vendor and their employees are

strictly prohibited from the Site:

Alcoholic beverages,

Illegal drugs,

Unauthorized controlled substances,

Synthetic Drugs,



Any abnormal substances which may affect the senses motor functions, or alter a person's perception or judgment.

Contractors must have and administer a formal substance abuse interdiction

policy. Such policy must include provision for testing (such as urine drug screens

or blood plasma test) to determine the use of any illegal or unauthorized

substances prohibited by this policy.

2.2.9 Temporary Construction Facilities

The Contractor shall furnish and maintain temporary construction facilities by their

own responsibilities & costs and provide site services such as:

Temporary site offices.

Fire protection during works

Temporary sewage treatment system

Temporary communication systems

Temporary lighting system for the facility

Temporary drainage and dewatering system

Temporary site roads

Temporary facilities for site water distribution

Temporary site parking lot and lay down area

Site entry control facilities

Warehousing and material controls

Materials, equipment, tools, vehicles, lifting facilities and consumables required for the work

Site environmental protection during work.

On-site first aid services.

The Contractor shall prepare a Site Facilities Plan showing the expected location

and arrangement of site facilities and shall submit to the APSCL and Engineer for

review and comments.

2.3 Quality Management

2.3.1 Quality management requirements

2.3.1.1 General

This section of the Specification outlines the general and detailed requirements for a quality Control Programme, which shall be implemented by the Contractor, to ensure that the quality of all the Works is controlled in full compliance with the Contract and law of Bangladesh.

In addition, this section identifies the role of the Engineer in the overall Quality Control Programme for this Contract.

2.3.1.2 Scope

These requirements shall apply during the Demolition, Disposal process and site preparation.

The Contractor shall have sole responsibility for ensuring compliance with the overall quality requirements of the works, and shall ensure that any sub-contractor used implement those quality control activities that are appropriate to the extent and nature of their work.

The principle to be adopted where specific references are made to items of plant and equipment is "where included in the scope of work".



2.3.1.3 Definitions

The Quality Control programme shall mean all those activities, procedures and documents which are established and implemented by the APSCL and the Contractor to control and verify the processes relevant to the works. The part of the Quality Programme applicable to each item shall include all those controls that are normal elements of the Contractors QA or QC system, together with any additional or revised controls necessary to ensure compliance with the Contract.

2.3.2 Contractor's Quality Management

2.3.2.1 Quality Systems

In carrying out the Works, the Contractor shall adopt and implement the Quality Management principles specified in the ISO standard 9000-1987: “Quality Systems. The Contractor/ Sub-contractor shall have ISO 14001 certification.

Wherever the Contractor's established organization and procedures for controlling quality do not comply with requirements of the standard, appropriate modifications and changes shall be made and implemented on a priority basis, in order that full compliance is achieved throughout the Contract duration.

2.3.2.2 Quality Planning

Immediately after award of Contract the Contractor shall completely receive the Contract and take all necessary action to establish quality control procedures in accordance with the requirements of these Conditions of Contract.

Particular care shall be taken to identify any specified requirements that are different from, or additional to the Contractor’s normal quality control practice, and to initiate the necessary measures to ensure that such additional requirements are implemented satisfactorily.

2.3.2.3 Quality Documentation

In addition to any document submittals required by other parts of the Contract the Contractor shall forward the following Quality Control documentation to the APSCL.

Initial Documentation Required after Award of Contract

Documents shall be supplied to indicate the followings:

i. Identification of main items for demolition.

ii. Programme for demolition and disposal of major items of

equipment.

2.3.3 Engineer’s Quality Control

The Engineer will verify that the Contractor is fully implementing all the Quality

requirements of the Contract by means of the activities listed below. The

Engineer’s activities are designed to complement not to replace the Contractors

quality contract and the extent of surveillance and inspection necessary will

depend upon the Contractor quality control performance, as determined by the

Engineer’s evaluations and assessments.

2.3.3.1 Evaluation of Quality System

The Contractor’s Quality System will be evaluated by the examination of quality Manuals, QC Plants and other such documentation.



2.3.3.2 Assessment of Effectiveness of Quality Control

The effectiveness of the planned quality control, will be assessed during early stages of the work, by examining records of controls carried out, and by witnessing the application of special processes.

2.3.3.3 Surveillance

Throughout the work, the continuing satisfactory implementation of all control procedures will be verified by surveillance activities. Surveillance will include a visual inspection of work, witnessing of any special processes currently in progress and examination of the manufacture’s records of all controls carried out up to that point.

2.3.4 Procedural Requirements

2.3.4.1 Quality control Plans

On receipt of the Quality documentation the Engineer will mark on the Contractors Quality Control Plans, (I&TPs) the various inspections he wishes to make, the items he requires to witness and the stages at which he requires to carry out surveillance and will issue these to the contractor as a formal record of the extent of the Engineers initial Quality control activities.

The Contractor shall ensure that all his workforce are aware of these requirements if the Engineer requires to modify these requirements during the execution of the Contract, the modifications will be formally notified to the Contractor in writing.

2.3.4.2 Right of Access

The Employer & Engineer secures the free access to Contractor’s works to verify full compliance with specific Requirement’s. Access is also required to records all the Contractor’s controls, Inspections and tests carried out on any items of the Contract works.

2.3.4.3 Quality Control Records

At the end of each site visit to carry out quality control activity, the Engineer’s Representative will complete a Quality Control Record and handover one copy to a responsible representative of the Contractor.

The Quality Control Record (QCR) will identify the item checked and the nature of the QC carried out and will list all points which require remedial action by the Contractor, before the subject item can be released.

3. SCOPE OF WORK

In general the work comprises the demolition, disposal and site preparation of the existing 146 MW (56MW Gas Turbine-1 + 56MW Gas Turbine-2 + 34MW Steam Turbine) power plant and all its associated facilities. It also includes the removal from site of all demolished materials to be either sold off to others or to be disposed off in an approved manner by the Contractor.

The demolition and disposal work to include in all respects but not be limited to:

a. Inside Power Station Building: -

i) 2×56 MW Gas Turbine Generator sets complete with main stack, bypass stack, flue gas duct, lube oil tanks, pumps, coolers, valves, electrical panels, cables, controls and instruments etc.

ii) 1×34 MW Steam Turbine Generator set complete with condenser, lube oil tank, feed heaters, deaerator, ejectors, pumps, coolers, valves, interconnecting piping, electrical panels, cables, controls and instruments.



iii) Heat Recovery Steam Generator set complete with evaporator, drum, economizer, superheater, motors, pumps, valves, interconnecting piping, electrical panels, cables, controls and instruments.

iv) Balance of plant system including:-

Fire Fighting System-comprising of piping valves, sprinklers, detectors, hydrants,

extinguishers hoses, fire alarm panels and cabling etc.

Instrument and Service Air System comprising air compressors, air driers receiver’s

valves, interconnecting piping, electrical panels, cabling, controls and instruments

etc.

Ventilation and Air Conditioning System comprising of louvers, fans, packaged air

conditioner units etc.

Auxiliary Cooling Water Systems - coolers, pumps, strainers, piping, valves, etc.

Diesel Generating Set – complete with fuel tank, exhaust ducting, silencer, batteries,

cables and controls etc.

Lighting Systems

b. Outside Power Station Building:-

i) Generator Transformers

ii) Auxiliary Transformers

iii) Cooling Water System – comprising valves, pipework, discharge culverts, electrical

panel’s cables, controls and instruments etc.

iv) Radial Crane in Steam Turbine Hall

v) Firefighting lines and valves

vi) Underground pits, services

c. Building i) GT-1, GT-2 and ST Buildings at plant site

ii) Electrical and mechanical section buildings at plant site

d. Others

i) All underground & over ground structure/foundation of the existing plant & auxiliaries

and all underground structure/foundation from the rest of the Project area.

APSCL will retain all office equipment, furniture including fans, lamps, window type AC, stationery, stores, Battery & Battery chargers & it’s all equipment according to annexure 1.

The contractor shall not use the demolition material/equipment for construction of the project.

It is noted that the Contractor shall maintain the temporary and permanent laydown area at their own responsibility and costs.

4. List of Equipment and the Register

A pre-requisite for safe demolition of the total generating site is the availability of a comprehensive list of Plant, Structures and Register of External service connections, covering all the installed plant and structural items within the Demolition Area. APSCL shall prepare such a List of Equipment and Register.

Prior to giving the Contractor a clearance to enter the Demolition Area the APSCL shall undertake to decommission all items of plant listed in the list. This shall include the termination of all external services connections listed in the Register.

During the Tender Period the Bidders shall have reasonable access to the Demolition Area and the opportunity to identify any structural problems and risks associated with flammable or hazardous substances at their own cost and responsibilities.

Upon receipt of the equipment’s list and the Register the Contractor shall check and agree with the APSCL that all identified external connections have been terminated.



5. THE REGISTER OF EXTERNAL SERVICE CONNECTIONS

A fully detailed register of all external service connections to and from the site must be compiled by the APSCL prior to-handing the site over to the Contractor. The Register shall be available to support the formulation of a structured demolition programme in accordance with a Site Demolition Procedure.

The Register of all connections must include not only those which the site requires for continued operation of the site and convenience of the staff, but also those which the site provides to external parties.

Typical external connections to and from the site that require full and accurate detail of their scope and physical arrangement.

5.1 Electrical Supplies

The main outgoing power connections for the GT-1, GT-2 & ST generator units are connected from the unit generator transformer to the 132kV switchyard by underground connections. It will be necessary to isolate these connections as part of the decommissioning process by isolation in the switchyard and removal of the underground line cables.

Auxiliary power supplies for the GT-2 is derived from an 11/0.4 kV transformer located in the adjacent to the switchyard of Gas Engines connected by underground cable. This supply should be isolated in the 11/0.4 kV transformer and disconnected prior to demolition. It may be possible to utilize this supply for decommissioning supplies.

Light current connections isolated at the upstream connection.

Phone connections used for data transmission and voice communications should be isolated at the source in the local distribution circle.

5.2 Cooling Water Supply & Cooling Water Outfall

The cooling water supply to the 34MW steam plant is provided by a pumped river intake system outside the existing plant area. The discharge piping from the CW pumps runs underground to the condenser within the steam power plant building.

The cooling water outfall from the condenser through an underground pipeline to the river adjacent to the existing plant.

5.3 Towns Water Supplies

There is no record of there being a mains supply of potable water to site, Consideration will have to be given to provision of potable bottled water and sanitary facilities.

5.4 Sewage

The sewage effluent is discharged into a septic tank that is emptied on a regular basis. No information exists about an overflow tank from the septic tank and the assumption must be that the overflow discharges directly into the river.

5.5 Waste Disposal

The Contractor has a duty of care to ensure that any waste or hazardous substance is disposed of in appropriate manner e.g. at licensed waste disposal sites, incinerating plants etc. It is required for the Contractor to create and maintain a list of the hazardous materials, including a record of any on-site and off-site treatment and disposal.

Examples of the types of substances which should be considered are:

transformer and lubricating oils

lead and acid in station batteries

Mercury in instrumentation e. g, Kentometers, Bailey Flowmeters etc.

CO2 gas cylinders

Other contaminants arising from plant usage

The suggested procedures for Waste Disposal are indicated below but shall not limited to:



Waste lubricating oils may be treated as a supplemental fuel in rotary cement kilns or other industrial boiler that is licensed to accept such wastes.

Transformer oils should be tested for the presence of polychlorinated bi-phenyls (PCBs) using commercially available field test kits. For oils with PCB<5 ppm, on-site co-disposal after stabilization may be acceptable if local authorities approve in advance. For oils with PCB<50 ppm, co-disposal with lubricating oils in cement kiln or other industrial boiler is acceptable if the kiln or boiler facility has appropriate licenses. For oils with PCB>50 ppm, treatment and disposal at a licensed treatment and disposal facility is required.

Lead and acid in batteries may be recovered and reused in licensed recovery facilities. Open burning of such wastes will not be allowed.

Mercury from plant instruments should be double-contained and may be reused off-site for other industrial applications (e.g, in new instruments). Reuse in caustic soda manufacturing that utilizes mercury-cell technology is acceptable only as a resort and only if approved by local government authorities at the power plant site and the receiving plant site.

Carbon dioxide (CO2) gas cylinders should be drained in a controlled manner and may then be disposed as scrap metal.

Scrap metal may be treated offside by recycling only after washing to remove visible physical contamination. Wash water should be contained and treated to comply with national minimum industrial waste water discharge standards prior to discharge to public waters.

5.6 Entrance and Exit Ways

It is necessary to establish a directory of people and organizations who have a usual entrance and exit to the Demolition Area during the demolition period.

A security system to manage normal, routine and ad hoc site access and egress requirements should also be in place.

5.7 Transmitting & Receiving Aerial Facilities from High Structures: Should be followed

5.8 Site Licenses and Insurances

The position of all site licenses and insurances should be documented and understood in relation to the demolition period and activity.

When an item of plant or an operating system has been decommissioned the APSCL shall issue to the Contractor a clearance of Plant/System Final Operation.

When an item of plant or an operating system has been isolated from all external connections the APSCL shall issue to the Contractor Clearance of Plant/System Terminal Isolation.

6. PLANT INSULATION ISSUES

The 34MW Steam Power Plant is likely to incorporate large quantities of thermal insulation. The insulation installed is mainly manufactured from three-types-of material:

Materials Containing Asbestos

Calcium Silicate

MMMF (Man Made Mineral Fiber)

With respect to asbestos thermal insulation, sprayed coatings and asbestos board it is a requirement to handle these materials in accordance with the statutory legislation and requirements that are relevant to the removal, encapsulation and disposal of asbestos.

Very few and incomplete records exist as to what type of insulation is present on any one item of plant. The Main Power Building is clad in asbestos cement corrugated sheeting. After each item of plant has been handed over to the Contractor a Hazard Risk Study shall be carried out. One of the key elements of the Hazard Risk Study is to identify the type and classification of the insolation.



To date the APSCL's Policy covering the control of asbestos insulation has not included the marking of the boundary interfaces between sections of plait insulated with asbestos and asbestos free insulating materials and the recording of the boundaries.

To meet recognized international good practice there is a requirement to ensure that all areas where asbestos insulation is present on plant are clearly identified prior to the start of plant demolition and disposal, (it will be necessary to establish asbestos insulation boundary marking procedures and records).

Failure to carry out the above procedures prior to plant demolition and disposal will result in, at best, a requirement to treat all insulating materials when removed as a threat to health which results in high insulation removal and disposal costs; or, at worst the Demolition Contractor obtaining the operational control of asbestos insulation records and making assumptions from them as to the presence of asbestos and non-asbestos insulating materials. This may result in asbestos materials being removed in an uncontrolled manner, contaminating the environment and exposing demolition personnel to asbestos dust levels which are above the recommenced limits.

It is therefore recommended that asbestos insulation boundary marking procedures are implemented at Ashuganj Gas & Steam Power Plant as an integral part of the run up to demolishing the plant.

Asbestos Insulation Boundary Marking Procedure

Utilizing the existing plant thermal insulation records and the Hazard Risk Study results establish a

list of plant areas that are insulated with asbestos free materials.

Scrutinises the existing plant insulation records and the Hazard Risk Study results and then

examine the areas of plant insulated with asbestos free materials in order to establish if

unambiguous boundaries exist between non-asbestos and asbestos insulating materials. If there is

any doubt as to the position of the boundary local insulation samples will require to be taken in

order to establish the boundary position.

Following the establishment of the boundaries apply red bands (approximately 50 mm wide) to the

surface of the insulation adjacent to the asbestos boundary point.

Apply green bands (approximately 50 mm wide) 10 the surface of the asbestos free thermal

insulation approximately 250 mm from the red band.

To provide a future reference embossed metal tags stating “Asbestos Boundary" and giving details

of the location and date of fixing require securing to the insulation at each asbestos boundary point.

The positions of all the asbestos insulation boundaries require to be clearly identified in the stations

permanent insulation records.

Note: In the interim operational period prior to demolition it is important that all thermal insulation

activities which involve asbestos incorporate the above marking system.

Standards & Procedures for Removal & Safe Disposal of Asbestos Containing Material

[ACM]:

Bulk samples (< 100 grams) should be collected by cutting a small piece of suspect ACM

and placing it in a sealable plastic bag or similar container. Samples should be analyzed by

a qualified laboratory using Phase Contrast Microscopy (PCM) or Transmission Electron

Microscopy (TEM) to determine which form of asbestos is present.

During removal, suspect ACM should be kept moist using water sprays. ACM should be

double contained in 80-mll trash bags, and then disposed in a secure landfill (engineered

liner system with run-on and run-off water controls).

7. DETERMINING STRUCTURAL HAZARDS

All structural forms that are to be demolished shall be identified where possible complex items such as building shall be subdivided into Identifiable units capable of independent structural analysis, e.g. roofs, suspended floors etc.,

The method whereby leads are transmitted to the ground shall be identified and the behavior of the structure under the influence of the loads shall be understood.



Structures with load paths that are hidden or are not clearly understood should be subject to analysis by experts.

Elements of structures that are stability sensitive should be identified. This shall apply particularly when the sequence of demolition is critical to maintaining stability, e g. cable stayed roof, stressed skin structures, cantilevered structures. An incorrect sequence in the removal of these parts could result in premature and unplanned collapse.

A sequence of operations should be established which allows debris to be cleared on a regular basis so that floors do not become overloaded and horizontal pressures on walls is avoided.

Where a chimney is demolished by hand debris may be dropped down the inside and cleared at intervals through a narrow opening cut at ground level.

Consideration shall be given to causes of structural instability. This could include interruption of a load, the redistribution of loads, loading from temporary structures. The effect of weather should also be considered.

Consideration shall also be given to the condition of the structure that during its history may have been subject to flooding, fire, and overloading or blast damage. The age of the structure is often a significant feature to be considered.

Materials shall be carefully inspected.

Concrete shall be examined for, amongst other defects, deformation, spelling and corrosion of reinforcement and concrete repairs any of which could lead to premature collapse.

Steel and iron work should be inspected for deformation, corrosion, missing fasteners, site welded amendments etc.

Timber shall be inspected for deformation, splitting and cracking, knots, shakes, infestation and rotting.

8. HAZARD IDENTIFICATION STUDY AND PLANT ITEM CHECK LIST

A Hazard Identification and Risk Evaluation Study (the Hazard Study) shall be prepared by the Contractor for the existing plant and systems at Ashuganj Power Plant as a basis for understanding the measures required to safely demolish the item in question.

In undertaking a Hazard Study the use of BS IES 62882:2001is recommended.

The purpose of a risk assessment is to ensure that no hurt or illness comes to either operatives or the general public as a result of the work activities. A risk rating shall be given to each identified hazard. The severity of each hazard shall be classified as either major, serious or minor and the potentially of each hazard occurring shall be classified as highly likely, likely or unlikely.

The action necessary to overcome the hazard shall be identified and the date of the action specified.

8.1 Health Hazards

Health hazards in demolition arise primarily from substances which are inhaled or ingested, or which can react with or be absorbed through the skin. Noise and vibration are also hazardous to health. The following are the health hazards most likely to be encountered in demolition:

a. Lead: Lead as a toxic dust or fume arises from cutting and burning steelwork covered with lead based paint and the handling of old petrol tanks. In demolition, it is essential to identify any lead paint or lead containing material before operations begin.

b. Asbestos:

c. PCB: PCB's (Polychlorinated Biphenyls) are toxic substances which were used as dielectric filler fluids in electrical transformers and capacitors. In demolition it is important to identify equipment containing PCB’s either from labels or by enquires from manufacturers or former owners. Where equipment is to be removed or transported, leakage of PCB fluid is always a danger and check for leakage at welds or flanges must be made. If equipment is to be dismantled or broken up it is



essential that the fluid is removed and disposed of first Disposal of the fluid must be come in accordance with the national or international Regulations.

d. Entry into confined spaces: It is essential that any confined space which is to be entered is ventilated and the atmosphere tested before it is entered or any demolition work is permitted Entry to and work in confined spaces should be controlled by pre-planned "permit” system and backed by a rescue procedure.

e. Noise: Demolition plant such as compressors and concrete create noise “levels” in excess of the recommended 100 dB(A). Jobs likely to expose workers to an 8 hour noise close above 90 db (A) should be identified and arrangements made to ensure that ear muffs or plugs are provided and worn.

f. Vibration: Pneumatic drills and breakers are among many hand held tools likely to give rise to vibration white finger. Plant and tools should be selected as far as possible, to minimize the harmful effects of vibration or jolting motion.

g. Dust: Dust cannot always be identified as toxic but will always constitute an irritant and as such should be controlled by constant spraying of water.

A Plant Item Check List shall be prepared by the Contractor. The principle of the Hazard Study shall be extended to a system of Plant Item Check Lists. The purpose of a Plant Item Check List is to audit and list all of the inputs and energy sources necessary to secure operation of each individual item of plant or system. In reverse application a check list can be used to define all of the inputs and energy sources necessary to be terminally isolated for demolition purposes. With information from a Plant Item Check List, augmented by the data of the Hazard identification document it is possible to arrive at a complete assessment of measures needed to effect a controlled demolition of any plant item or system - if not totally sate from all causes, at least to a known, specified and agreed condition for further action post decommissioning.

If there is a risk that unauthorized entry on to the site could represent a significant source of danger special consideration should be given to erecting a fence around the Demolition Area and access controlled by a system of permits.

Special attention is required for those Hazards subject to relevant legislation and regulations. Care must be taken to establish all components and systems which contain hazardous substances e.g. mercury, PCB, sources of ionizing radiation etc.

9. MANAGEMENT OF DEMOUTION - SITE DEMOLITION PROCEEDURE

A Site Demolition Procedure shall be prepared and issued by the contractor and guide for the safe demolition. The procedure shall recognize the authority of all safety rules which apply on the site.

Enactment of the procedure will be the responsibility of the contractor.

The procedure shall, as a minimum requirement, address and encompass the following aspects of the demolition process.

9.1 Scope

Identify the role of the procedure, what plant, structures and systems it applies to, when it is to be enacted, what safety rules apply during demolition, when safety rules cease to have authority and when the procedure ceases to have authority. The Procedure shall also contain Method Statement s an all major items to be demolished,

9.2 Definition

Ensure that all terminology, titles and reference to other bodies, rules and companies are defined such that they are unambiguously understood and consistently used throughout the procedure.

9.3 Planning-

The planning of the demolition programme, including

a. objective



b. strategy

c. support service requirements

d. liaison with other parties

e. legal insurance and regulatory compliance issues

f. event sequence and timing

shall be basic requirements.

The planning will have need to craw upon the Information contained in the separate documents covering list of equipment, Register of External Service Connections, Plant insulation issues and Hazard identification Study, Plant item Check List and identification of Structure Hazarded in order for the strategy and programme to be defined

9.4 The Strategy

The strategy may take the shape of 'phased' or 'total' demolition with implications as to the need for physical barriers defining operational and demolished areas of the site. The extent and period of requirement for site demolition electrical supplies will also need to be defined as a matter of policy in the strategy.

9.5 Practical Stages of Demolition

The specification of the practical stages of demolition of plant items and or systems, from Handover of Site to the issue of the Closure report need to be defined.

The stages would need, as necessary, to embody the steps of:

a. Receipt of the Clearance of Plant/System Final Operation and of Plant System Terminal Isolation signaling the final operation of the plant or system.

b. Receive permission to operate within the Demolition Area.

c. Identification of Asbestos Boundaries

d. Removal of residual dangers where possible - drawing upon the detail of the Hazard Study, Plant Item Check Lists and identification of Structural Hazards. Asbestos or other toxic waste should be removed before starting demolition of any structure.

e. Affixing barriers and notices as appropriate to identify demolished plant and systems.

Implicit in the above is the specification of the standards of physical disconnection required and the wording and making of terminal isolating points appropriate to a demolition exercise e.g. removal of pipe section, fittings of approved blanks and plugs to approved method earthling, cutting, capping and removing power supply cables; design and fixing of purpose made notices and skiing good any damage to essential services.

9.6 Clearance of Plant/System Final Operation

Issued by the APSCL to the Contractor and confirming that identified plant and or systems ceased operational duty and can be released for the terminal isolation stage of the demolition programme.

9.7 Clearance of Plant/System Terminal Isolation

Issued by the APSCL to the Contractor and confirming that identified plant and/or systems have been securely terminally isolated with safety precautions and notices applied under authority' of site safety rules.

Specifying the conditions under which physical disconnections may be made.

9.8 Closure Report

When the demolition is complete, the contractor shall prepare a Closure Report. The acceptance of the Closure Report by the APCL shall not discharge the Contractor from any further liability in the area covered by the Closure Report.



9.9 Nomination of Staff

The nomination, by accountable senior Management, together with any associated authorization, of staff charged with specific roles and responsibilities for carrying out the planned demolition programme shall be established.

The Site procedures and standards used for nomination and authorization of activities under Site Safety Rules should be considered as an option for enacting the discipline of the demolition process.

The nominations of accountability must be for all levels of involvement and activity of staff during the demolition period, including who shall:

a. be in charge as Manager of the demolition activities

b. be required to formulate the planned programme

c. declare final operation of plant and or systems

d. be in control of execution of the prograrmme with responsibilities to initiate and instruct the activities of each stage

e. who shall have authority to respond to demolition instructions.

f. have authority to sign associated certificates

g. have accountability for notifying interested parties of completion of the objectives set for demolition

10. SITE DEMOLITION SUPPLIES

An assessment of the need for continuity of electrical supplies to specific items of equipment must be made in order to determine the policy with respect to their provision, either from existing network or from site demolition supplies.

Examples of such items that will inevitably require continuity of electrical supplies for the whole or part of a demolition phase are lighting; hearing; drainage; sump and sewage pumps and drainage. A detailed list of all items will be required, to define the extent and period of their need for supply

It is implicit that provision of site demolition supplies will require safety control to the standards of the existing site safety rules requirement.

11. POST CONSTRUCTION SECURITY

The site, in its current operational form, has open access to any person gains access to the main complex.

When the Contractor receives the permission to enter onto the Demolition Area it is likely that the Contractor will establish a secure fence enclosing the complete Demolition Area.

On completion of the Works including the EPC works for the new Plant the security of the site will be to a level agreed between the APSCL and the Contractor.



12. List of Equipments and Structure/Foundation (to demolished and disposed)

12.1 GT-1 and its auxiliaries

Title

Motor Rating

Quantity Remarks

voltage (kv) Power (kw)

TURBINE Two Stage Turbine

1

Serviceable

COMPRESSOR 13 Stages Compressor, Compression Ratio: 8:1

1

GENERATOR Frame: TG 940-4600-2160, Type: Revolving field, cylindrical Rotor Brushless. Generating Voltage: 13.8 KV, Power output with cooling air inlet temp. of 350C 55.67 MW at Power Factor 0.8

1

Diesel Starter Type: KTA3067P, HP:1400HP at 2150 rpm water cooled, V16, 4-Stroke

- 1

BEARING Exciter Non-driver End Bearing (Journal) Generator Exciter End Bearing (Journal) Generator Turbine End Bearing (Journal) Compressor End Bearing (Journal) Turbine End Bearing (Journal) Turbine Thrust Bearing (Journal)

6

TORQUE CONVERTOR Manufacturer: Cummings Engine Company Features: Turbo Charger, after cooler Model: 4-56-2223-0 Torque Convertor with a combined step-down output gear-box

1

Main Exciter Frame Type: RA 48/65/14/8, Brushless Max. (Full load) output-188 kw

1

Unit Transformer 13.8/132kv 76MVA 1

Auxiliary Transformer 13.8/6.6 KV 1500 KV 1

Instrument Air compressor 0.4 4 1

AC lube oil pump 0.4 22 1

DC lube oil Pump 0.110 6 hp 1

Generator Jacking oil pump DC 0.110 2.5 1

Turbine jacking oil pump DC 0.110 7 B.H.P 1

Lube oil tank vent fan 0.4 1.5 1

Turbine cooling air cooler 0.4 5.5 1

Combustion chamber vent fan AC 0.4 1.5 1

Combustion chamber vent fan DC 0.11 1.5 1

Battery room vent fan 1&2 0.4 .25 2

Turbine hall vent fan 1& 2 0.4 7.5 2

Fuel annex vent fan AC 0.4 0.25 1

Fuel annex vent fan DC 0.110 0.75 1

Lube oil cooler 1&2 0.4 11 2

Station battery charger (110 Nos battery) 120-150 VDC

26 KVA 2

Diesel engine battery charger (1 battery) 24 V DC 34 A 1

Control cubicle in Unit control room 4

Battery charger for fire protection 24 V DC 1

Fuel gas system within GT1 Lot



12.2 GT-2 and its auxiliaries

Title

Motor Rating

Qty. Remarks voltage (kv)

Power (kw)

TURBINE Two Stage Turbine

1

Serviceable

COMPRESSOR 13 Stages Compressor, Compression Ratio: 8:1

1

GENERATOR Frame: TG 940-4600-2160, Type: Revolving field, cylindrical Rotor Brushless. Generating Voltage: 13.8 KV, Power output with cooling air inlet temp. of 350C 55.67 MW at Power Factor 0.8

1

Diesel Starter Type: KTA3067P, HP:1400HP at 2150 rpm water cooled, V16, 4-Stroke

- 1

BEARING Exciter Non-driver End Bearing (Journal) Generator Exciter End Bearing (Journal) Generator Turbine End Bearing (Journal) Compressor End Bearing (Journal) Turbine End Bearing (Journal) Turbine Thrust Bearing (Journal)

6

TORQUE CONVERTOR Manufacturer: Cummings Engine Company Features: Turbo Charger, after cooler Model: 4-56-2223-0 Torque Convertor with a combined step-down output gear-box

1

Main Exciter Frame Type: RA 48/65/14/8, Brushless Max. (Full load) output-188 kw

1


Auxiliary Transformer 13.8/6.6

KV 1500 KV

1


AC lube oil pump 0.4 22 1

DC lube oil Pump 0.110 6 hp 1

Generator Jacking oil pump DC 0.110 2.5 1

Turbine jacking oil pump DC 0.110 7 B.H.P 1

Lube oil tank vent fan 0.4 1.5 1

Turbine cooling air cooler 0.4 5.5 1

Combustion chamber vent fan AC 0.4 1.5 1

Combustion chamber vent fan DC 0.11 1.5 1

Battery room vent fan 1&2 0.4 .25 2

Turbine hall vent fan 1& 2 0.4 7.5 2

Fuel annex vent fan AC 0.4 0.25 1

Fuel annex vent fan DC 0.110 0.75 1

Lube oil cooler 1&2 0.4 11 2

Station battery charger (110 Nos battery) 120-150

VDC 26 KVA 2

Diesel engine battery charger (1 battery) 24 V DC 34 A 1

Control cubicle in Unit control room 4

Battery charger for fire protection 24 V DC 1

Fuel gas system within GT1 Lot



12.3 Waste Heat Recovery Unit (WHRU), Steam Turbine (ST) and their auxiliaries

Title Motor Rating

Quantity Remarks voltage (kv) Power (kw)

Boiler Type: 4 stage Super-Heated Manufacturer: Babcock Power Ltd, UK Capacity: 126 ton/hr. Pressure: 39 bar

1

Serviceable

High Pressure Superheater 1 set

High Pressure Evaporator 1 set

Forced flow section 1 set

Low Pressure Evaporator 1 set

High Pressure Steam Drum Capacity: 11 ton (water mass approx.)

1

Deaerator Tank Capacity: 18.8 (water mass approx.)

1

Gland Water Tank 1

Make-up water Tank; Capacity: 11 ton (water mass approx.)

1

Lube oil Tank; Capacity: 9550 Liters 1

Lube oil Filter 2

TURBINE (GEC) : Type: Impulse/Reaction Manufacturer: GEC Turbine Generator Co. UK Rated Capacity: 34.33 MW; Number of Stages: 17

1

Boiler feed pump Main & Standby 6.6 367 2

Barring Motor 0.4 15 1

H.P Circulating Pump 1 , 2 & 3 0.4 90 3

Gland Water pump Main & Standby 0.4 5.5 2

L.P Circulating Pump 1 , 2 & 3 0.4 3 3

H.P Dosing mixer pump 0.4 .55 1

H.P Dosing pump 0.4 0.75 1

L.P Dosing mixer pump 1& 2 0.4 0.55 2

L.P Dosing pump 1&2 0.4 0.1 2

Make up water pump Main & Standby 0.4 3 2

Gland vent condensate extraction fan 0.4 0.75 1

Oil tank vapor fan 0.4 0.55 1

Dump system hydraulic pump 0.4 4 1

Flushing oil pump 0.4 4.2 1

Building vent fan 1,2,3&4 0.4 0.56 4

Condensate extraction pump main & Standby 0.4 1.25 2

Spray water pump Main & Standby 0.4 30 2

Vacuum Pump Main & standby 0.4 30 2

Lube oil pump Main & Standby 0.4 30 2

Flushing oil pump(DC) 0.11 4.1 1

Jacking oil pump (DC) 0.11 1.5 1



Auxiliary Transformer 6.6 /0.4kv 750KV 1

Control Cubicle in MCR 8

Control Desk in MCR 4

Overhead crane in ST Hall, Cap : 30/0.5 Ton 1

12.4 Others

All over ground & underground structure/foundation of the existing plant & auxiliaries and all underground structure/foundation from the rest of the Project area.



13. Annexure 1

Sl. No. Description of Furniture/Equipment Quantity

1 All furniture within the Control building and other buildings Lot

2 Auxiliary transformer 6.6/0.4 KV 3 no.

3 Battery and battery charger complete in all respects lot

4 All kinds of Fan Lot

5 All Air conditioner Lot

6 All lamps Lot

Volume-2 of 3 (Part-B) Page-21

Technical Specification of Plant Ashuganj 400 MW CCPP (East)

TECHNICAL SPECIFICATIONS

1. PROJECT DESCRIPTION

1.1 General

A Combined Cycle Power Plant of total net 400 (±5.0%) MW capacity at site conditions (35ºC, 1.013 mbar, 98% R.H.) is intended to be set up by Ashuganj Power Station Company Limited inside the existing premises.

The proposed Plant will be installed in the land as shown in the site layout. The Project will be implemented on turnkey basis.

The Power Plant will be connected with the existing Ashuganj 400 kV Gas Insulated Switchgear (GIS) Sub-Station with necessary electrical equipment as shown in the single line diagram that is about 2.5 km away from the proposed site.

1.2 Summary Scope of Work of Contractor

The Contractor shall commence work on the facilities from the Effective Date and the plant shall be completed ready for Turnover and having successfully completed all the tests on completion within 1080 (one thousand eighty) days for the combined cycle.

The Bidder shall provide a completed Schedule of works based on the start and completion dates defined above with its tender.

The project scope will include, but is not limited to, the following broad areas. More details are provided later in the sections below. This specification mostly defines the functional design and operational requirements. It also provides site specific data and defines the environmental constraints within which the plant must operate.

a) Demolition and disposal of the existing Plants and Auxiliaries including over ground & underground structure/foundation of the plant area and all underground structure/foundation from the rest of the project site.

b) Land development, dredging for intake channel if required and landscaping of the proposed site.

c) Design, manufacture, inspection, supply, delivery at site, construction, erection, testing & commissioning of the CCGT power generating facility.

d) The Facility shall be a combined cycle power plant in single shaft configuration with Facility Guaranteed Net Capacity at Site Conditions 400 (±5%) MW.

e) Equipping and connecting the power plant to under construction 400 kV GIS Substation double Bus at 450MW CCPP (North) Project premises through underground 400KV XLPE cable with cable trench and also connecting the 6.6KV grid auxiliary power supply to the existing outdoor 230 kV GIS Sub-station through a 230/6.6 KV start-up transformer with underground 6.6KV XLPE cable and trench.

f) Supply and Construction of all civil work including a Turbine Building, Central Control Room, Gas Booster Compressor building, Waste Water Treatment Building, security room, Modernization of the existing workshop, warehouse, chemical Laboratory, refreshment room, internal roads, boundary etc. Supply and Construction of all civil works of drinking water system including Clarifiers, Sediment Basin, and overhead storage tank etc. in all respects.

g) Supply and construction of entire Gas Fuel system for the plant, fire protection system, Fire Hydrant etc.

h) Supply and installation of CCTV at Main Gate, Central Control Room, Electrical Medium/ Low Voltage Switch Gear Room, Gas Turbine Unit and Steam Turbine Room, Generators, Exciters, Main generator voltage switch gear including Transformers, relay and protection equipment,GT Control System and ICMS for the Power Plant.

i) During the Defect Liability period of 24 months, the Contractor shall supply all

Page-22 Volume-2 of 3 (Part-B)

Ashuganj 400 MW CCPP (East) Technical Specification of Plant

necessary equipment/spares, materials, consumables [like Turbine intake air filters, oil & air filters, lube oil, grease, chemicals, compressor cleaning agents etc.] including spares and consumables for Scheduled Inspections of GT during equivalent 24,000 operating hours as per manufacturer’s guidelines and recommendations. Supply of all necessary spares and consumables shall be the responsibility of the Contractor at its own cost. These shall be supplied before the commissioning of the power plant.

The Facility shall be comprised of a complete gas fired Combined Cycle power generating Facility of 400 (±5%) MW Guaranteed Net Capacity (0.80 lagging power factor) with all support facilities required for reliable commercial operation. More specifically, the scope of work shall include, but not limited to the following items:

1.2.1 Scope of Works

The proposed power plant should be constructed by the EPC Contractor after

demolishing and disposal of the existing Plants and Auxiliaries including over

ground & underground structure/foundation of the plant area and all underground

structure/foundation from the rest of the project site. The scope of works to be

provided by the Contractor for engineering, procurement, and construction of the

Facility shall include, but not be limited to the following:

the overall management and control of the works

control and supervision of the Contractors and Subcontractor

provision of all labor, supervision, management, materials, equipment, construction power and water, on Site storage and material handling and control of the complete works

site investigations and surveys, as required

site preparation

obtaining consents

study work

engineering and design

detailed engineering

procurement

expediting

inspection

manufacture and fabrication

painting

packing, shipping, delivery to Site and insurance

construction and erection

protection and preservation

testing and pre-commissioning

commissioning and testing

Performance Tests and Reliability Tests

other services as specified or necessary to complete the Project

temporary construction works and facilities, including camp facilities if required

24 months Defect Liability

provision of all necessary documentation

1.2.2 Scope of Supply

The Facility will comprise, but not necessarily be limited to the following:



combustion turbine generator (CTG) designed to operate on Natural Gas and their auxiliary and ancillary equipment

heat recovery steam generator (HRSG) and auxiliaries

exhaust stack and silencers without bypass stack

one steam-turbine (ST) with all auxiliaries

Natural Gas receiving system

open loop condenser cooling system for the steam turbine exhaust steam

raw water system

service water system

steam, feed water, and condensate systems

raw water, and waste water treatment plants

Equipment for connection from demineralized water system to the terminal point from 225MW CCPP

Potable/Drinking water system

closed loop auxiliary cooling system,

HRSG/boiler feed water treatment system

generator step-up; start-up, station and auxiliary power transformers; and associated protection and control equipment, as required

generator breaker for combustion turbine-generators

SWAS (Steam and water analysis system)

Town Border Station (TBS)

Gas Reducing and Metering System (RMS)

Gas pipe and Ultrasonic flow meter for GTCL’s gas manifold

Ultrasonic flow meters with flow computer and online gas chromatograph

Turbine flow meter with chart recorder

Station electrical distribution system

DC equipment, batteries, and UPS systems

power, control and instrument cabling

earthing (grounding) and lightning protection

Emergency diesel generating plant for emergency auxiliaries and lighting etc.

emergency lighting system

cathodic protection

lighting and small power services

compressed air system

cranes and lifting gear

maintenance tools and equipment for electrical workshops, stores, and chemical laboratories

modernization of the existing workshop

fire detection and protection system

firefighting systems

chemical storage tanks

chemical feed systems

condensate water tanks

central water sampling station

Natural Gas metering system

metering systems for fuel, electrical energy export, and electrical energy import, including backup systems



control system for combustion turbine generator & steam turbine unit

local control equipment for auxiliary plants

plant distributed control system

load dispatch control interface facilities

foundations for all plant and buildings

civil and structural and building works associated with the plant buildings including, but not limited to:

Turbine House for GT/Steam Turbine

Central Control/Electrical Room

Cooling Water Pump Station

Raw Water Pump

Waste water treatment house with chemical laboratory

Fire Protection Pump House

Gas Booster Compressor Building

3 (three) storied warehouse each floor 500 Square meters storage area (including overhead crane and hoist crane).

Internal roads

potable water system and other building services

HVAC facilities

Site lighting

Site access road from main highway

Natural gas Pressure reduction and Heating station

Raw water storage

All necessary external works including roads, fencing, gates and drainage within the power plant

Mandatory spare parts specified in this Bidding Document

Spare parts required for commissioning, operation, and maintenance

Special tools and maintenance equipment. Tele-communication systems within Facility, connection to public network, and connection to PGCB telecommunication networks

Communication protocols, Automatic Generator Control (AGC), etc. as required by PGCB

All consumables throughout the specified operating period

Connections to the 400 kV Indoor GIS Sub-Station through approx. 2.5 Km underground 400 kV XLPE Cable and also connection to the outdoor GIS of the existing 230KV Substation for Startup Transformer through approx. 600 meter 6.6 KV XLPE underground cable.

Associated relays and controls

The Bidder shall be deemed to have included in his Proposal any additional plant

and equipment necessary to meet the design, performance, operation, and

environmental criteria for the Facility, but which are not specifically identified

above, and to form a complete power plant which is fit in all respects for its

intended purpose and use.

The Contractor should pay special attention to complying with the Bangladesh

(GOB Environmental Conservation Rule 1997) requirements regarding air

emissions. It is Bidder’s responsibility to investigate through the Bid Date the

issuance of any new or additional or revisions to existing guidelines for thermal

power plants and their applicability to and implications for the Project.



1.3 Terminal Points and Interfaces

The Contractor shall be responsible for obtaining sufficient data regarding the interface conditions for the plant, to ensure safe, efficient and reliable operation of the Works within the environmental limitations, under all operating modes and climatic conditions. The Contractor shall be responsible for making all the connections, including breaking into other systems, as necessary.

The Contractor shall assess the proposed termination points for all services and shall agree with the Employer an appropriate tie-in point and tie-in schedule. The location and schedule shall, where applicable, be designed to minimize inconvenience to other users of the systems. The Contractor shall clearly identify in the Contract Programme the date it requires the terminal points to be available.

The Contractor shall be responsible for the delivery of the Works in its entirety and for ensuring its connection to the services required for satisfactory and safe operation. Terminal point for natural gas shall be 2.2 km away from the project site.

1.3.1 Natural Gas

An indicative analysis of the natural gas is included in Section 2.2 below for

information. The Contractor shall be responsible for the obtaining sufficient data

regarding the natural gas quality and other parameters, as necessary to ensure

the appropriate sizing of gas delivery and handling facilities to provide the required

natural gas flow and quality to satisfy the requirements of the gas turbine and

other possible users within the site.

1.3.2 Water

The Contractor will be responsible for water supply for the Facility. A complete

system shall be provided to deliver water at full demand conditions to the plant for

all raw, fire, potable and demineralized water consumers. The demineralized

water shall be taken from the Demi water tank of Demineralized water plant of

225MW CCPP by pipe connection including pumps, valves, water storage tank,

control system, cable etc . The demineralised water quality of the said plant is

included for information.

Conductivity : 0.1 µs/cm at 250C

Silica as SiO2 : ˂0.02 ppm

PH : 6.5 ~ 7.4

Total Iron : ˂0.02 ppm as Fe

An indicative analysis of the river water is included for information (Table 12).

However, the Contractor shall be responsible for obtaining of sufficient data

regarding the water supplies for the plant, including analyses as necessary to

ensure the appropriate handling/storage facilities to satisfy Plant water supply

requirements.

1.3.2.1 Raw Water

Raw water shall be drawn from the Meghna River. River flows, levels and other relevant information is included. The river water will be the source of raw water used for makeup of the Facility’s steam cycle and open loop condenser cooling system. The Contractor scope shall include the water pipeline and pumping facility necessary to deliver water to the Site. The Employer will acquire rights of way for the water river water pipeline.

1.3.2.2 Potable Water

The Contractor shall use properly treated water providing potable water system for the Facility.



1.3.3 Drainage

1.3.3.1 Surface water

The surface water system should collect precipitation of the whole station into a system of underground pipes, manholes and discharge it to the Meghna River.

1.3.3.2 Sanitary and Sewer Facilities

The Contractor shall provide for adequate sanitary facilities during Facility construction and Facility operations, and treat sanitary sewer as described in Section 5.3.4 of this specification before discharging it off site.

1.3.3.3 Oily and Chemical Drains

Oily water and chemical drains shall be treated to an approved quality before discharge to the Meghna River. All drains and other liquids, if discharged from the Facility shall at all times comply with appropriate environmental regulations and meet the quality standards specified in GOB Environment Conservation Rule (1997) Schedule 9 and Schedule 10.

1.3.4 Electrical Connections

1.3.4.1 Characteristics of the System Load

The load generation gap will continue for years and the proposed capacity, which is only 4.80% of the demand forecast for 2013, will be absorbed in any time. Moreover the proposed plant would replace an existing plant of about 146 MW capacity. It should be accommodated within the intermediate zone of the load curve, just around the shoulder of the load duration curve.

1.3.4.2 Present Network for Transmission of Power

The Ashuganj power station has three large 132kV, 230kV and 400 kV switchyards and through these switchyards it is connected to national grid. The proposed power plant will be connected to national grid through 400 kV GIS Bus bar system with necessary equipment and interface to existing bus-bar differential protection & other protection and control system etc. will be within the scope of offer.

1.3.4.3 400 kV GIS Sub-Station for power evacuation

Generation of power shall be at 11~22 KV for CCGT units and stepped up to 400 KV by Unit transformer(s). Generated power will be evacuated through 400 kV GIS switching station connected by underground XLPE cable and trench.

Bay of 400 GIS double bus bar system fully equipped with CT, PT, LA Disconnect switches, Earth switch etc. shall be provided to evacuate generated power from the proposed 400 MW Combined Cycle Power Plant to National Grid. Step-up transformer shall be three phases with a capacity not less than of 525 MVA and the unit will be connected to the 400 KV GIS bus-bars through the circuit breaker.

Extension of 400 KV GIS Bus and new bay equipment including CB, DS, CT, PT, ES, Protection relays and interface with existing bus-bar differential protection & other protection and control system etc. will be within the scope of offer.



1.3.5 Interface Summary Table

The following services may be either internal or external to the Site. The responsibility for obtaining these service connections including other connections (not listed below) shall lie with the Contractor. The services that may be off site may include, but not necessarily restricted to, the following:

Table 1: Terminal Points and Interfaces (Note 1)

Item Terminal Point Interfacing

Body Detail

1 Fuel (natural gas) (*) APSCL/ BGDCL/ GTCL

Connection point at GTCL’s Valve station-3

2 Raw Water (CW) supply

APSCL Meghna River as per EPC design

3 Potable water APSCL No town supply; use treated water

4 Demineralized water make up

APSCL Connection point is in the existing Demi. water Tank of Ashuganj 225 MW CCPP

5 CW and HRSG blow down discharges(**)

APSCL As per EPC design

6 Domestic sewage APSCL Treated at site as per EPC design

7 Storm water discharge run-off

APSCL Treated as per EPC design and discharged to river

8 Underground 400 kV cable

APSCL/PGCB 400 kV under construction GIS Sub-Station

9 Underground 230 kV cable

APSCL/PGCB 230 kV existing outdoor GIS Sub-Station

10 Construction power for site

APSCL EPC Contractor to provide

11 ICMS APSCL/PGCB Fiber optic multiplexer 400 kV SS (OPGW)

12 Hydrogen APSCL As per EPC design

13 Chemicals APSCL As per EPC design

14 Waste oil disposal APSCL Treatment and disposal as per EPC design

15 Stack emissions Environment Stack

16 Site roads APSCL As per EPC design, to tie into existing road

17 Remote fire alarm telemetry

APSCL HPS main fire indicator panel

18 External telecommunications

Phone utility Main Distribution Frame (MDF)



Item Terminal Point Interfacing

Body Detail

19 Site boundary APSCL Brick wall

20 Gas (town supply) Employer Nearest point

* Note that final connection to gas supply is within the scope of the Contractor.

** Metered and monitored separately before common discharge (as process blow down).

Key for interfacing bodies:

NG: Natural Gas

Note 1- EPC Contractor is solely responsible for interconnection with terminal point

1.4 Site Description

1.4.1 LOCATION

The Ashuganj power station complex is located about 90 km North-East of Dhaka

City on the left bank of the River Meghna across Bhairab Bazar and connected by

motor/rail ways with Dhaka and Chittagong. There also exists good waterways

connection of Ashuganj site with seaports of Chittagong and Mongla and then

overseas. Access to power grid is very easy as large 132kV, 230 kV and 400 KV

substations exist here already. Moreover, Ashuganj is also the hub of gas

transmission system where all the sources meet. The location is ideal for power

station; in spite of this, a review would be made.

The following site ambient and other conditions presented below as indicative but

the Contractor shall be conducted all necessary surveys within the quoted price

for Plant design:

1.4.2 Site Condition

1.4.2.1 Topography

The Contractor shall carry out surveys as are necessary for the proper design and execution of the Works without additional cost. The results of such additional surveys together with the survey drawings shall be submitted to the Engineer for approval.

1.4.2.2 Site investigation

The Bidder may conduct soil investigation, ambient air quality investigation, river water/ underground water quality investigation if deemed necessary at his own cost before submission of the bid. However, after signing of contract the soil investigation, soil improvement/ development, ambient air quality investigation, river water/ underground water quality investigation at the cost of the Contractor is mandatory for detailed design of the civil work/ other equipment. Soil improvement/ development (if required) shall have to be done by the Contractor at his own cost. Additional money cannot be claimed for poor quality of soil/ air/ water.

1.4.2.3 Soil conditions

The proposed power plant should be constructed by the EPC Contractor after demolishing and disposal of the existing Plants and Auxiliaries including over ground & underground structure/foundation of the plant area and all underground structure/foundation from the rest of the project site.



The Bidder may conduct soil investigation if deemed necessary at his own cost before submission of the Bid. The Contractor shall be performed the soil investigation before foundation design of the proposed plant within the quoted price.

1.4.2.4 Seismic Conditions

Bangladesh and North-East India have historically been in the active seismic zone. According to Bangladesh National Building Code 2015 draft, Bangladesh has been divided into four seismic zones i.e zone I, zone II, zone III and zone IV. Ashuganj power station site is situated under zone III. Seismic coefficient for zone III is 0.28g.

1.4.2.5 Meteorological Condition

Bangladesh Meteorological Department, Government of Bangladesh located at Agargaon, on the Begum Rokeya Sarani maintains the meteorological data for about 28 stations spread throughout Bangladesh. Ashuganj Power Station site has no reference station. Nearest reference stations are Comilla, Sreemongal and Sylhet. Comilla Weather Station which is about 60 km southeast of Ashuganj is considered appropriate as the reference station for weather data for the proposed Ashuganj Combined Cycle Power Plant. The following data were collected from the Climate Division, Bangladesh Meteorological Department for a period of sixty years from 1948 to 2008.

Monthly average Maximum & minimum Temperature in Celsius, total Rainfall in millimeter, Maximum Wind Speed data in knots and Direction in Degrees (counted from the direction of north, clockwise), average Relative Humidity data are in percentage. The climate of the site is wet and tropical throughout the year.

The meteorological conditions of the area are summarized as Maximum ambient air temperature 41.80C, Minimum ambient air temperature 6⁰C, Relative humidity (Max) 96%. Maximum Wind Speed 28 knots at 50 counted from north.

1.4.2.6 Hydrological Conditions

Ashuganj power station is situated on the left bank of the Meghna River. Hydrological data of the Meghna River were collected from Surface Water Processing Circle of Bangladesh Water Development Board (BWDB), for the years 1988-2008. There is one (1) measuring station, namely, Bhairab Bazar that is located about 1 (one) km downstream of the Ashuganj Power Station.

This station measures the following data of the Meghna River.

- Water level in meter (m)

- River water discharge in m³ /sec

- Velocity in m/sec

River width Water Level

The Bhairab Bazar station records the level of river water. We studied all the available data on water level for the period between 1987 and 2015. It was found that the river at Bhairab is affected by tide. In general, the Meghna River starts rising from the month of March and attains peak level in July and August. After September water level in the Meghna River starts receding and becomes lowest in February. From 1987 to 2016 lowest and highest water level of the Meghna River at Bhairab Bazar was recorded as follows:

- Lowest water level 0.5 m PWD (January, 2016)



- Highest water level 7.78 m PWD (July, 2004)

In designing intake structure and discharge channel the above figures should be taken into consideration.

River width, discharge and velocity

The river width recorded at Bhairab Bazar station varied from 821.60m to 843.35m. The river flow at Bhairab is affected by tide, and river flow goes down with tide. The effect is pronounced in dry season. Maximum and minimum discharges at Bhairab Bazar are shown below.

- Maximum discharge: Qmax = 16558.27 m3 /sec.

- Minimum discharge: Qmin = 2050.319 m3 /sec

- Average minimum discharge: Qav. min = 7234.552 m3 /sec

Minimum discharge of 2050.319 m3 /sec as shown above is the discharge of November 26, 1998 which will always be available from the Meghna River. It may be mentioned that the above maximum and minimum figures have been obtained from the hydrological data provided by the Surface Water Processing Circle of Bangladesh Water Development Board. Data before 1998 was not available. Data of such short period from 1998 to 2006 for statistical purposes may be inadequate.

- Maximum velocity: Vmax = 1.75m/sec

- Minimum velocity: Vmin = 0.267m/sec

1.4.2.7 Water Supply

Adequate water appears available throughout the year from the

Meghna River for the proposed 400 ( 5.0%) MW combined cycle plant. The cooling water requirement is estimated to the about 35000 m³ /hour considering 50C rise of the condenser discharge water which would attain a temperature 370C, and mixing with equal amount of river water would attain a temperature 33.50C in the immediate vicinity. The channel between the bank and the island appeared to have silted up causing criticality in dry months.

1.4.2.8 River Water Quality

Environmental Consultants appointed for river water quality study carried out surface water quality tests of Meghna River near Ashuganj Power Station on 16 July 2009, that are given below.

- Dissolved Oxygen : 6.6 mg/1

- Chloride : 3.0 mg/I

- Conductivity : 132 µs/cm

- Iron : 0.1 mg/I

- Silica : 32 mg/I

- PH : 6.8

- Turbidity : 65 JTU

1.4.2.9 Air Temperature

The temperatures recorded during 1948-2008 showed that the minimum temperature as 60C (Jan 1993) and the maximum temperature was 41.80C (April 1960).



1.4.3 Existing Power Plants at the station

Ashuganj power plant was established by BPDB in the period from 1970-1988 in

phases.

The existing power station of APSCL at Ashuganj consists of 2 units of 64MW

steam power plant + 3 units of 150MW steam power plant + 1 unit of 225 MW

combined cycle power plant + 2 units of 450 MW CCPP + 1 unit of 53MW gas

engine. The power is generated at 11 kV, 13.8 kV, 15.75 kV & 22 kV by different

machines and is stepped up to 132kV, 230kV (AIS & GIS), 400 kV (GIS) in future

and thereby connected to the national grid system.

All the power plants are fuelled by natural gas through respective RMS, feeder

lines, metering stations from the main gas transmission line belonging to

Bakhrabad Gas Distribution Company Ltd (BGDCL).

The 132 kV Sub-station built with the 2x64MW power station was commissioned

in 1970 and the 230kV was built later on, with the 3x150MW power plant. The 230

KV GIS substation was commissioned in December 2015 whereas 400 KV GIS

will be commissioned in the year of December 2016. The AIS Sub-station is

located very close to the south side of the power plant. Recently Ashuganj 225

MW Combined Cycle Power plant is connected to 132 KV bus bar systems.

The132kV is a double bus sub-station with one bus bar conductor 450 mm² T-

Aluminium and estimated capacity of 1000A. The 230kV switchyard is also a

double bus system with 2 x 500 mm² copper conductors having estimated

capacity of 2000A.



2. PERFORMANCE, OPERATING AND MAINTENANCE REQUIREMENTS

2.1 Plant Design Criteria

The Plant shall be a combined cycle power generating facility in single shaft without bypass stack with net capacity 400 (±5%) MW at the reference Site Conditions (ambient

temperature of 35C, relative humidity of 98% and barometric pressure of 1.013 bar) together with all associated auxiliary equipment and systems including gas booster compressors (GBC), pumps, and circulating water system, unit step-up transformer, and high voltage (HV) underground cable for power evacuation.

The gas turbine shall not be equipped with the bypass stacks and diverter dampers to allow continuous and reliable simple cycle operation.

The gas turbine shall be not equipped with inlet air cooler. Provision of additional firing with fuel gas i.e. supplementary firing of HRSG shall not be included.

2.2 Fuel Gas Specification

The fuel gas composition varies on a daily basis in accordance with the operating conditions of the upstream gas production facilities. It is understood that variations of the gas composition throughout Bangladesh are small. The calorific values of the gas (LHV) have been ranging between 35,222.9 kj/Scm. and 39,064.1 kJ/scm. Table 2 shows a “typical” gas composition provided by Bakhrabad Gas. This composition shall be used for performance guarantee purposes.

Table 2: Typical Gas Composition & Properties

Particulars % Mole % Wt

Nitrogen 0.430 0.712

CO2 0.109 0.283

Methane 96.246 91.268

Ethane 2.049 3.642

Propane 0.545 1.421

i-Butane 0.169 0.580

n-Butane 0.119 0.408

i-Pentane 0.068 0.289

n-Pentane 0.045 0.190

Hexane 0.113 0.561

Heptane 0.082 0.468

Octane 0.019 0.125

Nonane 0.001 0.008

Decane+ 0.006 0.045

Total 100.000 100.000

SG 0.5841 at ISO condition (150C, 101.325kPa)

Ideal Density kg/scm3 0.7155

Real Gas Density kg/scm3 0.7172



Particulars % Mole % Wt

Mole Weight gm/mol 16.9182

Compressibility (at std conditions) 0.9976

Higher Heating Value MJ/scm 39.0641

Lower Heating Value MJ/scm 35.2229

Notes: Sample date: 02 April 2015; Sample Origin: APSCL; by: Bangladesh University of Engineering & Technology (BUET)

Standard conditions" for the above data are 150C, 101.325 kPa (590F and 14.6956 psi)

The Employer is not aware about presence of H2S in Bangladesh gas. If required, the Contractor shall independently verify that no H2S is present in natural gas during the detailed design stage.

The above sample was provided by Bakhrabad Gas as typical for the local gas supply, but is based on the gas analysis performed on the specified date. This gas composition is to be used for bidding and performance guarantee purposes. The performance test results will have to be corrected based on the actual gas composition burnt during the performance test in accordance with Contractor’s test procedures.

Gas compositions will vary with the mix of fields and production conditions. To cater for fluctuating gas compositions, all gas components, such as pipelines, valves, vessels and process equipment (including compressors) should be designed with a suitable capacity margin. The Contractor shall include the appropriate margin in their design. The margin shall be no less than 10% of the design gas flow.

The Contractor shall investigate the potential variations of gas compositions and ensure that the power station can operate within the entire range of the fuel gas composition variations.

According to the Gas Transmission Company Limited (GTCL) data:

Water content of the gas is: max. 7 lb / 1,000,000 scf

Hydrocarbon condensate (carry over) at production: max. 2 US gal / 1,000,000 scf.

The Contractor shall independently verify this information.

Hydrocarbon (HC) condensate can be found at various locations in the upstream transmission system The Contractor shall assume that HC condensate is carried over to the power station and allow for adequate condensate removal in the gas conditioning system and gas skid before entering into GT.

The Contractor shall specify adequate HC condensate removal equipment, such as scrubbers, and explain the assumptions leading to its design.

2.3 Performance Guarantees and Operating Requirements

2.3.1 Performance Guarantees

A. The net output and heat rate of the Unit shall be guaranteed by the Contractor

at the following conditions:

a. Ambient temperature : 950 F (350 C)

b. Site elevation : less than 100 ft (msl)

c. Relative humidity : 98%

d. Barometric pressure : 1.013 bar

e. Generation voltage : 11,000 V- 22,000 V

f. Power factor : 0.80 lagging

g. Frequency : 50 Hz



h. Cooling water temperature : 90˚F (32.2˚C)

The Contractor shall guarantee the starting reliability of the Unit including all ancillary

equipment. The guaranteed reliability shall be stated in the Tender form together

with the number of consecutive starts to which the Unit will be subjected to

demonstrate this reliability. (This is for a starting reliability of 95 %, the Unit shall be

subjected to 20 consecutive starts of which 19 shall be successful) the maximum

speed rise after full load rejection is to be guaranteed (see Tender)

(1) Guaranteed net total base load capability at site Condition (350C, 1,013 bar, 98% relative humidity) Shall be without introducing any ancillary equipment, such as water/steam injection, evaporator, chillier etc. for combined mode.

: 400±5.0% MW

(2) Guaranteed average weighted net heat rate at site Condition (LHV, 350C, 1,013 bar, 98% relative humidity) Shall be without introducing any ancillary equipment, such as water/steam injection, evaporator, chillier etc. for combined mode. (According to the clause no. 3.6 (iii) of Volume 1)

: < 6700 kJ/kWh

(3) Minimum KVA rating of generator : The generator KVA rating at 0.80 power factor shall match or exceed gas/steam turbine drive output under all load operating conditions.

The Contractor shall guarantee the Plant performance as follows:

Table 3: Combined Cycle Mode - Output and Heat Rate

a) LHV Basis and

Particulars Units Guaranteed Value

Guaranteed Net Power Capacity at high tension side of the step-up transformer

kW To be quoted by Bidder

Guaranteed Net Heat Rate at 100% load

kJ/kWh To be quoted by Bidder





The guarantees quoted in Table 3 shall be based on the new and clean condition.

The guarantee basis Reference Conditions and testing protocol are provided in

Section 15.0.

B. Emissions

Plant emission requirements are indicated in Section 18.0. For combined cycle

operation, for the full range of stable operating loads and site conditions, the plant

shall meet the specified emissions limits, including:

Stack emissions NOx, CO, CO2 etc.

Thermal emissions (such as warm water discharges into the river)



Wastewater

Noise.

Refer to Section 18.0 for additional specifications on emissions and Section 15.0 for the test protocol.

C. Starting Times

Rapid unit starting is critical to the Employer. The Bidder shall nominate the

starting and ramp up times as set out in Table 4, below, for the offered equipment.

These times shall be demonstrated during the plant acceptance tests. The times

nominated must not be shorter than the manufacturer’s recommended time for the

particular phase of the start-up.

Table 4: Combined Cycle Start-ups

Particulars Cold Start Warm Start Hot Start

Time to Synchronization To be quoted by Bidder

To be quoted by Bidder


Hold Time at Synchronization




Ramp Rate, MW/Minute To be quoted

by Bidder To be quoted

by Bidder To be quoted

by Bidder

Time from Ending Hold at Synchronization to Full Load




Notes:

1. Above times shall be quoted in minutes.

2. The definitions of warm, cold and hot starts are indicated in Section 2.3.2.

2.3.2 Plant Operation Conditions

2.3.2.1 Plant Operating Profile

The projected year-round operating profile for the Unit is provided below. The Contractor shall optimize his design based on this profile:

Table 5: Plant Operating Profile

Period

Average Ambient DB

(°C) Day/Night Max/Min

Average Relative Humidity (%RH)

Max/Min

Plant Load %

No. of Equivalent Operating

Hour/Annum

Jan/Feb/Mar 27 / 17 83 / 38

100 1685

75 130

50 129

0 216

Apr/May/Jun 31 / 26 86 / 66

100 1703

75 131

50 131

0 219

Jul/Aug/Sep 31.5 / 27 92 / 79 100 1722



Period

Average Ambient DB

(°C) Day/Night Max/Min

Average Relative Humidity (%RH)

Max/Min

Plant Load %

No. of Equivalent Operating

Hour/Annum

75 133

50 132

0 221

Oct/Nov/Dec 28 / 20 88 / 64

100 1722

75 133

50 132

0 221

The following definitions regarding Unit starts shall apply:

Cold Start: A start after more than 48 hours of continuous shut down

Warm Start: A start after more than 8 hours, but less than 48 hours of continuous shut down

Hot Start: A start after less than 8 hours of continuous shut down.

2.3.2.2 The estimated number of starts per year is as follows:

Classification of Start Number of Starts

Hot Start 12

Warm Start 4

Cold Start 4

2.3.2.3 Availability and Reliability

The Unit shall be designed to achieve the levels of availability and reliability normally expected for similar modern combined cycle units, and shall be designed to achieve an average life time

Equivalent Availability Factor of no less than 90%.

In this specification the Equivalent Availability Factor Formula is defined in accordance with ANSI/IEEE Standard 762-1987, Appendix C, Equation C-7 as follows:

EAF + POF + UOF + UDF + SDF = 100

Where:

EAF = equivalent availability factor

POF = planned outage factor

UOF = unplanned outage factor

UDF = unit derating factor

SDF = seasonal derating factor

The equation above shows that there are recognized sources of energy loss due to planned outages (full), unplanned outages (full), unit de-ratings, and seasonal de-ratings. Each energy loss is represented by a separate index, POF, UOF, UDF, and SDF respectively. These indices are defined in such a way as to be additive. Therefore, the total per unit energy loss is the sum of the



four indices, and the remaining per unit energy not lost is called equivalent availability factor (EAF).

The unit shall be designed to achieve greater than 99% starting reliability.

2.3.2.4 Electrical Grid Requirements

The Bangladesh Grid operating requirements are as follows:

1. Frequency Limits

The power grid in Bangladesh operates at nominal frequency of 50 Hz. The Unit shall be capable of operation at frequencies as defined in the table below. It is not anticipated that the Unit will be required to operate for extended periods at frequencies above 50.8 Hz.

Frequency Range(Hz) Minimum Sustainable

Operation

48.5 to 51.5 Continuous

>47.5 and <48.5 10 minutes

>51.5 and <52.0 10 minutes

47.5 or less Trip Condition

52.0 or more Trip Condition

2. Voltage Limits/Current Limit

The power plant will connect to APSCL 400 kV GIS Substation and system voltages shall be selected from IEC 38, and shall be capable of operating over the range + 5% - 10% of the nominal voltage.

3. Power Factor

At rated voltage and frequency, the Plant will operate at 100% load with a power factor in the range 0.80 lagging to 0.95 leading. The curves from the manufacturer showing the Reactive Power capability of the generator shall be submitted by the Contractor with its proposal.

2.3.2.5 Other Operating Conditions

The Plant shall be designed to meet the required stack emission limits with dry low NOx burners, without requiring water or steam injection in the gas turbine.

It is anticipated that the Plant will trip on occasion. The bidder can assume the following quantity of trips per year:

CCGT Load Prior to Number of Trips

per Year

100% 7

75% 1

50% 0

The Plant shall be capable of continuing operations in combined mode. A suitable sized steam turbine bypass system shall be provided to provide this capability.

Black Start is not required.



The generator is required to sustain full load rejection without tripping. The turbine generator is further required to remain operating at synchronous idle condition for sustained periods following load rejection and supporting their own auxiliaries without dependence on station supplies.

The Plant shall be capable of automatic operation and control at loads between 100% and 25 % of the guaranteed capacity in combined cycle mode.

The Bidder shall state if there are any additional conditions or limitations, regarding the operating regime of the Plant in its proposal.

2.4 Operability

The Ashuganj CCGT Power Plant shall be designed and equipment shall be sized to permit reliable operation over the complete range of anticipated ambient conditions without limiting the plant output. The Ashuganj CCGT Power plant shall be designed to withstand and to function normally in the extreme ambient conditions indicated in Section 4.0.

2.5 Plant Dispatch

The plant shall be designed primarily for base load operation but it must also be capable of cyclic duty (two shifting). The CCGT Power Plant will be required to operate at high net capacity factors. Power generation shall be fully dispatchable at least between 25% and 100% of Net Guaranteed Capacity output. The CCGT Power Plant will be dispatched from the National Load Dispatch Centre (NLDC).

All turbine controllers shall be equipped (at the unit coordinating level) with automatic generation control (AGC) capabilities, for automatic regulation of the total power output of the CCGT Power Plant within predetermined limits. The automatic regulation shall be accomplished through communication links between NLDC and the generator equipped for such control (at the unit coordinating level).

However there shall be a Manual generation control (MGC) to control the load in accordance with the instruction received from the PGCB’s load dispatch centre.

2.6 Maintainability

Access around all equipment will be provided, in accordance with good utility practice, to allow effective inspection, maintenance and removal. Aisle ways adjacent to equipment and laydown areas shall be sufficient to facilitate all aspects of major maintenance and Plant overhaul. General arrangement drawings shall clearly identify the outline of all major plant equipment, their weights and associated floor loading capacity and lay down location.

Equipment requiring regular routine maintenance that does not have direct or mobile crane or forklift access shall be provided with monorail and hoists. Monorail, Bridge crane or forklift access shall be provided for moving heavy equipment. The heaviest maintenance lift equipment item and rating for each crane, monorail and hoist shall be specified. The lay down areas for all major plant equipment shall have adequate space for direct heavy transport and trailer access and direct mobile crane access. Laydown schemes shall eliminate double-handling of lifted loads to the maximum extent possible.

2.7 General Redundancy Requirements

The CCGT Power Plant shall be designed such that a failure of any equipment will allow the plant to run. Unless specified otherwise, the equipment spares philosophy for the CCGT Power Plant shall provide one spare piece of equipment for all applications.

If there are N pieces of equipment in use at full load, then there should be N + 1 pieces of that equipment installed, excluding the GTG, its starting equipment and generator step-up transformer, HSRG, ST.

Specific equipment redundancies for the CCGT Power Plant shall be per the requirements below which provides a greater level of redundancy.



Table 6: Equipment to be supplied

No. Description Sparing Philosophy or Process Option

1 Gas booster Compressors#* 3 × 60% capacity units (Centrifugal type)

2 Main cooling water pumps#* 2× 110% capacity units

3 Boiler feed water pumps#* 2 x 110% capacity units

4 Auxiliary (closed circuit) cooling water heat exchangers*β

2 x 110% capacity units

5 Lube oil pumps (for turbines and generators)* β

For GTG 2x110% capacity AC driven pumps, plus, DC motor driven pump for safe shut down of turbine in the event of total power failure.

For ST 2x110% capacity AC driven pumps, plus, DC motor driven pump for safe shut down of turbine in the event of total power failure

6 Minor auxiliaries, including :

River water make-up pumps*β

Gas coalescer filters*β

Lube oil heat exchangers*β

Critical control valves*β

Steam condensate return pumps*β

Main cooling water intake screens and screen

cleaners*β

Service and Instrument air compressors*β

Fire pumps in river intake wet well*β

2 x 110% units

7 Battery systems for essential supplies

Required for:

DC driven emergency lube oil pumps

Remote control communications systems

Emergency lighting and other safety systems

2 x 110% units

8 UPS system 2x100% with backup to operate plant ICMS controls,

9 Critical environmental protection items, e.g. oily water sump pumps

2 x 100% units

10 Critical safety and loss prevention

equipment, e.g. fire water pumps

2 x 110% capacity units.



No. Description Sparing Philosophy or Process Option

11 Steam turbine bypass 1x100 % automatic steam dump line to condenser

12 Cooling water to minor cooling water users

Use separate closed cycle cooling system with fully treated water

13 Gas supply bypass to gas turbine Provide connections for bypass line and Valves.

14 Controls I/O capacity 20% extra / redundant capacity to be provided at time of construction

15 Controls cabling 20% spare cores to be provided at time of construction

16 Gas piping vents and drains Double isolation valves to be fitted.

17 Critical valves Install small bore bypass valves

The Contactor shall be responsible for ensuring that a changeover from a failed duty machine / equipment to the standby up and running is achieved without tripping of the system (GT, ST etc. as applicable). The Contractor will also consider the changeover of all equipment of a system when both are running at the same time without tripping the system.

β Approximate value to allow Bidders / Contractor flexibility to choose the closest standard product range, subject to detailed design and Employer approval, with suitable allowance for safety factor and degradation.

Minimum value is to allow Bidders / Contractor flexibility to choose the closest standard product range, subject to detailed design and Employer’s approval, with suitable allowance for safety factor and degradation.

2.8 Plant Standardization

The CCGT plant electrical equipment (electrical panels, instruments, ICMS system) and mechanical components (such as small pumps and small valves) shall be standardised as much as reasonably possible throughout the CCGT Power Plant systems (same manufacturers, same type, same arrangement) to reduce the number of spare parts and to ease maintenance. This requirement shall not hinder the Contractor from using his standard design nor force the Contractor to breach standard purchasing agreements.



3. GENERAL REQUIREMENTS

Contractor’s work shall be governed by the following documents and specifications. If there is a conflict in the requirements, the documents are listed below in order or precedence:

Applicable laws, codes, regulations

The form of EPC Contract Agreement to be developed between the parties

The EPC Contract Exhibits.

In case of conflict between the above documents, the Contractor shall advise the Employer and obtain resolution as soon as possible.

3.1 Definition of Terms

In addition to the “Definition of Terms” in the EPC Contract Agreement, the following terms are defined:

ADB

AGC

APSCL

BGDCL

BMD

BOP

BPDB

CCGT

CCR

CPM

CPT

DLN

DOT

EIA

ELV

EMP

EPC

FAT

FRP

GCB

GOB

GT

GTAW

GTCL

GTG

HDPE

HVAC

IDB

I&C

Asian Development Bank

Automatic Generator Control

Ashuganj Power Station Company Ltd.

Bakhrabad Gas Distribution Company Ltd.

Bangladesh Meteorological Department

Balance of Plant

Bangladesh Power Development Board

Combined Cycle Gas Turbine

Central Control Room

Critical Path Method

Cone Penetration Test

Dry Low NOx

Department of Transportation (USA)

Environmental Impact Assessment

Extra Low Voltage

Environmental Management Plan

Engineer, Procure, and Construct

Factory Acceptance Test

Fibre-Reinforced Plastic

Generator Circuit Breaker

Government of Bangladesh

Gas Turbine

Gas Tungsten Arc Welding

Gas Transmission Company Ltd

Gas Turbine Generator

High Density Polyethylene

Heating, Ventilation and Air-Conditioning

Islamic Development Bank

Instruments and Controls



HRSG

ICMS

LTSA

MCB

MCW

NACE

NLDC

NGO

NCR

ODAF

Heat Recovery Steam Generator

Integrated Control Management System

Long Term Service Agreement

Miniature Circuit Breaker

Main Cooling Water

National Association of Corrosion Engineers

National Load Dispatch Centre

Net Guaranteed Output (combined cycle unit)

Network Control Room

Oil Directed Air Forced

OEM

OLTC

ONAF

ONAN

PGA

PGCB

PPE

PWD

RMS

RTU

SAW

SFC

SMAW

SPT

TFA

STG

VESDA

VDU

VSD

WB

XLPE

Original Equipment Manufacturer

On-Load Tap Changer

Oil Natural Air Forced

Oil Natural Air Natural

Peak Ground Acceleration

Power Grid Company of Bangladesh

Personal Protection Equipment

Bangladesh Public Works Department Datum

Regulating and Metering Station

Remote Transmitter Unit

Submerged Arc Welding

Static Frequency Converter

Shielded Metal Arc Welding

Standard Penetration Test

Technical Field Assistance

Steam Turbine Generator

Very Early Smoke Detection

Visual Display Unit

Variable Speed Drive

World Bank

Cross-Linked Polyethylene

3.2 Codes and Standards

All components, systems, and equipment shall be designed, manufactured, assembled and tested at manufacturers’ works, installed and, after installation at the Ashuganj Site, shall be tested and commissioned, in accordance with applicable internationally recognised standards, and statutory codes and regulations, including those specifically listed in this specification. The Contractor shall not only provide with its proposal a schedule of all the codes and standards but also supply the documents of codes and standard that he proposes to use for the project. If the Contractor proposes alternate codes or standards to those listed below, he must demonstrate that the alternate is of equal or superior stringency than the comparable code or standard system listed in this specification, and obtain the Employer’s approval. Approval will be solely at the Employer’s discretion. No proof of equivalence is required for the use of GTG, STG, and HRSG manufacturer’s own standards



for pre-designed equipment and systems within the GTG, STG and HRSG packages. Where specific codes are specified without the option for equivalent standards, the Employer’s approval must be obtained to use another standard or code.

Any of the standards published by the authorities listed here will not require further approval:

AASHTO

ACI

AGA

AISC

AISI

ANSI

API

ASCE

ASHRAE

ASME

ASTM

AWS

American Association of State Highway and Transportation Officials

American Concrete Institute

American Gas Association

American Institute of Steel Construction

American Iron and Steel Institute

American National Standards Institute

American Petroleum Institute

American Society of Civil Engineers

American Society of Heating, Refrigeration and Air Conditioning Engineers

American Society of Mechanical Engineers

American Society for Testing and Materials

American Welding Society

AWWA

BNBC

BS

DIN

HEI

HIS

IEC

IEEE

IP

ISA

ISO

JIS

MSS

NEMA

NFPA

SSPC

TEMA

UBC

American Water Works Association

Bangladesh National Building Code

British Standards Institution

German Standardization Institute

Heat Exchange Institute

Hydraulic Institute Standard

International Electro-technical Commission

Institute of Electrical and Electronics Engineers

Institute of Petroleum

Instrument Society of America

International Standards Organization

Japanese Industrial Standards

Manufacturer’s Standardization Society

National Electrical Manufacturers Association

National Fire Protection Association

Steel Structures Painting Council

Tubular Exchanger Manufacturers Association

Uniform Building Code

In the case of the Standards and Codes not published in English, the Contractor shall obtain English translation when required and send them to the Employer at no additional cost.

Unless otherwise agreed, the latest revision (at the time of EPC contract award) of all relevant standards and their addenda shall apply at least 3 copies each.

All interfaces with PGCB national grid shall comply with the requirements of PGCB. The natural gas supply system shall comply with all national standards and regulations.



The fire detection and protection systems shall provide coverage of Ashuganj Site and shall comply with NFPA codes (or equivalent) in addition to all statutory and local authority requirements. The Contractor shall cooperate with the Employer’s insurance carrier’s requirements to finalise the fire protection design.

The plant shall be constructed, installed and commissioned and be operable and maintainable in full compliance with relevant health and safety at-work orders, all related acts, regulations, codes and statutory requirements. All warning and instruction notices shall be in English.

The Contractor shall implement all special requirements concerning the nature, handling and storage of all classified substances including fuels, oils, gases and chemicals. Where possible, hazards should be reasonably avoided. Where appropriate, areas shall be classified to the relevant sections of the Institute of Petroleum (IP) Codes, or other recognised standards. Suitably certified equipment shall be used in the designated hazardous areas.

Equipment location and arrangement shall ensure that not less than two escape routes are available for personnel in case of fire or other hazard during normal operation and maintenance procedures.

All statutory environmental regulations shall be adhered to during the design, construction and operating phases of the Project.

3.3 Design Life

The durability (design life) criteria listed in Table 7, taking into account operational stresses, allowances for corrosion and normal maintenance, shall apply to Ashuganj CCGT power station:

Table 7- Design life

Facility Element Situation / Function Not less than

50 years

Not less than 25 years unless

noted

Civil / Structural

Foundations All X

Concrete Structures All X

Protective Coatings Difficult to access or replace.

X > 20 years

Moderately difficult to access or replace.

> 15 years

Mechanical X

Electrical X

3.4 Language and Units

All correspondence, drawings, catalogues, illustrations, specifications, and other documentation related to the project shall be in the English Language. The units of measurement shall be expressed in the SI system.

3.5 Site Regulations and Safety

The Employer and the Contractor shall establish Site regulations according to the General Conditions of Contract.

Work in existing substations shall be carried out while the station is in service, and only short interruptions for temporary connections and arrangement of safety barriers are



permitted. The Contractor shall arrange for all temporary connections and safety, which shall be approved by the Employer.

3.6 Notices and Permits

The Contractor shall give the requisite notice to Government Inspectors as may be required in the case of excavations, trenching and pay for all permits required prior to and during the execution of the Contract including those required for all temporary works.

3.7 Verification of Dimensions

Before work is commenced on any structural element required to be fabricated or provided under this Contract, the Contractor shall verify by measurement on site, the relevant dimensions of all work.

3.8 Site to be Kept Tidy

Throughout the progress of the Works, the Contractor shall keep the Site and all working areas in a tidy and workmanlike condition, and free from rubbish and waste materials. Other items, which are not required for use for the time being by the Contractor, the Contractor shall disperse those items about the site in an orderly fashion and shall store properly and securely.

The Contractor shall not remove any construction plant, materials, etc. from the Site without the consent of the Employer.

3.9 Reinstatement

Reinstatement of any areas, including existing amenities and structures, affected by the Contractor’s establishment, temporary works, access routes, spoil disposal areas and the like, shall include restoring such areas to at least the condition, degree of safety, drainage and stability as existed before the Contractor entered the Site. Restoration shall include clearing and removing all rubbish and waste, breaking up and removing all concrete slabs and hard standings and re-grading the ground to match adjacent slopes, replacing topsoil to a depth equal to that originally in place, fertilising and establishing an approved grass cover.

3.10 Site Supervisors

The Contractor shall provide the services of competent specialists to supervise the construction of the Works and erection / installation of Plant and Equipment at the Site.

The Contractor’s Site Supervisors shall be given full responsibility and authority to negotiate and agree regarding points arising out of the erection, in order that the works may proceed with a minimum of delay. Direction and instruction given by the Employer to the Site Supervisors shall be interpreted as having been given to the Contractor.

3.11 Occupational Health and Safety

The maximum safety, consistent with good erection / installation practice shall be afforded to personnel directly engaged on this Contract, or to persons who, in the normal course of their occupation, find it necessary to utilise temporary works erected by the Contractor to access the working area.

Once any section of the Works or Plant and Equipment has been energised, the Contractor shall establish a system for ensuring the safety of personnel and equipment. While the Works, Plant or Equipment is under the control of the Contractor, the Contractor shall be primarily responsible for the safety precautions. While the Works, Plant or Equipment is under the control of the Employer, the Employer shall be primarily responsible for these precautions.

The Contractor shall ensure sufficient screening on health issues in the recruitment of workers. Precautionary measures shall be taken against speeding of communicable diseases through awareness (information campaigns) and orientation aimed at both the Contractor employees and people residing in that area. The Contractor shall be responsible for the provision of adequate sanitary facilities and safe drinking water provision for all office employees at construction site.



The Contractor shall provide on-site emergency medical services with suitably equipped and serviced facilities. The facility shall be staffed on a full time basis by two (one roaster basis) tertiary qualified medical personnel. A suitable vehicle shall also be provided full time on-site and a planned system for removal to hospital of authorized persons requiring further treatment shall be provided by the Contractor to the satisfactory of the Engineer. Establishment of this facility and removal at the end of the Contract shall be covered under BOQ item.

3.12 Packing and Transport Identification

All parts of the Plant and Equipment shall be well packed and protected against loss or damage during the transport by sea and over land and whilst in storage under adverse climatic conditions. All packing shall be performed in such a way that the equipment will not be damaged by overturning of the packages. Dimensions of packages, crates, etc., shall be suitable for road transport. Instruction for handling shall be clearly marked on all parts, packages and crates.

All parts, packages and crates shall be adequately marked in order to enable identification. Each item contained in a package shall be clearly identified on the packing list by its description and part number and assembly drawing reference, and each item shall be marked or labelled to correspond with the packing list. The identification system to be used shall be as instructed by the Employer.

The cost of all equipment needed for the temporary fixing and supporting of the various parts of the Plant and the various packages to crane hooks, etc., during handling, transport and storage and the cost of load distribution beams, etc., where they form part of the packing or crates, shall be included in the Bid Price.

The Contractor shall be entirely responsible for all packing and any loss or damage shall be made good by the Contractor and, except where otherwise provided, at the Contractor's own expense.

Any transhipment of materials and equipment through countries adjacent to Bangladesh shall be the Contractor's responsibility. Any costs associated with transhipment of materials and equipment shall be deemed to be included in the Contract Price.

Identification, reinforcement or upgrading of roads/bridges for access to the Site and for transport of equipment and materials shall be the responsibility of the Contractor. Any costs associated with identification, reinforcement and upgrading of roads and bridges shall be deemed to be included in the Contract Price.

3.13 Identification Markings

A legible identification mark of origin shall be applied on all castings and forgings, particularly on conductor and overhead ground wire hardware, and on insulators and associated hardware. Insulators shall, in addition, be marked with the mechanical or electromechanical failing load or a corresponding code number. Each separate member of the structure shall be marked indicating tower/pole type and number and the piece corresponding to the shop drawings. These identification marks shall be embossed into the steel before galvanising, or concrete as part of the casting, in such a manner as to be plainly visible after manufacture.

3.14 Maintenance Tools and Appliances

The Contractor shall include and supply all tools and appliances that are required for the normal operation and maintenance of the equipment being supplied under the Contract. All tools and appliances shall be certified following inspections and/or tests for the specified functions and guaranteed in the approved drawings.

Instruction manuals of tools and appliances shall be submitted for approval in the same manner as the installation operation and maintenance manuals and when finally approved, one original and three copies shall be prepared and forwarded to the Employer.

Each tool and appliance shall have a clear identification mark showing its size and/or purpose and shall be packed in the appropriate box with six (6) sets of an operation and



maintenance instruction book. All name plates, duty labels and instruction plates on tools and appliances shall be marked in English.

3.15 Disposal and Pollution

The Contractor shall not dispose of any waste, rubbish, or offensive matters in any place not approved by the Engineer or statutory authorities having jurisdiction.

The Contractor shall not discharge into any oil, solids, noxious, floating materials or untreated waterborne effluent into any water bodies and take reasonable precautions to prevent their accidental spillage, contact with soil or discharge into water bodies.

The Contractor shall take all reasonable precautions to keep main and internal roads clear of any spillage or dropping from their vehicles. Any spillage or droppings which occur shall be cleared without delay to the satisfaction of the Engineer.

The Contractor shall conduct and submit to APSCL/ADB, prior to construction, base line environmental measurements on ambient air quality, noise and surface water quality, noise and surface water quality at the Meghna river and ground water quality, aquatic flora and fauna within the immediate vicinity of the cooling water discharges of the existing plant.



4. SITE CONDITIONS

4.1 General

Technical data included with this specification such as ground water data, river profile, flood water level data and river water current and quality, site meteorological data, etc., are for the Contractor’s information only. The Employer assumes no responsibility for accuracy of these technical data. The Contractor shall perform independent investigation including testing of water and air samples and soil investigation, as necessary to ensure accuracy of these technical data plus any additional investigation required prior to the project design within the quoted price.

4.2 Meteorology

4.2.1 General Description of Climatic Conditions at Ashuganj

Ashuganj has a tropical monsoon climate, where there are two distinct seasons.

These are a dry season from November to April, and a wet season from May to

October. The first part of the dry season from November to February is the coolest

and driest period of the year. The remaining months of the dry season are

characterized by increasing temperature and humidity, and thunderstorms. The

wet season has 85% of the annual rainfall, with high humidity and heavy rainfall

events of up to 50 mm to 75 mm in two to three hours. At the end of the wet

season from September to November there is a period with decreasing rainfall but

still high temperature and humidity, often associated with thunderstorms. However,

the rainfall for storm water systems design will be in accordance with Section 4.2.3.

The Site normally experiences only light winds of the order of 10 km/hr or less,

and peaks do not normally exceed 50 km/hr. However, the wind velocity for

structures design will be in accordance with Section 4.2.4.1.

Cyclones coming in from the Bay of Bengal are experienced in Bangladesh during

the periods April to May and October to November. On occasions these can cause

great damage and loss of life. The Ashuganj Site is some 150 km inland from the

Bay of Bengal and does not experience the full effects of such cyclones.

Much of the climatic data presented in this report is based on records from Dhaka

Airport which is some 20 km away, but can be regarded as representative of the

Ashuganj Site.

4.2.2 Temperature and Humidity

The dry bulb temperature, relative humidity and calculated wet bulb temperature

data for the Project Site are given in the technical appendices in Volume 3. For

quick reference, average extreme dry bulb temperatures are given in Table 8.

Table 8: Average Extreme Dry Bulb Temperatures in Celsius

Summary Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

High 24.9 27.7 30.6 32 31 31.4 30.2 31.3 31.6 30.5 28.9 26

Low 13.3 16.8 21.1 24.7 25.7 27.5 26.7 27.1 26.4 24.7 20 15.2

The coolest part of the year centred on the month of December also corresponds

with lowest humidity conditions. Day time temperatures average just under 25C

and night time temperatures approximately 14.5C. The corresponding relative

humidity’s are 47% and 86% respectively. From the records examined, the

minimum temperature is 8.2C.

As the dry season progresses through from January to March, temperatures

increase and relative humidity decreases slightly, until in April the humidity



increases as well as temperature. This is the start of the build up to the wet

season. At this time, average day and night time temperatures are 31.7C and

25.8C respectively, and the corresponding average relative humidity’s are 59%

and 81%. Note that peak temperature can rise considerably above the average,

with 39.4C having been recorded at Dhaka Airport.

The months of May, June, July, August, September and early October during the

wet season are typified with average day time temperatures between 30.5C and

31.7C, and night time temperatures from 25.4C to 27.8C. Respective average

relative humidity is 60% to 80% daytime and 80% to 90% at night.

October and November are a period of transition to cooler drier December

conditions from wet season conditions described above.

Temperature and Relative Humidity Extreme Values for Design:

Extreme maximum dry bulb: 41.8C

Extreme minimum dry bulb: 8C

Extreme maximum wet bulb: 35C

Extreme minimum wet bulb: 7C

Maximum relative humidity:100%

Minimum relative humidity: 35% Approx.

Temperature and Relative Humidity Values for CCGT Design Guarantee Point:

Gas turbine performance design/guarantee dry bulb temperature is 350C at 98%

relative humidity and barometric pressure of 1,013 mbar.

4.2.3 Rainfall

The average monthly data recorded for Dhaka, by the Bangladesh Meteorological

Department (BMD) for the years 1985 to 2005 is given in the technical appendices

in Volume 2.

A majority of the rainfall occurs during the wet season months, from May to

October, and ranges from 297 mm to 370 mm average per month. This is typically

not continuous raining all day events but occurs in downpours of several hours

duration during mid to late afternoon. The peak rainfall intensity is very much

higher than these average rainfall figures suggest. Average rainfall in the

remaining months of the year is in the range of 8 mm to 139 mm per month.

Design peak rainfall intensities are 190 mm/hr, 175 mm/hr and 95 mm/hr for

durations of 5 minutes, 10 minutes and one hour respectively.

4.2.4 Wind

Average monthly maximum wind speeds (knots) and directions for the period 1985

to 2005, recorded by the Bangladesh Meteorological Department (BMD) at Dhaka

Airport, are presented in given in the technical appendices in Volume 2.

The Site normally experiences only light winds of the order of 10 km/hr or less.

The prevailing wind direction for most of the year is south to southeast. Maximum

winds normally do not exceed approximately 50 km/hr at any part of the year.

However, squally northwest wind gusts of up 80 km/hr can be associated with the

thunderstorms in the pre-monsoon period. Property damage is sometimes

associated with these events.



4.2.4.1 Design Wind

The basis for establishing the wind forces for the strength design of structures at Ashuganj CCGT is the Bangladesh National Building Code, 2015 (BNBC-2015), draft. This code defines the minimum design requirements for buildings and structures in Bangladesh.

Figure 6.2.1 and Table 6.2.8 in BNBC-2015 give a basic wind speed, at 10 m above the ground, of 56.7 mile/sec for Brahmanbaria. This is for a 50 year recurrence interval or a 2% annual exceedence probability (AEP).

When applying the various formulae in BNBC-2015 to produce design wind gust pressures, the following parameters shall be adopted:

Structural Importance Coefficient, C1 = 1.15 (“Special Occupancy Structures)”. Refer also Section 4.4 Site Seismicity)

Terrain Exposure Category = B.

Using these parameters results in the following wind design pressures, at 10 m above the ground:

Sustained wind pressure = 2.10 kN/m2

Gusting (design) wind pressure = 2.6 Cp kN/m2 where Cp = pressure coefficient.

4.2.5 Air Quality

Air quality of the proposed plant Site is given below. The data was taken in 2004.

There is rapid industrialization in and around the Ashuganj power station complex.

Table 9: Air Quality of the Proposed Site

Location Date Air Quality

Concentration in µg/cu-m

Ashuganj Proposed Plant Site for CCGT

SPM NOx SO2

Plant gate about 100 meter west from the plant

23/4/04 361.72 28.0 ND

PDB gate about 500 meter west from the plant

23/4/04 370.62 36.52 12.40

Ashuganj Supermarket about 1000m west from the plant

23/4/04 385 45.24 18.20

Standard as per the revised National Ambient Air Quality Standard, July 2005 (DoE, 2005)

200c 100a 80a, 365b

World Bank 2008 Guidelines 50b/20a 200d/40

a 20a

Source: ECOMAC-EGCB 2004

Note: a: Annual Average, b: 24-hr Average, c: 8-hr Average; d: 1-hr Average

SPM: Suspended Particulate Matter, NOx: Oxides of Nitrogen, SO2: Sulfur- dioxide, ND= Not detectable

Air quality analysis was carried at two locations in 2006 on Ashuganj site which is near to the proposed Site are given in Table 10.



Table 10: Air Quality Analysis

SL No

Sample Location

Ambient Air Pollution Concentration in micro gram/cubic meter

Remarks

PM2.5 PM10 SPM SO2 NOx

1 Propose Project area

37 69 179 23.17 39.09 Wind direction was from

south-east to north-west

corner. It was sunny day

Duration 480 480 480 480 480

DoE (Bangladesh) standard for Industrial area

65 150 500 120 100

Analysis Method Gravemetric West-Geake

Jacob and Hochheiser

Analyses Conducted by: Adrior Engineers, 6/8, Sir Syed Road, Mohammadpur, Dhaka 1207.

Notice: PM2.5 - Fine particulate sampler, PM10- Respirable dust content; SPM- Suspended Particular Matter, SO2 - Sulfur dioxide; NOx – Oxides of Nitrogen.

4.3 Hydrology

4.3.1 General Description of Meghna River Adjacent to the Ashuganj Site

The Meghna River at the Ashuganj Site is a large navigable waterway, with

sufficient depth and width for use by river boats, barges and shipping. It will be a

viable means for transporting heavy construction loads for the proposed power

station construction.

The Ashuganj Site is some 150 km away from the open sea in the Bay of Bengal,

however, the terrain in this area of Bangladesh is very flat and gradients along the

river systems are very low. This is to the extent that water flows in the Meghna

River will reverse (go “upstream”) during low flow periods. At lower river flows tidal

effects are experienced at Ashuganj.

The normal flow variation in the river is for low flows to correspond with the dry

season and high flows to occur during the wet season.

Some of the hydrological data presented in this report is based on records at the

Bhairab measuring station some 5 km upstream of the Ashuganj Site. For

variations in river flows, and temperature conditions Bhairab records can be

considered representative of the river at Ashuganj. The level and bathymetry data

presented below is specific for the river at Ashuganj Site.

4.3.2 River Water Temperature

As noted in the technical appendices in Volume 2, data gathered in 2002 and

2003 showed the river water temperature is lowest during December when it

averages below 20C. The temperature then increases continually during the

balance of the dry season (up to April - May) to average figures in the range 29C

to 32.2C. The river water temperature is relatively stable during the wet season at

28C to 30C average. During October and November there is a period of cooling

back to the December low.



Meghna River Temperature Design Values:

Extreme maximum river water temperature: 36.0C

Extreme minimum water temperature: 15.66C

The thermal plumes from adjacent power station operations may add

approximately 1 to 3 degrees to the peak temperature given above depending on

current conditions and level in the river the measurements are taken from.

Appropriate allowance shall be made for possible future temperature rises.

4.3.3 River Water Flow and Velocity

As noted in the technical appendices in Volume 2, the average dry season flows

are typically steady at a little above 2000 m3/sec. Data available for this period is

very limited and the figures provided in the table for dry season months is

estimated only. During May and June average flow rises with the onset of the wet

season. It reaches, on average, 7234.552m3/sec by beginning of July. Average

flow remains at the 7234.552 m3/sec rate through to end of September, after

which flow steadily declines back to below 1500 m3/second by December.

Peak river flows vary to well above the wet season average of 7234.552

m3/second. The highest recorded flow in the data set received was 16558.27

m3/second.

Lowest actually recorded dry season flow is 196 m3/hr, and slightly below average

dry season flow.

There is an increase in velocity associated with increasing flow rate. Closer to the

banks and bed of the river, flows will be substantially less due to boundary layer

effects. There is no available data to quantify this. Peak velocity at 16558.27

m3/second flow is recorded at 1.48 m/second, and minimum peak velocity

recorded is 0.17 m/second. Actual minimum peak velocity is likely to be below this

since there were no velocity records supplied from the dry season months. There

is no simple relationship between flow and velocity due to the surface level also

varying with flow.

As noted above, the flow direction can reverse to upstream in the dry season.

Meghna River Recorded Flow Rate Extremes:

Maximum recorded: 16558.27 m3/second

Minimum recorded: 2050.319 m3/second

Meghna River Recorded Flow Velocity Extremes:

Maximum recorded: 1.75 m/second

Minimum recorded: 0.267 m/second

4.3.4 Water Levels, Depths and Bathymetry

The Bidder shall carry out the Meghna River Bathymetry Study for the design of

intake system and cooling water pumps. Preliminary data are given below. It can

be seen that river level will rise with flow, but this is not linear due to

corresponding flow velocity increases.

The tidal effect on river level ranges typically from approximately 0.08 m to 0.50 m.

River level range is approximately 6.6 m which is a significant factor to take into

account when designing the power station water intake system. Allowing for

adequate submergence of the intake pumps suction and freeboard of the site

above peak river level the pump suction will be approximately 15 m below the

filled site ground level for the power station.



The level data is based on Bangladesh PWD datum. Some reference material that

has been reviewed references the alternative “Survey of Bangladesh” datum

which is 0.50 m above the PWD datum. Level data should always be verified with

respect to which datum has been used.

The mean of these maximum water levels was 7.03 m PWD (Bangladesh Public

Works Datum) at a 50 year return period. The statistical range of this same water

level is 6.5 m to 7.6 m at the same return period.

The 1 in 50 year return period water level (2% annual exceedence probability)

near the Ashuganj Site has been simulated by the Institute of Water Modelling,

Dhaka, (IWM) as a mean level of 7.20 m PWD. Scaling from IWM this same mean

water level will be approximately 7.42 m PWD for a 1 in 100 year return period

water level (1% annual exceedence probability), with a statistical range between

6.9 m and 8.2 m.

4.3.5 Extremes in Records Data

Meghna river water level

Available data on water level for the period between 1987 and 2016 were studied.

It was found that the river at Bhairab was affected by tide. However, no rivers flow

occurred during the period. The Meghna River water level starts rising from the

month of March and attains peak level in July and August. After September water

level in the Meghna River starts receding and becomes lowest in February. From

1987 to 2016 Lowest and highest water level of the Meghna River at Bhairab

Bazar recorded were as follows

Lowest water level : - 0.5 m MSL (January, 2016)

Highest water level : 6.78 m MSL (July, 2004)

In designing intake structure and discharge channel the Bathymetry study

performed by the EPC Contractor should be taken into consideration with its own

cost.

4.3.6 River Water Quality

The water quality data given in the technical data should be viewed as indicative,

as it is based on a limited pool of data. From the indicative data available, the river

water is mildly saline with significant dissolved solids.

The data do demonstrate that the river water quality deteriorates during the dry

season, except for silica and suspended matter which are higher in the wet

season. The increase in the silica and suspended matter are presumably due to

materials carried down from upstream catchments during the wet season.

Whilst there is no data to be presented on gross contaminants in the river, such as

plastic bags and bottles, the Bidders will need to look for this when on site and

determine primary screening of intake water to suit.



Table 11: Surface water quality test report

Sl. No. Particulars Concentration

present

DoE(Bangladesh) standard for

Inland surface water

1 Alkalinity (as CaCO3) 35.8 mg/litre

2 Aluminium 1.67 mg/litre

3 Arsenic (As) ˂ 0.005 mg/litre

4 Cadmium ˂ 0.001 mg/litre

5 Calcium 6.0 mg/litre

6 Chloride (CI-) 1.29 mg/litre

7 Chromium ˂ 0.005 mg/litre

8 Copper ˂ 0.10 mg/litre

9 Fluoride ˂ 0.5 mg/litre

10 Hardness as CaCO3 31.6 mg/litre

11 Iron (Fe) 0.95 mg/litre

12 Lead (Pb) ˂ 0.01 mg/litre

13 Magnesium 3.32 mg/litre

14 Manganese ˂ 0.05 mg/litre

15 Mercury (Hg) ˂ 0.001 mg/litre

16 Nitrate ˂ 3.0 mg/litre

17 Nitrite ˂ 1.0 mg/litre

18 Oil & Grease 7.4 mg/litre

19 PH at 24.80C 5.65 mg/litre

20 Phenolic Compounds ˂ 0.1 mg/litre

21 Phosphate 4.55 mg/litre

22 Potassium 1.47 mg/litre

23 Sodium 3.63 mg/litre

24 Suspended Particle Matters 41.4 mg/litre

25 Sulphate ˂ 4.0 mg/litre

26 Total dissolved Solids (TDS) 62.0 mg/litre

27 TOC ˂ 0.5 mg/litre

28 Zinc(Zn) 0.8 mg/litre

Source: Institute of National Analytical Research and Service (INARS),

Bangladesh Council of Scientific and Industrial Research, Dhaka. Sample was

taken on: 11 November’ 2015. Sample was taken: From filter house 1 of the

existing plant.

4.3.7 Ground Water Quality (for information only)

The groundwater sample was collected from a deep tube well located within the

Ashuganj power station complex. The results of analysis of groundwater shows

that the measured parameters satisfy the Bangladesh drinking water standard

(Environmental Conservation Rules, 1997) and the WHO guidelines value for

drinking purpose.



Table 12: Quality of Groundwater Sample Collected from the Ashuganj Power Station Company Ltd.

Sl. No.

Groundwater Quality Parameters

Unit Concentration

Present

WHO Guideline

Value (2004)

ECR, 1997 Values for Drinking Water

1. pH -- 7.24 6.5~8.5 6.5~8.5

2. Color (filtered) Pt. Co.

Unit 4 15 15

3. Turbidity NTU 1.52 5 10

4. Carbon dioxide

(CO2) mg/L 33.0 - -

5. Total Alkalinity as

CaCO3 mg/L 317.0 - -

6. Total Hardness as

CaCO3 mg/L 274.0 500 200~500

7. Iron (Fe) mg/L 0.1 0.3 0.3~1.0

8. Manganese (Mn) mg/L 0.028 0.4 0.1

9. Arsenic (As) µg/L <1 10 50

10. Chloride (Cl) mg/L 185.0 250 150~600

11. Fluoride (F) mg/L 0.49 1.5 1

12. Nitrate- Nitrogen

(NO3-N) mg/L 0.20 50 10

13. Total Dissolved

Solids (TDS) mg/L 637.0 1000 1000

Source: Environmental Assessment Report prepared by BRTC, BUET dated March 2007 (page 4-27, Vol 1) (Prepared for 450MW South Project).

4.3.8 Ground Water Level

The ground water level varies considerably between the wet and dry seasons, and

is significantly influenced by the water level in the river. It is clearly advantageous

to carry out construction of major ground works items such as the main turbines

and HRSG foundations in the dry season. This will avoid significant dewatering

costs.

4.3.9 Other Notes on the Meghna River

The Meghna River is heavily trafficked by river boats, barges, and smaller

shipping boats. A significant loading facility for small ships is located nearby

across the river. There is a need to consider possible damage to the water intake

and service jetty from passing vessels.

4.3.10 Site Level

Section 4.3.4 identifies the maximum water levels in the Meghna River, adjacent

to the power station site. These are summarised in Table13.



Table 13: Meghna River Maximum Water Levels

Return Periods Maximum River Water Levels (PWD)

from Figure 1

1 in “x” years

AEP Mean Upper Bound Lower Bound

50 2% 7.20 m 7.8 m 6.7 m

100 1% 7.42 m 8.2 m 6.9 m

AEP = annual exceedence probability

The plant site level shall be based on the highest 1 in 100 year flood level (1%

AEP) in the adjacent Meghna River, plus a free board. Table 12 identifies that for

a 1 in 100 year return period, the mean value of the maximum river levels adjacent

to the power station site is 7.42 m PWD. Applying a freeboard of 0.5 m, the

minimum plant grade elevation should be 8.65 m PWD.

4.4 Site Seismicity and Seismic Design Codes

The Ashuganj Site is exposed to seismic conditions. The area is in Seismic Zone III as determined by the Bangladesh National Building Code (BNBC- 2015, Draft) and Seismic Zone 3 per the UBC Building Code, 1997. The peak ground acceleration (PGA) of the Site to be considered in the seismic design of the plant is 0.28g. This PGA corresponds to an earthquake that has an exceedence probability slightly less than 10% in 50 years. The Contractor shall study soil liquefaction potential and provide remedial measures, if require, to resist this design basis peak ground acceleration.

All buildings, structures and foundations shall be designed for this design basis earthquake and meet the Zone III earthquake design criteria of BNBC-2015 using a Zone Coefficient of 0.28. The design seismic lateral forces shall be determined either by the Equivalent Static Force method, or by the Dynamic Response Method, based on the requirements of the Bangladesh National Building Code (BNBC-2015). The ductile detailing rules of BNBC-2015 for zone III shall be met in design of reinforced concrete (per BNBC Section 8.3.3 and 8.3.6) and structural steel (per BNBC Section 10.8.12).

4.5 Geotechnical Investigation Requirements

A detailed soil investigation, and analysis to determine the soil liquefaction potential of the power plant site, shall be carried out by the Contractor. The underlying sub-soil of the power plant site shall not be susceptible to liquefaction under earthquake conditions following treatment, if required, after detailed soil investigation remedial measure carried out by the Contractor.

The scope of the Contractor’s geotechnical investigation programme shall comprise machine drilled boreholes supplemented with Cone Penetration Tests (CPT) to sufficient depth to determine overall ground conditions and founding depths for piled foundations. The number and extent of boreholes and CPTs’ shall be sufficient to accurately determine ground conditions across the site, and under all major structures (including the retaining wall along the river edge). Standard Penetration Tests (SPT) shall be performed in all boreholes, and piezometers shall be installed in sufficient boreholes to assess groundwater levels, and their seasonal variations.

It is anticipated that the following will be the minimum geotechnical investigation programme by the Contractor:

Boreholes, a minimum of 60 m deep

Boreholes, a minimum of 40 m deep

Geophysical tests in the above boreholes

Piezometers

Cone Penetration Tests to refusal

Standard Penetration Tests in all boreholes



Laboratory testing consisting of at least; classification tests, particle size distribution (grading curves), moisture contents, densities, Atterberg Limits, consolidation tests, triaxial compression tests, compaction tests, mica content, groundwater chemistry, soil electrical resistivity, and soil chemistry.

The laboratory testing shall also be sufficient to determine all of the parameters needed for the design of foundations, and the assessment of settlements, stability, soil liquefaction and lateral spread potential, vibration effects on adjacent facilities, etc.

The data, results, and conclusions from this geotechnical investigation programme shall be collated in a “Geotechnical Factual Report” for review by the Employer. The report shall also include recommendations on foundation types and foundation design parameters, assessment of short and long term settlements, and an assessment of the potential of the soils to liquefy under a range of earthquake accelerations, or vibration from the plants rotating machinery.

4.6 Site Access

The Ashuganj Site has road connection (about 3 km) to the national highway of Dhaka to Sylhet. The Proposed Site is in the east side of Sylhet road connected to the national highway. The Dhaka–Sylhet highway is the busiest national highway in the country to carry goods for import and export. More than 80% of the country’s trade are passing in or out through the Sylhet port. The Site is also accessible from the Chittagong port and the Mongla port by river. Major heavy weight equipment are generally transported through river system during rainy season. The Contractor shall evaluate the transportation system inside Bangladesh from the major ports to the proposed Site. It is the responsibility of the Contractor to transport all equipment from the major ports of Bangladesh to the project Site. If the Contractor transports equipment through river, the Contractor shall evaluate the unloading mechanism at the project side of the Meghna River and shall arrange all necessary facilities to be developed at the western bank of the Meghna River that is approx. 1.0 km apart from the project site.

4.7 Construction Facilities and Site Services

4.7.1 Lay Down Area

The Ashuganj site is fairly tight and though it is adequate for locating the proposed CCGT plant, it lacks space for sufficient construction lay down areas. No additional land will be made available for the project by the Employer.

The Contractor will be required to carefully plan equipment delivery to this site based on his construction sequences and the construction schedule considering the lay down space limitation on the site. The Contractor will have to sequence his construction activity to minimize the need for the laydown area. If required, the Contractor will be responsible for identifying and leasing space for the laydown area at his own cost.

There is no ready mixed concrete batch plant located in the vicinity of the project Site and if insufficient space is available on the project Site the Contractor will have to locate the batching plant on leased land in the project facility and deliver concrete to site by ready mixed truck.

4.7.2 Staffing / Accommodation

Overnight accommodation will not be allowed on the project site and the Contractor will be required to arrange suitable accommodation offsite for Contractor’s expatriate and out of town personnel. The Contractor will be responsible for providing transportation to/from the site, as required, for the Contactor’s personnel.

For security and safety purposes, a brick wall will enclose the Site. Normal access to the Site would be through a primary gate with security controls. Locked gates will be installed in the perimeter fencing for emergency, operations, and maintenance access.

The Contractor will be required to provide offices for its own construction staff.



4.7.3 Utilities

The Contractor shall be responsible for the provision of all site temporary or

construction services.

4.7.3.1 Construction Power

The Contractor will be responsible for providing all construction power throughout the project. If possible, the Employer will assist 11 kV supply terminal point available to be used for construction and the Contractor will be required to install a step-down transformer and associated switchgear. The Contractor will install metering equipment and it will pay the electricity bill to the respective authority.

If the 11 kV power source is not available for any reason, the Contractor shall supply and install at its cost permanent (for the duration of the construction period) diesel generators to generate construction power and supplemented by diesel engine powered welding machines.

4.7.3.2 Construction Water

The Contractor will be responsible for providing its own construction water supply. The water used for construction should be potable quality. The Contractor will use river water as a of construction water by following treatment. Drinking water for the construction workforce is expected to be provided from bottled water supplies or a potable water treatment plant. The Contractor may want to drill ground water wells on the Ashuganj site to provide a source of drinking water.

4.7.3.3 Gas for Commissioning

Fuel gas required for pre-commissioning and commissioning of the CCGT plant will be provided by the Employer free of charge. The Employer shall provide the agreed minimum or higher gas pressure at the interface point for commissioning of the gas compressor.

4.7.3.4 Electricity Feeding for Commissioning

The pre-commissioning and commissioning of plant auxiliaries prior to synchronizing, the auxiliary power will be feed by the Start-up Transformer.

4.7.3.5 Electricity Produced after First Synchronization

Electricity produced by the power plant after First Synchronization will be exported through the APSCL grid system. The Contractor will not be entitled to any proceeds from the sale of electricity produced by the power plant.



5. CIVIL, STRUCTURAL AND ARCHITECTURAL WORKS

5.1 General Requirements

The Bidder's proposal shall cover all requirements of the Bidding Document and any other items not specifically mentioned but which are deemed to be necessary for the satisfactory design, supply of materials, construction, and supervision of the civil works on the basis of a turnkey contract.

The Contractor shall upon examining the design of the foundations and major structures, develop and prepare the detailed design and the construction drawings of all civil structures for the approval of the Employer which shall meet the equipment and structures specification, to be supplied by the Contractor for the Project.

The Employer shall reserve the right to examine the Contractor's design and to instruct a change or modification by the Contractor.

These modifications shall be carried out by the Contractor without additional cost as a result of any claims made by the Contractor on the Employer.

Approval of the design by the Employer shall not relieve the Contractor of liability for the construction works.

The Bidder shall familiarize himself with the site levels, subsoil and any other data necessary to enable him to estimate the bearing capacity and foundation requirements,

5.2 Site Development and Site Level

5.2.1 General

The Ashuganj Site shall be raised above the 100 year flood plain with a minimum

free board of 0.5 m by the Contractor using suitable granular soil. It is the

Contractor’s responsibility to locate sufficient fill materials and transport them to

Site. All unsuitable on-site fill materials shall be removed and disposed off-site

prior to backfilling using suitable granular material.

All structures and foundations shall be set back a minimum distance of 1.2 m from

any boundary wall.

Final site grading and finishing shall be constructed after substantial construction

work has been completed. All back fill soil around the foundations, below the

roads and other work areas shall be compacted to a minimum 95% of Modified

Proctor per ASTM D1557 and in layers of maximum 150 mm thickness.

5.2.2 Earthwork

5.2.2.1 General

The Contractor shall prepare the drawing necessary for his construction purpose based on drawings and the specification as per BS 6031 or equivalent, and submit them to the Employer for approval at least eight weeks before work commences on the relevant areas. The Contractor shall be responsible for and shall complete all the earthworks as shown on the approved drawings or as directed by the Employer.

5.2.2.2 Excavation

Excavations shall be carried out to the width, lengths and depths shown on the approved drawings. The Contractor may excavate by any method he considers suitable, subject to the approval of the Employer.

Selected granular materials from the excavation as approved by the Employer shall be used in the filling. Unsuitable materials shall be removed from the Site to disposal areas.



Cut and fill slopes shall be designed for to be thorough stability. Unless otherwise indicated On the Drawing the exposed surfaces of all cuttings shall be soiled and turfs to the satisfaction of the Employer.

The Contractor shall take particular care during the excavation of the foundation to avoid deterioration of the ground due to exposure to the weather. The final 120 mm of excavation above formation level shall be carried out by hand immediately before the next stage of construction is to start. A similar method shall be adopted in the ease of the sides of excavation against which the structure is to bear.

The Contractor is solely responsible for all temporary work as necessary during construction of earthwork. The Contractor shall provide all strutting and shoring necessary for the safe execution of the Works and shall provide the necessary pumps, de-watering facilities, and temporary drains to ensure that all excavation shall be carried out in the dry.

The rates for excavation and filling shall be deemed to have included for the full cost of excavation and filling of the materials including site clearing, stripping of top soil, all pumping and temporary works necessary to keep the excavation and filling free from water, sheeting, temporary shoring, bracing, cribbing and timbering, trimming to line and level, stock-piling, handling, compaction, cutting, slope protection, removing surplus excavated material to spoil tips, together with all other costs incurred in complying with the contract requirements. The Contractor shall maintain records of inspection and testing of formations to ensure compliance with design and shall comply with the requirements of the local authority regarding notification and inspection.

The Contractor should be removed all obstacle during excavation.

5.2.2.3 Clearing and Grubbing

Areas to be graded shall be cleared of all brush and trees to within 150 mm of grade. All stumps and roots larger than 25 mm shall be removed. Waste from clearing shall be disposed of in an offsite disposal area in accordance with all environmental regulations and as directed by Employer.

5.2.2.4 Stripping

All topsoil and other organic materials shall be stripped from the areas to be graded before starting earthwork. Topsoil shall be placed in a stockpile for later recovery and use for landscaping the site.

5.2.2.5 Disposal of Unusable Materials

All excess excavated materials and all excavated materials unusable for fills shall be legally disposed offsite by Contractor.

5.2.2.6 Plant Grading

Plant grading includes the following items:

Shape the natural grade as required to accommodate permanent plant facilities and construction facilities while minimising earthwork.

Obtain proper cross-section, longitudinal slopes, and curvature for roads

Obtain proper area slopes to provide drainage without ponding of rain water.

Construct adequate surface drainage to discharge the 10-



year runoff without flooding roads and the 50-year runoff without flooding plant facilities.

Construct stable, erosion-resistant earthen side slopes.

5.2.2.7 Filling, Site Development and Compaction Requirements

The area to be filled if necessary shall be cleared of vegetation and the top soil shall be stripped and stockpiled. All soft yielding material shall be removed and replaced with granular selected material. Where fill has to be deposited against the hill slope, the Contractor shall take all necessary precautions to ensure that a good bond is achieved between the fill and the original ground.

No fill shall be deposited in the area to be filled until the Employer has inspected and given approval. Filling to the formation level shall be brought up from the bottom in uniform compacted layers. Excavated material obtained from the Site may be used for filling.

Filling, levelling and compaction on the Site shall be carried out in layers not exceeding 200 mm thickness. The Contractor shall carry out all necessary quality control works including in-situ soil density tests, moisture content and other laboratory testing to ensure that all materials used in the filling elsewhere are compacted in accordance with the specified requirements.

The maximum dry density (MDD) for the purpose of this specification shall be determined by the Standard Proctor Method (ASTM D1 557) or equivalent.

Area ASTM D1557

(Percent)

Structural Fills 95

Upper 2 m of fills supporting structures (See Note.)

95

Fills supporting roads or pavement 95

Drainage facilities (dikes, ditches, etc.) 90

General Fills 90

Note: Structures include items such as plant equipment, buildings, switchyard equipment, tanks, walls, retaining walls, and any other structures or equipment that are sensitive to settlement, unless foundations are supported on piles.

Minimum fill compaction shall be as follows:

The elevation of the finished ground level (FGL) shall not be less than 8.90 m PWD. The elevation of finished floors, concrete slabs and foundations shall be minimum 0.2 m above the finished ground level.

5.2.2.8 Backfilling

This section shall apply to the performance of all work in connection with the required backfill for the permanent works.

1) Material

Material for backfill shall be obtained from excavated soil or other sources approved by the Employer.



2) Workmanship

Backfill to all foundations trenches and pits etc. shall not be placed until the work has been inspected and approved. Backfill around sewers, water mains and other utility lines shall be carefully placed so that the piping will not be displaced or damaged. Fill in contact with pipes shall be entirely free of rocks. Backfill around service pipe shall be of sandy material. The backfill shall be compacted at optimum moisture content in layers not exceeding 150 mm to 95% of the maximum dry density. Compaction shall be carried out by vibratory plate compactor.

5.3 Site Drainage

5.3.1 Description of Site Drainage System

The plant shall be provided with the following drainage systems:

Storm water drainage system

Potentially contaminated floor drainage system

Oily water sewer system

Sanitary sewer system.

5.3.2 Storm Water Drainage Design and Construction

The Contractor shall design all operational plant water systems to ensure that any

discharges beyond the plant boundary, or into the surrounding ground comply with

all local environmental requirements.

The storm water drainage system shall consist of buried sewers with catch basins

and manholes, or stone masonry lined open and/or slotted cover trenches. Storm

water sewer pipes shall be of PVC or RC material, and culverts shall be

corrugated HDPE material, or approved equivalent.

The design of the site drainage system shall be based on a 50-year storm

frequency. Based on the rainfall data for the 50-year design storm, rainfall

intensity - duration curve shall be developed to estimate storm runoff flows and

volumes. Site drainage within each drainage area under consideration shall be

designed based on a storm duration that is equal to or greater than the time of

concentration for that area.

A hydraulic analysis shall be made for the storm water collection and conveyance

system using established criteria as for open channel gravity sewers having

uniform flow. Manning’s Equation shall be acceptable as being suitable for use on

this project.

Storm water drainage normally will be through swales and open drains. The drains

generally will follow the roads within the property limits and be kept clear of all

plant equipment and buildings. Storm water runoff will be collected by a series of

swales and arterial drains. All drains shall be constructed at a gradient. Culverts

shall be provided where roads cross drainage paths. Erosion and scour protection

for culvert inlets and/or outlets shall be provided where needed to prevent damage.

All drains or channels shall be reinforced concrete. Concrete sumps, silt traps,

screens and drain covers shall be incorporated in the design where it is

appropriate. All open drains should be covered by GI grating.

During the construction phase, the Contractor shall comply with all local

regulations for the discharge of storm water and water borne contaminants from

the site. Only clean rain water from the project site shall be discharged directly into

the river.



5.3.3 Contaminated Storm water Runoff

All storm water with the potential to be contaminated with oily waste or spills from

plant, equipment, or maintenance and storage areas; shall be routed through oil

separators prior to discharge outside of the plant boundary. Each oil separator

shall be placed as close as possible to each contamination source to prevent the

oily contaminants emulsifying in the storm water. Oil separators shall be sized for

the largest oil volume from a potential oil source, plus fire fighting water that may

occur simultaneously during an oil tank break. Package coalescing plate oil

separators having a minimum effluent quality of 15 mg/l shall be used.

Contaminated storm water runoff is storm water collected from areas that contain

hydrocarbons or chemicals. Typical areas requiring collection of contaminated

storm water runoff include the following:

Transformer areas.

Grade floor wash water

Oil-filled equipment areas.

Runoff from parking lot.

All chemical, oil, and lubricant storage tanks, including the filling connection, shall

be diked to retain all of the storage capacity of the tank(s) plus allowance for 24-

hour rainfall, minimum 0.3 m freeboard, and fire fighting water volume.

Separate underground piping systems with suitable sumps shall be provided to

route any oily water to an oil separator (or separators) and chemically

contaminated water to a collecting sump for disposal or routing to a neutralization

pit. All drains should be concrete made.

5.3.4 Sanitary Waste Water

Sanitary waste from various on-site buildings shall be discharged to a multi-cell

septic tank or aerated treatment tank, designed for a total of 130 persons. The

sanitary waste water collection, treatment, and disposal system shall be designed

to the minimum standard in draft BNBC-2015. The effluent water quality shall

meet the 2008 World Bank Guideline requirements and well as Bangladesh

Environment Conservation Rules 1997. Septic tank/aerated treatment tank

effluent shall be discharged by gravity or pressure pump to the river.

5.4 Potable Water supply

The contractor shall make an arrangement of potable water supply system for all personnel uses of the plant from the drinking water system to be constructed by the EPC Contractor.

5.5 Road and Paving Work

5.5.1 General

The design of all pavements shall conform to the requirements of the American

Association of State Highway and Transportation Officials (AASHTO), and Local

Highway Requirements or local standards whichever is more stringent.

The horizontal and vertical alignments of all roads, vehicle parking areas and

walkways shall be designed to meet the requirements of anticipated future

vehicular traffic. Delivery, operation and maintenance of station equipment will be

considered in determining the requirements for temporary construction access.

Permanent parking areas shall be provided. The size and arrangement of the parking area for vehicles, cars, motorcycles, and bicycles shall comply with Employer’s requirements. The parking areas will be provided with curbs, wheel stops, markings and slopes for quick storm water drainage.

All open drains should be covered by GI gratings (Steam drain).



5.5.2 Roadway Design

Plant access roadways shall be designed to accommodate AASHTO HS-20 semi-

truck loading with impact added. Parking areas for cars and light trucks shall be

designed for AASHTO H-10 loading. The roads shall be designed to sustain the

maximum loads from the vehicles likely to use them during construction and

throughout the life of the facility including articulated vehicles and transporters

used for the removal and replacement of major items of equipment during

maintenance. Proper slope shall be provided in order to prevent water logging on

loads.

5.5.3 Road Classifications

The main roads surrounding main facilities of power plant and connected to

outside via a main gate and one auxiliary gate. All plant roads shall be made using

reinforced concrete. Transportation system inside the power plant is divided into

three following road types. The plant General Arrangement drawings show the

conceptual layout of these roads:

Class 1 - Primary Roads. This is the primary plant entrance road subject to high volume of highway-legal truck loads

Class 2 - Secondary Roads. Roads within the plant such as plant loop roads and access to major buildings. They are subjected to infrequent use by heavy delivery and maintenance traffic

Class 3 - Tertiary Roads. Roads subject to light traffic

Class 4 - Parking Lots. Pavements subject to frequent use by cars and light trucks.

5.5.4 Road Geometry

The road geometry shall be as follows:

Class 1 roads - a minimum 8 m wide pavement with 1 m wide shoulders, a minimum turning radius of 25 m, and a design speed of 40 km/hour

Class 2 roads - a minimum 6 m wide pavement with 0.75 m wide shoulders, a minimum turning radius of 20 m, and a design speed of 30 km/hour

Class 3 roads - a minimum 4 m wide pavement with 0.75 m wide shoulders, a minimum turning radius of 15 m, and a design speed of 20 km/hour.

All roads shall have concrete wearing surface and shall be designed for HS20

minimum loading. The frequency of vehicle is designed not less than 150 times a

day. The concrete wearing surface, including any sub-grade repairs, shall only be

constructed near the completion of the project, after all heavy traffic movements

have ceased on site. Additional sub-grade strengthening may be required along

the routes of any heavy plant and equipment between the temporary unloading

jetty and plant and equipment final position(s).

5.5.5 Sidewalks

Sidewalks shall be provided from roads to interconnect all facilities and all building

doors. The walkways shall be reinforced concrete and shall be prepared with an

adequate depth of compacted base course and shall be minimum of 1.5 m wide.

Walkways will be formed with slopes and/or steps at the correct level to drain

storm water.

5.6 Structural Work

5.6.1 General

This specification sets forth the minimum structural design and construction

requirements for all buildings, structures and foundations for the power plant and



all other facilities. Design and construction requirements shall be in compliance

with current engineering practice and this document. Compliance with codes,

standards, and design manuals issued by the Institutions and Organisations are

listed in Section 3.2 of this Specification. The Contractor shall provide engineering

data where required to verify compliance with the requirements of this

Specification. Contractor shall provide key documents in accordance with the

general submittal requirements of the Agreement including, but not limited to the

established civil, structural and architectural design criteria.

5.6.2 Design Loading

5.6.2.1 General

All structures and all parts thereof shall be capable of withstanding code stress and deflection limits within prescribed settlements. The structures shall be designed for the critical load combinations including dead and live loads, wind, seismic, erection forces, secondary stresses, impact, temperature and shrinkage. Ultimate strength design shall generally be used for reinforced concrete structures. For structural steel design both the Load Resistance Factor Design (LRFD) method and working stress methods are acceptable. (See Below*) Anticipated deflections at service loading shall be considered and shall not result in inadequate performance or loss of normal functioning of cranes, cladding, finishes, or other associated elements. The design of foundations for all structures and equipment shall be such that differential and total settlements or other movements shall not exceed acceptable limits. Settlement limits shall be determined by the sensitivity of structures and equipments such that the functionality of the structure/components is not adversely impacted.

*However, the same methodology shall be used for all design work.

5.6.2.2 Live Load

Minimum live loads to be used in the design of power plant buildings and structures are given in Table 14. The Contractor is responsible for reviewing the provisions of the Governing Local Building Code for any specific design requirements that may require usage of greater live loads than the minimum loads listed in Table 14.

Table 14: Minimum Live Loads

Location Live Load

(kPa) (1), (7), (8)

Ground Floor (Grade Slab Area or Below Grade Concrete)

General 20 (2)

Concrete or Grating Trench Covers 10 (2)

Locker Rooms or General Office Rooms 5

Above Grade (Elevated Floors)

Concrete Floor 12 (3)

Grating Floor 10 (3)

Stairs 5



Location Live Load

(kPa) (1), (7), (8)

Elevator Machinery Floor 10 (3)

Roof 1.5 (9)

Access/Service Platform and Catwalks 4 (4)

Interior Roofs 5

Turbine Building

Turbine Operating Floor

Concrete 25 (5) (3)

Grating 10 (5) (3)

Turbine Generator Lay down Area Concrete 25 (5)

Grating 15 (5)

Turbine Mezzanine Floor (Below Operating Floor)

10 (3)

Electrical Control Room 10 (3)

Electrical Equipment 10 (3)

Storage / Special Use 17 (6)

Surcharge on soils/surfaces adjacent to retaining walls. This shall also apply to walls below ground level on all buildings and other retaining walls affected by traffic loads, construction loads or expected maintenance loads

15 (2)

Notes:

1. Equipment dismantling, laydown loads, maintenance equipment (welders), and parts staging maintenance loads to be used if greater than the table value. Live loads shall also provide for movable and transitory loads such as foot traffic, portable equipment and fixtures. Use more stringent of these loads, Contractor supplied data or the Governing Building Code.

2. Vehicular traffic wheel loads from fork lift, HS20-44, Dozer etc., per consultation and agreement with Employer shall be used.

3. Consider equipment removal laydown area, either vehicular or non-vehicular, after consultation and agreement with the Employer.

4. Access/service platforms and catwalks are elevated partial floors accessed by ladder from the nearest floor below or above.

5. Actual turbine lay down and dismantling loads shall be used if greater than table value.



6. Storage and Special Use examples include, but not limited to: batteries, oil drums, spare parts, equipment, etc.

7. Generally the minimum loading as listed in the table, shall be used unless the actual loads are larger.

8. Unless material spillage probability dictates a larger value to be used.

9. Greater value to be considered if equipments are erected on roof top

5.6.2.3 Dead Loads

Dead load shall be considered as the weight of all material forming a permanent part of the structure and all fixed service equipment. Dead loads shall include the operating weight of all vessels and equipment, structures, insulation, piping, electric conduit and cable tray. Except for the other rules, following minimum unit weight of the materials shall be used for static dead load calculation:

Reinforced concrete 2,500 kg/m3

Concrete 2300 kg/m3

Steel 7,850 kg/m3

Timber 770 kg/m3

Coil 1,730 kg/m3

Water 1,000 kg/m3

The above data is for reference only. Actual data shall be determined by the Contractor based on International Standards and approved by the Employer.

5.6.2.4 Piping, Conduit and Cable Tray Loads

The actual concentrated loads or equivalent line load shall be applied to the structural elements. Load due to internal pipe pressure, friction loads due to thermal movement etc. shall be considered.

5.6.2.5 Wind Load

Wind loads shall be calculated based on ASCE-7-05 and per draft Bangladesh National Building Code (BNBC), 2015, and the more stringent value shall be used. Per BNBC-2015 the basic wind speed, at 10 m above the ground is 56.7 m/sec for Brahmanbaria area. This is for a 50 year recurrence interval or a 2% annual exceedence probability (AEP).

When applying the various formulae in BNBC-2015 to produce design wind gust pressures, the following parameters shall be adopted:

Structural Importance Coefficient, C1 = 1.15 (For Special Occupancy Structures)

Terrain Exposure Category = B.

Wind loads for both overall building stability and local effects on building components shall be calculated

5.6.2.6 Seismic Load

All buildings, structures and foundations shall be designed and adopt necessary earthquake design criteria provided in Section 4.4.



5.6.2.7 Construction Live Loads

All structures shall also be designed for loads resulting from construction activities. Loading from construction activities whether of short or long duration, shall be considered as live load.

5.6.2.8 Equipment Loads

All equipment loads, dead and live, shall be obtained from Supplier's certified drawings. For purposes of design, the equipment live load shall consist of the greater of the operating, flooded, or hydrostatic test weight. The load location that produces the largest stresses and deflections shall be used in the analysis and design. Components such as vessels, storage bins, tanks and similar components shall be considered filled or partially filled as specified in the appropriate design codes. Short circuit torque forces shall be included as live load in the design of equipment supports and foundations.

5.6.2.9 Impact and Dynamic Loads

Design live loads (including seismic load, vibration force and dynamic effect of wind, generator or pump, fan, vehicle, etc.) must not be less than the defined values in the applied codes and in addition, dynamic loading capacity shall not be less than the minimum loading capacity values as follows:

a. Horizontal forces on crane girder

Crane girders will be designed to resist horizontal forces due to movement of the crane trolley as follows:

A lateral force of not less than 20% of the total of the weights of the lifted load and the crane trolley (excluding other parts of the crane), acting on the surface of the rail in either direction normal to the top of the rail

A longitudinal force not less than 10% of the sum of the maximum wheel loads of the crane applied at the top of the rail in either direction.

b. Vibration Forces and Dynamic Effects

Structures and foundations for heavy vibrating equipment including turbines, generators, reciprocating engines and centrifugal compressors and large pumps, will be calculated for response to vibrations and also forces with unbalanced moments. Such structures and foundations will be analysed by recognised methods of dynamic analysis and designed to ensure safe, smooth and trouble-free operation under any conditions.

Tall, slender structures will be investigated for dynamic response due to wind and seismic loading, including the effects of vortex shedding, wind-excited and seismic oscillations and also dynamic unstableness due to wind.

c. Impact Loads

When a structure, structural component or connection is subjected to moving or vibrating loads which do not warrant a dynamic analysis, the moving loads which induce impact will be multiplied by the following impact factors:

Elevator supports 2.00

Cab-operated travelling crane supports 1.25

Pendant-operated travelling crane supports 1.25



Rotating machinery supports 1.20

Reciprocating machinery supports 1.50

Floor and balcony hangers 1.33.

5.6.2.10 Monorail Loads

Monorails and their supporting members shall be designed as simple spans and their maximum centerline deflection shall be limited to the value recommended by the trolley Contractor or in accordance with customary industrial practice. Monorail beam shall be erected level. For monorail design, a minimum vertical impact allowance of 25% of the rated load shall be included for design purposes. A minimum longitudinal force of 10% of the rated load (plus dead weight) shall be applied to the supporting beam flange.1

5.6.2.11 Loads for Earth Retaining Structures

Earth retaining structures, including basement and trench walls, shall be designed for the applicable earth pressure plus appropriate surcharge loads from construction vehicles. Calculation and determination of lateral earth pressures shall be based on the recommendations of a qualified geotechnical engineer.

1 The Lateral Impact Load (normal to beam) shall be calculated based on the maximum wheel loads assuming that the hoist is rotated between 5 to 10 degrees about the support beam axis.

5.6.2.12 General Stability Loads

For purposes of design, every structure and foundation shall be designed to resist the overturning, hydrostatic uplift, and sliding effects caused by applied forces. Stability analyses shall be performed by superimposing all appropriate loads for each of the conditions being investigated in accordance with standard engineering practice as governed by applicable codes and standards. Listed below are the required minimum factors of safety for each type of stability analysis:

Uplift (wind, seismic, or hydrostatic) 1.5

Overturning (wind, seismic, or other) 1.5

Sliding (wind, seismic, or other) 1.5.

5.6.2.13 Column Stability Loads

The horizontal and vertical bracing system shall provide the requisite lateral stiffness necessary for column stability. Hypothetical stability loads shall be applied to the horizontal and vertical bracing systems, independent of all other lateral loadings to assure that the bracing adequately supports the columns at a particular level. All members and their connections that provide lateral supports to columns shall be designed for reversible lateral stability loads. The minimum stability loads shall be equal to 0.8% of the gravity loads in the column at the point under consideration.

5.6.3 Serviceability Limits

Deflection of supporting steel members under design loads shall not exceed the

following limits except where required by plant layout, equipment clearances, or

Code:

Structural beams and girders 1/150 of span



Roof beams and girders 1/150 of span

Girts (General) 1/180 of span

Girts adjacent to window openings 1/240 of span

Lateral drift due to seismic Per the International Building Code

Crane rail and girder deflections Per CMAA

Drift at eaves Shall not exceed 1/200 of eave height or the Governing Building Code requirement

5.6.4 Loading and Load Combinations

5.6.4.1 Loading Conditions

Load combinations shall be determined in accordance with the codes listed herein and the following:

Loading combinations are categorised on the basis of the nature and the probability of occurrence of each of the individual loads considered, and the resultant probability of simultaneous occurrence of these loads to form a loading combination. Evaluation of the strength and serviceability of a structure is based on providing a factor of safety appropriate to the probability of occurrence of the loading combination condition. Conceptual loading combination conditions are as follows:

Construction Condition: All events and loading during construction.

Testing and Upset Condition: All events and loads applied during pre-operational tests or equipment upset condition such as hydrostatic testing of equipment or loads caused by probable upset or malfunction of equipment. Each test event may be considered as mutually exclusive of other test events, if appropriate.

Normal Condition: All events and loads that could reasonably be expected during the operation, shutdown, and normal maintenance of the power plant. The magnitude of these events and loads shall be based on the probability of occurrence of at least once in the design life of the plant. Stability loads are considered normal loads.

Severe Environmental Condition: All loads due to infrequent site-related environmental events such as earthquake, severe wind, and severe flood. The magnitude of these loads and their combinations vary with the safety requirements of the structure.

Abnormal Condition: All loads due to postulated accident events, including pressure, temperature, and reactions (e.g., turbine generator emergency torque load)

5.6.4.2 Loads to be Considered

The Work must include as a minimum the following designated loads:

a. General Loads

1. Dead load, which includes self-weight of structures, waterproofing, insulation, fireproofing, siding, partitions, equipment, mechanical and electrical components, etc.



2. Dd - Self weight of the structure

3. De - Equipment load as specified in the equipment manufacturer's drawings

4. Live load, which includes loads as stated herein and loads that vary in magnitude such as occupancy load, etc.

5. Lc - Contingency loads on columns for unknown and uncertain data.

6. Ll - Lateral soil pressure.

7. Lh - Lateral hydrostatic pressure

8. Stability loads required to prevent buckling and to reduce the effective length.

9. Crane loading, C, as specified on manufacturers drawings including lifted load, weight of trolley and bridge and their impact. Impact shall be based on the Governing Building Code (AISC).

10. Po - Internal pressure at normal operating conditions consisting of:

11. positive pressure (outward)

12. negative pressure (inward)

13. To - Most critical transient or steady state thermal load condition on the structure at normal operating or shutdown conditions. This also includes other thermal effects such as frictional loads due to expansion.

14. Ro - Pipe, Cable Tray and Duct Support Loads

15. Mo - `Miscellaneous Loads - all other miscellaneous operating loads.

b. Construction Loads

The construction load should be appropriately considered during the course of design as dead load or live load. The design shall be reviewed by Contractor for the construction loads to ensure structural integrity. Reduced wind loads can be used with construction loads. Seismic loads need not be considered with construction loads.

c. Test and Equipment Upset Loads

These include blowout piping load, hydrostatic pipe load, and flooded equipment load caused by pre-operational tests

These also include loads due to probable mechanical upset conditions or equipment malfunctions including, but not limited to, thermal transients and water hammer

Design elements affected by upset conditions or equipment malfunctions shall consider the appropriate temperatures and pressures for the given upset condition or equipment malfunction.

d. Severe Environmental Loads

E - Seismic lateral, vertical and dynamic load

W - Design wind load

H - 1 in 100 year flood.

e. Abnormal Loads

Ra - Loads caused by postulated accident condition such as emergency torque of turbine generator.



5.6.4.3 Load Combinations

5.6.4.4 Load Combination (Allowable Stress Design)

Minimum loads and loading combinations shall be consistent with applicable Building Code requirements. Except when applicable codes provide otherwise, all loads listed herein shall be considered to act in the following combinations, whichever produces the most unfavourable effect in the building, foundation, or structural member being considered.

D + L + Lr

0.6D + W

0.6 D + 0.7 E

D + L + Lr + (W or E /1.4)

where

D = Dead Load

L = Live Load

Lr = Roof Live Load

W = Wind Load

E = Seismic Load

No increase in allowable stress shall be used with these load combinations.

The structural effects of fluids (F), Soil (H), and Temperature (T) of equipment, torque, friction, etc., shall also be considered in design.

5.6.4.4.1 Loading Combinations (Strength Design)

Except where applicable codes and standards provide otherwise, concrete structures, components, and foundations shall be designed so that their design strength exceeds the effects of the factored loads in the following combinations.

1.4 D

1.2D + 1.6L + 0.5Lr

1.2D + 1.0L + 0.5Lr + 1.6W

0.90 D + 1.6W

1.2D + (1.0)*(L + Lr) + 1.0E

0.9D + 1.0E.

The structural effects of F, H, or T of equipment, torque, friction shall also be considered in design at the following factored loads: 1.4 F, 1.7 H, and 1.4 T, etc.

5.7 Piling

It is preferred that foundation piles for this project be drilled, cast-in-place reinforced concrete piles. However, if the Contractor can demonstrate that using driven or vibration piling methods will not cause any damage, harm, or disruption to any adjacent plant or buildings, and their operation, driven or vibration piling methods may be used. A combination of different piling methods will be acceptable if the Contractor so chooses.

Prior to selection of the driven or vibration piling methods, a pre-construction inspection of any adjacent plant or buildings, located within 100 m of the plant battery limits, shall be carried out by an independent specialist engaged by the Contractor. The Contractor shall also be required to install suitable vibration monitoring equipment outside the battery limits,



at locations selected by the Employer. Vibration limits criteria shall be agreed between the Employer and the Contractor before any driven or vibration piling construction commences.

The Contractor shall submit a detailed design for the pile foundation to the Employer for approval. The bid price for the piling shall be lump sum and shall remain firm irrespective of the type of design.

5.7.1 Pre-cast Piles

The Contractor's arrangements for the provision of piles shall be to the approval

of the Employer. The Contractor shall submit full details of the manufacture

including details of formwork, placing of concrete, vibrators, curing, handling,

storage, and transport.

All concrete, reinforcement and other materials used for the manufacturing of piles

shall comply with the requirements of the relevant sections of the Specification

(ACI/BS 8110 and BS 4449 or equivalent). Concrete may need to be made from

sulphate resisting cement where necessary.

The reinforcement for a pile shall be fabricated to form a rigid cage. The main

longitudinal reinforcement shall be in one continuous length except where

otherwise approved and shall be finished level and cut square at the head of the

pile, and shall bear against pile shoe. The minimum cover to the main

reinforcement shall be 65 mm. The spacer blocks shall be made of concrete of the

same grade as that used in piles. Cast-in threaded inserts or metal tubes of an

approved type shall be used to form holes in the piles where required.

Pile shoes shall be firmly fixed during concreting to prevent any displacement. The

whole of the concrete in any pile shall be poured continuously. After a pile has

been cast, the date of casting and reference number shall be clearly inscribed

near the pile head.

The maximum variations permitted on the specified cross section dimensions shall

be -3 mm to +6 mm. The maximum departure from alignment on the face of the

pile shall not exceed +6 mm over a 3-metre length and 12 mm over the total

length of the pile.

Piles shall not be lifted without permission of the Employer and such permission

will not normally be given until the concrete in the pile has attained strength of

17.5 MPa. During lifting, adequate precautions shall be taken not to cause undue

stress to the piles. Piles shall be stored on adequate supports correctly located

and spaced to avoid undue bending in the piles. Due consideration shall be given

to future handling, curing and withdrawal of older piles without disturbing newer

piles.

All piles shall be kept continuously wet for a minimum 7 days from the date of

casting, or as directed by the Employer.

5.7.2 Driving Piles

The Contractor shall submit with his Bid full details of the performance, size and

type of his driving plant together with information on the type of hammer and the

number of rigs he proposes to employ on the works if precast piling is selected for

the foundations.

The driving rig shall be approved by the Employer.

Piles shall be adequately guided whilst being driven and the guides shall be held

rigidly in position down to the lowest level reached by the hammer.

The maximum departure of any pile head at cut-off level from the position

indicated on the drawings shall not exceed 75 mm. The maximum departure from

the vertical or the correct angle of rake shall not exceed 1 in 50.



The Contractor shall provide the Employer with three copies of the driving record

for each pile; these records shall reach the Employer not later than the day

following the driving of the relevant pile and shall contain details of the following:

(a) Location

(b) Pile details such as reference number, date of casting, length, and dimensions.

(c) Date and time of driving

(d) Type, weight and drop-of hammer or equivalent information if other type of equipment is used.

(e) Information on number and thickness of packing used during the driving of the pile and their condition after removal from the pile head.

(f) Number of blows per 150 mm over the last 3 meters of penetration.

(g) Number of blows per 50 mm over the last 150 mm of penetration.

(h) Toe level of pile.

(i) Other relevant information as may be required by the Employer.

If any pile is in any way considered unsatisfactory by the Employer, he reserves

the right to order the Contractor to remove the pile and/or to install replacement

piles at positions selected by the Employer, all at the cost of the Contractor.

No pile shall be driven until the concrete has reached the strength specified on the

drawings or as otherwise described.

5.7.3 In-Situ Piles

Before commencing the piling, the Contractor shall submit details of the type and

number of rigs to be used for in-situ piles.

The Contractor should be used auguring machine for boring purpose.

Jetting shall be permitted only with the approval of the Employer.

The spoil from the pile holes and material remaining from the cutting of piles shall

be removed by the Contractor.

Before pouring concrete into the core, the reinforcement for each pile shall be

made up to form a rigid cage and lowered into the core. Arrangements are to be

made to ensure that the minimum cover to the main reinforcement is 75 mm. The

main longitudinal reinforcement shall be in one continuous length except where

otherwise approved and the main bars shall extend at least 1 metre above cut-off

level.

The concrete for the pile cores shall comply with the concrete specification

(ACI/BS 8110 or equivalent). Concrete may need to be made from sulphate

resisting cement (ACI/BS 4027 or equivalent) where necessary. Concreting of the

core shall not commence until the Employer has inspected.

The concrete shall be transported and placed in such a way that it is

homogeneous with a high density, and care shall be taken to avoid segregation.

The method of placing and compacting the concrete shall be to the complete

satisfaction of the Employer. Care shall be taken that harmful materials do not fall

into the pile hole during concreting.

Curing of pile-heads expose to the atmosphere below cut-off level shall comply

with the concrete Specification where practicable.

The concrete shall be finished 40 mm above cut-off level. Concrete shall not

normally be placed in or through water. In particular circumstances only, the

Employer may allow the Contractor at his own expense to place concrete (using



suitable mix) through water by means of a tremie pipe. If the Contractor's piling

system does not normally exclude water during concreting, he should allow in his

Bid for the use of compressed air or other method to keep the pile hole free from

water whilst the concrete is being placed.

5.7.4 Testing

The design loading capacity of piles shall be confirmed by pile loading tests. The

Contractor shall submit the pile load test programme to the Employer for approval.

Pile load tests shall be done in the presence of the Employer’s nominated

personnel. Results shall be supplied to the Employer for review and approval. The

Contractor shall maintain accurate records of all pile installation. Copies shall be

supplied to the Employer for review. Pile shall be tested per:

ASTM D1143 (Compression load)

ASTM D3689 (Uplift load)

ASTM D3966 (Lateral load).

The Contractor shall install required number of piles for testing purposes in each

size of pile design. The EPC- Contractor shall submit a detailed driving record and

other data as directed by the Employer for the purpose of proving the proposed

pile design. Two piles shall be tested in compression, two piles for lateral and two

in tension (uplift) for each size of pile design and do the integrity test of all piles.

If this pile test does not satisfy the specified settlement, further piles shall be

installed and tested.

The Contractor shall provide all the equipment required for carrying out load tests

on piles together with the apparatus for measuring shall be to the satisfaction of

the Employer.

Measurement of pile movement during testing shall be by a means capable of

reading to 0.1 mm. This shall be related to a benchmark situated at a sufficient

distance from the pile to ensure a permanent datum.

The loading system shall incorporate a hydraulic jack, load cell or other apparatus

capable of measuring the load to accuracy with 2%.

5.7.5 Test Pile Load

The test pile load shall be twice the specified working load and shall be applied in

steps not exceeding 10 tons. Displacement readings shall be taken every 5

minutes after application of the load increment until two consecutive readings

show that the displacement has ceased. When the test load reaches the specified

working load, the displacement readings shall continue until it is established that

no further displacement has occurred over a 15 minute period.

The working load shall be then maintained for a further 24 hours, displacement

readings taken every 2 hours.

When no further displacement is apparent on completion of the 24 hour period or

when approved by the Employer, the load shall be removed in one stage and the

recovery readings shall be taken every 15 minutes until recovery has ceased.

The pile shall then be reloaded in one stage to the specified working load,

readings being taken every 15 minutes until displacement has again ceased.

The load shall be then increased in equal increments up to twice the specified

working load, the same procedure being followed as stipulated for the beginning of

the test. The maximum load shall be maintained for 24 hours or as directed by the

Employer after all displacement has ceased, and readings shall be taken every 2

hours during this period.



All loads shall be removed and the displacement on recovery shall be noted on

completion of this period or when approved by the Employer.

5.7.6 Settlement under Test Loads

The settlement of the pile head under test load shall not exceed -the following

figures under the loads stated:

Under 120% working load, settlement of 8 mm.

Under 200% working load, settlement of 25 mm.

After removal of test load immediate residual settlement of 3 mm for 120%

working load and 15 mm for 200% working load.

On completion of each pile test the Contractor shall supply the Employer with two

copies of a complete report which shall include graphs of load-settlement, load-

time-settlement and recovery of the pile as the load is removed.

5.7.7 Installation Tolerances

The piles shall be installed to the following tolerances:

(a) Pile head centre line within 50 mm of location shown on the drawings;

(b) Pile vertical alignment within 2 percent of the pile length;

(c) Pile cut-off elevation within +25 mm, - 0 mm.

5.7.8 Pile Layout

Where a single pile occurs it shall be supported in two directions at right angles to

each other by ground beams.

Where there are two or three piles in a group and where they are in a line they

shall be connected by pile cap. The pile cap shall be supported laterally by a

ground beam in a direction perpendicular to the line of the group.

5.7.9 Rejection of Piles

If any pile is found unsatisfactory to the Employer he reserves the right to order

the Contractor to install replacement piles at the locations selected by the

Employer at no extra cost.

The Contractor should be aware that until the existing substation is relocated,

piling work cannot commence under the several major foundations in the project.

5.8 Foundations

5.8.1 General

Once the final plant layout has been established by the Contractor, he will be

required to carry out a detailed geotechnical investigation programme.

A study of soil liquefaction potential shall be performed using parameters from the

geotechnical investigation performed by the Contractor and subject to the

Employer’s review and approval.

All structures shall be supported on piled foundations unless the Contractor can

clearly demonstrate by calculation that structural strength, stability, and settlement

limits, under all loading conditions, can be achieved with an alternative foundation

type for certain foundations. Foundations supporting operating plant and

equipment will be designed for both static and dynamic loads based on equipment

Contractor’s operational loading information and design criteria.



Seismic design best practice requires that all foundation elements within a

structure are rigidly interconnected at or near ground level using either tie beams,

or the intrinsic strength and stiffness of any ground floor slabs.

The turbine/generator pedestal foundations shall be independent of the enclosing

turbine building foundations.

The HRSG support structure and the associated chimney shall have an integrated

foundation and independent of the adjacent turbine building.

The design of all below ground open structures, such as pump pits, etc. shall

include seismic effects when assessing lateral pressures on earth retaining walls.

All large tanks shall be dimensioned so that their aspect ratio (height/diameter) is

less than about 0.4. The tanks can then be supported on ring type foundation

under perimeter walls. The Contractor shall demonstrate the adequacy of the ring

beam foundation, without piles, from total and differential settlement and will be

subject to Employer’s review and approval.

Construction activities in areas not requiring piling shall not be undertaken until the

construction areas have been fully compacted to the Contractor’s required

standard for construction purpose. It is expected that this will need to exceed 95%

compaction.

5.8.2 Equipment Foundations

Pertinent information about equipment such as the footprints, weights, anchorage

requirements, nature of equipment, whether rotating or vibrating, static or dynamic

loading criteria or any special recommendations by equipment manufacturers shall

be considered in the design of equipment foundations. In general, equipment shall

be supported on mat-type or spread footing type foundations; or, piling or drilled

pier (caisson) if required due to the soil conditions.

The turbine / generator shall be supported by a pedestal type foundation.

Supports and foundations for vibrating equipment shall be designed to limit

vibrations to an acceptable level. Also, they shall be reinforced with no less than

ACI minimum temperature and shrinkage reinforcing.

Foundations for transformers shall be constructed of reinforced concrete. Spill

containment curbs shall be provided for oil-filled transformers as required by the

applicable codes and regulations and the area shall be drained to an oil separator.

The Contractor shall perform dynamic analyses for the rotating equipment

foundations. The design of the foundations shall take due account of differential

settlement and dynamic loadings either from earthquake or rotating machinery

and possible ground subsidence.

5.8.3 Steam Turbine Foundation

The steam turbine shall be supported on a low tuned, concrete foundation that

shall be designed to minimise vibration. A dynamic analysis shall also be

performed by the Contractor. It shall be designed to accommodate all ancillary

equipment associated with the steam turbine generator in accordance with the

agreed upon general arrangement. Provisions shall also be made in the design for

the jacking, levelling, and setting of the steam turbine.

5.8.4 HRSG and Chimney Foundation

The HRSG foundation and the chimney foundation shall be designed to resist all

applicable loads including the overturning moments. Due regard shall be given

settlement between turbine, HRSG and Chimney foundations. The chimney height

shall be selected to comply with the limits of ground level concentration and local

environmental requirements but not less than 65 meter.



5.8.5 Building Foundations

As a minimum, the Turbine building, Control building, Administration Building, all

other buildings, HRSG and flue gas exhaust chimney shall be supported on

reinforced concrete foundations with piling or caisson as required due to soil

conditions. A reinforced concrete grade slab shall be provided when required. Spill

containment areas, including dikes, sumps, trenches and drains shall be designed

for equipment such as the feed pumps, blow down pumps and the blow down

tanks. Drains from all equipment in the area shall be contained and routed

properly so that they are discharged to the waste water system/oil separator.

Dikes and sumps shall be of adequate capacity to prevent any over-spill of blow

down water under any conditions.

All floor-mounted equipment in the area of the major equipment shall be mounted

on minimum 150 mm high concrete pads.

5.8.6 Transformer Foundations

Transformers shall be founded on suitable, reinforced concrete foundations within

a reinforced concrete pit and supported on piling if required. The concrete pit shall

be sized to retain any oil that may be accidentally spilled from the transformer

including water from fire fighting. Transformer oil sump drains shall be valved. The

transformer areas shall be fenced with lockable access gates. Blast walls

extending one metre above the highest part of the transformer shall be provided

between adjacent transformers. A two-hour fire barrier of appropriate height shall

be provided between any transformer and building in accordance with NFPA

recommendations/requirements.

The net volume of the pit (or pits) shall be sufficient to retain the spillage of the

total volume of the oil in the transformer plus 24-hour storm water or 10 minutes of

deluge fire water, whichever is the greater. A 150 mm freeboard shall be

incorporated into the design for these emergency conditions. Each transformer

area shall be provided with a drainage sump for the collection of an emulsified oil /

water mixture caused by the discharge of the fire fighting system or storm water.

The dimensions of each transformer area shall be adequate for installation,

operation and removal and to allow for sufficient cooling of the transformers. The

ground in front of the transformers shall be suitably treated to facilitate installation,

maintenance and replacement of the transformers. The pit walls internally shall be

coated with oil resistant epoxy paint.

5.8.7 Switching Area Foundations

Switching area foundations may be caissons or piles or concrete footings as

appropriate for the component and the soil condition but in case of concrete

footing it must be RCC.

5.8.8 Electrical Ducts and Manholes

Electrical ducts, lids, and manholes shall be constructed of concrete appropriately

sized for earth and hydrostatic pressures, and live loads applied by vehicles,

cranes or cable installation equipment. Manholes or access points shall be placed

at practical intervals to enable ease of inspection, maintenance, and cable

installation.

Cable crossings under roads and other services shall be installed in underground

reinforced concrete duct banks or laid in culverts under roads. Duct banks shall

have PVC or steel conduits and encased in reinforced concrete. Manholes with

removable covers shall be provided as necessary to facilitate cable pulling.



5.9 Buildings and Structures

5.9.1 General

The Contractor shall design and construct all the buildings for this power

generation facility. Building architecture shall follow the local design style and

practice for similar industrial type buildings and subject to Employer’s approval.

All buildings shall comply with the Bangladesh National Building Code-2006 for

selection of non-combustible construction materials, requirements for fire

protection and separation, lighting and lightning protection, building ventilation and

air conditioning of control and electronic equipment areas, office areas etc. as

required for such facilities.

All buildings shall be provided with suitably sized rainwater collection gutters and

downpipes, routed to the storm water drainage system. They shall be designed for

the rainfall intensity. Personnel access ways to and from buildings shall be

provided with canopies or substantial overhangs to protect personnel from rainfall

while entering and leaving the buildings.

Major equipment access doors shall be rolling steel doors. They shall be motor

operated with manual override.

All double and single vertical hinged doors shall be steel doors with door closer.

Double doors are provided where required for both equipment removal and

access. Doors for building entries and exits, control rooms, hallways, offices,

laboratories, and other high traffic areas, shall be fitted with glazed viewing

windows.

Where fire doors are required, the doors, door frames, and door hardware shall

have appropriate industry certification of the required fire rating.

Windows and louvres shall be manufacturer-standard aluminium, factory tinted,

used in commercial or industrial applications, as appropriate.

Steel-trowelled, surface-hardened concrete shall be used in unfinished concrete

floor areas. The floors for chemical contaminated areas shall be concrete

construction with a chemical resistant coating. Floors for offices and control and

electronic rooms shall have terrazzo tiles. For high moisture areas, such as

showers and locker rooms, ceilings shall have moisture resistant, lay-in terrazzo

tiles. Unglazed ceramic tiles shall be used on floors in high moisture areas, such

as locker rooms, showers, and toilets.

Suspended lay-in acoustical tile ceilings and recessed fluorescent lighting shall be

provided in control rooms, electronics rooms, offices, conference rooms, toilets

and lunch rooms.

All masonry wall plastered surfaces, ceilings, doors and door frames shall be

painted.

Building finishes, materials selection, paints selection, colour schemes, etc. will be

selected by Employer from samples and manufacturers’ catalogues submitted by

the Contractor.

Glazed ceramic tiles shall be used on toilet/shower room and chemical lab wall till

2m height.

5.9.2 Glazed Ceramic Tiling

Glazed export quality ceramic wall tiles shall be of minimum nominal size 200 mm

x 200 mm x 5 mm, colour to be selected. Fittings shall be obtained from a supplier

approved by the Employer. The ceramic tile fixing and grouting materials shall be



obtained from the same source. Floor tiles shall be of minimum 600mm x 600mm

x10 mm.

The Contractor shall ensure that the rendering is accurately formed and has a true

plumb surface which is free from all high spots and depressions.

The rendered backing for tiling shall be cleaned and will be wetted (just enough to

prevent it from absorbing water from the fixing bed) immediately prior to tiling. All

tiles shall be dipped in water to ensure that they are completely clean prior to

fixing. All tiles shall be immersed in water in clean containers for at least half an

hour before use. Tiles shall then be stacked lightly together on a clean surface to

drain with the end tiles, turned glaze outwards. They shall be fixed as soon as all

surfaces water has evaporated; they must not be allowed to dry out more than this.

Approximately two days after the fixing of the tiles, all joints shall be pointed with

neat white grouting cement; the finish shall be flushed and free from all voids and

irregularities.

All wall faces shall be finished plumb and flush throughout free from unevenness

and irregularities of plain; all angles shall be straight and true. The finished work

shall be left clean and free from all materials which will scratch or in any way

impair the finished work. Final polishing shall be done with a dry cloth. The

Contractor shall be responsible for the adequate protection of the tiling from all

damage until the handling over. Any damage which does occur shall be made

good by the Contractor at his own expense. The whole of the work shall be left in

a state satisfactory to the Employer.

5.9.3 Suspended Ceiling

Materials, samples and drawings showing details of construction of all types of

ceiling required shall be submitted to the Employer for approval.

Appropriate size of aluminium tees shall be gridded to the module of standard

panels to accommodate acoustic boards, or approved equivalent. The odd size

panels at perimeter shall then be arranged to equal dimension.

Fixing of hangers of galvanized steel to beams, floor slab and soffits must be

capable of carrying the load of ceiling boards. Ventilation grills should be

supported from the strengthened aluminium tee grids.

5.9.4 Gypsum Board Partitions

Gypsum panels shall be 1000 mm wide by 12 mm thick obtained from an

approved manufacturer.

The stud partition shall be extended from floor to ceiling with variation in heights to

suit. Studs shall be formed from approximately 0.75 mm thick cold rolled steel with

pre-punched holes in the web 120 mm on centre to allow horizontal passage of

utility lines. Studs shall be spaced 1000 mm on centre with horizontal spacer

channels and framing materials.

Glass panel framing shall be anodised aluminium with glazing recess. Glazing

shall be 6 mm clear sheet glass fitted with neoprene or vinyl gaskets.

The Contractor shall submit samples of metal and drawings showing details of

constructions for approval of the Employer.

5.9.5 Air Conditioning System

The detail design of air conditioning system for control building and administration

building shall be based on the following criteria:

Outside temperature : 36°C



Inside temperature : 24 ±2°C

Relative humidity : 50%

Type of system : Package air conditioning units

Air-conditioned rooms:

Control and Administrative Building: Control room, offices, conference room, electronics spares room and prayer room.

Design calculations and drawings shall be submitted to the Employer for approval prior to commencement of the work.

Details of the equipment proposed shall be submitted with the Bid. For more specific requirements for HVAC design see Section 11.9 below.

5.9.6 Ventilation System

All rooms in the control building, administration building, workshop, store, guard

house etc. shall be designed and furnished with functional ventilation systems.

Unless otherwise specified, natural ventilation will be acceptable for the minor

buildings. All toilets, battery room shall have exhaust fans of approved made.

All fans shall be statically and dynamically balanced to avoid vibration and shall

have blades to secure quiet efficient operation.

5.9.7 Plumbing and Sanitary Installation

The whole of the plumbing works in the buildings shall be provided in accordance

with the relevant bylaws and to the complete satisfaction of the Employer. Pipes

shall be connected to each point where water is required, with a minimum head of

2 metres at all outlets.

All cast iron pipe works and fittings as are necessary for the complete installation

of the sanitary system shall be supplied and installed in accordance with the

requirement of the local authorities and other standards approved by the Employer.

5.9.8 Lighting

The whole of the power supply and lighting system for the buildings shall be

designed and installed to the approval of the Employer.

5.9.9 Fire Protection of Buildings

Buildings shall be designed to comply with the NFPA or the relevant parts of BS

5588 or equivalent – Fire precautions in the design and construction of Building

and BS 5908 or equivalent – Code of Practice of fire precautions in chemical plant

(for water treatment plant).

Buildings permanently occupied shall be designed to provide fire protection of

structural steelwork in accordance with the Building Regulations, but in any case

the main structural building frames shall have a minimum of a half hour fire

resistance.

5.9.10 Lightning

All buildings, plant and structures over 15m in height shall be protected from

damage due to lightning strikes in accordance with BS 6651 – 1999 or equivalent.

5.9.11 External Louvres

Ventilation and air inlet / exhaust louvres shall be manufactured from either

extruded or pressed aluminium or hot dip galvanized steel. Sections shall be

suitable for their purpose to achieve required aerodynamic performance and rain

defence.



Removable panels, birds and vermin guards, sound attenuators and all other

components are to be designed and installed to suit the relevant technical and

performance requirements.

5.9.12 Buildings

The following is a brief description of the major buildings required for this project

including major construction materials. The Contractor shall determine the actual

building sizes during detailed design. The floor live loads indicated are a minimum,

however the Contractor shall determine the actual live loads based on equipment

Contractor's loading data. No price adjustment will be allowed for any change in

the building sizes.

5.9.12.1 GT/Steam Turbine Building

This building is a special purpose industrial type enclosure that provides weather protection to the power generating equipment. The external shell for this building will be a structural steel frame with sheet metal cladding on the walls and roof. Its structure shall be designed for all the loads and load combinations specified earlier.

All floor gratings shall be hot dip galvanised construction suitable for the floor loading. FRP grating shall be used where chemical spillage is expected.

Above the operating floor shall be a full width overhead crane sized to lift the heaviest parts of the power generating equipment during installation and plant maintenance. Other monorails trolley beams shall be provided as necessary to assist installation and maintenance. There shall be sufficient lay-down area for repair and maintenance work.

Toughened concrete flooring (to owner approval) shall be provided on ground and steam turbine operating floors.

5.9.12.2 Control Room and Electrical Annex

The structure shall be reinforced concrete load bearing frames, floors, and roof slabs, with plastered brick masonry infill panels and internal partitions. The building shall all be air conditioned. All floor slabs shall be designed for a minimum live load of 10 kN/m2.

5.9.12.3 Warehouse Building

The structure shall be reinforced concrete load bearing frames, floors, and roof slab, with plastered brick masonry infill panels and any internal partitions. The workshop will have an overhead crane able to access the full workshop floor and its lifting capacity will match the heaviest maintenance lifting load. The ground floor slab shall be designed for a minimum live load of 15 kN/m2.

The warehouse shall be furnished with sufficient robust shelving to store all mandatory and recommended spare parts, consumables, specialised tooling, and machine tools for machines in the workshop, raw materials, steel racking, fasteners and general engineering equipment for a minimum of two years operation.

Desks and chairs shall be provided for a minimum of four work locations in the warehouse for store men, engineering and purchasing personnel, each equipped with a PC for inventory control purposes.

Three storied warehouse each floor 500 Sq. meters storage area (including overhead crane and hoist crane etc.).



5.9.12.4 Water and Wastewater Treatment Buildings

The buildings are for:

Wastewater Treatment

Wastewater treatment buildings should be provided to accommodate demineralised water pumping equipment, tanks etc., as applicable. These structures shall be reinforced concrete load bearing frames, floors, and roof sla-bs, with plastered brick masonry infill panels and internal partitions where required. All floor slabs shall be designed for a minimum live load of 15 kN/m2. A testing laboratory is to be included in the Water Treatment Building. The laboratory and the water treatment system operator room must be air conditioned. The building(s) shall be provided with necessary sanitary facilities. A chemical room shall be included in the waste water treatment plant.

5.9.12.5 Fire Water Pump House

The structure shall be reinforced concrete load bearing frames, floors, and roof slabs, with plastered brick masonry infill panels and internal partitions where required. The ground floor slabs shall be designed for a minimum live load of 10 kN/m2.

5.9.12.6 Additional Site Access Points and Security

An additional site access point and a properly equipped guardhouse shall be provided on the Site. Also an elevated watch tower shall be provided on the boundary.

5.9.12.7 Miscellaneous Buildings

Miscellaneous buildings including but not limited to Reception cum Security Building. The Contractor shall provide any other buildings, structures or facilities if they are required to meet noise emission requirements or for other reasons, as determined by the Contractor.

5.9.12.8 Plant support Structures

Support structures shall be designed to resist vertical and horizontal loads as required. The strength and stiffness of the supports shall be compatible with the supported plate or pipe work, its flexibility and degree of restraint, under all design conditions. The structures shall have foundations appropriate to the ground conditions.

5.10 River Water Intake and Outfall Structures

5.10.1 Water Intake

APSCL has planned to install 400MW combined cycle power plant (Ashuganj

400MW CCPP, East) in the east side of existing Ashuganj 225 MW power plant.

The proposed plant will receive Condenser cooling water from a water intake

channel that will be situated at a distance of approx. 500 meter from the project

site crossing a 50 meter (approx.) wide cannel. The intake channel including

common suction chamber, screening system and all other associated system will

be constructed by the Contractor.

The Contractor shall be responsible to construct Condenser cooling water intake

system at a capacity of 2 X 110 % with redundant. The river water pumps station

supplies river water to various processes in the plant including potable water plant,

gas compressor system and Fire Fighting system etc.

Detailed design of the inlet structure to incorporate mitigation measures set out in

the Environmental Impact Assessment (EIA) and the Environmental Health and

Safety (EHS) General and Thermal Power Plant Guidance to minimize fish



entrainment including reduction of maximum through-screen design intake velocity

to 0.5 ft/s will be mandatory.

The bottom of the intake chambers shall be located below the lowest river water

level, plus the submerged height of pump suction pipes as required for the river

water pump model. Submerged pipes shall be placed between the intake and the

river bed for supply of river water to the intake chamber. All construction shall be

reinforced concrete. This may not be enclosed by a building above ground level.

Pumps and any travelling or stationary screens will be maintained by a gantry

crane. The pump structure below grade shall be designed for dead load, live load,

pump loads, lateral soil pressure load (static and seismic), hydrostatic lateral

pressure, buoyancy loads, etc.

The Contractor shall construct water intake channel as per with a provision for raw

water pumps and required quantity of water for fire fighting system also.

The intake area of the river shall be dredged if required.

5.10.2 Outfall Structure

The Contractor shall connect the discharge pipe from the condenser outlet

through a required dia. pipe (GRP) to the existing discharge channel of unit 1 & 2

to discharge the cooling water to the Megna river that is apart approx. 600 meter

from the project site. There should be electrical cables for control and protection of

different units to existing switchyard. Before connecting the pipe, Contractor is

asked to make a Topography and underground survey along the layout of pipe

routing by their own cost.

There will be no increase in the temperature of the thermal discharge above the

existing discharge temperature, and no increase above 3 degrees C of the

upstream background temperature at the edge of the mixing zone in both winter

and summer, Install an automatic temperature gauge on the discharge point for

the power plant and on the three canal discharge points to measure the daily

impact of this project and the contribution of the other power plants to the overall

temperature.

5.11 Unloading Facilities

It is Contractor’s responsibility to transport plant and equipment from manufacturer’s premises to the project Site at Ashuganj. The Contractor shall assess the inland transportation system in Bangladesh from the major sea ports to the project Site. Whether the Contractor uses the road facility or river facility for transportation of major plant and equipment, the Contractor shall develop appropriate unloading facilities at Site and the river side.

Bidders are advised to examine the condition of existing power plant area as a route to transport equipment to Site from the barge at Meghna River. Based on the results of their investigation, the Bidder may decide to include in their scope construction of a temporary jetty at the river bank and improvement of condition of the road(s) to be used for transportation of heavy equipment and materials. The temporary unloading facility will be approx. 0.7 km away from the project site.

After completion of transportation of all materials and equipment to the site, the temporary jetty must be demolished and removed from the river bank site.

5.12 Major Construction Materials

The Contractor shall maximise the use of locally available materials for construction of the civil, structural, and architectural work, provided the local construction materials comply with the codes and standards specified in Section 3.2. The following are the minimum requirements when applying those codes and standards:



All concrete for structures and foundations shall have a minimum compression strength of 30 MPa in 28 days

All structural concrete shall use Type 1 cement as per ASTM C150, unless the soil chemistry of the site requires a sulphate and/or chloride resistant cement suitable for the soil chemistry of this site. An alternative is to use Type I cement plus approved admixtures that will provide the required sulphate and/or chloride resistance

All concrete shall use crushed stone coarse aggregate, and natural sand fine aggregate, as per ASTM C33

Concrete mixing water shall be potable quality water only

All concrete admixtures shall comply with the Bangladesh National Building Code-2006

All concrete mix designs, including concrete admixtures, shall be subject to Employer’s review and prior approval

All reinforcement for concrete construction shall be deformed reinforcing bars with a yield stress exceeding 410 N/mm2, as per ASTM 615

All structural steel material shall be minimum ASTM Grade A36 for rolled steel shapes, angles, tees, plates, etc. having a minimum yield stress of 250 N/mm2

All handrails and posts shall be prefabricated, double rail type, hot dip galvanised steel pipe, with minimum 38 mm diameter and 4 mm wall thickness, as per ASTM A53

All floor gratings shall be a minimum 32 mm deep and hot dip galvanised, except that the turbine building operating floor grating shall be heavy duty suitable for the floor live load

All field connection bolts for structural steel shall conform to ASTM A325 and/or ASTM A490

All shop and field welding electrodes, welding procedures, inspection and testing of welding for structural steel work, etc., shall comply with applicable AWS Standards

The metal siding and roofing materials for the turbine building shall be industrial grade, with factory applied protective coatings on the exterior surfaces consisting of high performance Kynar 500 colour coating, or approved equal.

5.13 Concrete Work

5.13.1 General

Concrete work shall, as a minimum, be designed, specified, and installed in

accordance with applicable ACI requirements. Reinforced concrete structures and

foundations shall be designed in accordance with the applicable provisions of ACI

318, "Building Code Requirements for Reinforced Concrete." All water retaining

structures such as the sumps shall be designed and constructed in accordance

with ACI 350.

5.13.2 Material

The concrete design mix, as well as the type and proportions of all constituent

materials, shall be selected in order to ensure adequate strength and durability

with respect to the environmental and exposure conditions. The design mix shall

produce a workable concrete that conforms to applicable ACI requirements or

those of other international standards approved by the Employer. The design mix

shall be tested for compliance and documented for required strength and

characteristics before use in permanent works. Contractor shall conduct and

document material tests and concrete break tests as appropriate during all phases

of the work to ensure the quality and consistency of the concrete used. Contractor

shall ensure strict enforcement of all maximum permissible water-cement ratios for

all concrete. All grout shall be flowable, non-shrink and non-metallic natural



aggregate, or as recommended by equipment manufacturers. The mix design test

should be conducted in BUET.

5.13.3 Execution of Work

In executing the work, the Contractor shall conform to all applicable ACI

requirements with regard to:

Design and installation of formwork

Cutting, bending and placing of reinforcing bars

Mixing, placing, finishing and curing of concrete.

Construction joints shall be located where the strength and serviceability of the

structure is least impaired. Provision shall be made for transfer of shear and other

forces through the joints as required. Waterstops shall be provided in construction

joints in walls and slabs where necessary to maintain watertight integrity of the

structure. Water stops shall be located such that their presence does not affect the

performance of shear keys if they are present in construction joints.

5.13.4 Minimum Cover

Minimum clear concrete cover shall be provided to reinforcing or embedded steel

as indicated in BS 8110 or equivalent. Severe exposure conditions shall be

assumed unless otherwise specified.

For durability the minimum concrete cover to any reinforcing bar shall be as

follows:

a. Concrete above ground

Internal faces of slabs 25 mm

Internal faces of beams and walls 30 mm

Exposed faces of slabs, beams and walls 40 mm

All faces of columns 40 mm

b. Concrete below ground ( Including piles)

Faces in contact with soils including binding concrete 75 mm

All other faces (e.g. internal faces of basement wall) 40 mm

5.13.5 Other Requirements

The Contractor shall formulate and provide as part of the quality assurance (QA)

programme a system to monitor the quantity and quality of the concrete used. The

programme shall include the submission of monthly reports to the Employer

summarising the previous month’s results of the QA programme.

Concrete shall have surface finishes specified according to the relevant codes and

standards.

Concrete to be placed on the ground shall have the site prepared with a hardfill-

bearing layer overlaid by an impervious moisture membrane.

5.13.6 Tests

In order to control the quality of concrete to be placed, samples of concrete for

testing shall be taken and cylinder made as and when directed by the Employer.

Tests shall be done in accordance with BS1881 or equivalent Standards approved

by the Employer.

a. Slump test

b. Compression test



c. Air test

For each grade of concrete, six test cylinders conforming to ACI or equivalent

shall be prepared for each 30 cubic metres of concrete in each day's work. Three

cylinders shall be tested on the 7th day and the remaining three on the 28th day.

The slump and compression tests shall be carried out and the results shall submit

to the Employer in written form. If the test results of concrete cylinders are found

unsatisfactory, the concreting works shall be rejected.

The cost of preparing, storing and transporting test specimens to the place of

testing and testing shall be borne by the Contractor.

5.13.7 Cement

All cement shall be of ordinary Portland cement complying with BDS 232/ ASTM

C-150/ BS-12 or other approved standard. When required by the Employer, the

Contractor shall obtain for him the manufacturer's test certificate prior to any

delivery. All cement shall be stored dry in a well-ventilated and weatherproof

building. The cement shall be furnished either in bulk or in bags from the cement

factory approved by the Employer.

5.13.8 Admixture

The Contractor may use water-reducing and set-retarding agents as per ASTM C-

260, ASTM C- 494, BS 5075 or equivalent but the use of admixture must have the

prior approval of the Employer.

5.13.9 Water

The water used for making concrete, mortar and grout shall be clean, fresh and

free from salt, oil, organic-matter or any other deleterious substance. The water

used in mixing and curing concrete shall be tested by methods described in

AASHTO test method T-26.

5.13.10 Aggregate

The fine and coarse aggregates shall be durable, non-reactive hard materials

complying with BS 882, ASTM C-33 or internationally accepted standards

approved by the Employer. All aggregates shall be washed prior to use in order to

remove clay, silt, dust and adherent materials.

The aggregates shall be stored on drained concrete paved areas in such a

manner that intermingling of different sizes and types of aggregates is prevented.

The stock piles of the aggregates shall be protected from rubbish or windblown

dust.

Coarse and fine aggregates shall be well graded within the standard limits

specified as follows.

a. Standard Parameter of Materials Coarse aggregate (20 – 5 mm)

1) The Flakiness Index for all coarse aggregate test fractions as determined by STP 7.3.1 (or BS 812) shall be less than 30%.

2) The Elongation Index for all coarse aggregate test fractions as determined by STP 7.3.2 (or BS 812) shall be less than 30%.

3) The aggregate crushing value (STP 7.7.1) shall be less than 30% and the ten percent fines value (STP 7.7.2) shall be greater than 150 KN. Alternately the aggregate shall have Los Angeles abrasion loss as determined by AASHTO T-96 not more than 32%.

4) The weighted percentage loss of aggregate by use of 5 cycles of sodium sulphate test (AASHTO T104) shall be less than 10% by mass.



5) Water absorption as determined by STP 7.5(or AASHTO T-85) shall not be more than 2 %.

Sieve size (mm)

50.8 38.1 31.7 25.4 19.1 15.9 9.52 4.72 2.38

Percentage passing by weight

- - 100 95-100 - 30-70 - 0-10 0-5

b. Fine aggregate

1) The weighted percentage loss of aggregate by use of 5 cycles of sodium sulphate test (AASHTO T104) shall be less than 8% by mass.

2) Water absorption as determined by STP7.4 (or AASHTO T-84) shall not be more than 2.5%

Standard Grading

Sieve size (mm)

9.52 4.76 2.38 1.19 0.595 0.297 0.149

Percentage passing by weight

100 90-100 80-100 50-90 25-65 10-35 2-20

c. Limits of injurious material content

Maximum percent by weight

Silt / clay Volume lost by washing

test

Less than specific gravity

Coarse aggregate 0.25 1.5 1.0

Fine aggregate 1.0 7.0 1.0

5.13.11 Concrete Mixing

All concrete except where specifically approved by the Employer shall be mixed in

weigh batch mixing machines. The machine shall have a water storage tank with a

gauge so that a predetermined quantity of water can be injected direct into the

mixer drum. Hand mixing of concrete will not be permitted. The Contractor shall

take all precautions to protect the concrete from the effects of injurious materials.

Concrete mixture shall be designed as per BS 5328 or equivalent. The Contractor

should be used concrete which is made in batching plant.

5.13.12 Placing

The concrete shall be placed in the positions and sequences indicated on the

approved drawings immediately after mixing under the supervision of the

Employer or his representative.

Prior to placing the concrete all deleterious substance such as organic matter,

standing water, flowing water, wood fragments shall be removed from the surface

against which the concrete is to be placed. When concrete is to be placed against

a construction joint or adjacent to a set surface the whole surface shall be

thoroughly roughened. It shall be cleared of all loose and foreign matter and

washed with water immediately before fresh concrete is placed.



The concrete shall be fully compacted throughout the layer and shall be

thoroughly worked against the formwork and around the reinforcement without

displacing it. Unless otherwise directed by the Employer, approved power driven

vibrators of the immersion type shall be used. Vibrators shall penetrate to the full

depth of the concrete layer and shall re-vibrate that layer to ensure that the

successive layers are well knitted together. The placing of concrete shall not be

permitted under the following conditions unless specifically approved by the

Employer:

a. If it rains

b. If it is poorly illuminated during night work

c. If ordered to stop by the Employer or his representative

5.13.13 Transportation

Ready mixed concrete shall be transported speedily to the point of placing by

means that shall be approved by the Employer and which shall give little chance

for segregation of materials. Generally, the transportation of ready mixed concrete

shall be limited to within one hour. Concrete delivered in excess of the time limit

shall be rejected. When concrete is observed to have segregated or started

solidifying at the transportation of placing, it shall be rejected and replaced.

5.13.14 Curing

Concrete shall be protected during the first stage of hardening from the harmful

effects of sunshine, drying winds, hot weather and rain or running water. All

concrete shall be properly protected and maintained during the curing period.

Curing membranes, sprinkler application of water and ponding shall be acceptable

as appropriate for the curing of concrete. The concrete shall generally be wet

cured for at least 21 days. The curing method for concrete shall be submitted to

the Employer for approval. Gas turbine, steam turbine, generator, HRSG and main

stack foundations must be wet cured for 28 days.

5.13.15 Formwork and Timber

Formwork and timbering shall be so designed and constructed that the required

finishes in concrete works are achieved. Formworks shall be constructed

accurately to the required shape, position and level and shall have sufficient

strength to withstand the compaction pressure. The materials to be used for

formwork shall be approved by the Employer.

Forms shall be removed without damage to the concrete. The use of form oil or

other release agents shall be subject to the approval of the Employer.

The removal time of formwork and timbering shall be as follows

a. Vertical sides excepting beams: 3 days

b. Vertical sides of beams : 7 days

c. Soffits for span 6 m or less: 18 days

d. Soffits for span over 6 m : 21 days

5.13.16 Water Stops and Expansion Joints

The Contractor shall place water stops, water proofing membrane as per BS 8007

or equivalent and expansion joints at locations as are necessary for the proper

construction of the concrete structure. The materials to be used shall be submitted

in advance to the Employer for approval.



5.13.17 Finish and Repair of Concrete

5.13.17.1 General

The classes of finishes and the requirement for finishing concrete surfaces shall be as specified in this clause or as shown on the approved drawings. Surface irregularities in finishes shall be distinguished from construction tolerances, which are allowable deviations from established lines, grades and dimensions, as described herein.

Surface irregularities are designated "abrupt" and "gradual" for purposes of classifying finishes. Offsets resulting from displaced, misplaced, or mismatched forms or by loose knots in forms, or other similar forms of defects shall be considered "abrupt" irregularities and will be checked by direct measurement. All other surface irregularities shall be considered "gradual" irregularities and will be measured as a departure from the testing edge of three meter template.

Finishing of concrete surfaces shall be performed only by skilled workmen.

[[[[

Concrete surfaces shall be free from imperfections such as honeycombs and cracks. The Contractor shall at his own expense repair honeycombs, cracks, and irregularities promptly as directed by the Employer.

5.13.17.2 Concrete Construction Tolerances

Variations in alignment, grade and dimensions of the structures from the established alignment, grade and dimensions shown on the approved drawings shall be within the tolerances specified in the following tables. Concrete work that exceeds the tolerance limits specified herein may be required by the Employer to be remedied or removed and replaced by the Contractor.

Table 15: Construction Tolerances for Concrete

Variation from plumb:

In the lines and surfaces of columns, piers, walls, and in arrises

In any 3 m of length 5 mm

Maximum for the entire length 20 mm

For exposed corner columns, control-joint grooves, and other conspicuous lines



Variation from the level or the grades specified in the contract documents

In slab soffits, ceilings, beam soffits and in arrises, measured before removal of supporting shores


In any bay or in any 6 m length 10 mm


In exposed lintels, sills, parapets, horizontal grooves, and other conspicuous lines



In any bay or in any 6 m length 5 mm


Variation of the linear building lines from established position in plan and related position of columns, walls and partitions:

In any bay 10 mm



Variation in the size and location of sleeves, floor openings and wall openings: ±10 mm

Variation in cross-sectional dimensions of columns and beams and in the thickness of slabs and walls: -10 mm, +15 mm

Footings

Variations in dimensions in plan: -12 mm, +50 mm

Misplacement or eccentricity: 2% of the footing width in the

direction of misplacement, but not more than 50 mm

Thickness:

Decrease in specified thickness 5 percent

Increase in specified thickness No limit

Variation in steps:

In a flight of stairs:

Rise 3 mm

Tread 6 mm

In consecutive steps:

Rise 2 mm

Tread 3 mm

Placement of reinforcing steel ± 30 mm

Cover to reinforcing steel, 50 mm cover or less +10 mm, -0 mm

Cover to reinforcing steel, more than 50 mm cover +15 mm, -0 mm

5.13.17.3 Repair of concrete

The Contractor shall repair at his own expense the imperfections of concrete surfaces and the irregularities which do not meet the allowance specified in the preceding item. Repairing works shall be performed and completed within 24 hours after the removal of forms in accordance with the direction of the Employer.

5.13.18 Reinforcing Bars

The reinforcing bars for all reinforced concrete works shall be deformed steel bars

as per ASTM A-615, Grade 60 or equivalent. Dimensions, shapes, tensile strength,

yield point and other mechanical properties of the reinforcement bars shall comply

with relevant approved standards. All reinforcement must be free from oil, grease,



paint, dirt, loose scale or rust at the time of concreting. Contractor may use anti-

corrosive steel, reinforcement if necessary.

The physical properties of the deformed reinforcement bars shall have the

following values

Yield point : ≥ 410 MPa

Ultimate tensile strength : ≥ 700 MPa

Reinforcement bars shall be stacked off the ground on sufficient supports to

prevent distortion of the bars. Prior to fabricating and placing the reinforcement,

the Contractor shall prepare a bar bending schedule and drawings for submission

to the Employer for approval. Reinforcement shall generally be bent cold by an

approved means to the dimensions shown on the approved bar bending schedule

and shall be rigidly fixed in the positions shown on the approved reinforcement

drawings using annealed soft black iron binding wire to prevent movement during

concreting. The Employer shall have the right to select at any time samples of

reinforcement bar for testing for compliance with the Specifications. The spacer

blocks, prior to using, shall be submitted to the Employer for approval.

5.13.19 Stop Ends

Concrete should be cast in single monolithic pours. Before the concrete is mixed

the Employer shall inspect and sign-off as approved the volume to be concreted.

Concrete should not be placed unless the positioning, fixing and condition of

enforcement and any other items to be embedded, and the cleanness, alignment

and suitability of the containing surfaces of formworks in accordance with the

specification, design and drawings.

The concrete shall be deposited as nearly as possible in its final position without

re-handling or segregation and in such a manner as to avoid displacement of the

reinforcement, other imbedded items or formwork. Concrete shall not be dropped

through a greater height than 2.0 m.

A concrete pour shall always be terminated at a properly designed and installed

stop-end. Where appropriate the stop-end shall incorporate the means of

extending the pour with water bar, construction joint, expansion joint etc.

5.14 Masonry Work

Structural masonry, as a minimum, shall be designed, specified, and constructed in accordance with all applicable ACI requirements, local codes, standards and regulations, and with this document. Drawings for masonry work shall show the size and location of all pertinent structural elements; they shall also show the specified compressive strength of the masonry. The size, grade, type and location of the reinforcement, anchors and wall ties shall be shown for all elements. All walls and wall panels shall be of sufficient strength and thickness and adequately secured to primary structural members to withstand superimposed loads, self-weight, wind pressures and seismic forces without cracking or distortion. All masonry walls shall be fully restrained longitudinally and laterally. The free edges of vertical cantilever walls shall be restrained from movement or shall incorporate adequate brickwork reinforcement.

Material and Execution units shall be Type I conforming to ASTM C90. Design compressive strength shall be per ACI 530 and Governing Building Code. Grout compressive strength shall meet 13.8 MPa at 28 days, and Mortar ASTM C270, Type M, minimum compressive strength 17.2 MPa at 28 days.

All materials and components shall comply with the relevant standards for mortars. Lime shall be non-hydraulic or semi-hydraulic. Calcium chloride shall not be used in mortar.

Bricks, brickwork, or concrete masonry units shall be tested for absorption percentage, soluble salt content, drying shrinkage, moisture expansion, density, and dimensional tolerance. Sample panels shall be used to establish standards of workmanship that shall be



met in the work. All wall panels shall be so designed and constructed with expansion joints so as to prevent cracking or distortion due to thermal movements. Expansion joints shall be covered with approved flexible metal closer strips.

5.14.1 Brick Walls

Bricks to be used for walls shall be machine made. Unless otherwise specified or

as shown in drawing, the thickness of brick walls shall be more than 150 mm.

Mortar for use with brickwork shall be mixed in the proportions of 1:3 cement,

sand or 1:2:5 cement, lime and sand by volume. Mortar may be mixed by hand or

machine. Hand mixing shall be carried out on a clean, watertight platform. Cement

shall be of a quality as specification. Sand shall be well-graded (2.5 mm down)

hard and free from deleterious substances. Lime for mortar shall be pure calcium

carbonate properly burned, then hydrated, and finely ground. All joints shall be

completely filled with mortar. The thickness of the horizontal mortar Joints shall

not exceed 40 mm to every four joints. The mortar shall be used within 2 hours of

mixing with water and any mortar not used then shall be discarded.

All brick walls are to be reinforced with approved reinforcing material at every

fourth course.

The damp proof course shall be provided at joint and intersections, laid on a bed

of cement sand (1:1), bedded in and coated on the upper surface with liquid

bitumen.

External fair faced wall shall be weather struck; faces or wall which are to be

plastered or rendered shall have their joints raked out to form key.

5.15 Calking

The Contractor shall calk the joints to ensure water tightness of the building structures. Prior to calking materials and working method shall be approved by the Employer.

5.16 Carpentry and Joinery

5.16.1 Timber

All timber shall be of Chittagong/Burma Teak, perfectly dry and well-seasoned,

sawn square, free from sap, shakes, large loose or dead knots and all other

defects and shall be to the approval of the Employer.

5.16.2 Preservative

Timber to be used in shower rooms or in contact with the ground floor shall be

treated with an approved preservative against rot or termite attack. The backs or

frames to be fixed to walls and all other bedding surfaces shall be painted with two

coats of preservative before fixing. All fixing blocks, pallets, and other hidden

timber shall be so treated prior to fixing.

5.16.3 Joinery Fittings

All timber for Joinery fitting shall be of selected type properly seasoned and dry to

an agreed moisture content not exceeding 18%. The Employer shall have the right

to check all timbering used and to reject any timber found to have a moisture

content exceeding 18%.

Joinery fittings and built-in cabinet are to be constructed exactly as shown on the

approved drawings.

All work must be carried out by experienced cabinetmakers in a sound and

workmanlike manner with properly fabricated joints, dovetailed, mitred or mortised

and with concealed pins and screws. All joints shall be glued before pinning or

screwing.



5.16.4 Faults

Any defect in the wood works such as shrinks splits, fractures, etc. shall be

removed and replaced to the satisfaction of the Employer.

5.17 Doors and Windows

Prior to furnishing and installing, the Contractor shall submit the shop drawings indicating shape, dimensions, material including hardware and locking method of doors and windows for all buildings for the approval of the Employer.

The standard requirements of doors and windows are as follows:

a. Steel doors

Frame and Stile Plates: ≥ 2.3 mm thick

Stile and Panel: ≥ l.6mm thick

Thickness: 80 mm

Size: Double door 2.0 x 2.0 m

Single door 1.0 x 2.0 m or

Other sizes as per approved drawing

b. Wooden doors

Plywood for panel: ≥ 5 mm thick

Thickness: 40 mm

Size: 0.9x2.0 m or other sized as per approved drawing

Hollow flush door shall be painted 2 coats of rust resistant paint and finish coat. Hollow flush door shall be of the waterproof type.

c. Aluminium windows

Thickness: 70mm

Finishing: Alumite

Size: Double window 0.9 x 1.8 m

Single window 0.9 x 0.9 m or other sizes as per approved drawing Glass (tinted): 6mm

d. Aluminium swing doors

Frame and stile plate: ≥ 2.3 mm thick

Thickness: ≥ 45 mm

Size: As directed by the Employer.

All other type of doors and windows which are not specifically mentioned shall be provided to the satisfaction of the Employer.

5.18 Painting

5.18.1 Materials

All paint distempers and other materials shall be of an approved brand or brands

and shall comply with JIS Standard or other equivalent standard to be approved

by the Employer. Paint for use on concrete or brickwork shall be of a type

specially prepared for this purpose. Each coat shall be of a distinct colour from the

preceding one and all colours shall be approved by the Employer. Mixed paint and

synthetic resin emulsion paint shall be applied based on the following method.



(unit: kg/sq.m)

Particulars Metal Mixed paint

Wood

Synthetic resin emulsion

Concrete Brick

First paint

(Rust inhibitive paint) 0.14 0.09 0.13

Second paint 0.08 0.11 0.13

Finishing paint 0.04 0.09 0.13

Note: Rust inhibitive paint shall be either red lead or zinc rich lead type.

For painting of structural steelwork, see Section 5.20.

5.18.2 Surface Preparation

Prior to painting, the dust, grease, injurious adherent substance, rust shall be

removed from the surface to be painted. The planed grain, interlocked grain, fluff

in wood shall be ridded with sandpaper and all cracks, manholes open; duct and

other imperfection shall be made good with hard stopping consisting of paste

white lead and gold size stiffened with whiting. Cracks and holes on the concrete

surface shall be flat tended with cement paste, mortar, or cement filler.

5.18.3 Workmanship

All painting and decoration shall be carried out by skilled workmen according to

the best current practice in accordance with manufacturer's instructions.

All materials shall be applied by brush unless otherwise specified or approved.

5.18.4 Priming

All joinery, metal works to be painted shall be primed using appropriate and

approved primer before delivery assembly or fixing. No primer is required on

surfaces to be distempered or emulsion painted unless otherwise specified.

5.18.5 Number of Coats

Unless otherwise specified, the required finishes shall consist of the following

treatments, in addition to preparation, priming etc:-

a. Distempering Two coats

b. Emulsion painting Two coats

c. Oil painting Three coats on woodwork

Two coats on elsewhere

5.19 Steelwork

5.19.1 General

Steel work shall be, as a minimum, designed, specified, and installed in

accordance with applicable AISC requirements and this specification. Steel

construction, shall be as defined in the AISC specification. Structural steel shall be

mild carbon steel conforming to minimum ASTM A36, or conforming to ASTM

A572 grade 50 with special requirements per latest AISC Technical Bulletin.

Structural steel work shall generally consist of braced frames. Adequate horizontal

bracing and vertical bracing shall be provided in order to minimize lateral



deflections due to wind, seismic, and other lateral forces. For steel work, provide

coating for corrosion protection in line with ISO 12944.

5.19.2 Paint

Prior to delivery after shop inspection, the whole of the steelwork shall be

prepared for painting by an approved blast cleaning method.

All rust, grease, mill scale and harmful matter shall be removed. The surface shall

be blast cleaned to one of the following standards:-

Swedish Standard Sa 2 1/2 SIS OS 5900 1967

British Standard 4232 Second Quality

U.S.A. Standard commercial blast finishes SSPC-SP-6-63

The first coat of primer recommended by the manufacturer as suitable for use

under the prevailing condition at the application site shall be applied immediately

after blast cleaning (or within two hours).

No paint shall be applied to the surfaces to be embedded in concrete, to contact

surfaces for joints using high strength friction bolts and to surfaces within 50 mm

either side of joints to be welded.

Painting shall be carried out in a clean, dry building where air temperature shall

not be allowed to drop below 5°C. No paint shall be applied on the steelwork with

condensation. Painting shall not be carried out when the relative humidity is over

90%, or if in the open, during rain, fog or mist. After erection, the welded areas

and the edges of site joints shall be cleaned down, primed and painted all in

accordance with the standards specified.

Each coat of the paint shall be applied in a different colour. When paintwork is

damaged it shall be cleaned and re-painted following the procedures as approved

by the Employer. The manufacturer's instructions regarding inter-coat intervals

shall be strictly observed.

5.19.3 Connections

5.19.3.1 General

Structural steel shop connections shall preferably be welded. All welding shall conform to the latest issue and addenda of AWS D1.1, "Structural Welding Code.” Unless designed otherwise, structural steel field connections shall be bolted using high strength fasteners. Slip-critical connections shall be used in connections that are subject to load reversal. Slip-critical connections shall conform to the AISC Specification for Structural Joints using ASTM A325 or A490 Bolts.

5.19.3.2 Design

All beams, girders, and columns shall have standard framed connections (clip angles) unless designed otherwise. Beam connections for any member shall be designed for the actual reactive forces for that member except that the minimum beam reaction shall be considered to be one-half of the maximum allowable uniformly distributed load which the beam can support (considering flexural and shear capacities) with its compression flange fully laterally supported. When axial forces develop in floor beams and girders, the connections for such beams shall develop the axial load in conjunction with the appropriate design shear load. Prying action on the connection bolts and angles shall be considered. Moment connections shall be designed to develop the design moment or the full moment capacity of the member.



5.20 Perimeter Security Fencing and Gates

Security fencing shall be provided along the site boundaries. Fencing along the site boundary shall be 3 meter high masonry wall with reinforced concrete framing topped by an extension holding eight strands of barbed wire at 45º facing out.

Road gates shall be 3m high by 10m wide double swing gates with eight strands of barbed wire. The gate across the main road shall be motor-operated cantilever or overhead slide gate. The gate shall be operable from both guardhouse and the main control room.

A 3 meter high masonry wall with reinforced concrete framing is required around the new substation with one main gate and a smaller gate for personnel passage. The main gate shall allow for passage of a truck, both gates shall have provision for securing by padlock. Fence posts and gates shall be set in concrete foundations of adequate strength.

A 3 meter high wire fence is required around the fuel gas compressor plant. A bottom tension wire shall be provided. All parts of the fence shall be corrosion resistance, galvanized or aluminum.

The chain link shall have a mesh width of maximum 50 mm, and each wire shall have a minimum failure load of 2,000 N. Straight line posts shall have a minimum bending failure load, applied horizontally on the top, in the most unfavorable direction, of 600 N. Top and bottom tension wires shall have a minimum failure load of 5,000 N. In case of 2.5 m or higher chain link, the top wire shall be substituted by a top rail. Barbed wires shall have a minimum failure load of 3,000 N.

Straight line posts shall have a spacing not exceeding 3 m. Guyed tension posts shall be inserted each 50 m along straight lines. End and corner posts shall be adequately braced. Straight line posts shall have 800 - 1,000 mm deep foundations, either a 150 mm concrete tube filled with concrete, or a directly cast foundation, at least 200 mm wide. Foundations for corner or end posts shall extend minimum 1,000 mm below surface and consist of either a filled 230 mm concrete pipe, or be a directly cast foundation, at least 150 mm wide. The main gate shall be designed with a reinforced concrete foundation connecting both posts.

To prevent small animals from entering the enclosure, the space between the bottom of the chain link and the ground surface shall be filled in by a concrete kerb, consisting either of prefabricated slabs or cast at site.

The Contractor should be provided sufficient number of watch tower around the plant to ensure safety.

5.21 Site Laboratory

The Contractor shall provide a site laboratory with a concrete floor space adequately equipped to carry out quality control tests of material and workmanship in accordance with the procedures and tests as described in the relevant ASTM Standard or other approved standard. He may as an alternative to the provision of laboratory equipment, make arrangement for all necessary tests to be carried out by personnel with relevant experience from an approved laboratory.

5.22 Records and Drawings

The Contractor shall keep at the Site accurate and up-to-date records and drawings of the Works, and shall submit these records to the Employer at the end of every week. Such record shall include the amount of labour, plant and materials employed upon the Site during that week.

5.23 Samples, Testing and Inspection

The Employer may request at any time to test or inspect samples of construction materials and workmanship proposed and the Contractor shall furnish these immediately. When the Employer has approved the samples, material and workmanship not corresponding in quality and character with the approved samples shall be rejected. The costs of all sampling and testing to be conducted either on the Site or in an approved laboratory shall be borne by the Contractor. Before commencing the construction works, all construction materials shall be tested in the laboratory. If the test results are found unsatisfactory the Contractor shall not be allowed to use those materials.



5.24 Landscaping

All open areas within the plant boundaries shall be landscaped by the Contractor. The Contractor shall design the landscaping based on the following general guidelines and objective:

Present the plant as an industrial park set amongst, and compatible with, its surrounding area

Enhance the image of the plant.

Cover plant maintenance areas with a layer of compacted crushed stone

Cover all other open areas with grass, decorative gardens, and paved walkways

Include the planting of trees and bushes in some of the open areas.

The Contractor shall prepare detailed landscape drawings for Employer approval. These drawings shall include a complete legend of the work describing types of plants; plant heights and number of plants; grass type; maintenance areas crushed stone size, gradation, total thickness; etc.

5.25 Quality of local materials

All local materials quality i.e. rod, cement, bricks, sand, steel-bar, angel etc. should be tested from reputed organization i.e. BUET, BRTC etc. and the certificated shall be submitted to the APSCL.



6. GAS TURBINE

The design, manufacture and installation of the gas turbine (GT) shall meet the requirements of the following standards or their recognized equivalent:

API 616 Gas Turbines for the Petroleum, Chemical and Gas Industry Services

ASME Basic Gas Turbines B133.2

ASME Gas Turbine Fuels B133.7M

ASME Gas Turbine Control and Protection Systems B133.4

ASME Gas Turbine Installation Sound Emissions B133.8

ASME Procurement Standard for Gas Turbine Electrical Equipment B133.5

ASME Procurement Standard for Gas Turbine Auxiliary Equipment B133.3.

If there are conflicts between the above standards and the GT manufacturer’s specifications and standards, the GT manufacturer’s specifications and standards, along with the certifying agency standards shall take precedence.

6.1 Gas Turbine Package

The Contractor shall supply one GT package, including one 50 Hz Frame heavy-duty gas turbine, to be installed in single shaft configuration. The GT shall be capable of operating continuously in combined cycle mode.

he GT shall be installed within an acoustic, ventilated enclosure incorporating fire and gas detection and protection facilities. The GT shall be provided with all associated ancillary and auxiliary equipment and system for the safe, efficient and reliable operation of the unit in combined cycle mode.

Aero-derivative gas turbines are not acceptable.

The GT package shall be complete, including (but not limited to) the following:

All skids and enclosures

Air inlet filters system with ducts and silencer adequate to operate effectively under site conditions. (The inlet filter shall meet the GT manufacturer’s requirements and the further requirements of Section 6.5 of this specification).

GT compressor washing systems (on-line and off-line systems complete with all accessories, including wastewater handling)

Standard Dry Low NOx (DLN) combustors

Exhaust gas system with ducts, silencer without diverter damper and bypass stack

Three phase AC generator (Refer to Section 12.3 for generator specifications)

Lubrication oil system

Cooling system

Turning gear

Fuel supply system

Fire detection and protection

Microprocessor based GT controls and supervisory instrumentation, including a local control panel, connected to the plant ICMS

Turbine and generator protection system

Dehumidifier or inert systems and any other systems required for long-term and short-term layup

GT starting system

A starting motor or another acceptable starting mechanism for the CCGT shall be provided. As indicated in Section 12.3.7, a Static Frequency Converter (SFC) is preferred to utilize for CCGT starting. The Bidder shall describe the proposed starting methodology in his proposal.



The GT shall be provided with a full set of automatic control and protection equipment incorporating governor, temperature control and turbo-supervisory functions. Vibration levels shall conform to the relevant ISO standards and the GT manufacturer’s requirements. The GT shall be capable of start-up, shutdown and continuous operation in combined cycle mode on natural gas for the whole range of ambient conditions experienced at site.

The CCGT shall be capable of Automatic Generation Control (AGC) through the unit coordination control through the plant ICMS. The Contractor shall provide all the hardware, controls, wiring and the interface necessary for implementation of the AGC. The plant ICMS unit’s coordinating control shall interface with the load dispatch centre.

The GT shall be provided with on-load and off-load compressor blade cleaning systems to optimize GT output and availability. Suitable storage shall be provided for at least 3 off-load wash wastewater prior to disposal off site.

The GT shall be provided with all associated ancillary plant and systems for the safe, efficient and reliable operation of the units in combined cycle mode.

The Contractor shall carefully consider and take into account all movements and differential movements due to temperature gradients in all components and structural members during start-up, operation, and shutdown. The Contractor is fully responsible for all design considerations necessary to prevent buckling, distortion, misalignment or fatigue failure of components. The Contractor shall indicate on his drawings all such movements at interfaces with supports.

All compressor and turbine casings shall be designed for ease of inspection and maintenance and shall include suitable provisions for lifting and alignment.

The GT shall be provided with at least two (2) overspeed trips. Overspeed trips shall be a minimum of one each of automatic, mechanical and electronic types. The overspeed system shall trip the unit at 112% of rated speed. Equipment design shall allow testing of overspeed protective devices on line. The GT shall be furnished with speed and zero speed sensors.

All rotating equipment shall be capable of withstanding the normal fatiguing stresses from aerodynamically and mechanically induced excitation forces at all operating loads. Turbine blades shall not have a resonant mode at any speed between the upper and lower operational limiting speeds of 47 and 52.5 Hz.

The gas turbine shall be capable of handling transient over speeds up to the nominated over speed trip speed without suffering any damage or requirement for inspection before re-entering service.

The GT shall be designed to run down safely to stop condition with no damage to equipment in the event of loss of auxiliary power.

The GT shall be equipped with an exhaust temperature controller to limit power output (i.e., fuel input) commensurate with the maximum allowable exhaust temperature and shall effectively override all other devices or programs demanding increased power output.

The automatic speed governor shall be capable of controlling the GT speed at a value to prevent the unit from reaching the electronic over speed trip point in the event of a full load to no load condition.

Jack screws, lifting lugs, eyebolts and/or the equivalent on casings and ductwork shall be provided to facilitate the disassembly/assembly and alignment of the GT.

GT shaft bearings shall be provided with vibration monitors and temperature measurements. The Contractor shall furnish a vibration monitoring system to provide continuous measurements and monitoring of various GTG supervisory parameters. Temperature measurements of the turbine metal, the GTG bearings, and the generator stator shall be provided.

GT instrumentation shall include all the necessary temperature and vibration measurements for operation and protection of the GT including start-up, normal operation, and transients. The instrumentation will be connected to alarms and trips at designated set points by the manufacturer to prevent failures.

Couplings and guards shall be removable without removal of rotors of interconnected equipment and shall not prevent access to adjacent bearings and seals.



Borescope inspection ports shall be provided for internal inspections of critical components in the sections of the GT.

With the contract proposal, the Contractor shall provide a complete lift plan(s) for all scheduled inspections and outages both major and minor for the GT. This will include descriptions of the use and sizing of fixed and mobile cranes. During the design phase, the Contractor shall provide detailed models or drawings to demonstrate the ability to avoid all fixed interferences while completing all required movements and lifts and the ability of the specified mobile cranes to be driven to the required locations using only the road surfaces and maintenance pads designed for maintenance crane loadings.

6.2 Compressor

Variable inlet air guide vanes shall be provided. Variable inlet vanes will modulate airflow to enhance starting, to prevent compressor stall, and to maintain high exhaust temperature during part load operation. The design shall provide control at low temperature conditions to limit high-mass flow into the compressor.

Provision shall be made for bleeding off air from the compressor when necessary to prevent compressor surge or stall. During start-up and run-down of the GT the blow-off valves will be opened to prevent compressor instabilities. A special controller shall be included to maintain sufficient margins with respect to conditions and operating parameters that could cause a surge. In the case that surge does occur in spite of these features and measures, and surge protection pressure switches in 2-of-3 logic will trip the GT.

The bellmouth shall be calibrated for flow calculations and have connections to allow manometers to be connected for flow measurement.

6.3 Fuel Supply System

The Contractor shall provide all fuel gas conditioning equipment necessary to meet the GT fuel gas inlet requirements of the GT manufacturer. Natural gas conditions are provided in Section 2.2. The fuel gas supply system included with the GT package shall include all equipment and systems required to condition the fuel gas delivered by the project’s fuel gas supply system to the GT package. (See Section 7.0 for specifications for the fuel gas compressors and upstream fuel gas conditioning system.)

Natural gas pressure and temperature requirements at the GT interconnection point shall be indicated in the Contractor’s proposal. The fuel supply system shall be capable of accommodating the complete operating range of the fuel gas compressors and upstream conditioning system and the GT without affecting the stable operation of the unit. The unit shall be capable of full load operation over the full range of gas properties indicated in Section 2.2 and full range of ambient conditions.

A fuel control station at the GT to regulate and control the supply of natural gas to the unit shall be provided by the Contractor. The pressure regulating station shall include pressure regulating valves, pressure relief valves, normal and emergency gas shutoff valves, manual shutoff valves, and necessary controls for pressure regulation. The Contractor shall supply relief valves to prevent exceeding the GT manufacturer’s maximum allowable supply pressure.

If required by the GT manufacturer, the Contractor shall furnish and install equipment necessary to heat the fuel to a temperature acceptable to the GT manufacturer using either hot returned condensate, low-temperature HRSG economiser water, low-pressure steam, or other suitable means.

Wobbe index control shall be provided, to adjust for historical fuel supply variations and GT requirements, to ensure stable operation including prevention of unit tripping over the full range of fuel gas conditions.

The fuel filtering provisions shall comply with the GT manufacturer’s requirements, and the minimum fuel filtering standards shall be as follows:

Two coalescing filters shall be 100% effective for particles 0.3 microns or larger

The two filters shall operate in parallel so that there is no need to shut down the GT while performing maintenance on one of the filters



The coalescing filters can handle small slugs of liquids up to the required amount.

Each filter shall be sized to handle the flow associated with the CCGT operating at full load

Piping shall be carbon steel upstream of the filters and stainless steel downstream of the filters to the GT.

The Contractor shall provide all remaining system components including instrumentation and controls required for a complete system for firing natural gas such as but not limited to:

Stop and control valve assembly

Final inlet strainer

Ring manifold

Fuel metering for control

Interconnecting piping from gas module to the GT base.

Online Gas chromatograph

The Contractor shall provide stop valves on the natural gas piping at the GT base and on the off base gas module for fire protection isolation. Interlocks shall be provided to alarm and trip the GT on actuation of these stop valves. They shall be capable of closing on loss of power. This function may be incorporated into Contractor-furnished fast-acting valves. Gas stop valves shall be located near the turbine gas manifold to minimize the quantity of fuel available to the turbine following a trip or shutdown.

Two means for stopping fuel flow shall be provided at the gas reducing station. They shall respond to normal or emergency shutdown control signals.

The Contractor shall provide fuel flow measurement devices, as a part of the control system for the unit, with accuracy of ±1% and associated algorithms in their control system. Flow meters shall be included to monitor fuel at the GT unit. Indication shall be provided at unit's control panel. Meters shall be pressure and temperature compensated for accurate flow and flow totalisation. The meters shall include a calibrated flow section, and a remote transmitter.

A Gas chromatograph for on line analysis of fuel gas (including heating value estimation) shall be provided for gas turbine control.

The contractor shall be provides all the design and drawings and conducted the whole works with the approval of the BGDCL & Gas Transmission Company Limited (GTCL) in Bangladesh.

6.4 Combustion System

The natural gas combustion system shall be designed to meet the plant emissions limits, while maximizing combustion efficiency, combustion stability and equipment life using the specified fuel. Control of NOx emissions shall be through the use of dry low NOx components, including combustors and fuel nozzles.

The combustion chamber design shall be constructed to allow for individual removing of the burner inserts, the ceramic and metallic heat shields. Redundant flame detection shall be used to verify ignition.

Emissions standards to be achieved during operation are 51 mg/m3 or 25ppm NOx through adoption of dry low NOx burner (catalytic removal will be retrofitted if necessary following review of annual ambient air quality data) with dust filters on air intake to ensure no particulate or SO2 emission,. Automatic monitoring (Continuous Emission Monitoring System-CEMS) of stack emissions for NOx, SO2, CO2, CO, O2, SPM, PM10 and PM2.5 to be installed in the stacks. Monitor and record annual gas consumption to calculate annual emissions of CO2.

Thermocouples or other instrumentation in the exhaust path shall be furnished to ensure proper combustor operation.



The combustion system shall be designed to minimize unburned hydrocarbons and visible smoke, and shall not exceed Bachrach 2.5 or Von Brand 90, except during start-up and mode changes.

6.5 Air Inlet Filtering and Silencing

The GT air intake filtering system shall be appropriate for the local climatic conditions. The frames of the filter cartridges must be metallic or plastic. Cardboard or paper product is not acceptable. Filter and filter housing shall be designed to prevent filter bypass (bypass leakage).

The air intake filtering system shall be designed to protect the GT from the hazards present in the atmospheric conditions of the plant site. In particular the concerns to be addressed by the filter system design should include:

High ambient temperature

High humidity

Heavy rainfall

High particulates and possible filter fouling materials such as soil, soot from adjacent

industries and river boat exhaust, particle board and jute mill exhausts, and nearby diesel power plant generator exhausts

Low to moderate wind speeds

Periodic insect swarms.

Secondary and final air filters as required to meet gas turbine requirements.

The system shall be designed in conjunction with the GT manufacturer to meet his particle sizing requirements to meet or exceed the expected operating hours between cleaning and overhauls on the compressor and turbine.

The inlet air filtering system consists (but not limited to) of the inlet air filters, inlet silencer, ductwork, inlet hoods for weather protection, moisture eliminators, bird screens, expansion joints, instrumentation, controls, lighting, support steel, platforms, and stairs. The inlet air system shall be suitable for the environment as well as to provide reliable operation, efficient maintenance and economic parts life.

Three stages of air filtration shall be provided consisting of a pre-filter, a secondary filter, and then a high efficiency filter. The high efficiency filters shall use 95% DOP (sub-micron) filters with a design capacity not greater than 50 m3 per filter. Differential pressure measurement across each filter stage, linked through the ICMS, shall be provided to allow assessment of the optimum period to change filter pads. As these media filters require periodic replacement adequate permanent access and a service area shall be provided. Lifting facilities for the filter elements and interior lighting shall be provided.

At least one of the filtering stages (including the pre-filtering stage) shall be self-cleaning based on local practice of nearby gas turbine installations. However, a superior filtering product in lieu of the self-cleaning stage can be proposed as an option. Bidder shall include the self-cleaning stage(s) in his base offering. If the option is offered (i.e. without a self-cleaning stage), the Bidder shall provide references of the proposed filter’s successful use in a similar sized gas turbine inlet air filtering service in a similar ambient condition as Ashuganj for at least two years.

The base of the lowest air inlet of the filter enclosure shall be elevated a minimum of 2.3 metres above grade and shall be accessible by ladder.

All surfaces exposed to the inlet air path flow shall be constructed of stainless steel or acceptable alternate subject to Employer’s approval.

The filtering system shall include the following:

A metal inlet screen of 25 mm mesh shall be located immediately ahead of the inlet filter openings to prevent debris and birds from entering inlet. Inlets shall have drainage holes to prevent standing water during outages



A self-cleaning or washing pre-filter panel capable of handling and removing swarming insects, adhesive soil and clay dusts and wood fibers

A louvre or weather hood to minimize the entry of rain into inlet filter

Ladders, and platforms (for access and maintenance) meeting standard industry safety codes requirements and local safety codes as applicable

Methods to lift the filter elements to appropriate elevations to enable maintenance and replacement. Suitable ladders, platforms, and monorails shall be provided for access and for changing of the filters

Interior lighting with protection to prevent breakage during operation, and convenience outlets

Differential pressure gauge with alarm outside enclosure and on control panel

The filter shall be designed to minimize re-depositing particles expelled during pulsing, during maintenance, and due to migration of salts through the filters

Enclosure shall be sufficiently rigid to prevent vibration problems. Fasteners shall be suitably locked to prevent loosening especially those on the inlet that could be ingested by compressor

Cartridge or replacement materials that need to be exchanged on a minimal basis with the following requirements as a minimum:

6 months for pre-filters

12 months for secondary filters

24 months for high efficiency or final filters.

Silencers shall be designed to meet the noise requirements specified in Section 18.4.3.

Contractor’s drawings shall include full details of silencer construction including material description and acoustical insulation. Construction of silencers shall prevent the entry of baffle packing material into the gas stream and the silencers shall be protected from damage resulting from acoustical or mechanical resonance.

6.6 Exhaust System

The GT package shall be furnished with a complete exhaust system including the exhaust diffuser plenum, supports, thermal insulation, and noise protection walls.

The exhaust plenum shall direct the exhaust gases into the heat recovery steam generator (HRSG). The turbine exhaust system shall consist of an exhaust plenum terminating with a flange. The flange will mate up with the flange of an expansion joint that will connect the exhaust plenum to the transition duct to the heat recovery steam generator. All exhaust plenum growth due to thermal expansion shall be accommodated in the expansion joint such that allowable loading on the GT exhaust flange is not exceeded.

The exhaust plenum shall be designed to prevent separation of joints, loosening of turning vanes and braces and fracture of bolts due to thermal forces, operating forces and vibration.

The height of the main stack shall be determined by calculation by the Contractor to meet GoB, DoE and WB 2008 environmental requirements. A sample dispersion calculation is provided in Section 18.4.2 that indicates a stack height of 60 meters will be suitable, but the Bidder is responsible for calculating the height and allocating a price in the price schedule.

The exhaust system shall be designed for the maximum expected temperature plus Contractor’s normal design margin. The exhaust duct shall be provided with liners of stainless steel material.

The exhaust gas system will be equipped with noise protection walls, which are not accessible during operation. Insulation will be designed with a temperature difference between surface temperature and ambient temperature of 30ºC, at shade side. The noise protection wall outside skin temperature shall not exceed 60ºC for personnel protection during any operating condition at summer design ambient conditions with still air.

Hot end bearing tunnel temperature shall remain below 92ºC when operating at base load with summer design conditions. Expansion joints between the GT and the HRSG shall be



manufactured in accordance with industry standards and quality practices. The Contractor shall indicate in his bid the expected life of the expansion joints.

6.7 Starting Facilities

The GT unit shall be provided with a starting system capable of starting and loading the unit to the full rated load. The complete GT starting system shall include all the required equipment and all controls and indication interfaces. The starting system shall be capable of four consecutive starts within one hour.

The GT starting system shall be suitable for off-line water washing.

6.8 Wash System

The GT unit shall be provided with a complete on-line and off-line compressor water washing system. A minimum of two wash water skid units shall be provided for the GT unit (if portable wash water units are provided). The system shall be skid-mounted and consist of the following:

Detergent tank

One (100%) booster pump with AC-driven motor

Valves, piping, nozzles, and piping specialties

Instrumentation and controls

Water injection manifold piping and effluent drains on the GT

Demineralized water piping to water wash skid and the interconnecting piping between water wash skid and GT unit will be provided by Contractor. All other piping and accessories to be provided by Contractor

The system design shall not allow water or detergents to enter lube or control oil systems. All driven equipment shall be electrically operated

Detergent tank shall be stainless steel or HDPE. Piping, valves, etc., shall be stainless steel. All hardware shall be corrosion resistant.

6.9 Turning Gear

Normal control of the turning gear shall be through the Plant ICMS in the Unit Control Room. A set of turning gear control and monitor devices (feedback from oil supply valve to hydro motor) shall be provided. The local turning gear control panel will be for maintenance purposes and local start-up.

Turning gear shall be furnished complete with hydraulic motor (actuated by the lifting oil pump), positive displacement motor, piping, lubricating system, and auxiliary switches to indicate in and out of operation of the turning device. Turning gear shall also be arranged suitable for hand crank operations.

A suitable protective pressure device shall be provided to prevent the starting of the turbine generator by the turning gear until the proper oil pressure has been established in the turbine generator bearings.

Turning gear design shall be such that should the turbine be started while the turning gear is in operation, the gear will immediately be thrown out of engagement without shock and will not reengage.

An alarm device shall be furnished with the turning gear equipment to indicate failure of oil supply when the turning gear is in operation, and the protective equipment shall be connected so that if the oil pressure drops to an unsafe value, the turning gear will be stopped automatically.

6.10 Lubrication Oil System

The Contractor shall design the lube oil system to follow the GT manufacturer’s recommended procedures for margins between the lube oil temperature leaving the bearings and the high temperature alarm set-point for all ambient conditions.

Oil piping shall be pickled, rinsed, and protected against corrosion by coating with a rust preventative that is compatible with the GT oil specifications prior to shipment.



6.10.1 Lube Oil Pumps

Two full capacity AC motor-driven pumps shall be supplied with one DC motor-

driven pump. As an alternate, one full capacity shaft driven lube oil pump, one full

capacity AC motor-driven lube oil pump, and one DC motor-driven lube oil pump

shall be furnished by the Contractor. If the shaft driven pump alternate can be

offered as part of the Contractor’s standard design for this configuration, this is the

preferred alternate to reduce auxiliary power.

The auxiliary or redundant pump shall start automatically upon initial loss of

normal lube oil pressure. The DC auxiliary pump shall start automatically upon

loss of normal lube oil pressure after AC-driven auxiliary or redundant pump fails

to bring lube oil pressure back to normal. The redundant AC or the DC pump shall

be capable of being started anytime to verify readiness.

6.10.2 Lube Oil Coolers

Coolers shall be provided with inlet and outlet temperature indication, pressure

test connections, vent, and drain connections.

The two 110% lube oil coolers shall be provided. Coolers shall be arranged such

that any fluid leaks will not cause equipment damage.

6.10.3 Lube Oil Filters

A duplex, multi-element filter with a continuous flow transfer valve shall be

provided. The two 110% capacity nominal 25 micron filters with a manually

controlled continuous flow transfer valve shall be furnished by Contractor to filter

contaminants out of the lubricating oil. Both filters shall be easily accessible for

maintenance. High-pressure drop across the filter in use shall alarm on the unit's

control system and be visually indicated at the filter.

6.10.4 Vapour Extractors

The Contractor shall provide two 100% oil vapour extractors with mist eliminators

per the GT manufacturer’s standard design. Extractors shall purge the oil reservoir

of oil vapours.

Coalescent type mist eliminators shall be provided. Electrostatic type mist

eliminators are not acceptable. Oil shall be separated and returned to the lube oil

reservoir.

6.11 Fire and Gas Detection and Protection

The Contractor shall provide a fire protection and detection system for the GT, equipment compartments and for lube, control and seal oil systems. The generators shall be equipped with the manufacturer’s standard detection and protection systems. The fire detection system and other components of the fire protection system shall be designed and configured in a manner that permits inspection and maintenance without causing any interference with the GT operation.

The GT package fire protection and detection systems shall interface with the existing main fire alarm panel located in the central control room.

The fire protection and detection system shall comply with the requirements of the NFPA 12, NFPA 72, and NFPA 850, or recognized equivalent.

6.11.1 Fire Detection System

The GT fire detection system shall include smoke, thermal, and natural gas

detectors as follows:

Smoke detectors shall be mounted in all compartments. Smoke detectors shall be designed to provide instantaneous response to smoke. An



indication shall initiate an alarm at the unit local control and at the plant central control room

Thermal detectors shall be mounted in compartments and enclosures protected by CO2. Fixed temperature sensing fire detectors shall monitor absolute temperature or rate of temperature rise. Upon reaching temperature set points, the control system shall automatically and immediately initiate a unit shut down and dispense the CO2 automatic zoned fire protection system

Methane gas detectors shall be arranged in the GT and gas skid area. A stand-alone gas detection panel shall be provided for the GT. A warning shall be initiated at gas levels of 10% of the lower explosion level (LEL) and an emergency shut down when the combustible gas ratio reaches 20% LEL. The gas detector system shall include gas sensors, digital display and status indicators on the main control system, calibration equipment, and the necessary wiring.

6.11.2 Fire Protection/Detection System Controls

The fire detection controls shall be backed up by a DC system.

Each sensor shall be monitored by the unit control system and compared to alarm

and shutdown set points. An alarm or shutdown indication shall be sent to the

plant control system. A shutdown signal to the main control system will

automatically initiate an emergency shutdown of the unit.

Each sensor shall be connected in a closed loop circuitry to verify readiness. Fault

conditions such as defective sensor or wiring shall be indicated on the unit control

system and shall not initiate a unit trip or initiate a CO2 release.

The hose adjustment or attachment system with the main valve system of all the

fire hydrant points will be of coupling system (not screw system) in the project

facilities.

6.12 Cooling System

The Contractor shall provide a continuous source of cooling for the GT lube oil coolers and other cooling requirements of the GT package, for the full range of operating conditions, and for the simple and combined cycle operating modes. In the proposal, the Contractor shall describe the system and confirm that the full range of operating conditions is addressed.

6.13 GT Package Enclosures and Insulation

The GT shall be provided in an acoustic enclosure, capable of meeting the plant’s specified noise limits in Section 18.4.3. Insulation of the GT package equipment shall be used for personnel safety as required by standard industry safety codes and/or local safety codes as applicable, Personnel protection insulation will be designed to maintain a surface temperature of 50°C or below, at site summer design conditions with still air. Insulation and related products shall be asbestos-free. The exhaust gas system will be internally insulated; external cladding will not be provided. Exhaust gas system will be equipped with noise protection walls, which are not accessible during operation. Insulation will be designed with a temperature difference between surface temperature and ambient temperature of 30°C, at shade side. Aforementioned temperatures will be considered to be valid at outer surface of noise protection walls.

Insulation shall have aluminium lagging. Removable metal covers shall be used where access is needed for valves, pipe connections, instrumentation, etc.

The Contractor shall provide all ventilation, cooling, and heating in the GT package enclosures as applicable to maintain the proper temperature and humidity range during start-up, operation, shutdown, standby, and long term lay-up periods. These requirements apply to all GT package auxiliaries, including electronics, instruments and controls.

Redundant full capacity exhaust fans shall be provided for each compartment or enclosure. Failure of a single fan shall not cause the internal temperature to rise above equipment



design temperature, cause equipment de-rating, or restrict or shut down GT operation. The standby fan shall automatically start in the event the primary fan fails. Fan failure will be alarmed at the main control room.

6.14 Controls and Supervisory Instrumentation

The GT controls and supervisory system shall be a proven microprocessor based integrated system furnished by the GT manufacturer. The instrumentation, control systems, UPS system, and electrical power circuits for critical equipment shall be designed with sufficient redundancy in such a way that no single control system, instrument failure, controller failure, fuse, or circuit breaker shall interrupt the operation of more than one piece of redundant equipment.

The GT control system shall include the following features:

Interfaces to the ICMS as detailed in section 13. The ICMS HMI shall provide all the functions of the local control consoles for the GT. It shall be possible to perform all necessary workstation functions (programming, graphic display changes, etc.) from the ICMS HMI.

The GT control system shall include extensive self-checking to detect malfunctions of the I/O equipment, communications subsystems (i.e., data highways, etc.), memory priority errors, lost or spurious interruptions, program hang-ups, and other checks that indicate erroneous operation. When such checks show a problem from which the system can recover without intervention by plant personnel or interruption to the control system, a system error shall be alarmed. A message will be displayed on the operator console identifying the exact cause of the error and operation shall resume.

The GT control package shall be serial linked to the Plant ICMS to be used for data acquisition and monitoring of the GT. In addition, critical control functions will be hardwired to the Plant ICMS.

The GT control system shall scan critical sequence of event (SOE) inputs with one millisecond time resolution. The time tagged inputs shall be provided through data link for SOE recording in the plant ICMS.

All transmitters and indicators shall be capable of being maintained while the unit is on line and shall be provided with root valves. Root valves are required for all instrumentation. In addition, instrument manifolds shall be provided with all transmitters: 2-valve manifolds for pressure transmitters and 3-valve manifolds for differential pressure instruments.

The GT control system shall be designed for complete automatic start-up, synchronizing, loading, load sharing, protective shutdown, and manually initiated shutdown. The GT control system shall be designed for complete remote manual start-up, synchronizing, and loading. In the start-up mode, the system shall be capable of allowing the operator to initiate each step in starting sequence.

The GT control system shall receive a master clock signal for the GT controls ‘time synchronization with the master clock.

Factory Acceptance Testing (FAT) of the complete control package shall be performed using Contractor's standard testing procedures. All software logics, hardware, graphics, and alarming shall also be verified during the FAT. The tests shall be performed before shipment. The Employer’s approval of control screens is required

Triple redundant transmitters/switches shall be provided for critical measurements used in equipment trips or critical control loops. The control system shall employ the median select logic for analogue signals and a 2-out-of-3 voting logic for digital signals used for control

The GT system power supplies shall be redundant to comply with the single failure criterion.

Turbine stress monitoring shall be included in the GT control systems. In addition, a GT performance calculation and monitoring package shall be included with the GT control system.



Mechanical equipment on standby status shall automatically start-upon a trip of the operating equipment. All backup pumps shall automatically start to maintain Plant production rates.

The system shall be designed to require a minimum of operator action. The plant shall be operable from the control room by a single operator under all normal conditions from minimum to full load. The control system shall include all necessary logic to change the operating mode for selector stations safely under various operating conditions. The plant control system shall be capable of day ahead programming of key events (i.e. turning over unit to NLDC’s remote dispatch). The Contractor shall be fully responsible for the interface design with the NLDC’s remote dispatch system.

The Contractor shall keep a master set of the Contractor’s and manufacturer's wiring drawings, GT control system configuration, cabinet arrangement, power distribution drawings, instrument index, instrument and control valve data sheets, and P&IDs marked up to include all changes made during erection and commissioning.

All instrumentation and control devices to monitor and control pressure, temperature, flow, level, etc. required to properly monitor the equipment in accordance with good engineering practice and safe operation shall be provided by the Contractor. All instrumentation and control devices shall meet the applicable specification requirements indicated in Section 13.0 Control and Instrumentation of this Specification.

6.15 Trip and Alarm Functions

The following trip and alarm functions are required for the gas turbine as a minimum.

GT trip list:

Over speed – electronic 2 out of 3 polling

Over speed – mechanical bolt

Compressor surge – 2 out of 3 polling pressure switches

Low gas supply pressure

Emergency stop push button(s)

High thrust bearing temperature

High lube oil temperature in each bearing drain line OR high journal temperature thermocouples in journal bearing pads

High exhaust temperature

Flame loss in combustion chamber

Fire detection

Low lube oil pressure

Vibration detection in all bearings

Low flow sensors on return lines of external turbine cooling-air systems

Compressor bleed valve position – failure to open on start-up and shutdown OR closed when running

GT alarm list:

High thrust bearing temperature

High lube oil temperature

Low lube oil pressure

Exhaust temperature spread

Bearing vibration – all bearings

DP over inlet filter

High temperature sensors on return lines of external turbine cooling-air systems



7. FUEL GAS SYSTEM

7.1 Scope

The Valve Station-3 (VS-3) of Titas Gas Transmission & Distribution Company Ltd. (TGTCL) is located on the right side of the Dhaka-Sylhet highway and to the north-west of the APSCL boundary. This VS-3 has access to gas from Titas Gas Field, Habiganj Gas Field and from the Manifold of Gas Transmission Company Ltd (GTCL) RMS at Ashuganj. The probable receiving pressure of the station is 1000 Psig but the present pressure is 600-800 Psig.

The natural gas for the proposed Plant will be supplied from the 20 inch diameter incoming line (i.e. Gas Manifold, GTCL to VS-3) by a 12 inch diameter underground gas pipe line. The proposed gas pipe line will be connected at the receiving side of 20 inch diameter gas pipe line of VS-3. The length of the underground gas pipe line from VS-3 to the Regulating and Metering Station (RMS) (located at the garage of APSCL premises) approx. 2.2 Km. Gas pressure condition at the terminal/connection point is 600-1000 psig with a temperature of 15–350C but Bakhrabad Gas Distribution Company Ltd. (BGDCL) enforced APSCL to supply gas at a minimum pressure of 150 psig (10.2 bar).

The RMS will consists of three regulating pass of capacity 50% each (two pass for operation and the other standby) with a two stage regulation i.e. 1st stage (from 600-1000 Psig to 400-450 Psig) and 2nd stage regulation (from 400-450 Psig to 150-200 Psig). The gas receiving pressure of Gas Booster compressor is approx. 150-200 Psig.

The flow capacity for the 1st stage of the proposed RMS will be approx. 150 MMSCFD including additional 80 MMSCFD gas for future Power plant and after 1st stage the flow capacity will be 70 MMSCFD considering 120% for design of the proposed RMS.

From GTCL’s Manifold to VS-3 gas line, some portion of this gas line is 12 inch diameter, some portion of 10 inch diameter, some portion of 6 inch diameter and the rest portion is 20 inch diameter. At present the flow capacity of this 20 inch gas pipe line is about 200 MMSCFD due to some portion of approx. 4 feet of this gas pipe line is at reduced size (6 inch) and flow meter. In that case, APSCL will not getting enough gas without modifying the existing 6 inch diameter 4 feet long gas line and also replacing the existing flow meter at GTCL’s Manifold end. A modification work of the existing 4 feet long 6 inch diameter gas pipe line and replacement of flow meter will need to be done. The existing approx. 4 feet long 6 inch diameter gas line will be replaced by 10 inch diameter pipe and replacing the existing flow meter with a 10 inch Ultrasonic flow meter of approx. capacity of 300 MMSCFD including flow computer with necessary transmitters, electrical panel, fitting etc.

The Contractor shall provide approx. 5% of the total cost of the said TBS & RMS to BGDCL as supervision charge as per Gas sales Agreement (GSA) between APSCL & BGDCL.

The Contactor shall closely coordinate its design work with GTCL & BGDCL and obtain their approval for the final design. The Contactor shall use only a local Sub-Contractor of 1-4 category enlisted with GTCL & BGDCL for performing gas pipeline and RMS work in Bangladesh for construction of the gas facilities.

The complete fuel gas handling system from the defined incoming gas Terminal Point (i.e. source point) to the new RMS shall be the responsibility of the Contractor. The equipment provided shall be capable of removing contaminants from the fuel gas to achieve the required quality, and of supplying the required quantity gas to gas turbine at the required dry and clean conditions.

The Contractor shall have the responsibility to modify the 6 inch diameter about 4 feet long gas pipe line by 10 inch diameter pipe line and also to replace the existing flow meter by a 10 inch ultrasonic flow meter with necessary transmitters, electrical panel, fitting etc. at Gas Manifold of GTCL.

The Contractor shall design, manufacture, inspect, test, delivery to the site and install & commission of natural gas handling facilities with all accessories including interconnecting piping, gas booster compressors and natural gas treatment system to ensure sufficient natural gas flow to the plant. The Gas Turbine unit shall be furnished with a complete gas fuel system. The fuel gas system is to be designed to meet all operating conditions of the gas turbine. It includes the following main components:



a) Replacing of approx. 4 feet long 6 inch dia. Gas pipe line by 10 inch gas pipe line and supply & installation of 10 inch Ultrasonic flow meter of approx. capacity 300MMSCFD with necessary transmitters, online gas chronograph, electrical panel, fitting etc. at Gas Manifold of GTCL.

b) Transmission pipeline adequately sized to supply sufficient quantities of natural gas to the Plant (connecting from terminal point of VS-3 to the new RMS and the Plant)

c) Gas Compressors (including all package equipment item such as skids, motors, lube oil pumps, filters, storage vessels, noise attenuators, piping, instruments, valves, controllers, auxiliaries, safety equipments, cooling system, Nitrogen plant for sealing and purging etc. Reciprocating type Gas Booster will not be acceptable).

d) Gas pressure reducing station to supply gas to Gas Turbine at the required pressure.

e) Gas metering system (1 no. Turbine Check meter, 2 no. Ultrasonic flow meters for billing purpose, Online Gas Chromatograph for measuring the heating value of gas).

f) Gas Conditioning Equipment (including all major items such as knock out drum i.e. KOD, separators, filters, heat exchangers, water bath heaters, storage vessels with all included accessories, skids, instruments, valves, platforms and ladders etc.)

g) Gas Venting and Purging System (including vent pipes/ flares, bottle banks, instruments and valves etc.)

h) Piping (including main gas piping, bypass piping, drainage pipes, all manual valves, accessories, coating, heat tracing, insulation etc.)

i) Electrical sub-system (including local switchgear, protection, cables, cable trays, earthing, lighting, lightning protection etc.)

j) Instrumentation and Controls (including pressure, temperature, flow, level gauges, instruments and all other controls and safety devices, check meters, shut-off and safety relief valves, electronic controllers, displays etc.)

k) Civil Engineering (including foundations, noise barriers, buildings, pipe supports, ladders and platforms, drainage, trenches, surface covers, fences and road ways within the fuel gas system etc.).

l) Mandatory and Special tools necessary for equipment calibration, etc. shall be supplied by the RMS supplier.

m) Cathodic protection system

The fuel gas system has interfaces with the following systems of the station:

ICMS system

Central cooling system

Instrument air system

Earthing and lightning protection system

Power supply system

Power plant fire protection system

Plant security system.

7.2 Standards

The Contractor shall specify all standards relevant to the design of the fuel gas system in addition to the following minimum requirements for latest editions of the following codes and standards:

Bangladesh Natural Gas Safety Rules



ASME 31.8 - Gas Transmission and Distribution Piping Systems

API Spec 5L - for Line Pipe (for the branch pipeline only)

ASME Boiler and Pressure Vessel Code for all pressure vessels

ASME B 31.1 Power Piping for all pressure piping within the confines of the plant

ASME B 16.5 Pipe Flanges and Flanged Fittings

IEC Ex rules and standards relating to Electrical Apparatus in explosive atmospheres.

7.3 Guarantees

With regard to the Fuel Gas System, the Contractor shall guarantee the following:

Adequate fuel gas flow, pressure and condition at the inlet of the gas turbine for all specified operating conditions.

Safety by design of all fuel gas components for the design life of the plant.

Availability of the Fuel Gas System to match the overall availability of the power station.

Completion of the Fuel Gas System in time for the commissioning of the power station.

Construction of the transmission pipeline scheduled at a time coordinated with BGDCL/GTCL and construction of the transmission line to minimize potential costs to the Employer as well as costs to approval authorities and the local community.

Elimination of potential fire / explosion hazards.

Environmental impacts below the specified levels.

7.4 Gas Industry Relationships

The energy industries of Bangladesh are state-owned and the commercial relationships are regulated. The structure of the gas industry relevant to this Project is as follows:

MPEMR Ministry of Power, Energy and Mineral Resources (Energy Policy)

BERC Bangladesh Energy Regulatory Commission (Gas and Power Pricing)

Energy and Mineral Resources Division (responsible for the gas industry)

Bangladesh Oil, Gas & Mineral Corporation (PETROBANGLA) (Gas Production, Transmission & Distribution)

Department of Explosive

GTCL (Gas Transmission)

BGDCL (local Franchise Holder responsible for distribution, metering and billing).

The Contractor shall acquire all information and designed data relevant to the fuel gas supply in addition to this Specification, from parties of the Bangladesh gas industry.

7.5 Fuel Gas Composition

Details of the fuel gas composition are given in Section 2.2 of this Specification.

7.5.1 Regulating and Metering Station (RMS)

150 psig shall be the design outlet pressure of new RMS (to be constructed by the

Contractor) supplying the proposed Ashuganj CCGT at all flow conditions.

The Contractor shall consider in its design the pressure loss from the 20 inch

receiving pipe line of the VS-3 to the inlet of proposed 400MW CCGT RMS.



7.6 Fuel Gas Demand

The maximum and minimum fuel gas demand is to be specified by the Contractor and will depend on the rating and overall efficiency of the power station and the calorific value of the gas. The Contractor shall specify the range of fuel gas variation that the gas turbine can adjust to a) automatically and b) with a change of control settings.

7.7 Gas Metering

The custody transfer metering of the fuel gas will take place at the RMS, which is monitored by BGDCL, the local franchise holder. The metering standards are set by BGDCL, who is expected to use an automated online gas chromatograph for the calculation and recording of the calorific value and the determination of the energy input to the power plant should be installed by the contractor. The Employer is entitled to supervise the metering data of BGDCL including calibration records.. The Contractor shall install a common turbine check meter before 1st stage regulation and two Ultrasonic meters for billing purpose after 2nd stage regulation at new RMS with transmitters and flow computers. The meter shall produce electrical signals for input into the ICMS to record the hourly gas flow with automatic correction for pressure and temperature of the gas. Any type of metering bypass except Check meter is not acceptable.

Plant Layout:

The Contractor shall indicate on its general layout drawing the approximate location and space requirements for the fuel gas system and its main components. It shall also indicate the location of the gas vent (or flare) and the extent of the hazardous areas.

7.8 Branch Pipeline

The branch/transmission pipeline from VS-3 to the new RMS is exclusive to the power station and is included in the scope of the Fuel Gas System.

The outside diameter of the pipeline shall be selected by Contractor except the 12 inch gas pipe line from the terminal point at VS-3 after 1st stage regulation based on his analysis in accordance with ANSI/ASME B31.8 “Gas Transmission and Distribution Systems” And approved by GTCL.

The design pressure of the branch pipeline is to be stated by the Contractor and shall be above the inlet pressure of the gas turbine.

All other design aspects of the branch pipeline, including corrosion allowance, coating, cathodic protection, standards, etc. shall be identical to those of the new transmission pipeline. The Contractor shall acquire this information from BGDCL during the detailed design stage.

The cathodic protection system of the pipeline shall be compatible with the cathodic protection system of the transmission pipeline and shall not interfere with the earthing system of the power station. Electrical isolation flanges are to be installed where appropriate.

7.9 Gas Conditioning

GTCL and BGDCL are unlikely to guarantee complete removal of condensate and impurities at all times. The Contractor shall acquire design details of the RMS and its condensate removal and pressure control facilities to satisfy its need for information.

The Contractor shall provide a process flow diagram of the fuel gas system and specify the equipment that is necessary for the protection of the compressors and gas turbine, with equipment such as:

Inlet scrubbers (technology and volume)

Filter before 1st stage and after final stage

Knock out drum (KOD)

Liquid separators/KOD (before 1st stage, intermediate & after 2nd stage regulation)

Water bath heater



One condensate storage Tank of minimum capacity 10m3

Over- and under-pressure protection systems

Additional gas treatment equipment (e.g. heaters, coolers, filters, separators, storage vessels).

7.10 Gas Compressors

The Contractor shall specify compressors required to raise the gas pressure as required by the gas turbine.

The Contractor shall supply 3(three) Gas Booster Compressors each 60% capacity (two in operation and the other one standby). Standby capacity shall be provided to enable uninterrupted gas compression and to avoid lengthy cooling down periods of the power station in the case of a gas compressor failure. The standby capacity should be sufficient to ensure full availability of the power station, while one compressor is under repair. The Contractor shall explain the standby philosophy of the installed compressors.

The Contractor shall specify compressor technology that fits well with the proposed turbine technology and that best meets the availability, reliability and economic criteria of the plant. The Employer is confident about the use of multi-stage, integral gear mounted, centrifugal compressors, but is open to alternatives.

The Contractor shall specify the (guaranteed) performance data of the compressors, including the following:

a) Automatic switching of compressors for uninterrupted gas supply

b) Design gas flow in scm/h at given pressure ratio

c) Design inlet and outlet pressure of compressors. The design inlet pressure is to be existing RMS outlet pressure.

d) Gas temperatures at design conditions

e) Power demand at design conditions in kW

f) Installed power rating of drivers in kW

g) Type of drivers

h) Standby capacity

i) Availability of compressors over the lifetime of the power station

j) Pressure and flow control of compressors

k) Start-up sequences of compressors in relation to turbine start-up sequences.

l) Cooling of compressors at design conditions

m) Rating of cooling in kW

n) Lubrication of compressors at all operating conditions

o) Maintenance schedules of compressors

p) Noise emission of compressors

q) Optional noise enclosures

r) Specification of noise reduction with noise canopy

s) Oil Separation

t) Ventilation (without and with compressor noise canopies).

7.11 Gas Venting and Purging

The Contractor shall describe by means of text and a process flow diagram the venting and purging procedure of the pressure vessels and gas piping. Hazardous areas are to be indicated on the General Layout drawing.



Gas venting is required for maintenance purposes and small quantities of gas are assumed to be vented from the block and bleed arrangements of the fuel gas control system of the gas turbine. The Contractor shall explain the design of the venting and purging system. The discharge of gas shall be at a safe location and hazardous areas are to be restricted to be within the boundaries of the power plant.

7.12 Filtration and Pressure Reduction Equipment

The filtration equipment shall consists of two 120 (2 x120%) per cent duty and standby filter/separator units. The filter units shall be high efficiency horizontal type arranged to provide retention of solid particles and liquid droplets over the size of 3-4 micron. Each filter line shall be complete with all isolation valves, bypass line and the filter vessels shall be designed for ease of filler element removal.

The filters shall be provided with differential pressure gauges, which shall alarm the operator that the filter in service requires cleaning and changeover to the standby filler is necessary.

Gas condensate shall be drained from the filters to the gas condensate storage tank via automatic valves initiated by filter level equipment.

From the filter units the gas will pass to the pressure reduction/trimming valve stations. Three streams of pressure reduction/trimming shall be provided each sized for the 60% throughput of one gas turbine unit. Two streams shall be operational feeding two gas turbines whilst the third stream is in standby.

Each stream will consist of two pressure reducing valves in series. The valves shall be of the self-acting pilot type. The pressure reducing valves shall act to maintain the downstream pressure constant at the pressure required by the gas turbine making due allowance for pressure drop downstream of this equipment. In the event of the upstream pressure falling each pressure reducing valve should revert to its fully open position.

Each valve shall be designed to carry the full pressure reducing duty, one valve normally being the duty valve and designed to fail open. The second valve shall normally be the standby and be designed to fail closed.

The pressure reducing valves shall be controlled automatically to maintain the gas pressure within the required limits during normal operation and below the lifting pressure of the relief valves.

All streams shall be provided with upstream and downstream isolation of the pressure reducing valves. The upstream isolation shall comprise an automatic slam shut type valve together with a manual isolation valve.

All valves shall be provided with limit switches in the open and closed positions and these will be used for remote indication or alarm purposes as required.

Each pressure reducing stream shall have its own pressure relief valve and these shall be arranged to discharge to a safe location. Reducing station should have three identical streams each of 60% capacity and a full capacity by-pass with two isolating Dynamic/Pressure Balance Plug Valves and a Hand-Control Valve.

The gas reduction/trimming station and all its associated equipment shall be designed to give the highest level of availability. The operation of the gas reduction/trimming station shall be automatic over its complete flow and pressure range. Upon failure of a duty reducing valve or stream, the standby reducing valve or stream as appropriate, shall automatically commence operation in a bumpless manner.

7.13 Gas Piping

The underground branch pipeline shall be designed and constructed in accordance with the codes and standards applicable to the gas transmission pipeline of BGDCL, in particular with the standards referred to in Section 7.2 and with the material requirements of Sections 6.3 and 14.5.1.

All gas piping on the power station site is expected to be above ground unless specified otherwise by the Contractor, and shall be designed in accordance with the latest edition of relevant standards referred to in Section 14.5.1.



Equipment items designed and manufactured in accordance with different standards shall be identified and proposed as alternative options.

The Contractor shall explain its philosophy on “double-block” and “double-block-and-bleed” arrangements of valves.

The gas piping includes:

Pipe supports and foundations

Coating (preparation and painting to be specified)

Touch protection of hot surfaces

Insulation

Step ladders and pipe crossings

Drains.

H&S measures per the EHS onshore oil and gas development guidelines are incorporated, undertake quantitative risk assessment of gas-related elements to demonstrate there will be no increase in risk level at the nearest sensitive receptors from gas leak, fire or explosion.

7.14 Electrical Sub-Systems

The Contractor shall provide all interfaces between the main electrical systems as described in Section 12.0 with that of packaged components. The Contractor shall ensure that the design complies with all aspects of the international IEC Ex rules and standards.

7.15 Instruments and Controls

The Contractor shall provide a typical P&I diagram of similar plant showing all instruments and controls. The instruments are to be designed for local and remote indication and alarms. Electrical signals shall be explosion proof.

The Contractor shall describe the drive mechanism of the actuated valves. It is assumed that actuated valves have pneumatic actuators and actuation air will be supplied by the plant’s central instrument air compressor station. The Contractor shall specify the relevant scope allocations and interfaces.

7.16 Civil Engineering

The civil engineering shall include foundations, noise barriers, pipe supports, drainage, trenches, surface covers, fences, and road ways within the fuel gas system and instrument air compressor. A 3m high wire fence is required around the Fuel Gas Plant; refer to Section 5.20. The Contractor shall specify the relevant scope allocations and interfaces.

7.17 Consumables

The Contractor shall specify the quantities of consumable for:

Commissioning

First 10 years of operation.

7.18 Lube Oil / Condensate Removal

The Contractor shall specify:

Lube oil demand and replacement schedules

Condensate and compressor oil discharge methodology.

7.19 Noise Control

The requirements for noise control are set out in Section 18.4.3.



7.20 Documentation

Included in the scope of delivery for the Fuel Gas System (as for the other parts of the plant) are the following sets of documents, to be finalized and approved by the Employer:

Contract programme

Inspection and test programme

Performance and test procedures

Process Schematics, P&ID’s, and system descriptions

Detailed drawings of components, piping, etc.

Site layout drawings and arrangement drawings

Equipment and piping specifications

Certifications

Hazardous area drawings

Plant performance testing procedures and records

Commissioning and decommissioning instructions

Complete FAT (Factory Acceptance Test) documentation

Component lists

Operations manuals

Maintenance instructions.



8. HEAT RECOVERY STEAM GENERATOR


8.1.1 Applicable Codes

The design, manufacture and construction of the Heat Recovery Steam generator

(HRSG) shall meet the applicable sections of the latest editions of Bangladesh

codes, standards and regulations or their recognized equivalent. The most

stringent standards shall be applied in the event of any conflict between local

codes and regulations, and the following codes and standards:

American Boiler Manufacturers Association ABMA

American Institute for Steel Construction AISC

American Iron and Steel Institute AISI

American National Standards Institute ANSI

American Petroleum Institute API

American Society for Testing Materials ASTM

American Society of Civil Engineers ASCE

American Society of Mechanical Engineers ASME

American Welding Society AWS

Code of Federal Regulations CFR

Industrial Gas Cleaning Institute, Inc IGCI

Instrumentation, Systems and Automation Society ISA

National Electric Code EC

National Electric Manufacturers Association NEMA

National Fire Protection Association NFPA

Occupational Safety and Health Standards OSHA

The Society for Protective Coatings SSPC

Uniform Mechanical Code UMC

Heat Exchange Institute HEI

Deutsches Institut für Normung Standards DIN

Department of Environment, Bangladesh DOE

8.1.2 Specific Requirements

The Heat Recovery Steam Generator shall be selected, designed, supplied, tested,

installed, start-up and commissioned based on the requirements stipulated at

various parts of this technical specifications. The design shall be as per ASME

section 1 and shall meet the local regulatory requirements.

The HRSG shall be provided with all associated ancillary and auxiliary equipment

including de-aerator and systems for the safe, efficient and reliable operation of

the unit in simple and combined cycle modes.

Dry running capacity is not required for extended periods but should be possible

for short periods to allow start-up of the steam cycle.

The HRSG shall be triple pressure drum type with reheat (if reheat is cost

effective), natural or forced circulation, horizontal or vertical type. Each pressure

system shall have steam drum, economizer, evaporator and super heater sections.



The HRSG shall be designed to keep the vibrations to a minimum such that tubes,

casing, transition piece ductwork, by-pass stack with diverter valves and exhaust

stack under every operating condition are not subjected to deterioration or

destruction. The noise levels shall be kept below the limits stipulated elsewhere in

the specifications.

The casing system shall consist of a gas tight outer casing, insulation and an inner

casing. The inner casing shall allow free expansion in every direction. Flash or

otherwise seal casing and external skin penetrations against the leakage of gas or

the penetration of water from any sources including but not limited to precipitation,

dew, condensation or washing operations.

Tubes, coils and drums shall be designed with adequate cross-section and use of

suitable materials to prevent flow accelerated corrosion occurring.

The Contractor shall design and fabricate ducting for the HRSG with all necessary

insulation, turning and guide vanes or perforated plate, support structure,

expansion joints, access doors, sampling points, gas temperature and pressure

connections.

The Contractor shall supply internal insulation protected with a steel lining for the

ductwork extending from the turbine exhaust by-pass stack outlet flange to the

HRSG outlet (excluding duct to HRSG exhaust stack). The Contractor shall use

stainless steel lining for ductwork above temperatures of 2250C. The Contractor

shall provide 50 mm drain connections on the gas path low points.

The insulation shall be designed to limit external surface temperature of the HRSG

skin to 450C at 320C ambient temperature with zero wind conditions. Insulation

containing asbestos is prohibited.

Design and equipment provided for the HRSG shall comply with all relevant

sections of the specifications. The HRSG shall be complete with including (but not

limited to) the following:

Inlet transition ducting between the combustion gas turbine and HRSG inlet, including expansion joints and flanges

Steam drum, economizer, evaporator and super heater sections for each pressure level

Re-heater (if applicable)

Exhaust duct transition, expansion joint (if required) and carbon steel exhaust stack (with appurtenances and accessories including exhaust silencer, motorized damper etc.)

Platforms, stairs and ladders for access to the boiler valves, instruments, controls, and access ports

Boiler trim and accessories including but not limited to the following:

Boiler External Piping (BEP) and valves within the ASME Boiler and Pressure Vessel Code Section I jurisdiction boundary including super heater, evaporator and economizer interconnecting piping, steam and blow down sample connections and probes, and drain piping

Safety valves including drip pan elbows, discharge piping with supports, silencers and their supports, drain piping with supports

Drain, vent and instrument root valves

Feed water inlet piping with stop and check valves, including supports connecting to the steam drums

Boiler steam outlet stop (motorized) and non-return valves

Pneumatically operated high pressure, intermediate and low pressure continuous blow down control valves and motor operated



high pressure, intermediate and low pressure intermittent blow down valves

Other miscellaneous valves and fittings

Boiler accessories including pressure gages and temperature gages with fittings and piping and complete steam drum water columns with local gauge glasses and remotely located panel mount type water level indicators including valves, gaskets, high temperature wires, relays, and enclosures as necessary for a complete system

Steam, feed water, blow down and drains piping from boiler connections to approved interface points

Sampling piping from sample take off points till sampling system

Steam flow elements

Access doors

High pressure, reheat and intermediate pressure (if required) attemperators

Blow down systems complete with HP/IP/LP blow down tank complete with associated piping , valves and associated instrumentation

Continuous Water and Steam Sampling and Analysis systems complete with sample coolers, analyzers, instrumentation, associated piping and valves.

Intermittent manual emission monitoring system shall be provided as described at Sections 13.13.1 and 18.4 of this Specification.

The HRSG shall be controlled through the plant ICMS. The Contractor shall provide all the hardware, controls, wiring and the interface necessary for implementation.

Nitrogen blanketing system for long time preservation including nitrogen cylinders, pipe network and connection points.

Shop and site finish painting

Shop and site performance testing as per ASME test codes

Special maintenance tools

8.2 Casing and Refractory Materials

Refractory, tile and brick shall conform to ASTM C 64, high duty. Insulating firebrick shall conform to ASTM C 155, Group 23. Castable refractory shall conform to ASTM C 401. The refractory selection shall consider heat shock impact, corrosion resistance, and mechanical strength.

Alternate refractory designs will be considered provided they are of a proven commercial design guaranteed by the Bidder for the type of service. The Bidder shall supply a list of users with performance data from similar operating units.

The refractory shall be installed in the Contractor's shop before the steam generator components are shipped to site. The Contractor shall be responsible for using a refractory which will maintain integrity during shipment. The Contractor shall be responsible for sufficient shop curing before shipment.

8.3 Drums and Headers

The steam drums shall be designed for a minimum of three minutes storage capacity at maximum load conditions based on normal drum water level to low water level. The steam drums shall be designed as per ASME section 1.

The instrumentation and controls for the drum shall be as per standard industry practice and in line with specifications stipulated elsewhere.

8.4 Heat Transfer Tubes

The HRSG shall be designed, fabricated, and stamped in accordance with the ASME Boiler and Pressure Vessel Code, Section I (and Section VIII for the LP economizer) and all codes and standards required therein. Any additional country or local requirements for certification of the HRSG pressure vessel shall be met. All materials not covered by ASME codes shall



conform to the latest edition of the ASTM or any other international accepted standard (such as DIN, JIS, and BS). Other materials considered must be approved by the Employer.

All superheater tubes shall be seamless. Electric resistance welded (ERW) tubing is not acceptable for any HRSG pressure parts with exception of the evaporator, economizer and condensate preheater tubes.

Heat transfer sections with heat exchange surface modules and piping shall be pre-assembled in the factory to the maximum extent possible.

Heat transfer surfaces/ tube bundles shall be designed to promote uniform gas flow over the heat transfer surfaces, minimizing temperature differentials over the cross-section of the HRSG. Provision of flow straightening vanes, flow distribution grid or a combination of both to ensure even gas flow and temperature distribution is acceptable.

Superheater/ reheater tubes/ coils shall be provided with a minimum corrosion allowance of one gauge thickness for tubes or 3 mm thick for pipes. Tubes and fins shall be fabricated from materials suitable for the entire design and safety margin range of pressures and temperatures. Fins shall be continuously welded type. Seamless tubes/ coils shall be used. The tube bundle sections shall be completely drainable.

Evaporator tubes/ coils shall be provided with a minimum corrosion allowance of one gauge thickness for tubes or 3 mm thick for pipes. Provide full length evaporator tubes with no intermediate headers. Tubes and fins shall be fabricated from materials suitable for the entire design and safety margin range of pressures and temperatures. Fins shall be continuously welded type. The tube bundle sections shall be completely drainable. The circulation ratio shall be selected to ensure that dry-out does not occur during normal, steady operation in the evaporator risers.

Economisers shall be designed to avoid steaming at every operating condition. Design and fabricate the economizer sections to be fully drainable and provide connections for feed water bypass line. The tube bundle sections shall be completely drainable.

8.5 Blow down Equipment

Continuous/ intermittent blow down system completes with blow down valves, piping, and blow down tanks associated venting shall be provided for HP/IP/LP systems. The blow down water shall be led to the nearest plant drain system or recovered through waste water system to neutralize water PH.

8.6 Valves and Accessories

Control valves shall comply with control and instrumentation specification stipulated in Sections 13.0 and 14.0.

Fast opening steam vent valves shall be supplied. The Contractor shall ensure that valves can open fast enough to prevent lifting of safety valves when the steam turbine trips. The Contractor shall design and fabricate steam vent valve silencers to accept maximum steam temperature for up to 10 second duration multiple times.

Steam pressure relief valves, emergency relief valves shall be designed as per applicable codes and standards and shall comply with local regulatory requirements.

8.7 Exhaust Stack

The HRSG exhaust stack shall be a single wall, unlined and insulated, self-supported steel stack, complete with transition duct, expansion joints and the following features and accessories:

Access door

Wind spoilers or vibration dampers, as required by ASME STS-1 to prevent stack vibration and wind-induced resonance. Use the same material as for the stack wall

Lightning protection including two grounding lugs at stack base, 180° apart, and capable of connecting to 80 mm2 grounding cable

Stack test platform, davits and emission test ports as required



A red beacon lighting system with controller meeting the requirements of the local authority, including service platform

Noise silencers, as required, with factory installed support brackets and accessories

Stack damper to reduce heat loss from the HRSG during shutdowns. The damper shall be of either louvres or butterfly type, operated by a direct acting electric actuator mounted on the damper shaft. A complete system shall be supplied, including manual over-ride, access platform, limit switches, and actuator

The stack structure shall be designed to suit every operating condition (both internal and external) and appropriate combinations thereof including, but not limited to, internal gas flow effects, flue gas chemical composition, thermal variation and control, draft requirements, velocity requirements, static survival conditions, wind loads, seismic loads and dynamic survival conditions

The stack structure shall be designed with predetermined margins of safety with respect to critical shell buckling, material yield stresses, ovalling and fatigue stresses

A minimum shape factor of 0.7 with smooth cylindrical surfaces shall be used

The maximum allowable stack deflection, assuming 100% loss of corrosion allowance, shall not exceed 5 mm/m of stack height

Stack height to be calculated by the Bidder to be high enough to meet GoB DoE and WB 2008 requirements for the selected GT.

The exhaust stack exterior shall be covered with expanded metal for personnel protection to a height of 2.4 m above the base (or grade) and at the emissions sampling ports to a height of 2.4 m above the platform.

8.8 Water and Steam Sampling Analysis Systems

Water and steam analysis systems are required for each HRSG complete with sampling points at identified locations, piping, sampler coolers, analyzers, valves along with associated instrumentation and cabling to enable continuous monitoring of HRSG water chemistry. The system shall interface with plant ICMS systems.

8.9 Chemical Feed Systems

Appropriate chemical dosing systems to maintain the HRSG water chemistry to the GT, ST and HSRG manufacturers’ minimum specification shall be provided complete with dosing tanks, pumps, piping, valves, associated instrumentation and cabling. Dose pumps to be supplied in duty/standby configuration with automatic change over on detection of a fault. Where any treatment chemicals are liable to block in delivery lines, the lines shall be laid in duplicate to allow easy swapping of lines and subsequent flushing and cleaning.

8.10 Expansion joints

Exhaust duct expansion joints shall be non-metallic type, double baffle with ceramic fiber insulation pillow to handle 650°C continuously with gas tight seals. It shall be protected against ultra-violet radiation, ozone, and corrosion. The material and design shall be suitable to handle vibration from Gas turbine and HRSG. Adequate access for maintenance and repair shall be provided. Expansion joints design shall be capable of accommodating any combination of lateral, axial, torsional, or angular movement. They shall be designed to bolt on to equipment flanges.

8.11 Desuperheaters and Attemperators

Multiple nozzle spray-type desuperheaters with external spray water control valves shall be used for attemperation of high pressure steam. Probe type desuperheaters with internal stem and discs and integral actuators are not acceptable.

Inter-stage attemperation is required at high pressure, Intermediate pressure and reheater steam (if applicable) superheater headers. Terminal stage desuperheaters are not acceptable. They shall have necessary provisions to steam blowing without damaging the



attemperators. They shall be sized to provide sufficient flow during plant start-up, operation, and under transient conditions.

A desuperheater each shall be provided to control HP superheated steam, reheat steam and HP to LP bypass system steam temperature to the values shown on the HRSG data sheets. Desuperheaters shall be located for proper mixing. HP steam, reheat steam desuperheater spray water piping shall be provided including the following:

a) A control valve for each desuperheater nozzle. The control valve may be integral or separate from the desuperheater nozzle for HP steam and reheat steam desuperheaters.

b) A check valve and an isolation valve downstream of the check valve. The check valve and isolation valve shall be located between the nozzle and control valve when a separate control valve is provided.

c) A stop valve upstream of the separate control valve or check valve when the control valve is integral (required by ASME B31.1).

d) The Contractor shall provide all piping, valves and trim to take the desuperheating water from the demineralised water tank to the HRSG desuperheater.

e) Desuperheater water stop valves and control valves shall be operable without damage with the full pump shut off pressure upstream of the valve and no pressure downstream.

The control of the above desuperheater valves is to be carried out on the ICMS.

8.12 Drains

Manifold together small bore piping shall be supplied for drains and blow-offs where possible and terminated after the required valves at easily accessible locations.

Piping for the nitrogen blanketing system shall be terminated after the required valves at easily accessible locations. The Contractor shall ensure that valves are accessible from grade or from platforms. The locations of these terminal points will be approved by the Employer. The Contractor shall provide adequate support near these terminal points and make every effort to minimise the thermal movement at these locations. Piping at these terminal points shall be plain ended if not terminated at the valve outlets.

Double, one manual and one motor operated valve shall be provided all lines at or above 40 kg/cm2 pressure.



9. STEAM TURBINE AND AUXILIARIES

One steam turbine is to be provided to optimally generate power from all available steam from the HRSG. Steam pressures and temperatures are to be selected by the Contractor to meet the HRSG characteristics.

A tandem-compound, 3,000 rpm turbine Single Reheat Turbine shall be designed to operate with the cycle. The turbine shall be designed to withstand initial and HRSG reheat temperatures.

The steam turbine will be supplied with steam from a single steam generator (HRSG).

The blading shall be of the Contractor’s single flow or two flow exhaust design which has operated successfully in commercial services at 3,000 rpm.

The turbine shall be designed to be suitable for hot restarting, and will be provided with the100% steam bypass system for hot restarting, load throw-off and other upset conditions.

Noise emission control shall be provided in accordance with the latest codes and standards applicable for steam turbine units. It shall be the responsibility of the Contractor to demonstrate that emission of noise from the steam turbine unit is within the limits allowed by the applicable codes and standards and that the equipment has been designed and manufactured accordingly.


The steam turbine shall be equipped with all accessory equipment arranged for complete remote manual commissioning, auto/manual, synchronizing, loading, operation, and shutdown, from the control room, as required for a complete unit of the described size and type, including, but not limited to, the following:

Combination of stop and throttle valves, and removable steam strainers. Valves shall include coarse screens with removable fine screens for start-up

Piping and hangers between main stop-throttle valves and turbine high-pressure casing, piping, and hangers between reheat stop and intercept valves and low- or intermediate pressure casing, and turbine supported crossover piping between intermediate and low pressure casing (if required)

Reheat stop valves combined with intercept valves or with piping to intercept valves. Intercept valves shall include strainers and also hangers if not mounted on the turbine

Governing valves and hydraulic operating gear

Auxiliary electrical contacts mounted on the above valves for control interlocks and signaling, including governor no load position switch

Contractor's standard complete, micro-processor based digital electro hydraulic control system for the Unit, including:

Oil pumps, ac motor driven

Hydraulic fluid reservoir and filters (for electro hydraulic system)

Non-flammable hydraulic fluid (for electro-hydraulic system). The Contractor shall furnish 150% of normal initial filling quantity

Complete lubricating oil system for the Unit, including:

Main lube oil pump, shaft driven

Oil reservoir with filter

Two oil coolers each of full capacity with Admiralty tubes

Auxiliary oil pump, ac motor driven

Bearing emergency oil pump, dc motor driven

Two vapor extractor, ac motor driven (water ring vacuum pump with ejector)

Integral guard (supply piping inside of return) oil piping including oil cooler piping, hangers and transfer valves

Pressure switches for normal operation, and testing pumps



Wiring on oil tank from the accessories to a junction box located outside of tank

Local operating panel and gauge board.

Gland steam sealing equipment for all glands including piping and hangers between pressure regulator or controller, gland steam condenser, and turbine seals. Gland condenser shall be equipped with two full capacity ac motor-driven exhausters. Valves, piping, hangers, and insulation. From the turbine to regulator(s) and condenser including regulator feed valves regulator bypass and steam seal header bypass valve

Turning gear with ac motor drive, including controls and instruments for automatic or remote manual starting; motor amperes, and shaft speed indication

Speed governor, micro-processor based digital electro hydraulic type, with speed changer, including provisions for remote position indication

Load limit or steam flow limit

Initial steam pressure regulator for use when steam pressure falls below preset value and with provision for remote-manual cut-out for starting

Emergency over speed trip.

Three solenoids and redundant trip channels with "two out of three" logic for emergency trip

Low oil pressure trip device with "two out of three" logic and pre-trip alarm

Low vacuum trip device with pre-trip alarm

Dump valve, if required, to relieve inter-stage leakage to prevent reheater steam by passing the reheat stop and intercept valves and causing over speed. Means for testing valve operation at rated load shall be provided

Thrust bearing protective devices, including trip

Exhaust temperature limiting equipment, including contacts to actuate a high temperature alarm in control room

Pressure relief diaphragms on exhaust casings

Thermal insulation and metal housing

Turbine shaft grounding device and shaft voltage detector. This system shall include a method for monitoring the integrity of the voltage sensing brush when a two brush, 1 earth and 1 voltage, is employed

Gland steam and oil pressure gauges locally mounted at the turbine

Electronic pressure transmitters or pressure switches on the steam and lubrication system

HP/LP turbines bypass system.

Deaerator with a storage capacity of 10 minutes requirements of HRSG

2 x 110% capacity Boiler feed pumps at nominal operation

2 x 110% capacity Condensate Extraction pumps at nominal operation

Dual element thermocouples (or two independent thermocouples for each measured point) shall be furnished along with protection wells, as required, for measuring the temperatures of the turbine shells, valve chests, valve seats, exhaust casing, and thrust bearing plates, as required for controlled starting and operation supervision. Dual-element thermocouples shall be provided in all main bearing drains, thrust bearing drains, and oil inlet and outlet connections of oil coolers. All thermocouples shall be brought out to conveniently located reference junction boxes with lead wires identical to those used for the thermocouples. The Contractor shall ensure that compensating cable matching the thermocouple type, is installed between the thermocouple and the ICMS input where the cold junction compensating temperature is measured. Space and spare junctions shall be provided in the reference junction boxes to install reference junction temperature thermocouples, if required.

Each thermocouple shall be chromel/constantan for bearing metals, oil temperatures, and for turbine casing and valve metal temperatures.



Indicating thermometers shall be either dial or industrial type with separable socket. Abbreviated service designations shall be engraved on the dial. Dial-type thermometers shall be furnished at the exhaust hood at the front standard of the turbine for all main bearing drains, thrust bearing drains, oil inlet and outlet of coolers, and oil feed to bearing. Readings shall be in degrees Celsius. All pressure transmitters shall be electric type.

The Contractor shall provide all instruments and connections required to perform an American Society of Mechanical Engineers performance based on PTC 6, or approved equal. The Contractor shall provide all connections for steam pressure and temperature measurement at points on the turbine as required to guide a controlled start-up both manual' and automatic. The pressure connections shall include those for high pressure steam chest; reheat steam bowl, and the impulse chamber of "first stage pressure." This latter connection shall provide a pressure reading linearly proportional to turbine load. The temperature points shall be taken at those points in the turbine where it is critical to compare the steam and the metal temperatures during start-up.

For the temperature points, the Contractor shall furnish thermocouple wells made of material compatible with the metal through which they are installed. These wells shall be welded in place, and shall be furnished with dual-element chromel constantan thermocouples wired to a centralised reference junction box with lead wires identical to those of the thermocouples.

Insulation and aluminium lagging to include removable covers for stop and intercept valves, for flange joints and bolts. Insulation and aluminium lagging shall be provided for all surfaces and piping having a surface temperature of 50 0 C and higher.

The design shall permit inspection and change out of steam turbine bearings without dismantling the casing and, in addition, shall permit light beam vibrometer readings directly from the journals.

Turbine supervisory instruments, with sensors, transducers, amplifiers, solid-state logic, regulated electric power supply units, and indicating recorders with alarm contacts, as specified, shall be provided for turbine rotor vibration with alarm contact, rotor eccentricity with alarm contact; differential expansion with alarm contact, casing expansion, and metal temperatures. Rotor vibration shall be measured on the turbine shafts and not the bearing housings. Rotor vibration shall be measured utilizing at least two probes on each bearing. A micro-processor based signal processor and analyzer shall also be provided. Electronic output signals for alarms and trips shall be coordinated with the overall system design.

A sufficient number of independent contacts shall be furnished for alarm and trip functions, as well as for use as inputs to the ICMS, i.e., two contacts for pre-trip and three contacts for trip. The outputs from the sensors and transducers shall be suitable for feeding both the Contractor-furnished supervisory instruments and the ICMS. Electronic output signals are acceptable when coordinated with the overall system design.

The Contractor shall furnish curves showing the proper rate of metal temperature rise and the allowable metal temperature differentials to facilitate the setting of variable set point alarms automatic start-up and synchronization in the ICMS.

The Contractor shall be responsible for the wiring between the sending instruments and the ICMS thermocouple input module. The Contractor shall supply and install any special cable and connectors required for this purpose, and provide cold junction compensation.

The ICMS configuration and functions shall be capable of providing post-trip review, sequential trip monitoring, and efficiency calculations. Automatic start-up and synchronization and logging all pertinent turbine and generator operating data shall be provided. The Contractor shall provide a vectometer-type display in the ICMS that continuously plots the intersection of MW and MVAR magnitudes on the generator stability curve. The Contractor shall furnish and install all of the thermocouples, vibration probes, instrument contacts, electrical transmitters, or other equipment necessary for adapting the unit for complete surveillance of operating data with the ICMS.

Turbine bearing shaft lift pump(s), if required, shall be furnished by the Contractor complete with pressure switches and turbine zero-speed switch for interlocking with turning gear operation. The system shall be supplied complete with all piping and isolation valves.



Exhaust casing temperature alarm and trip contacts, thermometer and water spray system, including sensing elements and spray water control valves, shall be furnished by the Contractor. The water spray valve and its bypass valve shall be actuated by a solenoid pilot valve. The water spray valve and its bypass valve shall be air-diaphragm-operated control valves.

A speed switch or other suitable means shall be provided to prevent closing the field breaker before the machine has attained 90 percent speed.

A system to perform diagnostic checks and/or on-load testing of automatic and safety features, for example: oil pump cut-in. simulated over speed test, low vacuum alarm and trip, etc. Diagnostic checks/test shall be performed automatically and the results made be available to the operator.

The steam turbine shall be furnished with all necessary accessories including those for transmitting, indicating, and/or recording the intelligence for control and interlock as required to permit successful and safe unit operation including start-up, acceleration, synchronization, loading, unloading, and shutdown from the control room for start-up from a cold condition or for hot restarts.

The Contractor shall supply and install all instruments, control devices, and drives necessary for remote/ manual/auto starting under all conditions of the turbine and its auxiliaries.

The Contractor shall state in detail the equipment and special provisions he is including for adequate and proper remote starting and operation of the unit under all conditions.

All switches, lights, and interlocks for remote valve testing shall be mounted and wired on a subpanel for mounting on the steam turbine panel.

The turbine shall be equipped with a device which will limit the steam flow to the machine when the main steam pressure reaches a predetermined low point, and will continue to decrease the steam flow in proportion to further reductions in pressure. A simple means shall be provided for bypassing the initial pressure regulator when operating the turbine with low steam pressure during start-up. This device shall include remote control and indication.

9.2 Turbine, Stop, Intercept and Throttle Valves

The turbine shall be equipped with two stop valves or combination of stop and throttle valves, complete with insulated piping and hangers to the turbine. The valves shall be arranged to close automatically when the over speed governor trips or upon action of the various protective devices. Stop valve stems shall be back seated to eliminate steam leakage when the valves are in the wide open position. Stem bushings shall be arranged so that steam leakage may be piped to an open funnel drain.

Stop valve above seat drain nozzles and shutoff valves shall be 40 mm or larger.

All throttle, intercept valves, and reheat stop valves shall be equipped with limit switches in NEMA 4X enclosures on the valves. These switches are to be closed by the travel of the valves as the valves are closed. The switches shall be wired so that the main generator breaker is tripped when both throttle valves are closed, or a combination of any two intercept and reheat stop valves are closed

All turbine signal lights shall be for 110V DC nominal service.

Means shall be provided for remote manual testing of operation of each throttle valve, and for testing the control and protective system of the turbine during operation.

Throttle or stop valves shall be equipped with removable steam strainers for normal operation and extra-fine mesh temporary strainers for initial operation.

Throttle valves without controlled internal bypasses shall be interlocked to prevent opening and over- speeding the turbine when the steam admission (governing) valves are in the open position.

An internal bypass valve may be provided inside the main throttle valve disc and controlled by a motor-operated starting device for initial starting and loading up to approximately 20 percent of the turbine capability (if full arc admission is used). The Contractor shall furnish all required supervising instruments for this mode of starting and initial loading.



Intercept valves for location in the high-temperature reheat line, including piping, insulation, and hangers, if required between these valves and the turbine, shall be furnished by the Contractor.

These valves shall be equipped with auxiliary switches for control interlock and remote indication of valve position. Removable steam strainers with screens for normal operation and extra-fine mesh screens for initial operation shall also be provided.

The valve stems shall be back seated and the bushing on the stem of each intercept valve shall be arranged so that steam leakage passing the stems may be piped to an open funnel drain.

The hydraulic mechanism for each intercept valve shall be equipped with a test device to permit either remote manual or local operation to complete closing of one valve at a time while the unit is carrying approximately full load.

The Contractor shall furnish trip-type stop valves independent of the intercept valve operation for installation in the high temperature reheat line, one ahead of each intercept valve. The valves shall be arranged to close when the main steam stop or throttle valves trip.

Means shall be provided for sequentially testing full closure of these valves from the local panel and from the boiler-turbine panel when the machine is carrying approximately full load. Each valve shall be equipped with limit switches for control, interlock, and remote indication of valve position.

Remote manual test stations and signal lights for the reheat stop valves and intercept valves shall be mounted on the same subpanel.

Each of the hydraulically operated stop valves, reheat stop valves, and intercept valves with actuators integrated with the turbine control system shall be furnished with a valve travel limit switch assembly for indication of the valve position. Valve travel limit switch assembly contacts are to be used for remote indication of the valve positions, for alarm and interlock, as well as for use as input to the ICMS. All contacts shall be wired to terminal boxes.

9.2.1 Multiple Steam Control Valves:

The turbine shall be equipped with a suitable number of governor-operated steam

admission valves proportioned to permit economical operation and also to

eliminate dead spots and hunting throughout the governing range. When the

control valves and steam chest are outside the turbine casing, piping, hangers,

and insulation from the steam chest to the turbine shall be furnished. The design

and metallurgy of the valve disc, seats, stems, and stem bushing shall be such as

to eliminate seizing, resist wire drawing, and result in long life. The hydraulic

mechanism operating the valves shall be simple and rugged. This mechanism and

the valve chest shall be designed for easy accessibility for inspection and

maintenance of the valves.

9.3 Casing

The casing design shall be such as to permit inspection of all main bearings without dismantling the casing. The steam chest and all major parts of the HP/IP casings of the turbine shall be cast or forged carbon or alloy steel properly proportioned to avoid excessive thermal strains. The LP turbine casing shall be of welded steel construction.

Material tests and non-destructive testing of the steam turbine casings shall be carried out in the Contractor’s works to ensure that the castings are defect free.

Double-shell construction shall be furnished for all sections of the HP turbine.

All horizontal casing joints shall be made steam-tight with metal-to-metal contact and without grooves, gaskets, or joint compounds.

A rubber belt-type expansion joint between the turbine and condenser shall be furnished.

Diaphragms, blade rings, and packing shall be centreline supported.

The turbine exhaust shall be directly welded to condenser on spring supports.



9.4 Rotor, Blading, bearings and Couplings

The turbine shafts shall be of forged steel, heat treated, accurately machined to size, and proportioned so that critical speeds are remote from the operating speed. Vibration measured in any direction at the, journals of a shaft shall not exceed 5 hundredths of a millimeter, double amplitude or full wave, when operated under all loads at 3,000 rpm.

Adequate provisions shall be made to prevent turbine shaft current flowing between shaft and base through bearings and journals. This shall be in the form of one or more grounding devices between the stationary and rotating turbine parts. A shaft voltage indicator shall be furnished with provision built in the turbine shaft for testing possible current leakage.

All nozzles, blades, and buckets in the steam path shall be of hard corrosion- and erosion-resisting alloy steel suitable for the temperatures encountered. All blading shall be securely and adequately anchored, and rotor blading shall be readily renewable. Clearance shall be such as to avoid damage or rubbing under the operating conditions herein described.

Last stage(s) buckets of LP turbine subject to water erosion shall have erosion protection, shields, coatings, hardening process, etc. of the supplier’s proven design.

The blading shall be of a design which has operated successfully in commercial service at 3,000 rpm. It is important that the natural frequency of the turbine blades be such as to avoid resonant vibration at or near the normal operating speeds, including off frequency operations. The natural frequencies of the blades and blade groups shall have been determined by calculation and checked by rotation of a complete row of finished blades through a speed range sufficient to verify that resonance will not occur when the turbine is in service. Special attention should be given to the turbine last stage turbine blades.

The design of the steam turbine bearings should be such that bearings can be removed without dismantling the casing and, in addition, be provided with steel-backed liners to permit bearing change-out without dismantling of the casing. Bearing liners should be spherically seated and provided with backing pads to permit minor adjustments in alignment, without having to move bearing pedestal or bearing supports. Thrust bearings shall be of the Kingsbury or tapered-land type. Each bearing shall be provided with wells suitable for both a thermometer and a two element chromel-constantan thermocouple in the oil drain. Provisions are to be made in all steam turbine bearings so that light beam vibrometer readings can be taken directly from the journals.

A system including proximity type sensors shall be installed on the turbine to warn of excessive movement of the turbine shaft at the thrust bearing and to shut down the unit when the shaft has moved to a point indicating impending failure of the thrust bearing.

9.5 Gland Steam Sealing System

All glands shall be of steam sealed type, suitable for sealing under high vacuum. An automatic gland steam pressure regulator or controller with spill-over regulator suitable for pegging with steam from the main steam supply shall be furnished together with a gland steam condenser and air evacuator system consisting of two full-capacity ac motor- driven exhausters. All necessary equipment piping, strainers, valves, hangers, and insulation between the steam seal and spill-over regulator(s) and the turbine and between the gland steam condenser and the turbine shall be furnished.

The surface-type gland steam condenser shall be welded stainless steel, ASTM A 249 Type 304 tubed and designed for 22:8 kg/cm2 gage.

The gland steam condenser shell side design pressure shall not be less than 3.52 kg/cm2 gage.

9.6 Turbine Turning Gear

The turbine shall be equipped with a reversible AC motor-driven rotor turning gear to be used for slowly rotating the turbine shaft while the unit is being started or taken out of service. The turning gear drive shall be designed so as not to interfere with removal of the generator field when disassembling the unit. The turning gear shall rotate the steam turbine in the opposite direction to normal rotation when barring to eliminate the possibility of accidental clutch engagement and turning of the generator or GT whilst maintenance is being carried out on them.



The turning gear shall be located between the HP turbine and combined IP/LP turbine casings and be arranged so that the driving gears may be engaged either automatically by remote manual control from the turbine control room or manually by means of an external lever while the turbine is at rest. A pneumatic drive tool and air hose is to be provided for manually turning rotor.

When steam is admitted to the turbine and its speed is increased beyond that produced by the turning gear, the gear shall automatically disengage and latch in the disengaged position. Limit switches for control, interlock, and position indicating lights shall be furnished.

The turning gear shall be equipped with a zero-rotor speed indicator for showing the turbine rotor speed as the rotor approaches rest. The speed sensor shall transmit its signal to an indicator and alarm to be mounted in. the turbine control room and shall also initiate the automatic engagement of the rotor turning gear when the shaft has reached speed below turning. A protection shall be fitted to prevent steam admission while rotor is being turned in opposite to normal rotation direction.

The turning gear circuit shall be provided with a pressure-actuated switch to prevent the turning gear motor from starting before adequate bearing oil pressure has been established by the auxiliary oil pump.

A local panel for turning gear operation shall be furnished and shall have mounted one ammeter, two pushbutton stations each with "start" green and "stop" red indicating lights.

9.7 Turbine Lube Oil System

The system shall be complete with all reservoirs, pumps, coolers, purification facility, strainers, piping, vapour extractor, demister, locally mounted instruments, controls and other components for a complete and integrated system.

The lubricating oil system shall be capable of providing sufficient lubricant during start-up, shutdown, and during normal, transient and emergency operating conditions.

All lubricating oil lines shall be graded to provide drainage under gravity back to the lubricating oil tank. All lubricating oil lines under pressure shall be contained within guard tubes. Where there is the possibility of leakage from joints near to hot surfaces, the hot surfaces shall be protected with suitable shielding.

Suitable Points for condition monitoring and lubricating oil sampling shall be provided at each bearing drain.

The lubricating oil system shall be fitted with redundant lubricating oil filters and redundant lubricating oil coolers. The filters and coolers shall be arranged such that change-over between coolers or filters will occur without the flow being closed off to both simultaneously. It shall be possible to service the standby filter and cooler during operation.

It shall be possible to top up the lubricating oil system when the plant is operating at any load. The lubricating oil tank shall be equipped with oil vapour extractor, in order to maintain a pressure below atmosphere in the oil tank and oil drain pipes.

9.7.1 Lubricating Oil Pumps

One main and one auxiliary oil pump, each of 110% full capacity, shall be

provided. The main oil pump may be either shaft driven or AC motor driven, in

accordance with the manufacturer’s standard. The auxiliary pump shall be driven

by an AC electric motor and shall operate automatically upon the lubricating oil

system falling below normal operating pressure, and with a shaft driven pump if

turbine speed falls below the normal on-load operating range. The turbine

lubricating oil system shall have one reduced-capacity emergency oil pump driven

by a DC electric motor. The capacity of this DC pump shall be sufficient for the

turbine to run down to rest without bearing damage in the event of loss of AC

power.

A jacking oil system shall be provided to assist in starting and rotor mechanical

and manual barring and to prevent turbine blades shaking on barring. The jacking

oil system shall include two 100% jacking oil pumps, an AC driven jacking oil



pumps, each 110% capacity (One main pump and other standby). The jacking oil

pumps shall changeover automatically.

9.7.2 Lubricating Oil Coolers

Each lubricating oil cooler shall be designed for a minimum of 110% duty at the

maximum coolant temperatures, with fouling factors recommended by Tubular

Exchanger Manufacturers Association (TEMA). All piping and valves shall be

arranged so that a single cooler module can be taken out of service for

maintenance without affecting plant output. A thermostatically controlled valve

shall be provided to maintain oil temperature at the required operating value.

Temperature control valves and inlet and outlet changeover valves to coolers shall

be arranged so that they are not capable of shutting off the flow of oil to the

bearings whilst the turbine-generator is in operation and the coolers shall be

capable of changeover at full load without loss of functionality. Facilities shall be

provided for monitoring of oil temperature at the outlet of each cooler both locally

and remotely on the ICMS (indication and high temperature alarm).

The coolers shall be arranged so that access may be obtained to both ends of

every tube. Vent and drain connections fitted with valves and equipped with

padlocks shall be provided. Cooling water is to be supplied from the auxiliary

cooling water loop.

9.7.3 Oil Purifier

The purifier shall be a self-contained unit including filtration/separation equipment,

the necessary pumps and thermostatically controlled heating apparatus.

The oil purifier shall be of the centrifugal type, AC motor driven and shall have an

hourly capacity of not less than 12% of the total oil charge. It shall be permanently

connected in a closed loop to the main oil system in such a manner that it can be

used irrespective of whether the turbo-generator is running or shut down. The

design for the oil purifier shall incorporate safeguards to minimize oil leakage,

spillage, fire hazards and pressure build-up in isolated sections of the system.

9.7.4 Oil Pipe work

Cast iron pipes, valves or fittings, or any high pressure or compression type

couplings shall not be used in the oil system. No oil pipes shall be run adjacent to

steam pipes. To prevent the escape of oil on to hot parts, all governing and power

oil pipes shall be enclosed, the enclosure being adequately drained to the oil drain

reservoir. All other oil pipes shall be fitted with guards and drip trays at all joints

except welded joints. Oil guards and drip trays shall be drained to a common drain

tank.

9.7.5 Hydraulic Oil System

High Pressure hydraulic power for the turbine stop and control valves and the

protection system shall be supplied from separate electrically powered oil pumps

utilizing a fire resistant phosphate ester type fluid. The system shall include two

110% duty pumps, suitable fluid conditioners to remove suspended solids and

water from the fluid, heaters, and fluid sampling points at critical points in the

system. Stainless steel pipe work shall be provided from the fluid conditioners

onwards.

A system of pressure regulation, together with means of maintaining fluid pressure

during voltage disturbances and damping out system pressure surges e.g. from

pump changeovers shall be included. The system shall ensure continuous

operation of the governing system under all conditions of operation.



9.8 Steam Strainers

An annular steam strainer shall be stationary positioned therein for stopping the passage into the turbine of large metal particles in the steam, the improvement in the strainer which comprises:

Plurality of spaced through holes in a major portion of the strainer circumference, the through holes being of differing diameters, with holes of like diameter being positioned in longitudinally-extending, circumferential zones, holes of the largest diameter being disposed in zones where metal particles are least likely to enter the holes, holes of smaller diameter being disposed in zones where metal particles are most likely to enter the holes, and a longitudinally-extending, circumferential zone in the strainer without holes where the particle velocity and direction of movement would be damaging to any holes located in such a zone, the through holes each having an entrance end on the outer periphery of the strainer, an exit end on the inner periphery of the strainer, and an interior portion disposed between the entrance end and exit end, the exit end having a larger diameter than the interior portion to reversibly slow steam velocity and decrease steam pressure drop.

The interior portion of each hole being tapered for a portion of its length, with the taper terminating at the exit end.

Fine mesh screen positioned outwardly of and protects the zoned holes.

The holes shall have rounded entrance ends to minimize steam pressure drop and particle damage to the holes.

9.9 Exhaust Hood Sprays

The turbine shall be equipped with water sprays. The sprays shall limit the steam temperature of the exhaust under unusual conditions. Piping inside the turbine casing, the automatic controls, and actuating device shall be furnished by the Contractor. External piping shall also be furnished by the Contractor.

A temperature detecting device shall be located, in the exhaust of the turbine arranged for sounding an alarm in the turbine control room on high exhaust steam temperatures.

Pressure relief diaphragms shall be installed in the exhaust hood, designed to rupture and limit the internal exhaust hood pressure to within a safe margin with maximum steam flowing.

9.10 Governing System

A digital electro-hydraulic (DEH) governor shall be provided for turbine speed regulation during normal on-load operation and for control of turbine start up and shut down. The governing scheme shall comply with the requirements of IEC 60045 or equivalent and shall have self-diagnostic capability.

Governing shall be provided on all High Pressure/Low Pressure (HP/LP) governing valves to permit both turbine speed and load control when operating. In case of malfunction with the DEH, the steam turbine shall be capable of running in hydraulic mode.

9.10.1 Governor Speed and Reference Signals

The governor shall employ speed feedback signals derived from a shaft-mounted

system arranged to facilitate run-up speed control from barring as well as speed

control for synchronizing and load reduction on excessive speed. Redundant

speed inputs independent of the over speed protection system shall be provided.

9.10.2 Requirements for On-Load Governor Control

On load operation will normally be with valves wide open and turbine load is

controlled by HRSG pressure. The governor shall comply with the following

requirements for on-load duty:

For start-up and shut-down the governor shall be capable of loading and unloading the turbine based on generator load set point and feedback signals. The set point shall be adjusted based on turbine speed with a



nominal 4% droop setting. Under this condition steam pressure is controlled by the steam bypass systems.

Under normal operation the governor shall unload the turbine if turbine speed increases above a fixed set point.

Following a generator trip, the governor response shall be sufficiently rapid to prevent the unit tripping on over speed for any condition including a full load rejection.

The frequency dead band of the governor shall not exceed ±0.015 Hz under any control conditions.

9.11 Emergency Trips

A tripping system shall be provided to protect the turbine against dangerous operating conditions which may arise. The system shall be arranged to rapidly shutoff all possible steam supply to the turbine, independently of the action of the turbine governor. The equipment shall be fully compatible to the generator electrical protection equipment and circuit breaker tripping relays.

Operation of the tripping system shall result in:

Closure of all steam valves the closure of the stop valves being very rapid. The speed of operation shall be such as to ensure that, if the over speed trip operates at maximum load the maximum transient turbine speed shall not exceed the design over speed limit of the turbine or come within the range of any other critical shaft speed.

An initiating signal to the turbine bypass system controller.

Initiation of the appropriate alarms in the ICMS augmented plant control system.

The tripping system shall include protection for at least the following:

Turbine Over speed

Lubricating Oil Pressure

Lubricating Oil Level

Lubricating Oil Temperature

Bearing Vibration

Shaft Position

Shaft Eccentricity (Start Interlock)

Relative Expansion

Low Steam Temperature

Condenser Vacuum

Turbine Cylinder Exhaust Temperatures

Generator Cooling System Protection

Generator Protection

Under Frequency

Manual Trip (Local to Turbine and Remote)

Following a turbine trip the generator shall be tripped by reverse power.

9.11.1 Online Testing

All turbine safety devices shall be supplied with means for independently testing

when the turbine is at any load. If mechanical over speed bolts are used a

separate facility shall be provided to offload test the over speed protection by

raising the actual turbine shaft speed to the trip level. Interlocks shall be provided

to ensure that one channel always remains in service to provide actual protection;

it shall not be possible to test both channels simultaneously. All necessary control



initiating devices including a digital turbine speed display shall be provided via the

ICMS augmented plant control system.

For mechanical over speed trips provision shall be made for ready access for

adjustment and any special tools required shall be provided. It shall be possible to

easily adjust the setting of each emergency device to within +30 rpm without the

exercise of special skills.

9.11.2 Integrity and Reliability

The basic overall protection system shall have sufficient redundancy so that the

unit is protected under all conditions of operation to a Safety Integrity Level (SIL) 3.

The turbine supervisory and protection system shall be entirely independent of the

governor and other controls systems.

The plant shall be so designed as to enable the turbine to be started without need

to disable any protective function.

Removal of the condition that has initiated the operation of the tripping system

shall not automatically cause the trip gear to reset or the valves to re-open.

Provision shall be made for remote manual resetting from the ICMS augmented

plant control system. Until the trip gear has been reset it shall not be possible to

re-open any of the valves by any means.

9.12 Steam Turbine Bypass System

The Contractor shall provide and furnish the 100% turbine bypass system to provide for cold start-up, warm start, hot restart, load rejection, turbine shutdowns, and unit trips. The system shall be designed to provide pressure, temperature, and flow control of steam around and through the turbine by controlling each bypass valve, isolation valve, and associated desuperheater. The desuperheating function may be integral with the bypass valve.

The turbine-bypass system shall reduce start-up time under cold, warm, and hot conditions.

The turbine bypass system shall provide continuous flow through the superheater and the reheater. It shall also control superheater and reheater pressure during the entire start-up, keeping thermal transients in the HRSG to a minimum.

The turbine-bypass shall fast-act to allow cycle operation to continue at an optimal standby load while demand for turbine load is re-established after a load rejection. The turbine can cover house load requirements. Pressure and temperature transients invariably associated with GT and/or HRSG trip and restart shall be avoided.

Turbine-bypass system sizing considerations shall take into account all plant operating conditions such as the number of warm starts, hot starts and requirements for house load operation. Later in plant life, cyclic operation may become common. Sizing of low pressure turbine-bypass valves shall take into account the desired reheater pressure for turbine start as well as condenser capacity.

Turbine-bypass system shall meet the specific capacity requirements 50 percent of the maximum continuous rating (MCR) HRSG steam flow for the HP-bypass as well as for the LP-bypass and equipped with the necessary safe opening devices.

Bypass valves shall be able to perform these functions and achieve the desired pressures and temperatures without undue noise and vibration and without destructive valve-trim wear. In addition, bypass valves shall perform these functions under severe temperature cycling.

Turbine bypass systems shall also perform additional functions such as safe HP-bypass opening and LP-bypass closing for condenser protection during transient operating periods. It shall be designed to eliminate the stresses from thermal transients associated with cycling duty.

Isolation valves upstream of the LP-bypass valve for condenser protection shall combine the control function with a safe-closing function; unless the design requires a bypass system with separate control and isolation valves for reasons of a different plant safety philosophy.



The desuperheater shall complete evaporation of the injected water and shall be accomplished without any water droplets hitting the pressure boundary walls of the valve or downstream piping.

The Contractor shall ensure the factors affecting desuperheater performance which are the degree of atomization of the injected water and the mixing with the steam, and second, quick evaporation with proper location and direction of the spray water jet. Complete evaporation shall be attained before the first pipe bend to prevent any erosion caused by high-speed droplets contacting the pipe walls.

Spring-loaded nozzles are recommended for LP bypass applications, but can be used in all types of combined cycle power plant applications. The atomizing principle of spring loaded injection nozzles is based on high speed injection. Due to the design of the spring-loaded nozzles, a sufficient injection pressure and injection speed exists at minimum load. The injection speed results not only in good atomization but also in a sufficient penetration of the spray water into the steam flow.

Hydraulic actuators are well suited for applications requiring high force and high stroking speeds with complete system consisting of hydraulic cylinders, control devices, positioners and hydraulic power units. The hydraulic power units shall meet all safety requirements and consist of a fluid tank, pumps, filters, accumulators, and the necessary monitoring and controls.

The Contractor shall ensure the designed bypass controller smooth plant operation, especially during plant start-up, shut down, and load disturbances; and shall furnish turbine-bypass controller used with advanced control strategies to provide more precise control, thereby producing less thermal cycling stresses on valves and pipings.

9.13 Packing Leakage Dump Valve

A packing leakage dump valve shall be provided in the event the arrangement of the turbine steam packing requires it to prevent excessive reheated steam from bypassing the reheat and intercept valves through internal shaft packings. This valve shall open automatically when the turbine intercept valves are tripped closed and shall leak off the entrapped reheated steam directly to the condenser. Piping and hangers between the valve and the turbine packing shall be furnished by the Contractor and all other piping as required. Provision shall be made to permit measuring the steam pressure on the turbine side of this valve. Means shall also be provided for testing the operation of this valve with rated load on the turbine.

9.14 Low Vacuum Tripping Device

The turbine shall be provided with a low vacuum tripping device designed to shut down the turbine in the event of a serious rise in exhaust pressure based on "two out of three" logic. The device shall be arranged to avoid, in so far as possible, tripping during the start-up period. This device shall include remote control and indication.

9.15 Remote Trip

The turbine shall be equipped with a block trip unit consisting of three solenoid valves connected hydraulically in such a way that the turbine is tripped if at least two solenoid valves respond, so that the throttle and/or main stop valves, the reheat stop valves, and intercept valves may be tripped from a pushbutton station on the turbine control panel; or from anyone of two redundant sets of electrical protective devices when two of the three solenoid valves are actuated.

9.16 Microprocessor Based Digital Electro Hydraulic Control System

An electronically actuated high-pressure hydraulic system shall be offered for positioning the turbine stop and control valves.

The working fluid for this system shall be fire resistant and independent of the bearing lube oil and generator hydrogen seal oil systems.

Two full-capacity high-pressure AC motor-driven pumps shall be furnished for maintaining pressure in the control oil system. The second pump shall act as a spare. Control shall be such that the idle pump will start on drop of pressure.



The digital electro hydraulic control system shall be completely self-contained and shall include all necessary piping, filters, fluid storage tanks, and accumulators. All materials shall be completely compatible throughout the control system.

The microprocessor based digital electro hydraulic control system shall provide a full suite of operator interface capabilities including turbine auto start-up/operator guidance and turbine auto synchronization. It shall be a triple modulator redundant system.

9.17 Deaerator

Spray cum tray or spray only type deaerator shall be provided which shall reduce the oxygen content in the feed water to 0.003 ppm level. It shall be located over the feed storage tank having a storage capacity equal to 10 min. requirements of feed water at MCR conditions. .

9.18 Boiler Feed Pumps

Boiler feed pumps of 2 x 110% capacity at nominal operation shall be provided to suit the requirement of the boiler. Combined HP and IP Boiler Feed pumps may be provided with IP feed from an intermediate stage of BFP. Boiler feed pumps shall be provided with frequency controlled motor for meeting boiler water requirements at various loads with change in motor/BFP speed.



10. HEAT REJECTION SYSTEM

10.1 Condenser

10.1.1 Design

A surface type condenser set shall be provided for operation with steam turbo

generator.

The condenser shall be of the single- or two-pass design having water box and

hotwell.

As per the Contractor’s standard design, with divided water box arranged to allow

waterside cleaning of one half of the condenser with the steam turbine capable of

generating a minimum of 50% of its full load capacity.

The condenser shall be equipped with backwashing facility.

The source of condenser circulating water shall be from river basin only.

The plant in operation shall be able to meet the following specific performance

requirements.

(1) The condenser temperature at all loads shall be equal to the corresponding back pressure in the condenser at that load.

(2) The absolute pressure at turbine exhaust, as stated by the Contractor in 'TENDERER'S DATA SHEET" shall be obtainable with a condenser cleanliness factor of 0.8 with circulation water inlet temperature of 32.20 C and with heat duty as established for the turbo generator at guaranteed gross output in accordance with specified parameters as stated in "TENDERER'S DATA SHEET". The condenser shall be constructed in all details for a design gauge pressure corresponding to cooling water (CW) pump shut-off head in the water boxes and for a design gauge pressure of 0.5 bar to full vacuum in the steam space. The velocity of water in condenser tubes shall not exceed 1.8 m/sec.

The condenser shall be complete with all gauges, switches, and other necessary

fittings.

Supports shall be capable of taking resultant loads with flooded shells.

Cathodic protecting provided shall be of the impressed voltage type.

The condenser tube shall be material suitable for the specified river water. The

tubes shall be adequately stayed by supporting plates to prevent vibration and to

permit self-draining of the tubes, the contractor shall provide means to cater for

differential expansion between the tubes and the shell.

Water boxes shall be bolted to the tube sheet to permit removal of the water

boxed without disturbing the shell to tube sheet joints. Condenser inlet and outlet

valves shall be motorized butterfly valves.

The hot well outlet to the condensate pump suction shall be arranged to avoid

dead strange in the hot well.

Design of the water box shall ensure an even distribution of flow to all tubes.

The condenser shall be designed and provided with the following features:

Condenser tube leakage troughs

Man-ways to water boxes, hot well, and turbine exhaust hood (note: All man-way covers shall be marked and identified as “Confined Space Entries)

Air leakage meter



Hot well temperature indicator

Armored hot well level gauge glass

Hydraulic operated vacuum breaker valve.

Over-pressurization rupture disc

Split condenser water boxes with inlet and outlet entry doors adequately sized and located for routine maintenance. Inlet condenser tube sheet base designed to support ease of entry for routine cleaning (configured to help catch debris and not allow it to fall back into inlet piping).

Liquid ring vacuum pumps- 2x110% duty on capacity at nominal operation

10.1.2 Steam Bypass System

The condenser shall be designed and sized with an automatic steam bypass

system able to prevent a gas turbine and/or HRSG trip after loss of the steam

turbine. The turbine bypass dumps shall be designed with internal dispersion

tubes to adequately disperse the steam safely into the condenser for all possible

extreme transient scenarios. Adequate spare connections shall be provided. The

spare connections shall be positioned to prevent impingement on the tube

assemblies and located in an area easily accessible. The condenser shall be

designed to exceed HEI tube support requirements for bypass operation. The

system shall be fully automatic with no operator actions required.

10.1.3 Air Evacuation and Removal

Each condenser shell shall be provided with an air-removal section designed to

prevent any stagnant accumulation of air, non-condensable gases, and corrosive

vapours. Air off-take piping from each air-removal section shall be located at the

cold end of the cooling water circuit terminating outside the shell.

The condenser evacuation system shall consist of redundant with all accessories

liquid ring vacuum pumps with all accessories. The evacuation system shall

include two 110% capacity systems mounted on skids, including piping, valves,

controllers, and other accessories.

The system design shall allow operation of a single system to maintain vacuum

during the normal operating condition. The evacuation system shall provide the

capability to permit the turbine generator to accept full load within 30 minutes of

start-up. Provisions shall be incorporated in equipment design to prevent loss of

vacuum by backflow of air from atmospheric pressure through the equipment into

the condenser. Vacuum system suction and discharge piping shall be

continuously sloped and be free from non-drainable pocketed areas.

In addition to the shell evacuation system described above, the condenser water

box side shall have 2 x 110% liquid ring vacuum pumps to remove air from the

circulating water side of the condenser.

10.2 Condensate System

Two 110% vertical condensate pump sets shall be provided. The condensate pumps shall be designed and constructed in accordance with the requirements of the Hydraulic Institute (HI). The pumps shall be constructed of materials that are suitable for condensate at minimum and maximum temperature ranges.

The pumps should be sized at maximum steam turbine utilization. At a minimum, a 10% margin on capacity at nominal operation and 10% margin on total head shall be added for pump wear.

The condensate pumps shall be capable of pumping from the condenser hot well, through the condensate pre-heater (If provided in HRSG), gland steam condenser, HRSG LP



economisers, and any other equipment arrangements per the final cycle design. Motors shall be furnished and mounted by the driven equipment supplier on a common base plate.

The minimum flow shall be sufficient to meet the requirements of gland steam condenser.

The condensate system shall supply flow to the turbine exhaust hood spray, condensate pump seals, steam turbine bypass desuperheater, and gland steam desuperheater, along with online anlyzers.

A recirculation valve shall be provided to maintain minimum flow through the condensate pumps. The recirculation flow shall be routed to the condenser hot well. The hot well level shall be controlled automatically and excess condensate returned to the raw water tank. Demineralised water shall be supplied to the hot well when the level drops below a predetermined level.

Sampling connections shall be provided to monitor water chemistry into the condensate discharge to maintain water chemistry. The plant control system shall be designed to automatically start the standby pump when the operating pump fails. Automatic trips of the pumps shall occur if the condensate level drops below a minimum acceptable level in the condenser hot well.

As a minimum, PH, oxygen and conductivity shall be measured with this analysis system. Chemical dosing system shall be provided for dosing ammonia and other chemicals.

10.3 Circulating Water System

10.3.1 Main Cooling Water Pumps

Two 110% (minimum) capacity pumps shall be provided to circulate the main

cooling water to the condenser. Vertical centrifugal pumps shall be designed

based on maximum anticipated condenser demand (i.e., the greater of gas turbine

at maximum design flow producing maximum steam turbine output or with gas

turbine at base load and steam turbine in full bypass mode dumping all steam to

the condenser).

The circulating water pumps shall be capable of starting without lubricating water.

Strainers shall be provided for bearings and gland packing. Water for bearing and

seal lubrication shall be filtered to 2 micron quality or better. Flow sight indication

shall be provided (e.g. floating ball).

Pumps shall be of the heavy duty type suitable for continuous service under all

operating conditions and shall operate without undue strain or wear and without

damage to any part of the pumping unit. The suction branch shall be arranged

vertically downwards. The discharge piping and non-return valve shall be

arranged to facilitate withdrawing the complete shaft and pump casing as a unit by

splitting a pipe joint above floor level.

The selected pump casing and impellers shall be sized to allow for an increase or

decrease of at least 5% in head at design flow by a change of impeller.

Replaceable wear rings shall be installed on both the bowls and the impellers.

Impellers shall be statically and dynamically balanced. The impeller shall be keyed

to the shaft. Pinning and collets shall not be used.

Unless a double suction impeller pump design is offered, a vortex suppressor shall

be fitted to the suction. It shall be designed to reduce eddies and entrance loss,

thus reducing vibration, noise and wear.

The shaft shall have replaceable sleeves at the seals and bearings. Spacer type

couplings shall be provided to allow the vertical adjustment of impellers and

replacement of the seals without removal of the motor.

The Contractor shall be responsible for ensuring that the pump and motor operate

in dynamic balance as a unit without undue vibration or noise throughout the

range of operation. The Contractor shall verify that the critical speed of the



complete rotating unit (motor and pump) is at least 25% above the operating

speed. Two transducers shall be provided for each pump, 90° apart, for vibration

monitoring.

The circulating water pump basin shall meet the suction requirements of the

Hydraulic Institute standard. Alarms for high- and low-levels in the suction

chamber shall be provided in the main control room.

Length of the pump shall be established on the basis of the minimum specified

water level and continuous operation at flows ranging from minimum flow to

maximum flow in any pump configuration. Length of the pump shall also provide

sufficient submergence above the pump inlet to prevent vortex (OEM’s minimum

plus one meter).

10.3.2 Ancillary Systems and Equipment

The preferred material for the main cooling water system pipeline is filament

wound fiber glass pipe work (FRP) or GRP pipe. Pipeline design shall allow for

expansion of the pipe due to temperature changes in the cooling water.

Hydraulic operated main cooling water pump discharge valves shall be of the

slow-closing and opening type to minimize hydraulic transients. These shall be

designed to avoid damage from water hammer and reverse rotation of the pump

during start-up and shutdown, under the normal operating scenario, including a

unit trip.

Selection of the valves shall be based on the results of hydraulic study of the

cooling water system under various modes of operation. Hydraulic study report

and water balance shall be submitted to employer for approval.

10.3.3 Intake Screens

Circulating water pumps (2 x 110% capacity) used to pump water from the river

Megna for cooling the condenser from 2 x 110% capacity separate channel with

screening system and there should be a common chamber between two channels

after screening system. The screening system should be provided to remove

debris not more than 5 micron to clean the water so that it can pass through the

condenser. River water screening system including channel comprising to (not

limited to)

Rake operated bar screen with waste disposable system (Trash rack)

Travelling band screens (TBS) with spray water cleaning system and waste disposable system.

Emergency flap

Stop gate

Total automatic control system.

Screen aperture shall be optimized to minimize screen cleaning frequency while

avoiding blocking of condenser tubing.

The screens and associated cleaning equipment shall be manufactured from SS

316L.

A steel structure fitted with monorail and electric hoist shall be provided to enable

removal of the screens.

10.4 Auxiliary Cooling Water System

The closed cooling water system shall be designed for removing the maximum heat rejected from all the auxiliary equipment identified below and rejecting it via a heat exchanger to the river.



Plant auxiliaries requiring cooling water include, but are not limited to the following:

Gas turbine lube oil coolers

Steam turbine lube oil coolers

Generator coolers

Gas compressor oil coolers

Gas compressor motors

Gas coolers

Air compressor coolers.

Etc.

Two 110% capacity circulation pumps and two 110% cooling water heat exchangers, each isolatable for routine cleaning and plate type without plant curtailment shall be provided. An elevated water surge tank shall be provided for surge capability, system makeup, venting, and adequate net positive suction head (NPSH) for the auxiliary cooling water pumps.

The auxiliary cooling water heat exchangers and pumps shall be sized to supply adequate cooling water to the closed loop system. The system shall be designed to provide adequate cooling for the specified design ambient site conditions. The system design shall permit shutdown and maintenance of the individual items of equipment without interruption of the cooling function of the rest of the system.

Demineralized water shall be used for filling and topping up the auxiliary cooling water system. A corrosion inhibitor shall be added automatically as required.

The auxiliary cooling system shall transfer heat to the river water pumped through the heat exchangers.

Condenser cooling water pumps shall be sized to provide river water through the auxiliary cooling water system heat exchangers, (in addition to condenser water requirement) including all piping, valves, instruments, and accessories as necessary for a complete operating system. Equipment materials, strainers and the heat exchangers shall be suitable for the water quality expected in the system. Seasonal introduction of debris shall be considered in the design of the strainers upstream of the heat exchanges. The strainers shall be self-cleaning with automatic actuation on differential pressure.



11. MECHANICAL BALANCE OF PLANT

11.1 River Water System

11.1.1 General

River water from the Meghna River is to be used for cooling purposes as well as

for process purposes. An underwater intake is required supplying a pump station

of which the design will be supplying cooling water to the condenser and plate

heat exchanger of auxiliary cooling water system. Two 110% capacity cooling

water pumps shall supply the entire cooling water system. Two Separate raw

water pumps shall be provided to meet the requirement of drinking water plant,

potable water system and other systems if necessary.

11.1.2 Circulating Water Intake System

The Contractor shall design, constructed and install the raw river water intake

system to supply water for the cooling system, auxiliary cooling circuit as well as

cover other power plant needs such as service and GBC cooling water. River

water shall be taken in sufficient quantities to provide for all fresh water

consumption on the site. Water intake system shall have the facility for the

installation of following pumps:

Two CW pumps

Two raw water pumps to meet the plant requirements for the East Plants as well as make up to drinking water system, portable water system and Fire water Tank

The Contractor shall design and install an under river pipeline and intake structure

located sufficiently deep and far from the shoreline in the Meghna River to ensure

the intake is well covered with water all year round and taking water from the

coolest depths of the river. The river is navigable to ships and any structure

located on the river bed must not introduce a navigation hazard to passing ships

as well as posing a risk of damage to the intake structure itself due to impact by

ships. The structure must be capable of withstanding occasional flood and high

flow conditions without suffering erosion and damage.

Any permits and consents required by the regulatory authorities to construct the

intake system are to be arranged by the Contractor including payment of any fees.

The intake shall be fabricated from either precast or cast in-situ reinforced

concrete and be fitted with robust galvanized steel bars to prevent detritus

entering the pipeline. The pipeline to shore shall be buried below the river bottom

with a minimum cover of 1 metre between pipe and natural river bottom and be

fabricated from an appropriate material such as reinforced concrete or galvanized

steel pipe coated with GRP or PE encased in concrete.

The pipe bore shall be sufficiently large and the intake designed to have a

dynamic head loss not exceeding 1 metre water gauge when carrying maximum

design water flow rate when fouled with marine growth. Head loss to be measured

between the river static pressure and the intake pumps.


this EIA and the EHS General and Thermal Power Plant Guidance to minimize

fish entrainment including reduction of maximum through-screen design intake

velocity to 0.5 ft/s is mandatory.

EPC contractor will also provide sufficient number of required personal protective

equipments, life jackets and easy and safe man movement (man lifting through

chain/rope, cage system beside vertical ladder) system inside the intake point for



personnel working in deep water intake point for cleaning of water hyacinth and

trashes.

11.1.3 Common raw water suction chamber

A raw river suction chamber is to be designed and constructed by the Contractor

alongside the CW intake system. The suction chamber will receive river water

from the intake and pipeline, filter out suspended and floating debris and provide

location for the circulating water pumps for cooling system and raw water system

for the portable and drinking water treatment plant.

CW pump suction side depth shall be sufficient to provide the pump

manufacturer’s recommended minimum cover of the pumps (NPSHav) during the

driest recorded river level. Pump cover to allow for worst case dynamic head loss

in the intake system. Wet well volume shall be sufficiently large to not draw down

to the low level switch point on pump start-up before inflows are established to

maintain an operating level.

The CW pump station shall be constructed of reinforced concrete, either precast

or cast in-situ. It shall be divided into two sections connected by penstock valves,

or similar large bore valves, so one section at a time may be drained and cleaned

of detritus from time to time, while the other section provides water for normal

operations. A sump shall be provided so a submersible pump can be lowered into

the cell and it can be pumped dry.

Each section or cell shall be fitted with closely spaced vertical bar screens to

separate out floating and suspended material larger than 5 mm. The screens shall

be fitted with a powered raking system to remove and clean trapped material from

the screen bars. The rakes shall remove collected detritus to a collection bin.

Travelling band screens shall be provided after the bar screens so as to remove

particulate matter of size not acceptable for the CW and raw water pumps

Each section of the wet well shall be designed to house one circulating water

pump supplying the cooling water, one treated water raw water pump and a sump

pump to drain the wet well. Each pump shall be separated from the adjacent pump

by a partial height vertical wall to minimize hydraulic interference between the

pumps and formation of vortices. A thin stainless steel baffle plate standing

vertically upwards is to be located directly below the centre lines of each pump to

prevent the formation of a rope vortex between the pump inlet eye and the wet

well floor. The water intake and pump sumps shall be designed as per the

recommendations of HIS standard.

Personnel access is to be provided for cleaning and maintenance purposes. A

stairway from ground level to the bottom of the wet well shall be provided

generally meeting the requirements of Chapter 40 of NFPA 101 Life Safety Code.

Stairway may be cast concrete stairs with handrails cast into the wet well wall.

Fabricated steel stairs shall be hot dip galvanized as specified in Section 14.14.2

of this Specification.

The wet well need not be covered, however safety railings shall be provided

around the well’s periphery.

Pump intake shall be designed to comply with recommendations of Hydraulic

Institute Standards (HIS) and a model study carried out for the same to meet HIS

criteria.

11.1.4 Lifting equipment

The wet wells shall be provided with gantry cranes spanning the wells and be

capable of lifting any equipment in either well to the deck level of a truck on the

adjacent access road, and similarly lowering equipment to its operating location in



the well. The gantry crane shall be powered in both traverse and lifting. Both

modes shall have a slow speed inching capability.

Control of the gantry crane shall be through a radio operated portable handheld

control box.

11.1.5 Raw Water Pumps

11.1.5.1 Submersible Option

If the submersible pumps in the wet well option are selected; the following submersible pumps are to be located in the two raw water wet wells:

2 x 110% circulating water pumps

2 x 110% raw water pumps

Choice of pump manufacturer and pump sizing is to be made by the Contractor. The selected pump manufacturer shall be that of a reputable, well known manufacturer that has a servicing and maintenance facilities in Bangladesh.

Submersible pumps to be mounted on proprietary vertical track and rigid discharge pipe system provided by the manufacturer to positively locate each pump in its intended position and mate to the discharge pipe with minimal leakage. Check valves are to be provided adjacent to the pumps.

11.1.6 Pipe work

Pipe work for the cooling system shall be fiber glass. See Section 14.5 of this

Specification on the required standards for design, fabrication, erection and testing.

11.2 Raw Water Treatment System

Raw water from the Meghna River is to be used as feed for the drinking water treatment plant which shall produce clarified water for the potable water system around the proposed plant. The demineralized water for heat recovery steam generator (HRSG) should be taken from the DEMI plant of Ashuganj 225 MW CCPP.

Adequate supply source shall be available to support year round plant at full load operation. Refer to Section 4.3 for raw water makeup quality and chemical analysis.

Source water quality and temperature shall be within each application’s specified requirements. The water source system shall include but not be limited to pumps, piping, valves, and insulation.

.The clarified water shall be chlorinated to prevent biological growth and to a level to maintain sterility for drinking water purposes in the plant potable water system.

Adequate chemical storage shall be provided for at least 30 days of operation.

Augmentation system when required to augment the existing potable water system capacity.

11.3 Demineralised Water System

The makeup water treatment system provides boiler feed water and makeup closed cycle cooling water.

The terminal point for the demineralized water will be at the demineralized water tanks provided by the Ashuganj 225 MW Combined Cycle Power Plant. Bidder to include in his bid the makeup water pumps, service storage tanks and all other required equipment and piping. Demineralized water is to be stored in lined mild steel tank situated in a suitable place of the proposed power plant. Tank capacity shall be sufficient to meet plant requirements for a minimum of 12 hours operation at full load.



11.4 Potable/Drinking Water System

The Contractor shall construct a drinking water plant with a capacity of 100 m3/hr including all auxiliaries i.e. sediment basin, clarifier, ion exchange unit, overhead tank, pumps, valve, control system, dosing system etc. in all respect for supply potable/drinking water to all plants and residential areas.

The surface water of the Megna River is the source water for the drinking water system. The raw water shall be taken from the raw water system.

The height and capacity of the overhead tank shall be designed to meet the demand for all consumers at least 4 hours without running the system.

The Contractor shall meet the drinking water quality according to the DoE and WHO’s Guidelines for drinking water quality.

11.5 Waste Water Treatment System

The wastewater treatment and discharge shall be designed to process and treat all waste streams in accordance with approved discharge permit requirements meeting environmental requirements. Bangladesh discharge limits are given in Section 18.5.2 of this Specification.

Equipment drains and floor drains from the chemical feed and water treatment areas shall be collected in chemical waste sumps, which shall be provided with sump pumps. A pH monitor shall be provided in the sumps to monitor the sump water and alarm in the case of a chemical spill.

Boiler blow down shall be sent to a blow down tank, cooled by mixing with service water and collected in a common wastewater sump. Gas turbine evaporative cooler bleed water shall also be routed to the wastewater sump.

Wastewater containing hydrocarbons shall be collected separately and treated in an API oil/water separator system before the separated water is directed to the waste treatment plant.

The Contractor shall dispose of all wastes from initial chemical cleaning of the HRSG and piping. Disposal of these wastes shall be in accordance with applicable environmental regulations.

Sewage treatment facilities shall be provided on site to process all waste streams to an acceptable standard as set out in Bangladesh Environment Conservation Rules 1997 and the 2008 World Bank Guidelines. Adequately treated effluent may be discharged to the Meghna River.

Segregated collection systems shall be provided for oily and chemical wastewater. Neutralization and detoxification shall be provided for all chemicals containing wastewater streams (e.g., demineralizer regeneration, chemical storage, acid cleaning, gas turbine washing, and other wash water). The Contractor shall identify systems where wastewater produced will be stored temporarily on site and removed by truck periodically.

In addition, 100% redundancy shall be provided for all critical chemical treatment and wastewater processing pumps, motors and compressors. Adequate chemical storage for 30 days of operation shall be provided.

Adequate supply source shall be available to support year round plant at full load operation. Refer to Section 4.3 for raw water makeup quality and chemical analysis.

Source water quality and temperature shall be within each application’s specified requirements. The makeup water treatment shall be fully automated, instrumented and be provided with redundant pre filtering system. The water source system shall include but not be limited to pumps, piping, valves, and insulation. Existing clarifier shall be used for first stage water purification process.

Adequate chemical storage shall be provided for 30 days of operation.

Septic systems should only be used for treatment of sanitary sewage, and are unsuitable for process wastewater treatment.



11.6 Compressed Air System

Two discrete compressed air systems shall be provided: one for plant air and the other for instrument air.

11.6.1 Plant Compressed Air

The Contractor shall supply and reticulate a compressed air system to supply all

plant items requiring compressed air, excluding instrumentation, which is covered

by the instrument air supply system. Operating pressure shall be 7 barg ± 1 barg.

A minimum of 2x110% capacity compressors shall be supplied and located in a

compressor building. Installed compressed air plant capacity shall be not less than

the calculated maximum plant demand. Connect point may be provided for a

mobile compressor if required.

Compressors shall be either lubricated screw or reciprocating types with

intercoolers if multistage. They shall be manufactured by a reputable compressor

manufacturer with service and spares supply available in Bangladesh.

Compressors shall be water cooled from the auxiliary water cooling circuit.

Dual air receivers shall be provided, equipped with all necessary safety valves and

drains shall operate in parallel with the ability to isolate and de-pressurise one

receiver at a time for maintenance.

All air lines to slope down to manual drain valves. Air lines installation to meet the

requirements of the local pressure pipeline codes or ASME B31.3.

The compressor control system shall interface with the plant ICMS for remote

start/stop.

11.6.2 Instrument Compressed Air

The Contractor shall supply and reticulate an instrument grade compressed air

system to supply all instrumentation requirements and the instrument repair

workshop. Operating pressure shall be 7 barg ± 1 barg.

A minimum of 2x110% capacity compressors including intermittent air demand

shall be supplied and located in a compressor building. Installed compressed air

plant capacity shall be not less than the calculated maximum plant demand, plus

10%. Connect point is to be provided for a mobile compressor if required.

Compressors shall be oil free units, either reciprocating or screw type with

intercoolers if multistage. They shall be manufactured by a reputable compressor

manufacturer. Compressors shall be water cooled from the auxiliary water cooling

circuit.

Compressed instrument air is to be to ANSI/ISA 7.0.01 standard with dew point at

least 100C below the lowest recorded ambient dew point or not above 20C, unless

more rigid standards are demanded by end use equipment manufacturers.

Particulates shall be limited to <0.02 mg/m3 with 100% <0.01 µm/m3 and oil

vapours to 0.01 µm/ m3.

The Contractor shall install a pair of 100% air dryers rated to match the

compressor output and shall in a duty/standby configuration.

The Contractor shall install dual air receivers equipped with all necessary safety

valves and automatic drains. They shall operate in parallel with the ability to

isolate and de-pressurise one receiver at a time for maintenance. Adequate

instrument compressed air storage shall be provided to facilitate emergency

shutdown of the plant. The instrument air receiver and piping shall provide a

minimum of 3 minutes of compressed instrument air (pressure above minimum



instrument requirement) for plant shutdown without instrument air compressor in

operation.

The Contractor shall install duplex 10 µm coalescing filters to the discharge side of

the dryers.

All air lines to slope down to manual drain valves. Air lines installation to meet the

requirements of the local pressure pipeline codes or ASME B31.3.

The compressor control system shall interface with the plant ICMS for remote

start/stop.

11.7 Fire Detection and Protection System

This section covers the requirements for the power plant design, manufacturing, testing, supply, and delivery of a complete stand-alone fire protection and fire detection alarm and notification systems, and related subsystems, sprinkler systems, fixed water spray systems, fire protection water supply systems, clean agent extinguishing system, standpipe and hose station connections, and handheld portable Fire extinguisher, hereinafter referred to collectively as the fire protection system.

Compliance with this Specification does not relieve the Contractor of the responsibility of designing, fabricating, and furnishing a system in accordance with National Fire Protection Association (NFPA) requirements and recommendations, applicable to local Building and Fire Codes, and the local authorities having jurisdiction.

The fire protection systems and related subsystems are intended as a life safety system and equipment protection, and shall be designed and supplied consistent with that objective.

The fire protection systems specified herein is intended for installation by the Contractor familiar with the design, manufacture, installation, testing and proper application of such systems.

It is not the intent to specify all details of design and construction. The Contractor shall ensure that the equipment has been designed, fabricated, erected and tested in accordance with all building and fire codes, standards, recommendations and governmental regulations applicable to the specified services.

The fire protection system specified herein is intended to be operated by the power station operating staff. As such, it is required that the systems be designed and supplied so as to be "user-friendly" to the extent that the Power Plant employees can reasonably be expected to operate them effectively under emergency conditions.

It shall be the Contractor’s responsibility to interface and receive approval from the authorities having jurisdiction for the proposed fire protection system.

All design drawings and calculations shall be signed and sealed, as required by applicable regulations. The Contractor shall provide submittal packages for transmittal to the Local Authorities having jurisdiction for review, comments and approval of the various fire protection designs, equipment and installations.

11.7.1 Fire Protection Master Plan and Design Basis

The Contractor shall be responsible for preparing a Fire Protection Master Plan

and Design Basis. This shall consist of as a minimum the following documents:

Building and Fire Codes, and Life Safety Compliance Review Report

Fire Risk Evaluation Report

Hazardous Area Classification Evaluation

Building and Fire Codes, and Life Safety Compliance Review - The report shall identify and address for each building, pre-engineered and/or pre-fabricated building, equipment enclosure and/or structure, and outdoor process, equipment and storage areas at a minimum the following:

Applicable building and fire codes, standards, recommendations and amendments



Building classification, occupancy and permitted construction types

Building height and area limitations

Fire resistance requirements for floors, exterior and interior walls and structural supports

Egress and exiting requirements

Detailed exit analysis and calculations. Prepare exit analysis drawings documenting occupant loads, required exit widths, occupant load distribution and travel distances

Combustible and flammable gases and liquids process equipment and storage fire protection, quantity limitations, and storage requirements

Accessibility requirements

Fire Department access and firefighting facilities

Occupancy and area separation requirements

Fire alarm and detection systems

Sprinkler/Standpipe and fire hose station requirements (duration, flows, pressures and densities)

Fire protection water supply requirements

Emergency power and lighting requirements

Smoke control and ventilation requirements

Elevator Requirements, if applicable.

The Building and Fire Codes, and Life Safety Compliance Review shall be

performed by a firm experienced in the preparation of fire protection master plans,

building code reviews and reports and exit/egress analysis calculations and

diagrams.

Fire Risk Evaluation - A NFPA 850 fire risk evaluation shall be initiated as early

in the design process as practical to ensure that the fire prevention and fire

protection recommendations as described in this document have been evaluated

in view of the plant-specific considerations regarding design, layout, and

anticipated operating requirements. The evaluation should result in a list of

recommended fire prevention features to be provided based on acceptable means

for separation or control of common and special hazards, the control or elimination

of ignition sources, and the suppression of fires. The fire risk evaluation should be

approved by the Employer prior to final drawings and installation.

Hazardous Area Classification Evaluation - The basis for classification

evaluation shall be NFPA 70 (National Electrical Code [NEC]), NFPA 497, API 500,

bidder information and other standards, as applicable.

Reports on these three evaluations shall be submitted to the Employer for review,

comment and approval.

11.7.2 Codes and Standards

The fire protection systems shall be designed in accordance with the specified

codes, standards and recommendations, all applicable statutory requirements and

amendments, and this EPC (Turnkey) Specification.

The specified codes, standards and recommendations shall include:

Local Adopted Codes, Standards and Amendments



UBC, the local building and fire codes, standards, recommendations and amendments to be used shall be determined during the Contractor’s review of Building and Fire Codes, and Life Safety Compliance Review

Factory Mutual (FM)

Underwriter’s Laboratory (UL)

National Fire Protection Association (NFPA) Codes, Standards and Recommendations, including but not limited to:

NFPA 10, Standard for Portable Fire Extinguishers

NFPA 12, Standard on Carbon Dioxide Extinguishing Systems

NFPA 13, Standard for the Installation of Sprinkler Systems

NFPA 14, Standard for the Installation of Standpipe, Private Hydrants, and Hose Systems

NFPA 15, Standard for Water Spray Fixed Systems for Fire Protection

NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection

NFPA 22, Standard for Water Tanks for Private Fire Protection

NFPA 24, Standard for the Installation of Private Fire Service Mains and Their Appurtenances

NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems

NFPA 37, Standard for the Installation and Use of Stationary Combustion Engines and Gas Turbines

NFPA 50A, Standard for Gaseous Hydrogen Systems at Consumer Sites

NFPA 54, National Fuel Gas Code

NFPA 70, National Electrical Code

NFPA 72, National Fire Alarm Code

NFPA 101, Life Safety Code

NFPA 204, Standard for Smoke and Heat Venting

NFPA 221, Standard for Fire Walls and Fire Barrier Walls

NFPA 291, Recommended Practice for Fire Flow Testing and Marking of Hydrants

NFPA 497, Recommended Practice for the Classification of Flammable Liquids, Gases, or vapours and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas

NFPA 780, Standard for the Installation of Lightning Protection Systems

NFPA 850, Recommended Practices for Fire Protection for Electric Generating Plants and High Voltage Direct Current Converter Stations.

The fire protection systems shall include all equipment required to form complete

and operable systems as defined by NFPA codes. Any apparent conflicts between

the applicable codes and this Specification shall be brought to the attention of the

Employer for clarification.



The Contractor shall consider all ambient weather conditions in the design of the

fire protection system.

11.7.3 Fire Protection Water Supply and Water Storage

The required fire protection water supply (fire flow and duration) shall be designed

in accordance with the applicable NFPA codes and standards. The water supply

for fire protection shall be provided directly from the intake channel after screening

system. Fire water storage tank which shall be sized as per NFPA requirements.

Supply to Fire water Tank shall be from the raw water pumps installed at river

intake

11.7.4 Fire Pumps

The site shall be provided with two Factory Mutual Approved fire pumps both

located within a fire pump house enclosure. The fire pumps shall be sized to meet

the applicable code requirements and the largest postulated fire(s) per the Risk

Evaluation.

The types of fire pumps that shall be provided are as follows:

One 110% electric motor-driven centrifugal fire pump

One 100% diesel engine-driven centrifugal fire pump.

Two pressure maintenance pumps (jockey pump) shall be provided to maintain

pressure in the underground fire protection reticulation system and also will be

located in the fire pump house. The diesel engine driven fire pump shall be

installed with a residential low noise type muffler.

The pumps shall be suitable for both continuous and intermittent service and shall

operate satisfactorily without vibration, cavitation or distress of any part through an

operating range from the required minimum flow to 150% of the rated capacity.

The pumps shall be capable of providing 150% of design capacity at not less than

65% of total rated head. The shutoff head shall not exceed 120% of rated head for

horizontal split case pumps, nor 140% for end suction type pumps. The pump

head-capacity curve shall have a steady rise from 150% to zero flow.

Motors shall be furnished with complete across-the-line starter controllers and

control panels, designed and constructed in accordance with NFPA 20 and shall

be UL-listed or FM-approved. All medium-voltage motors shall be powered directly

from the station switchgear.

The engine drive shall be of the diesel type and shall be in accordance with NFPA

Nº 20, NFPA Nº 37, UL or FM approval and shall conform to the "Standard

Practices for Low and Medium Speed Stationary Diesel and Gas Engines" of the

Diesel Engine Manufacturer's Association (DEMA).

The fire pumps shall be designed and installed such that either fire pump can be

taken out of service without effecting the use and operability of the other fire pump

and the pressure maintenance pump.

The design, installation, and testing of the fire pumps and drives shall be in

compliance with the requirements of NFPA 20, 70 and 72.

11.7.5 Fire Detection Systems

The Contractor shall design and furnish a fire detection, control and alarm system

for all fire risk areas. The system shall consist of a central control panel located in

the main control room, local and/or zonal control panels, address-coded detectors,

interconnects, address modules and peripheral components.



The automatic fire detecting system shall be designed on the principle of

microprocessor functional control.

The fire detection system shall be provided with two power sources, one AC and

one DC. The system shall automatically change over to the DC power supply in

case of AC power failure. The design, manufacture, and testing of the fire

detection and alarm system shall conform to NFPA standards.

The type of fire detector(s) employed in all areas shall be in accordance with

NFPA codes and expected environment.

11.7.6 Fire Protection and Detection Systems

The following fire protection and detection shall be provided as a minimum:

Table 16: Fire Protection and Detection Systems

Equipment, Area, and/or Building

Fire Protection Suppression System

Buildings

Control Building

Class II hose stations located throughout the entire building, except in the Control Room, battery rooms and electrical rooms.

Manual pull stations located at each exterior exit door

Control Room

Clean agent fire extinguishing system using BOC FS125 gas system or approved equivalent

Smoke detectors at the ceiling level and beneath all raised floors

Maintenance Shop (includes Tools /Storage Room and beneath all Mezzanine)

Automatic Wet Pipe Sprinkler System

Spot type smoke detectors, including beneath raised floors.

Warehouse (includes Storage Room and above Interior Roof)



General Office Areas, Corridors, File and Copy Room(s), Conference Room, Janitor and Storage Room and Lunch Room



Telephone and Communication Rooms

Clean agent fire extinguishing system using BOC FS125 gas system or approved equivalent


Operator Equipment and Storage Rooms



Electrical Equipment Clean agent fire extinguishing system using

Spot type smoke





Rooms BOC FS125 gas system or approved equivalent

detectors.

Battery Rooms Pre-action sprinkler System – Electric Release

Smoke detectors at the ceiling. Note: If the room is classified per the Fire Protection Master Plan and Design Basis, explosion proof smoke detectors are required.

Electronics Rooms Clean agent fire extinguishing system using BOC FS125 gas system or approved equivalent


Gas Processing and Control Equipment

Automatic Water Spray (Deluge) System. Dry Pilot Sprinklers (Head) looped around each Unit if not fully enclosed. Total flood gas is fully enclosed

Gas Detectors, Infra-red detectors

Gas Turbine Generator

Total flood gas (by generator

manufacturer)

Contractor to provide network system. Main panel to annunciate all alarm, troubles and supervised conditions.

Each Gas Turbine Fuel Gas Conditioning Skid

Total flood gas (by generator manufacturer)

Spot type heat detectors.

Each Gas Turbine: CEMS Enclosure


Spot type photoelectric smoke detectors.

Each Gas Turbine: Packaged Electronic Control Centre


Spot type photoelectric smoke detectors.

GTG General building areas

As required by applicable codes and standards.


Transformers

Each Main Transformer

Automatic Water Spray (Deluge) System. Dry Pilot Sprinklers (Head) looped around each Unit, maximum of 3.3 m on centre, and in accordance with NFPA 72.





Each Start-up, Reserve, and Aux

Transformer

Automatic Water Spray (Deluge) System. Dry Pilot Sprinklers (Head) looped around each Unit, maximum of 3.3 m on centre, and in accordance with NFPA 72.

Steam Turbine

Steam Turbine (ST):

Pedestals, turbine under floor and mezzanines, including STG skirt (lagging)

Automatic dry pipe sprinkler system

Steam Turbine:

Lube oil reservoir, conditioner, piping and

hydrogen seal oil unit

Dry Pilot Sprinklers (Head) looped around the Unit, maximum of 3.3 m on centres, and in accordance with NFPA 72.

Steam Turbine Bearings: STG Bearings

Automatic and manual pre-action sprinkler system (spray) with electronic heat detection for alarm only.

Spot type heat detectors.

Steam Turbine:

Electrical Enclosures

Spot type smoke detectors.

ST Building As required by applicable codes and standards.


Chemical Feed Equipment Enclosure

Automatic wet pipe sprinkler system. Class II hose station located nearby.

Manual pull stations at each exit door. Spot type smoke detectors.


Fire Protection Suppression System Type

Detection or Actuation Devices

Demineralized water pump enclosure

Automatic wet pipe sprinkler system. Class II hose station located nearby.

Manual pull stations at each exit door. Spot type smoke detectors.

Warehouse and Storage Buildings

Automatic wet pipe sprinkler system. Class II hose station located throughout the entire building.

Manual pull stations at each exit door.

Cable galleries Medium velocity water spray system

Linear heat detectors



The specified required fire protection and fire detection outlined in the table above

defines minimum requirements only. The table may not include all requirements

necessary to satisfy the applicable local statutes, as required by the Local

Statutory Authorities, or the Specifications. The Contractor shall be responsible for

providing all additional fire protection and fire detection as determined by the Fire

Protection Master Plan and Design Basis reviews and analyses.

11.7.7 Fire Protection Alarms and Controls

Fire protection alarm and control system shall be provided with audible and visible

alarm signals on the centralized and local panels.

Activation of the automatic fire detectors or manual push buttons shall

automatically cause actuation of a common alarm bell and beacon in the protected

area and an alarm bell on the local panel, and shall automatically activate the

deluge valve.

The central control panel shall be installed in the control room. The panel shall be

designed to serve the needs of the units. The panel shall consist of a visual

display unit and a printer. All local panel fire and trouble alarms shall also be

indicated on this main panel. A separate local control panel shall be furnished for

each system, except that controls for multiple systems located in the same area

may be combined into a single local panel, subject to acceptance by Employers.

11.7.8 Hydrant System

A yard hydrant system consisting of underground ring headers and strategically

placed hydrant connections shall be provided to suit the site layout, in accordance

with NFPA 14 and 24. Two-way hydrants with hose cabinets shall be installed

along the yard loop. When selecting hydrant locations, the Contractor shall ensure

that hydrants will not be obstructed or become inaccessible under fire conditions

and hose lengths shall be kept as short as possible. The Contractor’s equipment

shall mate with couplings typically found on local hoses.

Valves shall be provided to allow isolation of a standpipe without interrupting the

supply to other standpipes from the same source of supply.

11.7.9 Portable Extinguishers

Portable and mobile (wheel-mounted) chemical (ABC dry powder, foam, soda acid,

and carbon dioxide) fire extinguishers shall be provided at suitable locations

marked with color and operation instruction stickers with wheeled box systems

(bottom side of box will be mesh system to release water/ rain water) to carry

easily throughout the plant area to be used during early stages of a fire to prevent

it spreading. The portable extinguishers shall be rechargeable locally. Fire blanket

is also mandatory in specific locations.

11.8 Cranes and Lifting Equipment

Maintenance of the gas turbine, steam turbine, HRSG and generators will be performed using a minimum of one mobile construction cranes supplied by platforms with suitable access. One shall be able to reach the highest and least accessible parts of the plant and be able to handle any load from those parts.

The steam turbine-generator located in the steam turbine building will be serviced by a full width overhead crane sized to lift the heaviest part of the steam turbine-generator power generating equipment during installation and plant maintenance. Other monorails trolley beams shall be provided as necessary to assist installation and maintenance.

Pendant operated overhead travelling cranes shall be provided in the following areas:

River water pump house

Waste water treatment building (if necessary)



Raw water and fire water pump house

The capacity of the cranes shall be sufficient for the heaviest expected maintenance lift in these areas.

During the design phase of the project and before any site construction, the Contractor shall provide complete lift plans for all scheduled inspections and outages both major and minor of the turbines and generators. This will include descriptions of the use and sizing of fixed and mobile cranes. The Contractor shall also provide models or drawings to demonstrate the ability to avoid all fixed interferences while completing all required movements and lifts and the ability of the specified overhead cranes to be driven to the required locations using only the road surfaces and maintenance pads designed for maintenance crane loadings.

All equipment in the plant shall be provided with a convenient arrangement for slinging or handling during overhaul.

A catwalk shall be provided on the pipe bridge to enable personnel movement between the steam turbine deck to all HRSG platforms and the drums. The Contractor will be provided on (but not limited to) for the following:

Gas turbine inlet filters

HRSG

Continuous Emissions Monitoring platform at the stack.

Fixed cranes and hoists will be designed, manufactured, erected, and tested in accordance with the specified standards and codes. All crane structures and associated lifting tackle will be tested at lifting loads 25% in excess of the rating of the crane. Lifting cables will have enough length to lift loads the entire height without intermediate stops to adjust lifting tackle. Cranes and lifting tackle over 5 tons lifting capacity will be electrically operated and controlled from floor level.

Each item of lifting equipment will comply with the minimum requirements of the applicable standards and codes with regard to:

Identification markings

Tests and inspection

Quality/grade of material

Dimensions.

Brakes of an approved type will be fitted to the lift and hoist and to the hoisting, traversing, and dwelling motions of each crane. The brakes will be designed to operate automatically on interruption of the electrical supply to the motors and to arrest and hold, at any position, the greatest load carried by the motor. Brake design will minimise shock loading during application of the brakes. Crane hoists will be equipped with an independent manually operated brake, capable of holding the maximum load lifting capability of the hoist.

A separately mounted “stop” push button (“E-Stop”) will be provided in such a position as to be readily available for use by the operator. The emergency stop push button will trip the main contactor.

Electrically operated hoists will be fitted with automatic self-sustaining brakes. Electrical motors will be rated for at least 40 starts per hour.

11.9 Heating Ventilation and Air Conditioning

HVAC shall be provided for all buildings. The HVAC System shall heat, ventilate and/or air conditioned plant buildings and enclosures for personnel comfort and protection of environmentally sensitive equipment. The HVAC system design shall generally comply with ASHRAE Handbooks and Standards.

Electric heaters in air-conditioned areas and ventilated areas shall provide any necessary space heating.

HVAC systems shall maintain the environmental conditions in terms of space temperature and humidity, air quality, and building pressurisation in order to provide efficient equipment operation and comfortable working conditions for personnel.



The following discussion applies to buildings, rooms, areas, and enclosures.

Due to the high ambient outdoor temperature conditions, maintenance of indoor environmental conditions shall be accomplished with air conditioning system where ventilation systems are normally used. Areas such as electrical switchgear rooms and battery rooms shall be maintained at temperatures above those typical for air conditioned environments, yet below temperatures equal to or in excess of the outdoor ambient design temperature. Pre-filter and final filters shall be used for all areas that are either air-conditioned or ventilated. Pre-filter efficiency shall be 30% and final filter efficiency shall be 80% based on ASHRAE 52.1-1992 or approved equivalent international standard.

Explosion-resistant construction shall be used in all battery rooms where hydrogen may be developed or released.

The fresh air intakes for the control room shall be elevated and separated by at least 1.5 m vertically and 4 m horizontally. Also, fresh air intakes shall not be located on the same wall as any ventilation discharge from the battery rooms.

All ductwork shall be galvanised steel. The duct system shall include fire dampers, balancing dampers, insulation, flexible connections, etc., needed for a complete system. Products shall meet NFPA 90A or approved equivalent international standard, and fire dampers shall meet UL 555 or approved equivalent international standard. No products used in the duct construction shall exceed the maximum rating of 25 for flame-spread and the rating of 50 for smoke-developed and fuel contributed obscuration.

A ventilation system shall be provided in the water treatment area. In general, this shall consist of powered roof or wall exhaust fans and sidewall manual intake louvres, as determined by physical arrangement of the facility. All air supplied to ventilated areas shall not be filtered, unless required for equipment protection

11.9.1 Air Conditioning Systems

The control room AC system shall be designed to meet the requirements of NFPA

75 Standard for Protection of Information Technology Equipment where ICMS and

electronic control, data logging and computing equipment is located.

A split packaged air conditioning system(s) shall be installed for rooms requiring

air conditioning including the main control room, offices, storage areas, and

battery room. The system(s) shall provide constant volume air supply with a

variable outside air supply capability of 10% - 100% (economizer) to achieve

energy conservation. When outdoor air temperature and humidity conditions

permit, the system will utilize outside air in lieu of refrigerant for cooling. Each unit

shall be provided with a compressor, evaporator coil, detached air-cooled

condenser, electric heating coil, and a pre-filter and final filter. The HVAC system

will continuously operate the year round. For the control room, two 100% capacity

HVAC systems shall be provided, one operating and one as standby.

The HVAC split units for the air conditioning system shall include a mixing section

with fresh air, exhaust air, and return air dampers, filter section (including pre-filter

and final filter), electric preheating coil section, cooling coil section, supply fan

section and return/exhaust fan section. The air conditioning system final filter shall

meet the requirements of 80% atmospheric dust spot efficiency based on

ASHRAE Standard 52.1 or approved equivalent international standard.

Duct-mounted electric reheat coils shall be provided for zone temperature control

as well as high humidity control.

Careful consideration shall be taken for locating outdoor air intakes and air-cooled

condensers away from prevailing wind direction and from airborne sand and dust.

11.9.2 Battery Room Exhaust

The exhaust system in the battery room shall be operated continuously to

maintain negative pressure in the space and to avoid accumulation of hydrogen



gas or its leakage to neighboring rooms. Ducted exhaust intake shall be directed

upward to remove hydrogen accumulated at ceiling level and in beam pockets.

Discharge air shall exceed the air supply by 15%. The supply air for the battery

room shall come from the air conditioning system. Indoor air temperature shall be

kept below 30°C. Exhaust air rate shall meet the requirement of not less than ten

volume air changes per hour. Two 50% capacity in-line exhaust fans shall be

provided.

Exhaust fans and motors shall be of explosion proof design. In lieu of lead acid

batteries requiring battery room hydrogen exhaust system, the Contractor may

provide sealed batteries which do not require hydrogen exhaust system.

11.9.3 Design Parameters for HVAC

Table 17: Design Parameters for HVAC

Room System Type Indoor Environmental

Conditions

Control room / Offices / I&C maintenance/ Administration Building / CEMS Enclosure

HVAC

24 ± 2°C, 50% RH

Battery room HVAC 30 ± 2°C

Electrical switchgear, switchyard control house

HVAC As required

Service Equipment Description

Control room/battery room HVAC split Packaged Unit 2 x 110%

Switchgear HVAC split packaged Unit

Administration building HVAC split packaged Unit

Offices, I&C maintenance room /laboratory and CEMS Enclosure

HVAC split packaged Unit

Warehouse/mechanical maintenance area

Wall/roof exhaust, louvres, dampers

Gas compressor building Wall/roof exhaust, louvres, dampers

Electrical building Supply fans, dampers, louvres

Fire pump enclosure Supply fans, dampers, louvres

Guard gate house HVAC, self-contained package, through-wall

Mechanical building Supply fans, dampers, louvres

11.9.4 HVAC Applicable Standards

The following standards or other international standards shall be used in the

design of the HVAC system.

ASHRAE Handbooks (Latest Edition):



Fundamentals

HVAC Systems and Equipment

HVAC Applications

Refrigeration

ASHRAE Standards:

52.1, Method of Testing Air Cleaning Devices Used in General Ventilation for Removing Particulate Matter

15, Safety Code for Mechanical Refrigeration

62, Ventilation for Indoor Air Quality

90.1, Energy Efficient Design of Buildings

ANSI/ASME Standards:

ANSI/ASME B31.5, Refrigeration Piping

SMACNA Standards:

HVAC Duct Construction Standards, Metal and Flexible

Round Industrial Duct Construction

Rectangular Industrial Duct Construction Standards

NFPA Standards:

75 - Standard for Protection of Information Technology Equipment.

90A - Installation of Air Conditioning and Ventilating Systems

90B - Installation of Warm Air Heating and Air Condition Systems

204 - Smoke and Heat Venting

IEC Standards:

60529 - Degrees of protection provided by enclosures (IP code)

ARI Standards:

410 - Forced Circulation Air-Cooling and Air Heating Coils

430 - Central Station Air Handling Units

AMCA Standards:

210-85 - Laboratory Methods of Testing Fans for Rating

500-89 - Test Method for Louvres, Dampers, and Shutter

11.10 Chemical and Bottled Gas Storage

Bottled or drummed gasses or pressurized liquids such as hydrogen, nitrogen, carbon dioxide and chlorine shall be provided with secure, sheltered and well ventilated enclosures as close as practicable to their consumption points.

The location of the chemical injection skids, distance to injection points, and line sizing shall be considered to ensure appropriate addition of chemicals avoiding long transport times and gassing issues.

Appropriate location in buildings or sunshades shall be provided based on the chemical requirements for the chemical storage areas, chemical skids, and transport injection lines.

Compressed gases and liquefied gases storage installations shall be in accordance with NFPA 55, Compressed Gases and Cryogenic Fluids Code, 2010 Edition. Bottled gas storage areas shall be provided with sunshade covers. Sunshade covers shall consider seasonal changes in solar exposure and daily exposure from sun movement.



Manifolded cylinders shall be secured in racks to limit relative movement. Manifolds shall be fitted with overpressure relief valves venting to a safe place outside.

11.11 Hydrogen Generation Plant (if necessary)

In case the offered generator is hydrogen cooled hydrogen generation plant of adequate capacity with the provision of O2 collection shall be provided by the bidder.

Storage/ generation of hydrogen shall be in accordance with NFPA 55, Compressed Gases and Cryogenic Fluids Code 2010 or other relevant code.

Quantities to be generated/ stored shall be in accordance with the generator manufacturer’s recommendations. The hydrogen storage area shall be fitted with fire suppression system in accordance with Section 11.7 of this Specification.

11.12 Emergency Diesel Generating Set (EDG)

One (1) set of emergency diesel generating set (capacity 1500 KVA at 0.8 p.f., 1500 rpm) complete with ancillary equipment having diesel storage capacity for 24 hours of continuous operation for supplying power to essential auxiliaries. EDG shall be of automatic starting system [compressed air/ Battery] including quick start & loading capability. The starting system shall be capable of carrying out at least five (5) consecutive start without auxiliary power supply. In case of power failure in 0.4 kV bus, EDG will start and supply power to 0.4 kV emergency bus in auto mode. EDG synchronizing facility with 0.4 kV live bus is also required.

EDG is required for the safe shutdown of the plant/ equipment under emergency condition and in case of power failure for certain essential applications like battery chargers, emergency lighting and all auxiliaries necessary for safe coasting down of equipment and turning gear/ barring operation of the turbines.

11.13 Modernization of the existing workshop

The Contractor shall modernize the existing workshop including civil works, installation, testing and commissioning by providing the equipment and tools but are not limited to the followings:

Sl. No.

Description of Equipment and Tools Q’ty

1

Heavy Duty high speed Lathe Machine (Model: MIVS 410) High of center over bed: 410mm Width of bed: 490 mm Bore of main spindle: 150 mm to 210 mm Diameter of tailstock spindle sleve:145 mm

Standard tool post: (Four Way tool post)

1

2

Precision Small type Lathe Machine (Type: KD 50 Bed Length: 400 mm High of center:50 mm Distance between center:180 mm Spindle bore: 8mm Longitudinal movement of the compound rest:75mm Transverse movement : 65mm Maxim turning diameter over Lathe bed:100 mm

Main Spindle Speed:280 rpm to 2900 rpm)

1

3 Heavy Duty Precision Small type vertical Lathe (Standard size) 1

4 Heavy Duty Precision Small type horizontal Lathe (Standard size) 2

5

Universe Milling Machine Model: FU 1000

Table Diameter:1500X1400 mm Transverse of table:200mm Transverse on request:340mm Vertical motion of the table:400mm Distance from spindle center :145mm

1



Sl. No.

Description of Equipment and Tools Q’ty

Distance from horizontal center :400mm Motor output: 5.6 HP

Total height: 1600mm

6 Heavy duty speed shaping Machine (Size: 550 mm) 1

7 Heavy duty Vertical Drilling Machine (Size: 0-25 mm, 25- 50 mm, 50-75 mm)

3

8 Spindle vertical drill machine (Size: up to 50 mm) 1

9 Heavy duty power hacksaw (Type: Sawing range 250mm (square and round).

1

10 Plate, Bar, Section shear Machine (Model: BF 11) 1

11

Precision bench type grinding machine Over all height:3.5 feet Maximum grinding area: diameter up to 10 inch

Rectangular 4 inch to 16 inch

1

12 Vertical grinding Machine (Size: 100, 115, 180, 210 mm) 4

13 Thread cutting Machine (Model: K75 Hand operated) 1

14 Thread cutting Machine (Model: K75 Motor operated) 1

15 Hydraulic pipe bender (Size: 0.5 inch to 4 inch) 2

16 Multipurpose plate bending machine (For folding, Cornice bending ,rounding bending, sheet bending)

1

17 Heat treatment furnace (Up to 2000 degree Centigrade) 1

18 Magnetic drill machine (Size: 2mm to 25 mm) 1

19 Roller bending machine (Size : 2 inch to 4 inch) 1

20 Sheet roller machine (Size : 2 inch to 4 inch) 1

21 Motor operated Valve grinding machine (Size: Standard) 1

22 Magnetic Grinding Machine (Size: Standard) 1

23 Vice Table (Size: Standard) 1

24 Heavy Vice (Foundation Bolt ) (Size: Standard) 1

25 Smith working table (Size: Standard) 1

26 Anvil (Size: Standard) 1

27 Gas welding set (Size: Standard) 1

28 Arc welding set (Capacity: 500 amp) 1

29 Combined Arc and Argon welding set (Capacity: 500 amp) 1

30 Hydraulic Ladder (For Light maintenance) (Capacity: Up to 50 meter) 1

31 Fork Lift (Capacity: 3 Ton) 1

32 Fork Lift (Capacity: 5 Ton) 1

33 Material Handling hydraulic Mobile crane (Capacity: 10 Ton) 1

11.14 Chemical Laboratory Equipment

The Contractor shall provide a fully equipped laboratory capable of carrying out all routine testing of boiler water, demineralised water, drinking water, lubricants, fuel and any other chemical testing demanded or recommended by generation plant equipment suppliers. The laboratory shall be provided with all necessary chemicals, reagents, instruments, precision weighing equipment, test kits, laboratory glassware, pipettes, flasks, mixers, and consumables covering operations over the commissioning and maintenance periods.

11.15 Electrical workshop Equipment

The Contractor shall have to provide Electrical Workshop tools which shall include but are not limited to the followings:



Current injection test set, Megger (HV: 2.5 to 6 KV, LV: 250V, 500V, 1000V, Multi-meter, Level Gauge (600mm), Mega Ohmer (ZC-25B), Portable Millammeter (BMA-1), Mimmivoltmeter (BMV-1), Wire Buffing Machine, Hand Shares, Pneumatic, Grease Gun, High Pressure Water Cleaner, Bearing Puller Kit, Bearing heater, Pistol Drill (medium), Temperature Probe, Power Meter Set (Include: Phase Rotation Meters, AC&DC Ammeters), Micrometers (Small, Medium and Large), Hydrometer, Tachometers, Hydraulic Crimpers, Insulating Oil Tester, Heat Gun, Portable Air blower, Portable Vacuum Cleaner, Ladder (Medium), Drawing, Consumable, Equipment Storage Cabinets(suitable sizes), Work Benches, Hand Equipment Trolley, Power Frequency LV, SF6 Gas Detector, Loss Factor Meter, Primary Current Protection Injection test Set etc.



12. PLANT ELECTRICAL SYSTEMS AND EQUIPMENT


This section provides the technical requirements for the electrical plant and all associated auxiliary equipment, and shall serve as the criteria for the design of electrical equipment.

The scope of supply of electrical equipment includes all electrical gears, transformers, motors, cables and associated equipment required for delivery of the generated power and energy to the interface points. The electrical system shall provide support to plant auxiliary mechanical and electrical equipment as well as provide protection and control requirements. The plant electrical equipment and systems shall be designed to provide a cost-effective, safe, reliable, coordinated power generation and delivery system with due consideration on simplicity in operation and maintenance.

The major components of the plant electrical systems shall include but not limited to the following:

Synchronous generators, complete with excitation systems and ancillaries

Generator circuit breaker for CCGT-generator

Generator step-up transformer(s)

Grid auxiliary transformer

Unit start-up transformer

400KV GIS equipments

230KV GIS equipments

Auxiliary transformers for the plant MV and LV systems

Isolated phase bus duct for the turbine generator

Medium and low voltage switchgears

Electrical auxiliary systems (AC and DC) and associated battery banks

Earthing and lightning protection system

Cables.

The Contractor shall provide all detail calculations related to equipment selection and designing of total earthing system, UPS, emergency lighting, battery etc. as applicable. .

12.2 Plant Start-up and House Load Operation

The plant shall not be required to independently start following a black out. Starting power supply shall be provided through back-fed power from the national grid. The unit shall be able to be synchronized across the generator Circuit Breaker (CB).

1(one) 11~22/6.6 KV unit transformer shall be provided for supply of auxiliary power required for starting/running the unit. During start up, Generator CB shall be left open and the Generator step up transformer shall be back feed from the 400 KV National Grid to provide supply to the unit auxiliary transformer. The unit auxiliary transformer shall supply power to the 6.6 KV auxiliary bus.

Alternately, a 230/ 6.6 KV, 32 MVA startup transformer from the existing 230KV outdoor GIS Sub-station with all necessary switch gear shall be provided for supply of auxiliary power to 6.6 KV auxiliary bus for starting up the unit. A 6.6 KV auxiliary bus auto changeover system shall be provided for the above two sources.

The plant shall be able to operate at house-load or isolated operation at a defined short period when there is a transmission line fault to avoid complete plant shutdown. The plant controls shall have provision to shift from droop mode to isochronous mode to operate the house-load operation within the frequency range 48.5 ~51.5Hz.

If the line is restored within the defined short period, the plant can be immediately synchronized with the grid rather than starting from a plant shutdown. In this scenario, the steam cycle shall be shutdown allowing the plant to maintain minimum auxiliaries for the gas turbine. The minimum load that the turbine can operate at house load operation at defined



time limits shall be specified by the Contractor. A fast feed forward signal (i.e. line-end open signal) from the switchyard circuit to the plant controls shall be provided as part of the house-load operation protocol.

12.3 Generator

12.3.1 Type

The generator shall be a two pole synchronous machine, 50 Hz and complying

with IEC 60034. The generator armature and field winding insulation shall be

Class F complying with IEC 60085 and insulation manufacturing process shall be

according to manufacturer’s standard. Temperature rise and rated load operating

temperature shall not exceed those allowed for Class B under any operating

condition.

12.3.2 Rating

The generator nominal rating shall have a terminal voltage within the range of 11

kV to 22 kV. The generator shall have a minimum MVA capacity that shall match

the turbines’ output throughout the whole range of loads, operating power factors

and voltages specified, and the full range ambient temperatures specified.

The generator shall be capable of withstanding 100% load rejection without

tripping.

In compliance with Bangladesh Grid Code, the generator shall be capable of

generating real power output within the frequency range of 48.5 to 51.5 Hz at -

15% to +15% of nominal voltage and at power factor range of 0.80 lagging and

0.95 leading. The minimum generator sub-transient reactance (saturated) shall be

12%.

The generator shall be configured to appropriately react to frequency and voltage

changes in the transmission system. The transmission system shall be normally

controlled to operate between 48.5 to 51.5 Hz (50±3%) and voltage range of

±10 %. During emergency, the transmission system may operate at -15% to +10%

of nominal voltage.

At emergency conditions, the generator shall be able to operate within the

frequency range of 47.5 to 51.5 Hz. The plant protection relays shall be configured

to protect the plant from frequency excursion beyond the said range.

The generator shall withstand the electro-magnetic and thermal stresses causing

from short circuit fault at generator terminal without damage.

12.3.3 Generator Construction

The generator shall have weather and sound proof outer generator enclosure. The

stator casing shall be of fabricated robust construction. End winding support

structure shall be capable of withstanding increase in forces due to sudden short

circuit fault. The stator core shall be built of thin, high permeability, low-loss, and

silicon steel segmental punching with a high inter-laminar resistance, thereby

reducing the losses caused by eddy currents.

The rotor body shall be built from a solid block and machined to accept the rotor

windings whose ends must be held securely by alloy steel rings. After assembly,

the rotor shall be dynamically balanced. The packing blocks used especially in the

rotor winding shall be of approved material and entirely suitable for the high

temperatures and mechanical forces which may cause on rotors.

The rotor slot insulation shall be mainly of epoxy resin or other approved material

and particular attention shall be given to the insulating and securing of coil to coil

and slip ring connections, if any, and to avoid vibration and the possible failure to

either the connector or its insulation.



Adequate precautions shall be taken against local overheating of the rotor surface

when neutral short circuits and single phase loading.

12.3.4 Cooling

A cooling system shall be provided for safe and reliable operation of the generator

stator and rotor. Complete full-capacity redundant systems shall be provided for

excitation system cooling.

The generator shall be either hydrogen cooled or totally enclosed water-to-air

cooled (TEWAC).The cooling system shall be rated such that load reduction of the

turbine generator is not required even under extreme ambient temperature

conditions.

The generator coolers shall be sized to maintain temperatures of the various parts

of the generator within values as herein specified under conditions of continuous

maximum MVA rating. The number and capacity of coolers shall be selected in a

way that the generator can deliver continuously 110% of its rated output with one

cooler out of service.

An automatic temperature alarm device shall be provided with the coolers, with

contacts designed for use in conjunction with the ICMS to alarm and take

corrective action, in case the air temperature should, for any reason, rise above

safe limits.

12.3.5 Accessories

The generator shall be provided with all required accessories for an efficient and

continuous operation within its whole range of operation, including closed circuit

water-air coolers if required, bearing oil coolers, lubrication oil pump, CO2 fire

protection system or approved equivalent, and H2 detectors (if hydrogen-cooled

generator is supplied), etc.

RTD type temperature detectors shall be provided to monitor the maximum

operating temperature of the machine. The detectors shall be built into the

generator, suitably distributed around the circumferences, and embedded in the

slots in positions normally having the highest temperature in accordance with

requirements of relevant IEC standards. RTDs shall also be provided in stator

core in accordance with manufacturer's standard. All detectors shall be wired out

to a terminal box.

Anti-condensation heaters shall be provided for the air cooled circuits, excitation

system and control cubicles. Heaters shall be capable of maintaining the air

temperature above that of dew point to prevent condensation. These heaters shall

automatically switch on when the protected equipment is taken out of service or

on maintenance outage for extended period.

Current transformers for instruments and relays shall be provided as needed for

all the protection, metering, and indication functions.

12.3.6 Excitation and Voltage Regulation

A complete excitation and voltage regulating system shall be provided. The

excitation system shall be static type and micro-processor based with PSS (Power

System Stabilizer) functionality.

The excitation system shall be selected to handle the entire operating range of the

generator and shall maintain the voltage of the unit within a tolerance of ±0.5% of

rated voltage regulation. The exciter shall have capacity to supply not less than

110% of the field current required by the generator at rated output, power factor,

frequency and voltage. The rated voltage of the exciter shall be 110% of the

machine excitation voltage at the rated output of the machine.



The excitation functions shall include but not limited to the following:

local and remote points of control

automatic and manual modes of operation

fault tolerant capability with bumpless change-over

over and under excitation limiter

V/ Hz limiter

automatic excitation run-up

reactive power compensation

rapid de-excitation by provision of field suppression equipment

Excitation system shall be fully redundant. Redundancy shall include but not

limited to the followings:

Automatic voltage regulator

Control power supplies and associated power sources

Communication interface with ICMS

Hard wired protection systems, filed devices and signal conditioning

modules

The excitation system shall have a PSS to enhance damping of generator

operation under all conditions of operations. The PSS shall be based on a speed

feedback signal preferably incorporating a second stabilising signal derived from

the generator electrical power.

An excitation power transformer shall be provided to supply power to the

excitation system. It shall be a two-winding, 3-phase, 50 Hz transformer of

sufficient size to handle the excitation requirement considering the harmonic

contents of its load.

Each high voltage bushing of the excitation power transformer shall be equipped

with two current transformers. Each low voltage bushing shall be equipped with

one current transformer. High voltage and low voltage bushing current

transformers shall be wired to shorting type terminal blocks to be located in a

control terminal box mounted on the side of the excitation power transformer. The

current transformers shall be supplied with volt-amp burden ratings suitable to

accommodate metering and protective relays without affecting their accuracy.

12.3.7 Turbine-Generator Starting System

Starting system for the turbine-generator shall use either an MV motor or Static

Frequency Converter (SFC) control factor according to manufacturer’s standard. If

an SFC type starter is used, a dedicated auxiliary transformer shall be provided

conforming to requirements specified in Section 12.6.5.

12.3.8 Generator Main Connections

Connections between the generator and the respective unit auxiliary transformer,

unit transformer, and excitation transformer shall be isolated phase bus bar.

Facilities shall be provided for VTs and CTs where necessary. The connections

shall be designed to withstand full asymmetrical peak currents under short circuit

fault conditions. Neutral connections shall be designed for full phase to earth

voltage, and shall be adequately rated to take the full unrestricted fault current for

three seconds.



Flexible connections shall be used to connect the bus bar to generators and

transformers.

Voltage transformers shall preferably be integral to the generator circuit breaker,

[or positioned in a ground mounted phase isolated cubicle]. CTs shall be located

within the generator terminal enclosure. CTs and VTs shall be provided for

statistical metering, protection, control, instrumentation, and AVR channels A and B.

12.3.9 Neutral Earthing

Generator neutral earthing shall adopt the scheme using single phase distribution

transformer with a resistor in its secondary winding for limiting earth fault current

to a threshold that the generator can withstand.

A single-phase, 50 Hz, dry or oil immerse type, naturally cooled neutral earthing

transformer conforming to IEC 60076 shall be provided. The continuous rating of

the earthing transformer and associated secondary resistor shall be determined by

the Contractor and shall be capable of withstanding an earth fault duration of 30

seconds and a maximum primary earth fault current of 10 kA.

12.4 Generator Circuit Breaker

The generator circuit breaker (GCB) system shall allow the generator to be synchronized to the grid, loaded to the full capacity and disconnect in the event of fault, in the system.

The GCB shall be indoor 11~22 KV GIS Circuit Breaker. The design for the GCB shall be based upon the maximum output of the generator and the fault current available. The GCB shall be designed and tested in accordance with relevant IEEE/IEC Standard.

The GCB interrupter shall have SF6 insulation. The GCB shall have a single operating mechanism operating all three interrupters simultaneously. The stored energy mechanism shall store sufficient energy to perform a close-open sequence after the loss of auxiliary power. It shall be provided with duplicate trip coils with trip circuit supervision.

12.5 Isolated Phase Bus Ducts

The Isolated Phase Bus (IPB) ducts shall connect the generator, step-up transformer and unit auxiliary transformer. It shall have a tee-off connection to the excitation transformer if the latter’s primary voltage is similar to the generator voltage. The IPB ducts shall be rated to carry the generator output with tee-offs rated according to their current flows with consideration on the maximum site ambient temperature and under direct solar radiation and that magnetic fields outside the bus should be reduced to a minimum value.

The isolated-phase bus shall be fabricated with high conductivity Copper and shall satisfy the requirements of IEEE C37.23 “IEEE Standard for Metal-Enclosed Bus”. The IPB shall consist of two concentric copper ducts with the internal current carrying duct supported by cast resin or ceramic insulators. The inner ducts shall be fully welded construction except for welded flexible expansion joints and provisions for flexible bolted connection to equipment.

Dry filtered air shall be used to pressurise the bus bars, with an alarm to the plant control system for high and low pressure.

Cubicles which form part of the IPB system shall be complete with anti-condensation heaters.

12.6 Transformer

12.6.1 General

All transformers shall be designed and tested in accordance with IEC 60076.

Transformers shall be complete with all accessories and necessary auxiliary

equipment. All three phase transformers shall be of core type construction.

The terminal arrangement and connections shall not restrict access to

maintenance and inspection.



All transformers shall be capable of operating continuously without damage

between 48.5 Hz and 51.5 Hz.

Cable boxes where ever used shall be suitable for the connection of XLPE

insulated cables. The body of the cable box shall be provided with an earthing bolt

or stud. Cable boxes shall be air insulated. Phase segregated cable boxes shall

be used for single core cables. LV terminals of auxiliary transformers shall be fully

insulated.

12.6.2 Technical Requirements for Oil-type Transformers

Core

(a) Type

The core of each transformer shall be built up of laminations made of the highest quality non-ageing grain orientated steel. The construction shall be of the core type. The core frame design shall provide a simple and effective means for re-clamping after dry-out e.g. jacking screws. The positions for hydraulic rams shall be clearly marked. The insulation between the core and end frames and any ducting within the core shall be Class F or H and shall not be cellulose.

(b) Flux Density

The flux density within the core shall not exceed 1.65 Tesla during normal operation; that is, with the rated primary voltage applied to the primary terminals at the principal tap and rated frequency.

Overfluxing of the core shall not occur under the above conditions.

(c) Oil Duct Electrical Strength

For any oil duct there shall be a minimum 35% safety margin between the corona inception field strength and the actual figure determined from the field plots supplied by the manufacturer.

(d) Earthing

The core and frames shall be single point earthed. A single connection from the core and another single connection from the frame shall be brought out separately via cables to two 2 kV bushing terminals, complete with shorting links, mounted in an external box located next to a hand hole cover in the tank top. To allow for testing of the insulation of the core and frame, the connections shall be earthed via a removable bolted link to an earthed stud on the tank. The cables, bushings and links shall be rated for the maximum possible circulating current in the event that the core or frame becomes inadvertently grounded. The bushings shall be labeled with “C” for the core and “F” for the frames in a permanent manner.

Windings

The winding conductors and conductor connections shall be constructed from high

conductivity copper and shall be burr free and profiled.

The strand paper coverings shall be of thermally upgraded paper where applicable.

All electrical connections within windings shall be brazed or welded (not soldered)

to withstand shocks of the type that might occur through handling, vibration during

transport, switching, earthquakes and other transient service conditions.

All connections from windings shall be mechanically sound, supported and

fastened to prevent movement and damage during site erection, and normal and

abnormal operating conditions. Crimped joints are not acceptable. The lead-out

from the LV winding shall be formed from the winding conductor and split into

groups such that the lead-out temperature rise in the vertical duct above or below

the start or finish section and the lead-out temperature in the horizontal duct



across the top of the winding is no greater than the temperature rise of the winding

at those points.

All cylinders/wraps shall be made of pre-compressed transformer board.

Machined wrapped paper cylinders/wraps are not acceptable. Scarfed overlap

shall be used to form the cylinders on either side of the coil face. On intermediate

cylinders the overlaps (if this method is used) are to be formed on the duct strips.

Only molded angle collars/caps shall be used. Petalled collars/caps are not

acceptable. All duct strips and spacers shall be made from the highest density

pre-compressed board, have contoured edge conditioning. Duct strips shall also

be of one piece and have contoured edges.

Metal backed paper shall not be used in the stress relieving of winding to lead

connections. Metal backed paper is not to be used in the manufacture of the

stress shields without the express approval of the Employer.

All copper conductor used in the construction of the windings must be enamel

coated. Note paperless windings will not be accepted. Enamel covered wires are

approved for use when the particular enamel and method of use has a proven

history, the radial thickness of the enamel is at least 0.100 mm for continuously

transposed cable, and for helical windings that are transposed by hand, the cross-

over/transposition is mechanically and electrically protected.

There shall not be any electrical out of balance of turns between the phase

windings.

Construction

Each oil-type transformer shall be enclosed in a suitably stiffened welded steel

tank and bolted cover. Each transformer shall be provided with overhead

conservator tanks for the main tank and OLTC (if required) switch chamber -

formed of substantial steel plates and arranged above the highest point of the oil

circulating system. The conservators may be physically separate tanks or fully

partitioned sections of a single tank.

Radiators which are connected directly to the tank shall be detachable. Radiators

which are mounted separately shall be mounted on a concrete base.

Safe access shall be provided to transformer conservators and Buchholz relay.

This shall take the form of an access ladder with hoops.

Sealing end chambers shall be oil filled, and be provided with removable covers.

The chambers shall accept the cable sealing ends, and provide testing facilities for

the cable. The main conservator tank shall maintain the oil level in the sealing end

chambers.

The transformer shall be provided with a skid base with four (4) steel wheels and

necessary jacks for setting and appropriate devices for locking in position of its

foundation.

Lockable drain valves shall be properly fitted to enable all oil filled compartments

to be drained, and adapters shall be provided for connection to oil filtration plant.

Sampling devices shall also be fitted independently of the drain valves. It shall not

be possible for:

The oil in the diverter switch compartment to mix with oil in any other compartment

The oil in the sealing end chambers to mix with that of the main tank.

All oil filled transformers shall be fitted with an oil temperature indicator that can be

manually reset. Temperature detector shall be installed at the point where the

highest temperature is anticipated. Alarm and trip facilities shall also be provided.



Transformer control cubicles for oil filled transformers shall be complete with

temperature indicators, test facilities, interposing relays for supervisory control,

control and protection for cooling plant with an auto-manual changeover switch.

Each cubicle shall include a single phase and a three phase socket.

Each transformer shall be set on a concrete pad. Oil containment shall be

provided. Drainage shall be routed to an oily water system

The earthing terminals of the transformer shall be copper faced steel pad, and

shall be welded on the tank wall near the base. The earth terminal shall be of bolt

fastened type, suitable for 100–200 mm2 hard or annealed copper stranded

conductors.

Bushings

Bushings that house current transformers shall be arranged so that they can be

removed without disturbing the current transformers, secondary terminals,

connections or pipe work. Internal connections to transformer bushings shall be

flexible.

The construction and mounting of all bushings shall ensure that, in the event of

flashover, current has a definite path around joints fitted with gaskets. On

capacitor type bushings a tapping shall be brought out to a separate terminal for

power factor testing at site. The terminal shall be earthed when the weatherproof

cover is in position. Stress shields shall be regarded as part of the bushing

assembly.

All bushings shall be of one-piece construction and shall comply with IEC 60137.

Insulating Oil

The insulating oil shall have sufficient insulation strength, and shall be excellent in

heat conductivity, low in viscosity and pour point, and high in flash point. The oil

shall not cause any corrosion to insulating materials and structured materials of

electrical equipment and shall be chemically stable for long years of use.

Oil Preservation System

Oil immersed transformers shall be provided with an oil preservation system in

which the insulating oil shall be isolated from atmospheric air. The oil preservation

system shall be of the diaphragm seal or air seal cell type conservator with silica-

gel breather. Oil level gauge with low level alarm contact shall be mounted on the

conservator.

ONAF Cooling System

An adequate number of unit coolers shall be fixed to the tank of oil immersed

transformers, and the cooling capacity shall be sufficient to operate the

transformer under the rated power. The transformer shall be able to deliver the

required output with one cooling fan out of service. The coolers shall be of such

structure that will not be affected by the vibration of transformer. A valve shall be

provided with each pipe connecting a unit cooler to the tank. Fixing bolts and

terminals shall be such that will never get loosened after being fastened. The

power source of the cooling fans shall be 400V 3 phase or 230V single phase.

The fans shall normally be controlled by an independent winding temperature

relaying device.

Protective Devices

The following protection devices shall be provided:

Buchholz relay and Pressure Relieve Device (PRD) similar type for alarm and trip

High temperature alarm and trip (winding and oil).



An aseismic Buchholz relay or oil pressure relay shall be fitted on pipe works

between the conservator and the main tank. If on-line tap changer is required,

another Buchholz relay shall be installed in pipework between OLTC compartment

and conservator compartment. A dial type thermometer with hand resetting

maximum indicator shall be provided. A Pressure Relief Device (PRD) with

operation indicator shall be provided.

The gas relay should be provided with double float (one operated by volume of

gas flow and other operated by mass gas flow). It should have following provision:

Gas release valve

Mechanical test button

Provision for testing both the floats by injecting air from outside

Drain cock

Transport graduated window.

The relay should be mounted at such a place that can be visible from the ground

without climbing on the transformer.

Wiring

All wiring mounted on the transformer shall be drawn through conduit pipes or

adequate protective tubes to the control cabinet which shall be properly located on

the transformer.

The wiring shall be connected at the terminal blocks terminating the outgoing

control cable. The flexible tube of the vapour tension thermometer shall be

covered by a protective tube.

Accessories

The following minimum accessories shall be furnished for each transformer:

Name plate with connection diagram

Valves for oil filtering and sampling

Air vent valve

Manhole and hand-hole including blind covers

Ladder fixed to the transformer tank for inspection of the upper part of the transformer

Hanging hook

Earthing terminals

Anchor device

Magnetic oil-level gauges with alarm and trip contacts for the main tank and OLTC (if required)

Dehydrating (Drycol) breather for the main tank.

Dehydrating (desiccant) breather for the OLTC tank (if required)

Pressure relief devices for the main tank and OLTC (if required)

Gas operated (Buchholz) relay between the main transformer and its conservator tank and between OLTC and conservator tank compartment

Resistance Temperature Devices (RTDs) and transducers for local and remote oil temperature indication

Transformer Control Cubicle equipped with:

An electronic system incorporating voltage and cooling controls.

Oil temperature thermometer to provide back-up trip, alarm and control contacts in parallel with the electronic control and monitoring system contacts.



Winding temperature thermometer with thermal replica device and associated CTs to provide back-up trip, alarm and control contacts in parallel with the electronic control and monitoring system contacts.

Terminals for wiring devices mounted on the transformer, e.g. oil and winding temperature indicators, Buchholz relay.

A thermometer pocket on each heat exchanger oil inlet and outlet pipe

Detachable radiators and associated valves.

Transformer Packing and Shipping

Each transformer shall be delivered in its tank, which shall be made moisture

proof by charging the tank with dry nitrogen under pressure. An approved means

of maintaining air pressure in the event of slow leakage shall be provided. Dry

nitrogen shall be to the appropriate industrial standard.

Impact recorders measuring impacts on all three axes shall be fitted to the main

tanks of transformers rated 10 MVA and up. If a recorded value exceeds the

earthquake maximum withstand value for the relevant axis, the transformer shall

be deemed defective and shall be returned to the factory for disassembly,

inspection, repair as necessary and retesting.

All transformer components and spares shall be packed securely within totally

enclosed wooden crates and protected against corrosion. The wooden crates shall

be strong enough to resist major impacts that can occur during shipping.

12.6.3 Generator Step-Up Transformer

The generator step-up transformer (GSUT) shall be oil type two winding with ONAN/ONAF cooling. The ONAN capacity shall not be less than 75% of ONAF capacity.

Low voltage shall be similar to the generator voltage and high voltage shall be 400 kV. Transformer high voltage winding shall be solidly connected grounded wye. Transformer low voltage winding shall be connected delta.

The transformer shall have sufficient capacity to carry the maximum power output of the turbine generator with a 10 % margin. It shall be also able to deliver the generator maximum net output with one cooling unit (fan or pump) out of service. The transformer shall withstand 10% overfluxing due to low frequency.

The impedance voltage shall be within 14-18 % range on the forced air cooled rating on the rated tapping (11~22 kV/400 kV) and the tap changer setting range shall be -15% to +15% of rated high tension voltage. The on-line tap changer shall have 25 tapping positions with 1.25% tapping steps.

The transformers shall be designed and constructed to withstand without damage the thermal and dynamic effects of external short-circuit under the conditions specified in IEC 60076-5.

The thermal withstand capability shall be based on a short circuit current duration of 3 seconds. The radial short circuit strength of the windings shall be based on free buckling.

The tank construction of the step-up transformer shall have manhole access doors for maintenance inspection both at the top and at the side of the tank. HV bushing manhole access shall also be included to allow bushing removal. Isolation valves for transformer filling and filtering under vacuum shall be supplied.

Surge arresters shall be provided at its high voltage side.

12.6.3.1 230/6.6 KV, 32 MVA Grid Auxiliary Transformer

The Grid Auxiliary transformer (GAT) shall be oil filled with ONAN/ONAF. The ONAN capacity shall not be less than 75% of the ONAF capacity.

The Transformer shall be wye-delta-wye with OLTC to cover ±15% in 25 tap positions on HT side. Percentage Impedance shall be 14%.



12.6.3.2 11~22/6.6 KV, 32 MVA Unit Auxiliary Transformer

The Unit Auxiliary transformer (UAT) shall be oil filled with ONAN/ONAF. The ONAN capacity shall not be less than 75% of the ONAF capacity.

The Transformer shall be wye-delta-wye with OLTC to cover ±15% in 25 tap positions on HT side. Percentage Impedance shall be 14%.

12.6.3.3 GSUT On-Load Tap Changer

The transformer shall have an on-line tap changer (OLTC) on the high voltage side with provision for remote monitoring and control. On load tap changers shall comply with IEC 60214. The tap changer controller should have provision for communication with the grid control and monitoring system.

The tap changer shall be of high speed transition resistor type with diverter switch compartment separated from the main tank. Transformer oil in these compartments shall never be mixed. The tap changer compartment shall include provision for oil sampling. The tap changer control shall be housed inside a panel directly beneath the tap changer tank. Mechanical stops with limit switches shall be provided to prevent over-travel. The tap changer control shall be operated in local by hand, local electrically and remote electrically with interface to the ICMS control system. Local mechanical tap position and remote tap position indication shall be provided.

The OLTC shall comply with all provisions of this specification.

The OLTC is of MR, Germany, ABB, Sweden or equivalent.

12.6.4 Auxiliary Power

The auxiliary power at starting shall be supplied from the national grid through a

230/6.6 KV, 32 MVA startup transformer connected to the existing outdoor 230KV

GIS substation to be installed at the project site by approx. 600 metre

underground XLPE cable laying through cable trench. 1 (one) 11~22/6.6 KV self-

auxiliary transformer shall be connected to the CCGT unit bus to supply the power

to the 6.6 KV auxiliary bus for running the units.

Alternatively, the starting auxiliary power shall be provided through back-fed

power from the 400 KV grid Substation.

12.6.5 Auxiliary Transformers

The auxiliary transformers shall reduce further the selected medium voltage (6.6

kV) to low voltage (400V AC) for station and unit loads. The Contractor shall select

the number of auxiliary transformers required to cater all plant loads including

those for generator excitation and static frequency converter (SFC) for starting if

required. SFC and excitation transformers may have different secondary voltage

as per manufacturer’s standard. Alternatively, the Contractor may opt to have an

excitation transformer with its primary voltage similar to that of the generator and

shall have a tee-off connection to the generator bus duct.

Auxiliary transformers shall be outdoor type.

Outdoor type with ONAN cooling shall have suitable oil bunding with fire protected

enclosure and located as close as possible to its respective switchboards.

Off-circuit tap changers shall be provided on primary windings of all auxiliary

transformers. The tap changer shall be designed to provide at least 5 tapping

steps at 2.5% per step to achieve voltage range of ±5% of rated primary voltage.

Interlock or locking mechanism shall be fitted to prevent the changing of tap

position while the transformer is energized.



12.6.6 400 KV GIS Equipment

12.6.6.1 GENERAL

Power from the proposed plant will be evacuated through 400 KV existing GIS of Ashuganj 450 MW CCPP (North) project. The Contractor shall provide all equipment for connection of extended bay of indoor 400 KV GIS which shall comply with relevant IEC standard. The 400 KV GIS bus bar shall be segregated and conductor should be copper and minimum capacity of each bus 3150A. The Contractor shall make sure to include all equipment to provide a fully working scheme.

12.6.6.1.1 DESIGN EQUIPMENT

1. System Voltage.

The system shall be as follows:

- Nominal system voltage : 400 KV

- Highest system voltage : 440 KV

2. Insulation level

The insulation level of the switchgear, equipment shall be as follows:

- Lighting impulse withstand test voltage

(1.2/50 micro sec.)

1425 KVPeak

- Switching impulse withstand voltage

-

: 1050 KV

3. Design Conditions

Switchgear equipment shall be designed to avoid local corona formation and discharge likely to cause radio interference, and to endure short circuit current without thermal and mechanical failure for one (1) second. All cubicles and enclosures shall be vermin proof, dust resistance & weather proof.

12.6.6.2 400 KV GIS EQUIPMENT

12.6.6.2.1 400 KV CIRCUIT BREAKERS

1. Type

Three (3) pole high speed, indoor GIS, trip free in any position, spring operated SF6 gas buffer type complete with wiring, and all other necessary accessories.

2. Ratings

a. Rated Voltage

: 400 KV

b. Rated insulation level

a.

- Lighting impulse withstand voltage (1.2/50 micro sec.)

: 1425 KVPeak


: 1050 KV



c. Rated frequency : 50 Hz

d. Rated short circuit breaking current

: 50 VA

e. Rated transient recovery voltage for terminal faults and rated characteristics for short line faults shall be in accordance with IEC 60056.

f. Rated short circuit making current ratings

: 125 KA

g. Rated duration of short circuit : 3 sec

h. Rated operating time

1. Closing time : < 76 msec

2. Opening time : < 25 msec

3. Breaking time : < 50 msec

3. Control System

The rated supply voltages of closing and opening devices shall be 220 V/110 V DC.

4. Requirements for Design and Construction

a. The circuit breakers shall be provided with a push button switch with cover to prevent inadvertent switching.

b. The circuit breakers shall be provided with an electrical anti pumping relay.

c. The supporting structure shall be free from mechanical vibration and loosening under long term use.

d. The circuit breakers shall be designed to facilitate inspection, especially for those parts which need inspection frequently.

e. The circuit breakers shall be filled with sufficient SF6 gas.

f. SF6 gas leak detector shall be furnished.

g. The Contractor shall furnish all control cables, pipes or ducts and fittings between each phase and control box.

12.6.6.2.2 400KV DISCONNECTING SWITCHES

1. Type

Indoor GIS, three (3) pole, single throw, group operated, rotating insulator, remote controlled motor operated type.

2. Ratings

a. Rated Voltage

: 400 KV b. Rated insulation level

b.


: 1425 KVPeak


: 1050 KV


d. Rated nominal current : 2000 A

e. Rated duration of short circuit current

: 3 sec



f. Rated short circuit withstand current

: 50 KA

g. Rated peak withstand current : 125 KA

h. Rated short circuit making current

: 125 KA


a. The disconnecting switches shall be so designed and Constructed in accordance with IEC 60129.

b. The contact part of the blade shall be silver coated.

c. The porcelain insulator shall be an outdoor and post type, and shall have creepage distance not less than 25 mm/ kV of phase to phase voltage. The glazing colour shall be of brown.

d. An electrical or mechanical interlocking device shall be equipped between its related circuit breaker.

e. Revolving parts shall be so designed that operation will be sure and smooth under long term use without necessity of inspection, oiling.

f. Auxiliary switches with three (3) spare parts “ a-b “ contacts, terminal blocks, indicator lamp sockets, etc. shall be accommodate in a control box shall be of the weather and dust proof type with locking device.

12.6.6.2.3 400KV VOLTAGE TRANSFORMER

1. Type

Indoor GIS, single phase, oil immersed with level indicator or gauge, N2 gas sealed Electromagnetic type voltage transformer.

2. Use

For metering and protection

3. Rated voltages - Primary : 400/ 3 KV

- Secondary

i.

0.110/ 3 KV

Rated insulation level

c.

a. Lighting impulse withstand voltage Full wave (1.2/50 micro sec.)

: 1425 KVPeak

b. Switching impulse withstand voltage

: 1050 KV


d. Rated burden

- Secondary

:

100 VA

e. Accuracy class : 0.2


: 50 KA




a. A protection device shall be provided against short circuit of the secondary circuits of the voltage transformers with remote alarm for MCB failure.

b. Unless otherwise specified, the characteristic and others shall comply with the requirements of IEC 60186.

12.6.6.2.4 400KV CURRENT TRANSFORMERS

1. Type

Indoor GIS, single phase with 5 cores.

2. Use

Two core for metering and other three core for protections.

3. Ratings

a. Rated current - Primary :

1600-800-400 A

- Secondary

j.

: 1-1-1-1-1 A


d.

- Lighting impulse withstand voltage Full wave (1.2/50 micro sec.)

: 1425 KVPeak


: 1050 KV


d. Rated burden

:

60 VA for protection and 40 VA for measuring

e. Rated continuous thermal current

: 120%

f. Short time current ratings

- Thermal rating

(r.m.s for one sec.)

: 50 KA

- Dynamic rating (peak)

: 2.5 times the thermal ratings

g. Accuracy class

h. For metering : 0.2, n‹5

i. For protection : 5P20


a. Separate junction boxes with terminals for metering and protection shall be provided for the secondary circuit connections.

b. Each current transformer shall be equipped with terminal block of short circuiting type.

c. Unless otherwise specified, the characteristics and others shall comply with IEC 60185



12.6.6.2.5 400 KV LIGHTNING ARRESTERS

1. Type

Outdoor, single phase, self-standing, Metal-Oxide type with surge operating counter.

2. Use

For protection of 400 kV outdoor switchyard equipment and transformer windings.

3. Electric system to be protected

Three (3) phase, three (3) wire, neutral point solidly grounded system.

4. Rating and Performances

a. Rated voltage : 380 A

b. Rated frequency : 50 Hz

c. Nominal discharge current

:

15 KA

d. Type of Duty

: Heavy, long duration discharge

e. Pressure relief class : C

f. Lighting impulse insulation level (1.2/50 micro sec.)

: 1425 KVPeak

g. Maximum residual voltage

400 KV

h. Power frequency spark-over voltage

: 170 KV

5. Operation duty

The arrester shall successfully interrupt the dynamic current repeatedly conducted by impulse wave


a. The series gaps shall be so designed that for practical purposes the various characteristics will not alter under the change of weather conditions.

b. The various parts of the lightning arrester shall be of complete moisture proof construction so that the characteristics shall not be impaired under long term use. Sealed parts shall be so designed to prevent to ingress of moisture or water under long term use.

c. The operation counter shall be equipped on the lightning arrester in each phase and consist of a sure current recording and measuring device, such as a magnetic link surge crest ammeter, and counter for the number of discharges of the lightning arrester. It shall be located at the position convenient for inspection.

d. Creepage distance of bushing shall not be less than 25 mm/ kV of phase to phase voltage. The glazing colour shall be of brown.

e. Unless otherwise specified, tile characteristics and others shall comply with IEC 60099-1.



12.6.6.3 STEEL STRUCTURE

12.6.6.3.1 TYPE

The steel structure shall be lattice truss construction made of galvanised formed steel and assembled by bolts and nuts.

The component members of steel structure shall have inter-changeability with other identical members. The basis framing of the steel structure shall be identical on all four (4) faces below the bend line.

12.6.6.3.2 DESIGN CRITERIA

The steel structure shall be designed in accordance with the following criteria.

1. Load due to the tension of conductor and wire.

- 400 kV bus and outgoing conductor

900 kg per conductor

- Overhead grounding wire 450 kg per wire

2. Vertical loads

The weight of the conductors, grounding wires, insulator strings and steel structures shall be taken into consideration.

3. Human Loads

240 kg at the centre of the beam.

4. Wind loads

Wind loads shall be calculated with wind speed of 40 m / sec, but the wind loads on unit projected area shall not be less than the followings:

- On conductors and grounding wires

: 125 Kg/sq.m

- On insulators and other circular section

: 130 Kg/sq.m

- On lattice structures or beam structure

: 230 Kg/sq.m

5. Seismic Coefficient (Horizontal)

: 0.28g

: Z=0.28

6. Working Conditions

The normal working condition for various loads shall be deemed to work simultaneously. The wind direction shall be classified into transverse, longitudinal and oblique components to the line route and the largest load acting on the line shall be taken as the design stress of the component material.

7. Combination loads

The Contractor shall calculate the maximum and minimum stresses at any combination of loading conditions. The design of each type of steel structure shall be made by the same manner of analysis. The design stresses of individual components shall be largest value of maximum stresses in the respective loading conditions.



8. Minimum Thickness and Size of Steel Members

Minimum thickness and size of steel members shall be as follows:

a. Formed steel

.

: not less than 45 x 45 x 4 mm

b. Plate : not less than 4

mm thick.

9. Slenderness Ratio

The slenderness ratio shall not exceed 105 for main members, 200 for bracing and 250 for other members.

12.6.6.3.3 REQUIREMENTS FOR DESIGN AND CONSTRUCTION

1. Workmanship

Workmanship shall be first class throughout. All pieces shall be straight, true to detailed drawings and free from lamination, flaws and other defects. All clippings, back nuts, grindings, bends, holes, etc. shall be true to detailed drawings and free of burrs.

2. Galvanising

The steel structure shall be completely galvanised (Hot-Deep), except for part which shall be embedded in concrete foundation. All ferrous materials shall be galvanised to meet the requirements of IEC.

3. Materials of Steel Structure

All materials shall be hot rolled structural steel and/or high strength structural steel.

4. Marking

All products shall be marked with systematic numbers and / or colours for convenience of assembly.

5. Future Extension of Structure

In designing the steel structure, consideration shall be given in the design criteria to permit easy extension of steel structure in the future and same loading conditions shall be taken into account in accordance with the Specifications.

6. Bolts and Nuts

All the members shall be connected by bolts and nuts. The diameter of the connection bolts and step bolts shall not be less than 16 mm.

12.6.6.3.4 DESIGN ITEMS

The Contractor shall submit to the Engineer for approval design sheets and drawings including calculation of Loads, selection of constitution and members, selection of connecting bolts and calculation of reaction load against base concrete.

12.6.6.3.5 ACCESSORIES

Accessories shall be provided as per requirement.



12.6.6.4 INSULATORS AND WIRING MATERIALS

12.6.6.4.1 INSULATORS

1. Type and requirements

a. The insulator assembles shall consist of suspension insulator discs, bushings, hardware, strain or suspension clamps as required.

b. The suspension insulators shall he of ball and socket type and shall conform to the requirement of IEC 60120.

c. The insulator unit shall be standard 254 mm porcelain disc type or fog type 254 mm porcelain disc type, and have a spacing of 146 mm between discs.

d. Total creepage distance of the insulator assemblies shall not be less than 6125 mm. for outdoor

e. The insulators shall be wet-process porcelain of the highest glade, dense and homogeneous. The glaze shall be smooth, hard, dense and uniform and shall not be effected by weather or sudden change in temperature, salty atmosphere and lighting during certain periods of the year. Colour of porcelain surface shall be brown. All ferrous metals shall be galvanised except for female thread and stainless steel. Each insulator shall bear symbols identifying the manufacturer and indicating the year of manufacturer and tension proof test load.

2. Characteristics of Suspension Insulators

a. Porcelain disc diameter : 254 mm

b. Unit spacing : 146 mm

c. Minimum electromechanical

failing load : 21000 Kg

d. Dimension of ball socket and pin : Conform

to IEC

3. Characteristic of Insulator Assemblies

a. Nominal system voltage : 400 kV

b. Highest system voltage : 425 kV

c. Creepage distance not less than : 10500 mm

d. Breaking strength of complete set : 21000kg

e. System insulation level

- Basic impulse insulation level

(1.2/50 micro sec.) : 1425 kVpeak

- Switching impulse withstand

voltage : 1050 kV

12.6.6.4.2 FITTING

The suspension and tension clamps for bus works and outgoing feeders, tension clamps for overhead grounding wires, U-bolts, ball eyes, anchor shackles,



etc. for wiring of switchyard shall be furnished by the contractor. Unless otherwise specified, all hardwire fittings shall be made by malleable iron or forged steel hot dip galvanised or aluminium alloy.

All metal shall be free from rust, burrs, sharp edges, lumps and dross and shall be smooth so that interconnecting parts will fit properly and the parts may be assembled and disassembled easily. Hardware shall have ultimate strengths exceeding three (3) times tension load of bus work and overhead ground wire.

The cramps shall not be occurred in excessive heating by magnetising or other causes.

12.6.6.4.3 STANDARD CONDUCTORS FOR OVERHEAD LINE

1. 850 mm2, hard drawn aluminium conductor

The hard down aluminium stranded conductor of 850 mm2 shall be used for 400 kV bus bars and for feeder circuit. The conductors shall comply with the requirements of IEC.

2. Galvanised Steel Wire

The galvanised steel wire of 55 mm2 shall be used as overhead grounding wire.

3. Spools for Conductors

The spools for conductors shall be made of steel and treated against corrosion and rust, and the following marking shall be indicated on an appropriate side of the spool.

- Conductor number.

- Kind and cross sectional area of conductor.

- Conductor length

- Spool weight

- Name of manufacturer or abbreviation

- Date of production

- Position of beginning of conductor

- Direction of rotation of spool

- Indicator showing the remaining length of conductor

12.6.6.4.4 MISCELLANEOUS MATERIALS

All miscellaneous materials such as phase mark plates, angle steel, C-shaped steels, conduit pipes, cable cleats, bolts, nuts, and other materials for completion of the switchyard shall be provided by the Contractor.

12.6.6.5 400 kV SWITCHGEAR CONTROL AND PROTECTION

12.6.6.5.1 400 kV SWITCHGEAR EQUIPMENT PANEL

The DCS shall include 400 kV system switchgear equipment for controlling, indication and protection but not to be limited to, in the Central Control Room (CCR). The 400 kV protection and control system shall be interfaced with existing system where necessary. Numerical bus-bar differential protection and fault



monitoring system shall be provided for 400 kV switchyard.

12.6.7 230 KV GIS Equipment

12.6.7.1 GENERAL

The auxiliary power at starting shall be supplied from the national grid through a 230/6.6 KV, 32 MVA startup transformer connected to the existing outdoor 230KV GIS substation to be installed at the project site by approx. 500 metre underground XLPE cable laying through cable trench.

The Contractor shall provide all equipment for connection of extended bay of outdoor 230 KV GIS which shall comply with relevant IEC standard. The 230 KV GIS bus bar shall be segregated and conductor should be copper and minimum capacity of each bus 2000A. The Contractor shall make sure to include all equipment to provide a fully working scheme.

12.6.7.1.1 DESIGN EQUIPMENT

1. System Voltage.

The system shall be as follows:

- Nominal system voltage : 230 KV

- Highest system voltage : 245 KV

2. Insulation level

The insulation level of the switchgear, equipment shall be as follows:

- Lighting impulse withstand test voltage

(1.2/50 micro sec.)

1050 KVPeak


-

: 460 KV

3. Design Conditions

Switchgear equipment shall be designed to avoid local corona formation and discharge likely to cause radio interference, and to endure short circuit current without thermal and mechanical failure for one (1) second. All cubicles and enclosures shall be vermin proof, dust resistance & weather proof.

a. IEC 60185.

12.6.7.2 230 KV GIS EQUIPMENT

12.6.7.2.1 230 KV CIRCUIT BREAKERS

1. Type

Three (3) pole high speed, indoor GIS, trip free in any position, spring operated SF6 gas buffer type complete with wiring, and all other necessary accessories.



2. Ratings

a. Rated Voltage

: 230 KV


e.


: 1050 KVPeak


: 460 KV


d. Rated short circuit breaking current

: 50 VA

e. Rated transient recovery voltage for terminal faults and rated characteristics for short line faults shall be in accordance with IEC 60056.

f. Rated short circuit making current ratings

: 125 KA

g. Rated duration of short circuit : 3 sec

h. Rated operating time

4. Closing time : < 76 msec

5. Opening time : < 25 msec

6. Breaking time : < 50 msec

i. Rated operating sequence (<2.5 cycles)

: 0-0.3 sec-CO-3 min-CO

j. Rated normal current : 2000 A

k. Suitable for single phase auto re-closer or gang operated where ever applicable.

3. Control System

The rated supply voltages of closing and opening devices shall be 220 V/110 V DC.


a. The circuit breakers shall be provided with a push button switch with cover to prevent inadvertent switching.

b. The circuit breakers shall be provided with an electrical anti pumping relay.

c. The supporting structure shall be free from mechanical vibration and loosening under long term use.

d. The circuit breakers shall be designed to facilitate inspection, especially for those parts which need inspection frequently.

e. The circuit breakers shall be filled with sufficient SF6 gas.

f. SF6 gas leak detector shall be furnished.

g. The Contractor shall furnish all control cables, pipes or ducts and fittings between each phase and control box.



12.6.7.2.2 230KV DISCONNECTING SWITCHES

1. Type

Outdoor GIS, three (3) pole, single throw, group operated, rotating insulator, remote controlled motor operated type.

2. Ratings

a. Rated Voltage

: 230 KV


f.


: 1050 KVPeak


: 460 KV


d. Rated nominal current : 2000 A

e. Rated duration of short circuit current

: 3 sec


: 50 KA

g. Rated peak withstand current : 125 KA

h. Rated short circuit making current

: 125 KA


a. The disconnecting switches shall be so designed and Constructed in accordance with IEC 60129.

b. The contact part of the blade shall be silver coated.

c. The porcelain insulator shall be an outdoor and post type, and shall have creepage distance not less than 25 mm/ kV of phase to phase voltage. The glazing colour shall be of brown.

d. An electrical or mechanical interlocking device shall be equipped between its related circuit breaker.

e. Revolving parts shall be so designed that operation will be sure and smooth under long term use without necessity of inspection, oiling.

f. Auxiliary switches with three (3) spare parts “ a-b “ contacts, terminal blocks, indicator lamp sockets, etc. shall be accommodate in a control box shall be of the weather and dust proof type with locking device.

12.6.7.2.3 230KV VOLTAGE TRANSFORMER

1. Type

Outdoor GIS, single phase, oil immersed with level indicator or gauge, N2 gas sealed Electromagnetic type voltage transformer.



2. Use

For metering and protection

3. Rated voltages

- Primary : 230/ 3 KV

- Secondary

k.

0.110/ 3 KV

Rated insulation level

g.

a. Lighting impulse withstand voltage Full wave(1.2/50 micro sec.)

: 1050 KVPeak

b. Switching impulse withstand voltage

: 460 KV


d. Rated burden

- Secondary

:

200 VA

e. Accuracy class : 0.2


50 KA


a. A protection device shall be provided against short circuit of the secondary circuits of the voltage transformers with remote alarm for MCB failure.

b. Unless otherwise specified, the characteristic and others shall comply with the requirements of IEC 60186.

12.6.7.2.4 230KV CURRENT TRANSFORMERS

1. Type

Outdoor GIS, single phase with 5 cores.

2. Use

Two core for metering and other three core for

protections.

3. Ratings

a. Rated current - Primary :

1600-800-400 A

- Secondary

l.

: 1-1-1-1-1 A


h.

- Lighting impulse withstand voltage Full wave(1.2/50 micro sec.)

: 1050 KVPeak


: 460 KV




d. Rated burden

:

60 VA for protection and 40 VA for measuring

e. Rated continuous thermal current

: 120%

f. Short time current ratings

- Thermal rating

(r.m.s for one sec.)

: 50 KA

- Dynamic rating (peak)

: 2.5 times the thermal ratings

g. Accuracy class

h. For metering : 0.2, n‹5

i. For protection : 5P20


a. Separate junction boxes with terminals for metering and protection shall be provided for the secondary circuit connections.

b. Each current transformer shall be equipped with terminal block of short circuiting type.

c. Unless otherwise specified, the characteristics and others shall comply with IEC 60185

12.6.7.2.5 230 KV LIGHTNING ARRESTERS

1. Type

Outdoor, single phase, self-standing, Metal-Oxide type with surge operating counter.

2. Use

For protection of 230 kV outdoor switchyard equipment and transformer windings.

3. Electric system to be protected

Three (3) phase, three (3) wire, neutral point solidly grounded system.

4. Rating and Performances

a. Rated voltage : 230 A

b. Rated frequency : 50 Hz

c. Nominal discharge current

:

10 KA

d. Type of Duty

: Heavy, long duration discharge

e. Pressure relief class : C

f. Lighting impulse insulation level (1.2/50 micro sec.)

: 1050 KVPeak

g. Maximum residual voltage

400 KV

h. Power frequency spark-over voltage

: 170 KV



5. Operation duty

The arrester shall successfully interrupt the dynamic current repeatedly conducted by impulse wave


a. The series gaps shall be so designed that for practical purposes the various characteristics will not alter under the change of weather conditions.

b. The various parts of the lightning arrester shall be of complete moisture proof construction so that the characteristics shall not be impaired under long term use. Sealed parts shall be so designed to prevent to ingress of moisture or water under long term use.

c. The operation counter shall be equipped on the lightning arrester in each phase and consist of a sure current recording and measuring device, such as a magnetic link surge crest ammeter, and counter for the number of discharges of the lightning arrester. It shall be located at the position convenient for inspection.

d. Unless otherwise specified, tile characteristics and others shall comply with IEC 60099-1.

e. Creepage distance of bushing shall not be less

than 25 mm/ kV of phase to phase voltage. The glazing colour shall be of brown.

12.6.7.3 STEEL STRUCTURE

12.6.7.3.1 TYPE

The steel structure shall be lattice truss construction made of galvanised formed steel and assembled by bolts and nuts.

The component members of steel structure shall have inter-changeability with other identical members. The basis framing of the steel structure shall be identical on all four (4) faces below the bend line.

12.6.7.3.2 DESIGN CRITERIA

The steel structure shall be designed in accordance with the following criteria.

1. Load due to the tension of conductor and wire.

- 230 kV bus and outgoing conductor

: 900 kg per conductor

- Overhead grounding wire : 450 kg per wire

2. Vertical loads

The weight of the conductors, grounding wires, insulator strings and steel structures shall be taken into consideration.

3. Human Loads 240 kg at the centre of the beam.



4. Wind loads

Wind loads shall be calculated with wind speed of 40 m / sec, but the wind loads on unit projected area shall not be less than the followings:

- On conductors and grounding wires

: 125 Kg/sq.m

- On insulators and other circular section

: 130 Kg/sq.m

- On lattice structures or beam structure

: 230 Kg/sq.m

5. Seismic Coefficient (Horizontal) : 0.28g : Z=0.28

6. Working Conditions

The normal working condition for various loads shall be deemed to work simultaneously. The wind direction shall be classified into transverse, longitudinal and oblique components to the line route and the largest load acting on the line shall be taken as the design stress of the component material.

7. Combination loads

The Contractor shall calculate the maximum and minimum stresses at any combination of loading conditions. The design of each type of steel structure shall be made by the same manner of analysis. The design stresses of individual components shall be largest value of maximum stresses in the respective loading conditions.

8. Safety Factors

The safety factors shall not be less than two (2) under the normal working conditions.

9. Minimum Thickness and Size of Steel Members

Minimum thickness and size of steel members shall be as follows:

a. Formed steel : not less than 45 x 45 x 4 mm

b. Plate : not less than 4 mm thick.

10. Slenderness Ratio

The slenderness ratio shall not exceed 105 for main members, 200 for bracing and 250 for other members.

12.6.7.3.3 REQUIREMENTS FOR DESIGN AND CONSTRUCTION

1. Workmanship

Workmanship shall be first class throughout. All pieces shall be straight, true to detailed drawings and free from lamination, flaws and other defects. All clippings, back nuts, grindings, bends, holes, etc. shall be true to detailed drawings and free of burrs.



2. Galvanising

The steel structure shall be completely galvanised (Hot-Deep), except for part which shall be embedded in concrete foundation. All ferrous materials shall be galvanised to meet the requirements of IEC.

3. Materials of Steel Structure

All materials shall be hot rolled structural steel and/or high strength structural steel.

4. Marking

All products shall be marked with systematic numbers and/or colours for convenience of assembly.

5. Future Extension of Structure

In designing the steel structure, consideration shall be given in the design criteria to permit easy extension of steel structure in the future and same loading conditions shall be taken into account in accordance with the Specifications.

6. Bolts and Nuts

All the members shall be connected by bolts and nuts. The diameter of the connection bolts and step bolts shall not be less than 16 mm.

12.6.7.3.4 DESIGN ITEMS

The Contractor shall submit to the Engineer for approval design sheets and drawings including calculation of Loads, selection of constitution and members, selection of connecting bolts and calculation of reaction load against base concrete.

12.6.7.3.5 ACCESSORIES

Accessories shall be provided as per requirement.

12.6.7.4 INSULATORS AND WIRING MATERIALS

12.6.7.4.1 INSULATORS

1. Type and requirements

a. The insulator assembles shall consist of suspension insulator discs, bushings, hardware, strain or suspension clamps as required.

b. The suspension insulators shall he of ball and socket type and shall conform to the requirement of IEC 60120.

c. The insulator unit shall be standard 254 mm porcelain disc type or fog type 254 mm porcelain disc type, and have a spacing of 146 mm between discs.

d. Total creepage distance of the insulator assemblies shall not be less than 6125 mm. for outdoor

e. The insulators shall be wet-process porcelain of the highest glade, dense and



homogeneous. The glaze shall be smooth, hard, dense and uniform and shall not be effected by weather or sudden change in temperature, salty atmosphere and lighting during certain periods of the year. Colour of porcelain surface shall be brown. All ferrous metals shall be galvanised except for female thread and stainless steel. Each insulator shall bear symbols identifying the manufacturer and indicating the year of manufacturer and tension proof test load.

2. Characteristics of Suspension Insulators

a. Porcelain disc diameter : 254 mm

b. Unit spacing : 146 mm

c. Minimum electromechanical

failing load : 21000 Kg

d. Dimension of ball socket

and pin :Conform to IEC

3. Characteristic of Insulator Assemblies

a. Nominal system voltage : 230 kV

b. Highest system voltage : 245 kV

c. Creepage distance not less than : 10500 mm

d. Breaking strength of complete set : 21000kg

e. System insulation level

- Basic impulse insulation level

(1.2/50 micro sec.) : 1050 kVpeak

- Switching impulse withstand

voltage --- : 460 kV for 1 min.

12.6.7.4.2 FITTING

The suspension and tension clamps for bus works and outgoing feeders, tension clamps for overhead grounding wires, U-bolts, ball eyes, anchor shackles, etc. for wiring of switchyard shall be furnished by the contractor. Unless otherwise specified, all hardwire fittings shall be made by malleable iron or forged steel hot dip galvanised or aluminium alloy.

All metal shall be free from rust, burrs, sharp edges, lumps and dross and shall be smooth so that interconnecting parts will fit properly and the parts may be assembled and disassembled easily. Hardware shall have ultimate strengths exceeding three (3) times tension load of bus work and overhead ground wire.

The cramps shall not be occurred in excessive heating by magnetising or other causes.

12.6.7.4.3 STANDARD CONDUCTORS FOR OVERHEAD LINE

1. 850 mm2, hard drawn aluminium conductor

The hard down aluminium stranded conductor of 850 mm2 shall be used for 230 kV bus bars and for



feeder circuit. The conductors shall comply with the requirements of IEC.

2. Galvanised Steel Wire

The galvanised steel wire of 55 mm2 shall be used as overhead grounding wire.

3. Spools for Conductors

The spools for conductors shall be made of steel and treated against corrosion and rust, and the following marking shall be indicated on an appropriate side of the spool.

- Conductor number.

- Kind and cross sectional area of conductor.

- Conductor length

- Spool weight

- Name of manufacturer or abbreviation

- Date of production

- Position of beginning of conductor

- Direction of rotation of spool

- Indicator showing the remaining length of conductor

12.6.7.4.4 MISCELLANEOUS MATERIALS

All miscellaneous materials such as phase mark plates, angle steel, C-shaped steels, conduit pipes, cable cleats, bolts, nuts, and other materials for completion of the switchyard shall be provided by the Contractor.

12.6.7.5 230 kV SWITCHGEAR CONTROL AND PROTECTION

12.6.7.5.1 230 kV SWITCHGEAR EQUIPMENT PANEL

The DCS shall include 230 kV system switchgear equipment for controlling, indication and protection but not to be limited to, in the central control room. The 230 kV protection and control system shall be interfaced with existing system where necessary. Numerical bus-bar differential protection and fault monitoring system shall be provided for 230 kV switchyard.

12.7 Medium Voltage Switchgear

The medium-voltage switchgear shall receive power from the unit transformer. The MV nominal rating is 6.6 kV as shown in conceptual single line diagram, but final voltage rating shall be selected by the Contractor. MV feeders shall include loads for:

MV drives (pumps and fans)

Auxiliary transformer(s)

Station (BOP) transformer

Excitation transformer (if required)

Static frequency converter for gas turbine starting (if required).

The MV switchgear shall comprise indoor metal-clad, draw-out, segregated switchgear cubicles; air insulated bus-bar with instrument transformers and front panel mounted control, instrumentation, protection, and metering all mounted together to form one board. It shall be



single bus-bar design, type tested, fully factory assembled and manufactured according to IEC 62271-200.

Withdrawable type vacuum or SF6 circuit breakers shall be used for switching main incomer, transformer and large motor feeders. Fused vacuum contactors shall be considered for motors rated less than 2 MVA for 6.6 kV.

All switchgear shall have local and remote status indication and control facilities. Switchgear cubicles of a particular rating shall be interchangeable with others of the same rating.

The MV switchgear shall have at least 20% equipped spare circuit breaker cubicle and 20% equipped spare motor starter of each size cubicle. All motor feeder circuits shall be protected by electronic thermal protection relays with single phase and earth fault protection. All transformer and feeder circuits together with bus-tie circuits shall be protected by three phase and neutral overcurrent relays. The protection relays shall be self-monitoring microprocessor based. Protective relays shall conform to the requirements of the applicable parts of IEC 60255.

All feeders shall be provided with three phase panel mounted ampere meters. All meters can be configured to send metering data to the ICMS either through 4-20 mA analogue output or serial RS-485 communication.

All medium-voltage breakers and motor starters shall utilize either 110V DC or 220V DC control power and shall be designed to eliminate arc flashing and personnel hazards.

Surge arresters or limiters shall be provided for motor feeders with locked rotor current of 600A or more. The arresters may alternatively be placed near motor terminals rather than inside the switchgear.

12.8 Low Voltage Switchboards and Motor Control Centres

400 V switchboards and Motor Control Centres (MCC) shall be supplied to control all electric motor driven auxiliaries and supply power to other electric loads of the plant. Nominally there shall be four low voltage (400V) switchboards: the unit auxiliary switchboards, station service or BOP switchboard and the essential switchboard. The Contractor may opt to add or reduce the number of LV switchboards or MCCs with each station and auxiliary boards having dedicated auxiliary transformers in order to reduce the switchboard fault current rating.

The essential switchboard shall be split into two buses and provided with bus coupler. It shall have main incomers from auxiliary switchboards 1 and 2 and alternate incomer from a diesel emergency generator. Interlocking shall be implemented between the main incomer and alternate incomers. A spare circuit breaker with suitably rated power outlet shall be provided as a second alternate incomer.

The essential switchboard shall supply power to essential loads. Normally it is fed from main incomer CBs of the two unit auxiliary switchboards. During plant outage, main incomer CB shall open and emergency generator CB shall automatically close with signal coming from the plant ICMS. LV loads and motor starters shall be classified into normal and essential groups and connected to their associated switchboard.

All LV switchboard shall comprise indoor, metal clad, draw out, segregated switchgear cubicles; air insulated busbars with instrument transformers and front panel mounted control, instrumentation, protection, metering and ICMS transducer facilities, all mounted together to form one switchboard.

The incoming and bus-tie circuits shall be controlled by circuit breakers with overcurrent and earth fault protection. The feeder circuits shall be short circuit protected by thermal-magnetic type circuit breakers, with 3-pole bi-metallic ambient compensated overcurrent protection and contactors providing overload protection and control facilities. Incoming circuits shall be by three phase and neutral, non-segregated bus ducting. Outgoing circuits shall be by power cables. All feeder circuits shall have one CT and panel mounted ampere meter. All meters shall be digital type and can be configured to send metering data to the ICMS either through 4-20 mA analogue output or serial RS- 485 communication.

All switchboards shall have local and remote status indication and control facilities together with sufficient terminals and auxiliary contacts for motor space heater circuitry and switching,



and a control power transformer with primary and secondary fusing. Switchgear cubicles of a particular rating shall be interchangeable with others of the same rating. One spare cell of each rating shall be provided within the switchboard, and blank panel space left for future cells.

System connections shall be in accordance with the requirements for a multiple earthed neutral (MEN) system. Earth busbar shall be connected to the nearest earth grid conductor.

The short circuit current rating of switchboards shall be determined after initial review on the fault contribution from the utility, the connected motors and from the main generator.

Consideration shall be given to using intelligent low voltage switchboard and motor control centre products, if technical and cost factors are seen to be beneficial over the project life cycle.

The switchboard voltage dip at starting of large motor drives shall not cause disturbance to Works operation.

Air circuit breakers shall be used as switching and protection device for power transformers, bus-tie and large motors. Contactor close and trip design shall have a latching mechanism. Contactors shall have AC-4 rating. Sufficient auxiliary contacts are available for control circuit. Combination fuse switch unit shall be of withdrawable modular type.

The motor starters and numbering systems shall be consistent across each of the plant MCCs.

All indicator lamps shall be of the LED type. No incandescent types are allowed.

The Contractor shall also be allowed to offer a different LV switchboard configuration as long as adequate redundancy and reliability of power supply to critical equipment is considered. Any alternate switchboard arrangement shall be subject to approval by the Employer.

12.9 Bus Ducts (as required)

If bus ducts are used in between transformers and switchgears, they shall be factory tested. All bus ducts shall be preassembled at the factory before shipment to ensure fit-up dimensions and shall come assembled (if possible).

12.9.1 Non-Segregated Phase Bus Duct

Non-segregated phase bus shall be copper bus insulated with a thermosetting

insulation. The non-segregated phase bus duct shall be a self-cooled design. Bus

ducts shall be fabricated according to requirements of IEEE C37.23. The bus shall

be rated to carry the maximum nameplate output of the equipment. It serves +10%

continuously under the maximum temperature rises specified by ANSI C37.20.

Vapour barriers or fire stops must be supplied at all building wall/floor entrances to

prevent the transfer of indoor and outdoor air as well as maintain the fire rating of

any penetrated walls or floor.

Capacity of buses shall be rated for the maximum operating conditions with an

additional capacity margin of +10%.

12.10 Electric Motors

Electric motors shall conform to the requirements of both IEC 60034 and IEC 60072 as applicable or NEMA MG-1 (minimum Design B).

Motors shall have a 1.15 service factor with class F insulation and a class B temperature rise. They shall be totally enclosed fan cooled (TEFC) shall have an enclosure rating of IP54 for indoor applications and IP55 for outdoor, unless special applications define otherwise. Motors shall be designed to operate at least 2 years continuously without major maintenance.

Motors must be capable of producing the rated torque at any frequency between 48 and 51 Hz together with any voltage variation between ± 10% of nominal voltage. With the driven



machine coupled, the motors should be able to accelerate reliably considering a maximum voltage drop at the motor terminals to 80% of nominal voltage at rated frequency.

Motors rated 200 kW and up is recommended to have medium voltage rating while units less than 200 kW shall be low voltage. The Contractor shall be allowed to have flexibility in selecting the threshold on low and medium voltage ratings of motors as other factors such as cabling and equipment location shall determine the most economical option.

Direct current (DC) motors shall generally be specified by the relevant driven equipment supplier to fulfill the duty required at the minimum specified DC system voltage.

Die-cast terminal boxes shall be provided on motors 200 kW and below. They shall have threaded conduit entries, be rotatable through 360° in 90° steps and be set up for bottom cable entry. Terminal boxes shall have an IP 65 rating.

Motors with 200 kW and above capacity may have fabricated steel terminal boxes. These shall be of sufficient thickness to prevent buckling, be oversized to accommodate the surge capacitors, and be provided with a full size aluminum gland plate suitable for bottom cable entry. All leads between the motor housing and terminal box shall be fully sealed.

Condensate drains shall be fitted to all motors. All drains shall be fitted with threaded metallic plugs.

All horizontal motors 200 kW and above shall be equipped with jackscrews for vertical adjustment during alignment.

All motors shall have a grounding connection on the motor frame, and all terminal boxes shall have an internal ground connection point.

A separate terminal box shall be provided and be dedicated to the terminations of accessory equipment (temperature sensors, space heaters, etc.).

LV motors rated more than 15 kW and less than 200 kW shall be fitted with one embedded PTC thermistor per phase. 220V AC space heaters shall be furnished for all motors 18 kW and larger.

Motors from 200 kW shall be fitted with two RTD temperature sensors within each phase of the stator winding and wired to its motor controller.

Each bearing shall be fitted with temperature sensor for all motors rated above 200 kW and wired to its motor controller.

As per motor manufacturer’s recommendation, medium voltage motors may be provided with adequately rated surge capacitors installed within the motor main power supply terminal box.

The application of a variable speed drive (VSD) shall be considered where it can be demonstrated that the VSD shall benefit the operation, maintenance and efficiency of the plant. Requirements for VSD-controlled motor shall include but not limited to the following:

Selected VSD must ensure EDM (Electric Discharge Machining) does not occur. Output filters shall be provided as required by VSD manufacturer.

VSD rated cables with low inductance screen shall be used from the VSD to the motor if VSD manufacturer does not allow use of typical industrial cables.

12.11 Protection Relays

The Contractor shall make short-circuit calculations to determine the fault currents at various points in the power system a prerequisite for selecting system components (e.g. circuit breakers, fuses, protective relays, etc.) having adequate capacity for the fault currents, and for designing a discriminating protective system.

The generator, generator step-up transformer and unit transformer shall be provided with duplicate main protection systems.

Duplicate main protection system shall be provided, such that there are either duplicate protections, or two different main protections which have a similar probability of detection.

The protection systems shall incorporate overlapping zones of protection provided with Main protection systems in addition to Backup protection systems.



Duplicate Main protection systems, and Backup protection systems which provide mutual backup shall be placed in different protection groups. The different protection groups shall:

Use different relays for Main1 and Main2 protection systems, either by using relays from different manufacturers, or from the same manufacturer provided the measurement principles are different

Use separate current transformer cores and cabling for the Main1 and Main2 protection systems

Use separate voltage transformer supplies, separately fused at the VT and separately cabled, and supervised, for the Main1 and Main2 protection systems

Use separate DC supplies, separately fused at the DC panel, and supervised, for the Main1 and Main2 protection systems

Trip into separate tripping circuits, with each trip circuit supervised, for the Main1 and Main2 protection systems

Use separate test facilities for the Main1 and Main2 protection systems.

The protection relays shall be of ABB, Areva of European origin or equivalent.

12.11.1 Generator Protection

Generator protection system shall consist, but not limited to, the following:

Differential

Single-phase earth faults (stator)

Multiple-phase earth faults (stator)

100% earth fault protection (stator)

Single rotor earth faults (rotor)

Multiple rotor earth faults (rotor)

Pole slip

Loss of excitation

Over excitation

Under excitation

Over/under-voltage

Over/under-frequency

Reverse power

Over fluxing

Negative phase sequence

Stator overload

Turbine trip.

12.11.2 Transformer Protection

Recommended protection system for Step-up Transformer and Unit Transformer

includes as follows:

Overall differential

Transformer differential

overcurrent and earth fault

winding temperature

oil temperature

sudden pressure/gas protection (buchholz)



Tap changer surge.

In the step-up transformer duplicated protection; one shall be designated as

“overall differential protection” and the other as “step-up transformer differential

protection”. The unit transformer shall be equipped with differential protection and

also be included in the zone of the “overall differential protection”.

The excitation transformer shall be identical to the unit transformer but shall not be

included in the overall differential protection zone.

12.11.3 400 KV Bus-bar Differential Protection

Numerical Bus-bar Differential Protection shall be provided.

12.11.4 Circuit Breaker Fail Protection

Circuit Breaker Fail Protection shall be provided to detect failure of a circuit

breaker to interrupt the current, which it is carrying and to back trip all other circuit

breakers connected to the same bus bar.

12.11.5 Medium Voltage Switchgear Protection

Incomers and feeders shall have overcurrent and earth fault protection against

overloading, short circuits and multi-phase and single-phase earth faults.

Motors shall be protected by a multi-function electronic relay with overload, earth

fault, and single phasing protection and metering features.

12.11.6 Low Voltage Switchboard Protection

Incomer circuit breakers shall have overcurrent and earth fault protection against

overloading, short circuits and multi-phase and single-phase earth faults.

Motors starters above 150 kW shall have electronic motor protection relay. Motor

starters below 150 kW shall be equipped with thermal overload with single phase

protection. Motors 1,000 kW and larger shall use multi-function relay with

differential protection.

Non-motor loads shall be feed from thermal magnetic moulded case breakers

sized to protect supply and individual loads.

12.12 DC and UPS Systems

The DC and UPS system shall consist of:

220V /110 V DC battery and charger

24V DC (220/24 DC/DC converter or 110/24 V DC/DC converter)

231V AC UPS (inverter with back-up AC supply)

48V DC battery and charger for communication equipment. (as required)

The main DC voltage shall either be 220V or 110V. The main DC loads shall be as follows:

Generator circuit breaker closing and tripping

DC lubricating oil pumps for CTG and STG rotating plant

Protection relay systems

HV switchyard equipment controls

MV/LV Switchboard and motor control centre closing and tripping.

The main 220V/110 V DC system shall consist of 2x100% battery and chargers each connected via individual fuses to dedicated 100% battery banks. Each battery shall supply its respective distribution board. There shall be a tie feeder breaker between the two distribution boards.



The 24V DC systems are powered via 2x100% redundant DC/DC converters. Their mains are taken from the 220V /110 V DC battery system. Main consumers of 24V DC are the main ICMS cabinets. Each I&C cabinet shall receive two in-feeds from the redundant DC/DC converters via decoupling diodes.

The 2x100% UPS system (231V AC) shall provide power to essential AC consumers which are sensitive to short power failures, e.g. main ICMS computers. This system is fed from the 220V DC system via an inverter, which provides a regulated single-phase 231V AC supply. The inverters shall also be provided with static bypass switch to the normal bus and emergency bus. The two UPS shall supply its dedicated distribution board. There shall be a tie breaker between the two distribution boards.

There shall be 48V DC batteries redundant chargers. The system shall be independent from the 220V DC system. The 48V DC system shall provide power to communication systems.

Batteries shall consist of single cells connected to provide the appropriate voltage. Cells shall be valve-regulated type nickel-cadmium. The rated life of the batteries under normal operating conditions with constant current and constant voltage charge shall not be less than 18 years. The battery capacity shall be rated for safe plant shutdown (including emergency oil pumps and barring gear) plus operation of UPS for a minimum of five (05) hours without AC power.

Two unit battery chargers scheme shall be implemented and connected in parallel with the DC standing load and float charge current being shared equally by the chargers. Either charger may be taken out of service leaving the other to carry the full duty.

Each battery charger shall be continuously rated to supply 100% of the design load, in addition to battery charge requirements, under the most severe variation of AC supply input.

A dedicated battery room shall be provided which should be well ventilated. Battery chargers shall be located external to the battery room. The battery room shall be equipped with facilities for the safe handling of battery acid, and with an emergency eye washing station and a safety shower.

12.12.1 Battery Charger Performance

Battery charger performance shall conform to the battery manufacturer’s

recommendation.

Chargers shall be identical in design and rating. One charger shall be in service

whilst the other shall be in standby mode. Switching between service and standby

mode combinations shall be done manually by the operator.

Each charger shall be capable of recharging the battery from fully discharged

condition to 100% of the fully charged capacity in not more than 12 hours while

supplying the design loads.

The chargers shall be of the automatic with I/U characteristics.

The charger output voltage regulation range shall be less than 1% for:

Frequency variation of ± 5 percent of 50 Hz

Rated input AC voltage variation of ± 10 percent

Output between 0 and 100 percent of rating.

The charger shall be short circuit proof.

Each charger shall include at least the following instrumentation and indicating

facilities:

AC and DC voltage and current

Programmable settings of float and equalizing voltage

Alarm indication for AC/DC failure

Polarity of current



Charger status and fault conditions shall be signaled at the operator interface.

Input voltage 400 volts, three phase

Input voltage stability ±10%

Input frequency 50 Hz

Output Voltage To suit battery and load voltage limits

Output current To suit load and battery requirements

Control Constant voltage with current limit

Output ripple Less than 5% of the nominal dc voltage

Indications Output voltage

AC/DC Currents

Alarms Over-voltage trip (switch rectifier off)

Over-voltage alarm

Charger failed alarm

Under-voltage alarm

Output circuit disconnected alarm

12.12.2 UPS Performance

Static uninterruptible power supply (UPS) systems shall be sized to feed the plant

critical loads related to ICMS, work station computers, communications/telemetry,

fire protection/detection and turbine/generator control panel. Each system shall

consist of a inverter section, bumpless static transfer switch, maintenance bypass

switch and voltage regulated bypass transformer. The output shall feed a

dedicated AC distribution panel and shall be rated to carry actual connected load

plus 20%. Battery capacity (ampere hour rating) shall be determined by the

Contractor.

Bumpless transfer to and from AC source and the battery shall be ensured via the

static transfer switch. Transfer to and from “bypass” mode shall also be bump less

and require specific sequence switching. “Bypass” mode shall be visually

indicated on the local UPS panel and the operator interface in the control room.

Under normal operating conditions, the AC load shall be supplied by the inverter

system via the static transfer switch.

Upon an inverter fault, the static switch shall transfer the ac load to the ac input

supply or an auxiliary ac supply line with a “no break” in power supply and inhibit

further switching until the fault is rectified.

UPS status and fault conditions shall be signaled at the operator interface.

12.12.3 Batteries Performance

Batteries shall comply and be sized in accordance with IEEE 485 "Recommended

Practice for Sizing Batteries for Power Stations".

Each battery shall be the high performance, low-maintenance, valve-regulated

nickel-cadmium type. The battery shall be designed for a life expectancy of at

least 18 years at an average ambient temperature of 30°C.

Battery capacity shall be suitably de-rated to allow for ageing factor, temperature,

and maintenance factors. An ageing factor of at least 125% shall be used in the

capacity calculation. An additional spare capacity for future growth of load shall be

allowed of at least 20%.



All battery cells shall be numbered consecutively and each terminal shall be

marked to show polarity.

Each battery shall have three spare cells installed and kept fully charged by

connecting in parallel with cells in the battery or by other approved manner.

Batteries shall be mounted on multi-tier racks braced to withstand earthquake

forces. Racks and mountings shall be designed to allow easy inspection and

replacement of individual cells. The separate battery room shall have sufficient

space to access batteries. The room shall be ventilated to remove hydrogen gas

and optimize life of battery.

12.13 Power and Control Cabling

Cabling from switchgears to loads shall be combination of duct banks, cable trays and conduits. The selection of cabling methods shall be decided as soon as equipment location and pipe layouts are confirmed and an optimized cable routing solution can be drawn out. To achieve a substantial level of redundancy for critical equipment, cables shall be laid as far as possible into separate routes.

Cable sizing procedures should ensure that a short-circuit fault shall not result in damage to the cable prior to normal operation of interrupting devices. The fault duration rating of the cables shall be determined by the total operating time of the complete protection system. The maximum current carrying capacity for any cable shall consider the worst case on where the cable shall be routed (tray, conduit, duct, or direct buried). Voltage drop and factors related to ambient and ground temperature should also be considered in sizing of cable. All cables shall be rated in accordance with IEC 60287.

All cables shall be capable of withstanding the normal mechanical and electrical stresses expected during installation and service without mechanical deformation or damage.

All cable materials shall be of high quality and be able to withstand the corrosive effects of soil, underground water, chemicals, heat, moisture, ozone, rodents, termites etc. to which the cables may be exposed. Cables shall be provided with water-blocking material to prevent radial and longitudinal migration of water.

All cables shall be suitable for indoor or outdoor installation in cable tray, embedded ducts, direct burial, and conduit. For outdoor installation, the cable may be exposed to direct sunlight, rain, and blowing dust (UV rated).

12.13.1 Conductors

Conductors shall be stranded, annealed copper for all power and control cables

and extra flexible stranded copper for all instrument cables.

Conductors shall be compact round and Class 2 stranded for power cables in

accordance with IEC 60228.

The conductors shall be unbroken for each complete drum length of cable. Drums

with spliced conductors shall be unacceptable.

12.13.2 Conductor Screen

Semi-conductive tape shall be used for stress controlling XLPE insulation and

onto the stranded conductors which shall be temperature resistance up to 250°C.

The semi-conductive extruded cross-linked material shall provide a smooth

cylindrical equi-potential to which the insulation can be intimately bonded. The

material shall be compatible in all respects with its conductor and insulation

materials.

12.13.3 Cable Insulation

Minimum insulation requirements shall be:

Medium voltage cable insulation 133% insulation level, high grade, low loss, extruded XLPE rated 90°C



Low voltage 400V power and control cable insulation 600V/ 1 kV, high grade, low loss,

extruded XLPE rated 90°C

Instrument cable 150 V, flame retardant, gas vapour tight UVPVC rated 70°C

On emergency and fire systems, mineral insulated metal sheathed cable with a UVPVC sheath (MIMS-PVC) or equivalent high temperature (110°C) cable shall be used.

The insulation shall be based on a design voltage stress which has been proven

to be completely satisfactory in service. As maximum freedom from the possibility

of failure is essential, highly stressed insulation which has not been fully proven in

service shall not be used even if it has satisfactorily passed the type test.

The average thickness of insulation shall be in accordance with IEC 60502.

Minimum insulation thickness at any point shall not be less than the nominal

values specified in Table III of IEC 60502.

The thickness of any separator or screen on the conductor or over the insulation

shall not be included in the thickness of the insulation.

12.13.4 Filler and Binder

Flame retardant and moisture resistant fillers shall be used in the interstices of the

multi-conductor cable to give the completed cable a circular cross-sectional shape.

A suitable inner jacket shall be extruded over the completed circular multi-

conductor cable to keep the fillers in place.

The material used for inner coverings and fillers shall be suitable for the operating

temperature of the cable and compatible with the insulating material.

12.13.5 Insulation Screen

Semi-conductive compound of extruded layer firmly bonded to the XLPE insulation.

The conductor screen, the insulation and the insulation screen are to be extruded

in a single process to keep the interface smooth.

12.13.6 Metallic Screen

Where the cable core screens are inadequate to meet the earth fault current

specified, a metallic layer of adequate cross-sectional area shall be included in the

design applied over the screen.

12.13.7 Oversheath

The over-sheath shall be tough UVPVC or high density polyethylene (HDPE),

termite resistant and suitably prepared against cracking and decomposition under

the prevailing service conditions at site. The outer sheath shall be covered with a

black semi-conductive layer. Preference is given to an extruded semi-conductive

layer rather than graphite coating. Cable sheath shall be fire-retardant complying

with IEC 60332, Part 3, Category A.

The oversheath shall be permanently identified to clearly show the following:

Manufacturer's name

Rated circuit voltage

Conductor size

Number of conductors

Insulation material (not trade name)



Outer jacket material (not trade name)

Year of manufacture

Sequential footage marks in metres.

12.13.8 Sealing and Drumming

Immediately after the works tests, both ends of the cable shall be sealed against

the ingress of moisture, dirt and insects and the end projecting from the drum shall

be adequately protected against mechanical damage during handling. The cable

drums shall be arranged to take a round spindle and be lagged with strong,

closely fitting so as to take a round spindle and be lagged with strong, closely

fitting battens so to prevent damage to the cable. Only steel cable drum shall be

used.

The complete cable shall be rolled on steel cable drums capable of withstanding

the rough handing during transport without damage of the cable and enabling

easy and safe unrolling of the cable during erection. Each drum shall have marked

in indelible point on both flanges, the following indications besides the shipping

instructions:

(a) Destination

(b) Type of cable

(c) Exact length

(d) Net and gross weight

(e) Trade mark

(f) An arrow pointing in the direction of unrolling.

12.13.9 Accessories

Straight joint and termination kits which are compatible with the cables shall be

provided. Straight joint materials shall be suitable for direct burial or outdoor

installation on a cable tray. The integrity of the joint shall match the cable in all

performance characteristics.

Cable terminations shall be suitable for air insulated cable boxes which are an

integral part of electrical equipment. The termination shall allow for termination

and connection to earth of the copper wire screen.

Any special tools required for cable jointing or termination shall be provided.

12.14 Earthing and Lightning Protection

12.14.1 Earthing

The plant earthing system shall be designed according to IEEE Standard 80. The

earthing design calculation should show that the system is able to protect plant

personnel and equipment from hazards occurring during earth fault conditions.

Together with protection relays, the system should be able to detect earth faults

and provide necessary preventive measures for equipment and personnel

protection.

The earthing system shall be composed of copper-clad ground rods and bare

copper conductors interconnected in a grid pattern and bonded together using

exothermal welding process. Sizing for earthing conductors and ground rods and

their configuration shall consider step and touch potentials, grid resistance, grid

voltage rise and other parameters required in IEEE 80.

In the plant area, earthing connections shall be brought through the ground floor

and bonded to the building steel and equipment. The earthing system shall extend



to include all plant and equipment external to the main power plant building.

Metallic perimeter and security fences shall be bonded to the earth grid.

All vessels and structures taller than 10m shall have at least one dedicated

earthing electrode connected to it. All platforms shall be electrically bonded to the

associated process piping as well as the local earthing grid.

All switchboards and distribution boards shall have at least two independent

earthing connections.

The Contractor shall provide, install and connect up all earthing and bonding to all

plant, equipment, etc. as required by this Specification and drawings, relevant

Codes, Standards and Authorities.

Metallic ground-mounted lighting poles shall be provided with an earthing stud and

be separately bonded to earth via an earthing lead. The earthing lead shall be run

up within the pole.

All cable ladder and metallic conduits shall be bonded to provide earth continuity

over their entire length.

Cable armouring, if applied, shall be bonded to earth. Cable armouring shall be

used for earthing purposes and may also be supplemented with additional cores

within the cable. The appropriate compression gland shall be used for glanding

the armoured cable. The gland shall be complete with an integral earthing tag

suitable for bonding to the equipment earthing terminal via an earthing lead with

compression lug type connections.

Isolated buildings and distant areas with electrical equipment, which are secluded

from the main plant earthing grid shall have local earth grids and equipment

bonding systems similar to that in the plant area. Remote grids shall be

interconnected with the main plant earth grid to minimise the possibility of

transferring earth fault potentials to the remote area through interconnecting cable

shields.

Above ground earthing cables shall be PVC sheathed, coloured yellow/green The

PVC sheath is a protection against electrolytic corrosion.

The Power Station earthing design and extension shall include following general

guidelines:

Generator neutral end winding transformer/resistance earthing to limit generator phase to earth fault currents

Unit transformer LV Star neutral resistance earthing to limit MV bus, phase to earth fault currents

Interconnection of Power Station and switchyard earth grids with transmission line towers and steam piping and steamfield earth grids

Fault current contribution from the generators and grid power system

Combined primary protection relay and circuit breaker operation time for determination of maximum fault current flow in the human body for step and touch voltages

Backup protection time for determining current rating of earth grid conductors

That the typical human body weight for body current limit calculations shall be 50 kg

Major items of equipment, such as switchgear, secondary unit substations, motor control centres, relay panels, and control panels, shall have integral earth buses which will be connected to the station earth grid



Electronic panels and equipment, where required, shall be earthed utilising an insulated earth wire connected in accordance with the manufacturer's recommendations

All earth wires installed in conduit or copper free aluminium tray shall be insulated.

12.14.2 Lightning Protection

The lightning protection system shall be designed and reviewed in accordance

with IEC 61024. They shall consist of interconnecting air terminals with down

conductors to provide a low impedance path to ground and to the earth grid.

Lightning protection shall be provided for HV grid sub-station stacks and the top of

tall, unshielded buildings as required by the structures and plant arrangement.

Lightning protection for the stacks and buildings shall consist of air terminals

installed around the top of the structure. Air terminals shall be arranged to provide

protection for roof penetrating devices, such as piping, air moving equipment, etc.

Lightning down conductors shall follow the most direct route to earth. Lightning

conductors should have their own electrodes and should not be connected in any

way to the station earthing system.

All field electronic and communications equipment cables shall be protected from

lighting over voltages by surge arrestors at the termination panel.

12.15 Lighting System and Power Outlets

12.15.1 General Design Requirement

The plant lighting system shall provide illumination for operation under normal

conditions, and emergency lighting to perform manual operations during outage of

the normal power source, and include all equipment specified herein.

Suitable light fixtures, power outlet sockets and switches with associated control

distribution and lighting boards shall be provided for illumination and

miscellaneous power supply in all areas. Each lighting fitting and power outlet

shall be suitable for the respective location and degree of hazard in which it is

installed.

Wiring for lighting and power outlet sockets shall comply with local Electrical

Regulations.

All indoor fixtures shall be controlled at the lighting panel/switches located at the

entrance areas. Photo-cells shall control outdoor lighting circuits and shall include

bypass switches. Lighting panels shall be sized with a minimum of 20% future

spare capacity. Lighting panels shall be provided with a variation of spare

breakers and blank spaces.

Circuits at the distribution panel shall be wired in such a manner that they are

balanced within ±15% between the phases

12.15.2 Lighting Sources

Lighting fittings shall be of the following types:

a) High bay, flood lighting and general yard area - High Pressure Sodium

b) Control rooms and office areas - Fluorescent (Glare control is required)

c) Stairways, ladders, local lighting (pumps etc.) - Mercury Halide or Fluorescent.

12.15.3 Emergency Lighting

Adequate emergency lighting shall be provided to enable safe operation and exit

from the plant on failure of the main lighting. Emergency lighting is required in all



operating areas. Green internally illuminated EXIT signs shall be provided at

emergency exit doors and where required to guide people to emergency exits.

The emergency lighting systems primarily consists of lights fed directly from the

DC station battery for control room, electrical, and computer equipment room

areas. This system is supplemented by self-contained battery pack units and

emergency lights. The self-contained battery pack units shall be 2-hour rated with

nickel cadmium cells. Testing facilities shall be provided as an integral part of

these units. Each battery shall be automatically maintained charged by a mains

power supply dedicated to emergency lighting circuits.

Each emergency light shall switch on automatically upon loss of its battery charger

power supply and on failure of the local area lighting when the average residual

lighting level is below twice the minimum level specified for the emergency lighting

and switch off at four times the minimum level.

12.15.4 Outdoor Lighting

Light fittings and accessories for outdoor lighting shall be IP 65 rated. Fitting

bodies shall be constructed from die cast aluminium or other suitable non-

corroding construction with toughened glass face. All fitting shall have high grade

reflectors.

Poles shall be flange mounted in accordance with the pole Manufacturer's

requirements. All cabling shall enter each flange mounted pole from below ground

level.

A "gear opening" complete with lid shall be provided at the base of each pole. This

opening shall be used to gain access to the earthing stud and terminations

between the buried cabling and cabling within the pole up to the light fitting. All

equipment shall be mounted on a gear plate within the pole.

12.15.5 Power Outlet Sockets

Stores, workshops, the turbine halls, unloading bay areas and rooms containing

relays and switchgear shall also have three phase socket outlets rated not less

than 20 amps at intervals not exceeding 20m along the walls and 0.5m above

workbenches in workshops. These shall be additional to outlets required for

building services, operational and general equipment requirements.

All items of outdoor plant shall have one single phase and one three phase socket

outlet installed at a convenient junction box within 20m of it. The junction box may

be shared with cabling for the plant or outdoor lighting, but shall not be inside a

cubicle containing moving parts such as mechanism boxes associated with

equipment.

Residual current devices shall be fitted to all sockets that could be used to supply

equipment or appliances located either outdoors or in a wet or damp environment.

12.16 Fire Detection System

The fire alarm system shall be initiated from the detection system and manual push-buttons. Fire detection shall be a combination of devices that sense heat and those that detect smoke. Heat sensing detectors shall either respond to the rate of rise of temperature or activate at set temperature. Smoke detecting devices shall actuate in sensing both visible and invisible products of combustion.

The detection system shall be self-monitoring. If a fault occurs on the system, the monitoring shall be able to indicate the area and the detector that is faulty. The system shall consider duplicate alarm panels. The panels shall be programmed to allocate the plant into relevant zones, each with alarm and fault lamps complete with a mimic.



The control and electrical rooms and other enclosed buildings containing electrical equipment shall be provided with Very Early Smoke Detection (VESDA) systems. The VESDA systems shall detect abnormal heat and smoke from the vital areas and send audible alarms and electronic signals to the plant main control system. Areas to be provided with detection devices include but not limited to rooms, under-floor spaces, ceiling spaces and within switchboards. A reference cell located outside the plant building shall be provided to avoid false alarms.

Push-button stations shall be installed at strategic locations for manual actuation of a fire alarm. A Fire Indicator Panel (FIP) shall be used to supervise and control the fire detection system. The FIP shall be installed in a lockable cabinet accessible only by authorised emergency personnel and shall be located in a secure central location. The system shall include local supervisory panels at local valve stations and shall report to the FIP. Fire alarm or fault signals from the FIP shall instantly alert the facility operator, communicate the alarm to the control room and the plant ICMS (Integrated Control Management System). All local supervisory panels shall be provided with audible fire and trouble alarms. Battery backup shall be provided on all panels.

12.17 Cathodic Protection

Deteriorating effects of galvanic corrosion on vital metallic structures shall be mitigated using either of the two types of cathodic protection techniques: the distributed galvanic anode system and impressed current anode system. Selection on the type of protection system on affected structures shall be determined by the Contractor based soil analysis conducted in actual locations. Cathodic protection systems shall be designed to meet the protection criteria on structure and materials as required in the latest versions of National Association of Corrosion Engineers (NACE) International standards.

The structures that shall be protected include, but not limited to, the following:

The metallic base or bottom of over-ground concrete pad mounted fuel oil storage tanks

The exterior surfaces of buried metallic piping including carbon steel, stainless steel, copper, and brass pipe

The exterior surfaces of large diameter steel pipes for circulating water system

The interior surfaces of shell and tube type auxiliary cooling water heat exchanger channels wetted by circulating water

The interior surfaces of shell and tube type condenser water boxes wetted by circulating water

Travelling water screens.

Bar screens and water submerged structures

12.18 Electrical Apparatus in Hazardous Areas

The Contractor shall identify in a drawing all areas with potentially explosive atmospheres zoned into the appropriate risk categories. For the purpose of the tender specification, it is sufficient if the hazardous areas are shown on the general layout drawing. Detailed drawings with relevant views of the plant are required for the later approval of the design.

All electrical equipment and cables within these areas shall comply with the rating of these zones and be manufactured and certified accordingly. Intrinsically safe switchgear and wiring located outside hazardous areas, but connected with circuits leading to hazardous areas, shall be designed and certified accordingly.

All electrical equipment used in hazardous areas shall be certified and comply with API RP 505 Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class 1, Zone 0, Zone 1 and Zone 2 and NFPA 70 National Electrical Code 2008. The Contractor shall ensure that equipment items sourced internationally and designed to the national standards of the manufacturer comply with international standards.



The zoning of hazardous areas will impact on operating procedures of the plant operator. Access to these zones may be restricted and special precautions may be required, which shall be considered in the design of the plant.

Risk analysis study along with Hazardous Area classification Report as per NFPA 497 (or equivalent) shall be submitted for Owner approval after award of contract.

12.19 Power Evacuation

APSCL has planned to install a 400 MW combined cycle power plant in the east side of existing Ashuganj 225 MW CCPP plant premises. Generated Power (400 MW) from plant will be evacuated through under construction 400 KV GIS to National Grid.

Step-up transformer shall be three phase with a capacity of not less than 525 MVA and the unit will be connected to the 400 kV GIS bus-bars through the circuit breakers. Connection with 400 KV Bus bar and new bays equipment including CB, DS, CT, PT, ES, Protection relays and interface with existing bus-bar differential protection & other protection and control system etc. will be within the scope of offer. Proposed power plant should be connected to under construction 400 KV GIS substations at a distance of 2.5 km through underground 400 KV XLPE cable.

12.19.1 Cable Construction

The conductor shall consist of plain annealed high conductivity copper wires of

99.99% purity in accordance with class 2 requirements of IEC 60228. The

conductor shall be clean and free from metallic and foreign particles, which may

contaminate the insulation or cause high stress points.

Provision shall be made to prevent the longitudinal passage of water. This shall be

achieved by the application of water swelling tapes around each layer of

conductor wires to form a water barrier to prevent water penetration along the

conductor in case the cable is broken. A radial water barrier over the conductor

alone is not acceptable.

The conductor screen shall consist of a semi-conducting binder tape applied over

the conductor and a layer of black extruded super-smooth semi-conducting

compound which shall be firmly bonded to the inner surface of the insulation. The

semi-conducting material shall be compatible with the insulation and the semi-

conducting tape.

The thickness of the extruded conductor screen shall be as specified in the

Technical Data Sheets.

The outer surface of the conductor screen shall be cylindrical, smooth and free of

protrusions and irregularities. The outer surface of the conductor screen shall be

firmly and continuously bonded to the inner surface of the insulation and shall

have no tendency to separate from the insulation due to the effect of bending

during installation, load cycling and short circuit under service conditions.

The volume resistivity of the extruded conductor screen shall not exceed 1,000

Ωm at 900C.

12.19.2 Insulation

The insulation shall consist of a homogeneous extrusion of super-clean cross-

linked polyethylene (XLPE) complying with the requirements specified in IEC-

62067 recommendations. The cross-linked polyethylene insulation produced shall

be free from micro voids, contaminant, protrusion and moisture content as

specified in the above standards.

The insulation screen shall consist of an extruded layer of black, thermo setting

semi-conducting super-smooth material applied directly over the insulation. The

thickness of the insulation screen shall be as specified in the Technical Data

Sheets.



The inner surface of the insulation screen shall be smooth and free of protrusions

and irregularities and shall be firmly and continuously bonded to the outer surface

of the insulation and shall have no tendency to separate from the insulation due to

the effect of bending during installation, load cycling and short- circuit under

service conditions.

The volume resistivity of the extruded insulation screen shall not exceed 500 Ωm

at 90ºC.

12.19.3 Manufacturing Process of Conductor Screen, Insulation and Insulation Screen

The conductor shall be covered with three layers (screen, insulation, screen) the

insulation being of super-clean HV insulation compound, extruded under high

pressure and heat treatment. The conductor screen, the insulation and the

insulation screen shall be mutually compatible and shall, in the same

manufacturing process, be continuously extruded and completely dry cured by a

common head (simultaneously).

For insulation row material handling, direct feed system and for cooling after

vulcanization, dry cooling are preferred.

To reduce the methane content of XLPE a heat treatment for minimum 22 days at

750C after curing shall be carried out. The Contractor shall provide evidence to

have degassed the cable as mentioned before.

The extruded conductor screen, insulation and insulation screen shall be

manufactured to the highest standards of concentricity, diameter roundness and

longitudinal diameter stability.

The Contractor shall provide a detailed description on the extrusion, curing,

cooling and heat treatment after curing processes.

12.19.4 Bedding Tape

The core shall be taped overall with semi-conducting tape(s) to prevent

mechanical damage to the cable core during manufacture and in service.

12.19.5 Insulation Screen (Metallic)

For the purpose of increasing the total short circuit current rating of the cable, a

copper wire screen of suitable cross-sectional area shall be applied over the semi-

conducting bedding layer. A suitable counter helix tape shall be applied over the

copper wire screen. The dimension of the copper wire screen shall be fully

compatible to the respective design of the overall cable construction.

12.19.6 Longitudinal Water Blocking

Means shall be provided to prevent the longitudinal passage of water in the space

between the insulation screen/insulation screen copper wires (if applicable) and

the inside of the lead sheath.

Any material used shall be sufficiently conducting to prevent the development of

harmful voltages between the lead sheath and insulation screen/insulation screen

copper wires (if applicable) of the cable under all operating conditions of the cable

system.

The longitudinal water barrier shall consist of a semi-conducting water swellable

tape applied over the extruded insulation screen/insulation copper screen wires (if

applicable). The water barrier shall be applied such that the complete cable will

meet the requirements of water penetration test as per the relevant latest IEC

recommendations.



12.19.7 Metallic Sheath

The water impervious sheath shall consist of a seamless and continuously

extruded tube of lead alloy. The lead alloy used for the sheath shall meet the

requirements of BS EN 12548 and BS 3908 recommendations. A thin layer of

bitumen shall be applied over the sheath.

The lead alloy sheath shall be of best quality, and shall be tightly extruded over

the water blocking layer.

The metallic sheath shall be impervious to moisture, tightly fitting and free from

defects and impurities such as oxides that could give rise to failure under working

conditions. The lead alloy sheath shall also have good creep ductility to provide

the necessary mechanical strength for the cable due to the effect of bending

during installation, load cycling and short circuit under service conditions.

12.19.8 Short-Circuit

The Bidder/Contractor shall prove by calculation that the metallic sheath and the

insulation screen copper wires (if applicable) of the cable can withstand not less

than the system short time current rating specified in the Technical Data Sheets.

When carrying the short-circuit current, the integrity and performance of any part

of the cable shall not be deteriorated due to the rise of the surrounding

temperature. The sheath temperature under specified short circuit conditions shall

not exceed the allowable temperature rise of the insulation or the allowable short

circuit temperature of the sheath protection covering whichever is lower.

12.19.9 Outer Sheath

The outer covering shall be of high density polyethylene (HDPE), termite-resistant

and suitably prepared against cracking and decomposition under the prevailing

service conditions at site. The outer sheath shall be covered with a black semi-

conductive layer. Preference is given to an extruded semi-conductive layer rather

than graphite coating. On the outer sheath the following shall be embossed at one

metre interval starting from 000 (if the starting number is not 000 then it has to be

marked on the flange of the delivery drum as well as the ending number) against

each drum length:

Voltage designation

Cable size

Manufacturer's name

Year of manufacture

Employer's name as “PROPERTY OF APSCL”

Sequential length marking at every metre interval starting from 000.

12.19.10 Testing and Inspection

The Contractor shall carry out electrical and function tests in accordance with the

latest edition of IEC recommendations when installation of the cables has been

completed.

12.19.11 Site Test Insulating Barrier of Joints

10 kV DC Test for 1 minute on insulating barrier of joints before cable jointing.

12.19.12 Special Bonding Test

Correctness of special bonding: With the links in the link box in their correct

positions, a three phase current of approximately 100 A shall be applied to the



main conductors. The currents and voltages shall be measured and agreed with

theoretical values supplied by the Bidder/Contractor.

Contact resistances: The contact resistances of the links shall be measured and

compared with specified values.

SVL characteristics: A test current of 10 mA shall be applied to the SVLs, which

shall be disconnected from the links. The measured voltage shall conform to the

characteristics declared for site tests by the Contractor in the Technical Schedule.

12.19.13 Impedance Measurements

Measurements of the actual zero sequence impedance and positive/negative

sequence impedance of the installed cable.



13. CONTROL AND INSTRUMENTATION

13.1 Description of Control Architecture

13.2 Introduction

This Section describes the control, instrumentation and communications philosophy for the Ashuganj CCGT including interfaces with the indoor 400 kV GIS grid substation and the Bangladesh National Load Dispatch Centre (NLDC). The control and instrumentation system is defined as an Integrated Control Management System (ICMS).

13.3 Scope

The ICMS systems shall be supplied as part of the Contract for the complete power station and associated works. The Contractor's Scope of Works comprises the turnkey design, engineering and supply, construction, testing and commissioning of plant and equipment, all as necessary to meet the design criteria specified, including all and everything within the specified limits, to achieve the defined design and operating criteria and to provide and maintain the services and facilities listed within this section.

The ICMS scope of this Contract shall include, but not necessarily be limited to, the design, supply, integration, programming, testing, installation and commissioning of control, instrumentation, ICMS and communications equipment consisting of:

Turbine control systems

Generator control systems

Fuel gas control system

Heat Recovery Steam Generator control system

Steam bypass control

Instrumented protective systems including fire and gas detection systems

Balance of plant distributed control system including communications interfaces

Instrumentation and Field bus connections to the instrumentation

ICMS system including communications interfaces

LAN and WAN equipment to link all systems on site

Plant health and asset management system

Plant performance evaluation system.

Peripheral systems such as data historian interface, station clock system, building services and closed circuit television system

Cable to monitor the status of the ASPCL 400 kV substation circuit breakers and isolators used to connect the Ashuganj CCGT to the national power grid

Cable, software, SCADA and communication equipment required to interface the ICMS to the National Load Dispatch Centre (NLDC) communications equipment in the APSCL 400 kV substation control building

Software modification works at the NLDC master station to incorporate the Ashuganj CCGT.

13.4 ICMS Design Principles

13.4.1 General Design Principles

The following general ICMS design principles shall be followed:

Consistent Design Standards: A consistent set of design standards for control

and instrumentation shall be adopted throughout the Contract, project-wide,

including all plant packages and auxiliary plant.

Safety: The control system shall ensure that the plant is operated in a safe

manner to protect personnel and equipment. In order to remain safe for personnel



and equipment, the control system shall maintain safe operation as long as it is

feasible, or be able to shut down the plant in a safe manner.

Fault Tolerance: The ICMS shall have the flexibility of fault tolerance in all key

areas such as local area network (LAN), ICMS, safeguard systems, human

machine interface (HMI), input/output (I/O) field termination racks (FTR) and I/O

field devices. Fault tolerance shall be effected via redundancy using backup (hot

standby) items both in hardware and software.

Self-Diagnostics: The ICMS components shall have self-diagnostics

(maintenance software) and be hot-swappable (including main processors)

without any impact on unit operation. Programming changes shall be able to be

achieved in simulation mode, tested and transferred on-line without any impact on

unit operation. Card level/Channel level diagnostic shall be made available at

operator station level to facilitate smooth operation/maintenance of the plant.

Maximize Plant Availability: The control system shall be designed in such a way

as to cater for maximum plant availability at all times; maintaining production for

as long as is required while maintaining safe operating conditions. Strategies to

assure this shall include automatic changeover of redundant plant, alternate

control strategies to allow for plant maintenance and minimization of outages

under plant failure conditions. This shall include equipment condition analysis

through real time condition monitoring.

Reliability: The components of the ICMS shall be selected and implemented to

provide maximum reliability. A single item failure in the ICMS shall result in only a

limited degree of degradation in the system facilities. The system architecture

shall allow for redundancy, fail-over and fast system recovery to cater for

maximum reliability.

The ICMS and equipment shall be designed to comply with the following general

criteria:

No single channel fault shall cause the complete failure of the control system

No single fault shall cause the protection system to spuriously operate or cause the protection system to become inoperative

No single failure of any system equipment or power source shall interrupt or disrupt any system function

No single failure shall cause any controlled equipment to change status, except as specifically described in this Specification

No single communication link failure shall render forced outage of any plant

For redundancy provisions of equipment, no single fault within the control system shall cause the failure of the duty equipment and at the same time cause the standby plant to be unavailable. With duty equipment in service, any failure within the control system that causes the standby equipment to be unavailable shall be alarmed to the operator

No failure within the ICMS system or wiring shall impose any earth path for any power source provided

Alarms and trips shall remain active in manual and automatic modes, including transitions between modes

All system failures shall be alarmed and logged for historical analysis

All operator commands shall be logged in a journal for audit purposes

The system integrity shall be such that the over-all system reliability is 99.98%.



The system shall be designed for a minimum service life of 25 years with normal

routine maintenance.

Operability: The system shall be designed to ensure ease of operation in a safe,

efficient and ergonomic fashion. Operators shall be provided with all of the

information necessary to monitor plant operation and diagnose problems to

maintain proper plant control. Operators shall be able to easily modify the plant

operating parameters within appropriate limits to meet production demands.

During the normal on-line operation of the power plant, the main operator-

functions, as carried out from the Central Control Room (CCR), shall be those of

supervision and selection of the appropriate pattern of running plant to meet the

electrical load demand target with optimum fuel economy, generation and

production security within any operational plant constraints.

The essential plant operational management functions of starting up, shutting

down and load demand setting of the power plant units shall remain directly under

the operator's control whilst the on line regulation of the plant component (e.g.

turbines, generator etc.) shall be fully automated.

Maintainability: The system shall provide all tools and facilities to enable all of the

necessary regular and intermittent maintenance.

All control systems shall be designed so that, in the event of failure of a redundant

item or module, then the failed item can be removed and replaced whilst the

control system is on line without disturbing plant operations in any way.

Maximum interchangeability of work station functions shall be provided through

industry standard platform independent software. Efforts should be made to

accommodate combined engineer/operator station, operator/historian station,

operator/link station etc. these arrangements or combinations shall ensure that if a

failure occurs in any station the corresponding software may be loaded in another

station without creating a functionality loss. The Bidder shall advise to what extent

this shall be achieved.

Flexibility and Expandability: The control system shall be able to change and

grow to suit the future needs of the plant. The control system shall be flexible

enough to adapt to changes in control strategies.

Commonality of Sourcing: The Contractor shall, where possible, apply a policy

of commonality in selection of vendors for all control and instrumentation

equipment including ICMS components, software, control valves, motorized valves,

actuators, transmitters and programmable logic controllers. The Bidder shall

advise to what extent this shall be achieved.


The equipment shall comply with the following codes and standards and with the

requirements of any statutory or local authority having jurisdiction over the

equipment. Where equipment is manufactured to standards other than those listed,

it shall be the responsibility of the Contractor to prove that the equipment complies

with the following standards:

BS 1024 Specification for Measurement of Fluid Flow

BS 3693 Recommendations for Design of Scales and indexes On Analogue indicating instruments

BS 6739 Code of Practice for Selection, installation and Maintenance of Electrical Apparatus for Use in Potentially Explosive Atmospheres

BS 759 Specification for valves, mountings and fittings



BS 7671 Requirements for Electrical installations of IEE Wiring Regulations

BS EN 50014 Electrical Apparatus for Potentially Explosive Atmospheres

BS EN 55011 Specification for Limits and Methods of Measurement of Radio Disturbance Characteristics of industrial, Scientific and Medical Radio Frequency Equipment

BS EN 60051 Direct Acting Indicating Analogue Electrical Measuring Instruments and their Accessories

BS EN 60079 Code of Practice for Selection, installation and Maintenance of Electrical Apparatus for Use in Potentially Explosive Atmospheres

BS EN 60584 Thermocouples

BS EN 60654 Industrial-Process Measurement and Control Equipment – Operating Conditions

BS EN 60751 Specification for Industrial Platinum Resistance Thermometer Sensors

BS EN 837 Specification for Bourdon Tube Pressure Gauges.

IEC 60255-5 Electrical Relays - Part 5: Insulation coordination for measuring relays and protection equipment - Requirements and tests

IEC 60255-21 Electrical relays - Part 21: Vibration, shock, bump and seismic tests on measuring relays and protection equipment

IEC 60255-25 Electrical relays - Part 25: Electromagnetic emission tests for measuring relays and protection equipment

IEC 60297 Mechanical structures for electronic equipment - Dimensions of mechanical structures of the 482,6 mm (19 in) series

IEC 60529 Degrees of protection provided by enclosures (IP Code)

IEC 61000-4 Electromagnetic compatibility (EMC)

IEC 61131-3 Programmable controllers - Part 3: Programming languages

IEC 61158 Industrial communication networks - Fieldbus specifications

IEC 61508 Functional safety of electrical/electronic/programmable electronic safety-related systems

IEC 61511 Functional safety - Safety instrumented systems for the process industry sector

IEE 80 IEEE Guide for Safety in AC Substation Grounding

IEEE 1050 IEEE Guide for instrumentation and Control Grounding in Generating Stations

IEEE 665 IEEE Guide for Generating Station Grounding

IEEE 802-3 Ethernet LAN

NFPA 850 Recommended Practice for Fire Protection for Electric generating Plant and High Voltage Direct Current Converter Stations.

The Bidder shall submit his methodology of justification for the Safety Integrity

Level proposed for the plant in accordance with IEC 61508.

The ICMS standard symbols and documentation shall conform to either ISO or

ISA standards or codes.



13.5 ICMS Architecture

In view of the above and current design practice, it is proposed that the ICMS be of the general arrangement. The arrangement is intended to be generic and not based on specific vendor equipment although modern control and automation systems shall generally follow this approach.

13.5.1 Distributed Control System

The control system shall be designed with a distributed architecture with the

following objectives:

Distributed Architecture: Database shall be global or distributed in nature

architecture with the point database being resident in all of the station controls.

This shall ensure availability of plant data on all the operator stations for the

purpose of increasing the reliability of the power plant operation.

Open Structure: The system shall be truly of open structure type and

accommodative to accept all third party equipment/software with properly defined

path and with minimum constraint to the human machine interface (HMI).

Industry workstations shall be directly connected on the redundant communication

bus WITHOUT any proprietary interface (protocol conversion) hardware. Provision

for Laptop computer connections shall be included in the workstations.

Functional Distribution: It is expected that each control sub-system shall be

responsible for the control functions for a particular group of plant.

Failure Independence: If a failure occurs in any sub-systems, functionality shall

be such that it does not affect other sub-systems.

Physical Isolation: The effects of problems such as fire or extreme electrical

interference shall be minimized by physically isolating each of the components of

the system where necessary.

Connectivity: The communications network shall allow passing of information

between each of the controllers and access to information by operator stations

and higher level computing facilities. This shall be such as to allow for engineering

workstations to gain access to all levels of the ICMS networks for maintenance

purposes.

Performance: The system architecture shall be such that the amount of network

traffic is kept to an optimal level to assure system performance criteria are met at

all times.

Minimal Complexity: The system shall be designed to optimize communication

traffic and the requirement for communication between sub-systems and the

various components to reduce complexity.

Functional Distribution: The controls shall be functionally distributed. The

functional process controllers shall be implemented redundantly with automatic

take over by the redundant device on failure of the primary device. Controller

redundancy shall be provided in a one to one fashion. No one failure on one

processor shall cause a failure on the backup processor during changeover.

13.5.2 Data Communications Network

The distributed controller modules communicate with the operator stations and

with each other through high speed data highways (Ethernet). The data highways

shall be dual redundant fibre optic cable capable of data transmission over a

distance of a minimum of 1,000m without any repeater.

However, extension of the data highways shall be possible.



Data highway shall be Industry Standard such as 100 MBPS, redundant switched

fast Ethernet full duplex communication network. No modifications shall be made

to the Industry standard IEEE 802.3e communication protocol.

The communication system shall have all necessary fault diagnostics. Any errors

shall be alarmed and recorded in the Central Control Room (CCR). Non-active

links shall be continuously monitored for healthy status and an alarm raised if a

failure is detected.

Operation of dual highway system shall be such that failure of one highway shall

not affect the operation of a power plant unit and control shall be automatically

switched from failed highway to the functioning one.

The two highways of the dual system shall be specially separated and the cable

ducts shall take different routes. If the data highway has no automatic switch over

facility at a regular interval, integrity checking of the hot stand-by system shall be

provided.

Loading of the data highways shall be such that there is at least 25% spare

capacity even under extreme disturbed condition.

In case of loss of both data highways, the individual controllers must remain in

operation. Under no circumstances shall one single failure lead to an outage of the

complete data system.

The data protocol used shall safeguard against erroneous data transmission and

allow for error detection, recovery and initiate switch-over to the redundant data

highway.

13.5.3 Network Components

The hubs, switches, routers, bridges and other components provided for the local

and wide area network communications shall be of the industrially hardened type

and shall be capable of continuous operation under the range of environmental

conditions experienced on site.

All network equipment shall obtain power either from the DC battery system or

from UPS supplied AC.

13.5.4 Field Bus

It is preferred that field instruments and actuators be connected by a standard

industrial fieldbus such as Foundation Fieldbus, Profibus or one of the other field

buses defined in the IEC 61158 standard.

If any instrumented protective systems utilize fieldbus connections then this bus

system shall be certified for use in safety applications.

13.6 ICMS Characteristics

The ICMS should have the following general characteristics:

The control system shall have been developed for power generation plant control, incorporating proven hardware and firmware for such applications

The control system shall have a demonstrable development history

The manufacturer shall operate a design policy incorporating compatibility between versions / generations of equipment

The version of system proposed shall be the manufacturer's latest current design (state of the art) and shall be identified

Engineering support facilities are in place regional to Bangladesh



The control system must have a satisfactory reference list illustrating power generation applications. The Bidder shall submit the 5 year reference list with their bid.

The manufacturer shall provide with the Bid, his undertaking to provide support, in terms of spares provision / compatible solution, maintenance and engineering for a period of 25 years from the taking over date for the station. The manufacturer shall provide with the Bid an explanation of the history of his customer support policy by outlining the duration of support provided for previous generations of control system

The control, instrumentation and monitoring equipment to be provided shall be suitable for faultless and safe control and supervision of entire power plant during all operating conditions and shall be suitable for the location in which it shall be mounted

Control processors and instrumentation shall be provided such that no single failure can cause a forced outage of a generating plant or the power station. Triple modular redundant control system (2 out of 3 voting) shall be provided for all plant safety critical control and protection systems

All components shall be of an approved, modern, compact and reliable design incorporating the latest developments in proven technology and in use at other similar projects and similar conditions. The highest extent of uniformity and interchange ability shall be reached across the entire plant. The design shall facilitate an easy maintenance and repair of the components

All components shall be tropicalized and designed for the applicable ambient and site conditions 3

As a general rule, measuring points and measuring equipment for interlocking and protection purposes shall be separate and not combined with measuring equipment for monitoring or automatic control equipment.

13.7 ICMS Functionality

The ICMS shall:

Perform “limited attendance” unit operation through a Ashuganj CCGT control room operator-initiated “single push button” cold start, synchronize on line, run up to demand generation as set by either (selectable) the Ashuganj CCGT control room operator or the National Load Dispatch Centre (NLDC) set point generation control within the range of lowest continuous rating (LCR) and 100% maximum continuous rating (MCR) and conversely run down to cold stop under safe and controlled conditions

Perform a Ashuganj CCGT control room operator-initiated “single push button” hot re-start

Provide expert system and high level operator assisted control

Automatically ensure safety of personnel and equipment under all Plant operating conditions.

Supervise and control all the facilities provided for the Plant

Maximize the availability and efficiency of the Plant

Enable the Plant to be operated and maintained with the minimum of appropriate personnel consistent with cost effectiveness and safety

Provide station auxiliary electrical supervision and control, including but not limited to monitoring of the associated 400 & 230 kV switchyard equipment

Provide interfaces as defined elsewhere, including but not limited to:

The remote NLDC, transmitting and receiving data to meet the requirements of the Power Purchase Agreement and system operational requirements.

A facility for remote monitoring of the status of the control system thereby enabling remote diagnosis of faults

Provide real time performance monitoring of the Plant

Provide life-consumption monitoring of the Plant



Provide an interface for the application of equipment for condition monitoring for major items of Plant enabling the Employer to carry out reliability centered maintenance; the condition monitoring system shall be interfaced with the ICMS to facilitate correlation with process variable data

Meet the operational and design requirements as specified

Provide filtered Plant alarm monitoring and interlock functions to provide a means of alerting assistance for conditions where limited attendance operation cannot be achieved included plant shut down

Provide Plant data logging, including but not limited to sequence of events, historical storage and retrieval, trending, reporting, and data management and display

Minimize the cable requirements on Site.

13.8 Points of Monitoring and Control

The Plant equipment will be controlled at four levels as follows:

Locally at individual plant items for maintenance and testing purposes

Locally at Process Stations for monitoring and testing of subsystems

Central Control Room

Generator set point control remotely from the NLDC and monitoring of selected Plant I/O by the NLDC.

Full automatic control of the plant is only available from the CCR.

In addition, Human Machine Interface (HMI) software and equipment shall be provided for the following:

Engineer’s Workstation for software maintenance

Plant Manager’s Workstation for monitoring, data compilation/ reporting

Plant Conditioning Monitoring Workstation

Performance Monitoring Workstation.

13.8.1 Locally at Auxiliary Equipment

For maintenance and testing, it shall be possible to operate some equipment such

as pumps and valves from a local panel. A “Local/Remote” switch shall be

provided which will, when in the “Local” position, enable local Start/Stop or

Open/Close etc. controls. The status of the Local/ Remote switch shall be

monitored to provide a warning when remote control is unavailable.

13.8.2 Process Stations

There shall be Process Stations associated with some subsystems, such as the

governor for the turbines, demineralized water plant and gas booster station, from

which it will be possible to monitor the operation of the subsystem and control

sections of the plant for maintenance and set-up purposes.

A “Local/Remote” switch shall be provided at these stations which will, when in the

“Local” position, enable local operation of the section of plant. All safety interlocks

associated with the section of plant shall still be in effect under local control. The

status of the Local/Remote switch shall be monitored to provide a warning when

remote control is unavailable.

13.8.3 Central Control Room

All normal electrical and mechanical plant operations shall be initiated and

supervised from the Central Control Room (CCR). During such operations there

will generally be no need for staff to intervene locally at the plant itself.



The CCR and adjacent areas shall be laid out to meet the needs of the shift

management, the plant operators and the maintenance team and the storage of

documentation, such as manuals, printouts and magnetic media. The Contractor

shall produce a CCR design for the approval of the Employer early in the Contract.

The plant shall be operated by three operator workstations each comprising two

wide-screen 22 inch TFT flat panel VDUs (resolution of 1680 x 1050 or better), a

mouse device and functional keyboard. Any functional display can be called-up on

any VDU. Ease of use, thereby minimizing human error, is achieved by the design

approach which dictates that all the VDUs will operate with the same general

format of displays, graphics and associated system firmware. Consequently the

operator will always adopt the same interactive procedures, whichever part of the

combined cycle plant he addresses. Each workstation shall be able to be

configured as either an operator’s workstation, a supervisor’s workstation or an

engineer’s workstation through the entry of different passwords.

The system of VDU operator workstations outlined above shall be supported by a

small number of hardwired emergency stop pushbuttons and conventional

indicators.

The question of availability and reliability is resolved by the fact that, when

operator workstations are utilized in significant numbers as proposed here, the

failure of anyone of them has little impact.

The operator workstations shall be grouped together in the form of a control

console at which up to three operators can be seated.

The Contractor shall provide all furniture for the control room including operator

chairs, tables for printers and lockable cabinets for the storage of printouts, files

and consumables. A 60 inch wall mounted, high resolution LCD screen shall be

provided to display any chosen workstation screen.

Screens and windows shall be able to be selected from any of the three operator

workstations.

2 (two) high speed A3 colour laser printer and two black and white A4 laser

printers shall be provided for display and report printing from any workstation.

The control desk(s) shall designed to accommodate the VDU’s, keyboards,

telephones, public address controls, CCTV monitor and all other such devices.

The above design is proposed to:

Allow the manual start-up of the station by two operators and a supervisor

Facilitate training

Allow the presence of several operators enabling a consensus views to be achieved in the event of operational difficulties occurring.

Automation of plant groups shall be supplied, enabling the unit to be started up

fully automatically at the operator's request. However, the CCR operators shall

also be able to perform the start-up sequences manually so that operators retain

familiarity with the details of plant start-up. Manual start-up sequence shall be

monitored by the ICMS to prevent mistakes by the operators.

13.8.4 National Load Dispatch Centre (NLDC)

The NLDC is located in Dhaka (Rampura and Biddyut Bhaban) and was

constructed by Areva T&D of France. The NLDC is connected through a fibre optic

network to communications equipment and a remote terminal unit (RTU) located

on the ASPCL 230 & 400 kV substation control building. (NCR)



The following controls and indication are to be transferred between the Ashuganj

CCGT ICMS and the NLDC:

Power Plant to NLDC

Analogues

Station net output: MW (3 phase), MVAr (3 phase)

Voltage (VR-N, VY-N, VB-N)

Current (IR, IY, IB)

Load frequency control, real power setting

Fuel flow.

Single Indications

Load frequency control (LFC) on/off switch - status of actual LFC for the unit.

Power set on/off switch - status of LFC real power and maximum power variation amplitude for unit

Load frequency control unit fault

Local / remote switch for generator

Synchronizing in progress

Turbine trip

Generator trip

Accumulated fuel flow (pulse accumulator)

Megawatt hours (pulse accumulator)

Megavar hours (pulse accumulator)

Generator unit stopping

Generator unit available

Generator unit running

Generator unit stopped.

Double Indications

Generator MV circuit breaker closed

Generator MV circuit breaker open

Generator circuit breaker isolator closed

Generator circuit breaker isolator open

Generator HV circuit breaker isolator closed

Generator HV circuit breaker isolator open.

NLDC to Power Plant

Real Power set point

Status indications for all circuit breakers, isolators and earth switches in the Ashuganj 230 & 400 kV substation. A separate display shall be provided on the MMI to show this information.

The Contractor shall be responsible for implementation of AGC function in the

Power Plant in conjunction with existing NLDC control centers. The operating

modes of Power Plant shall be manually set by the plant operator and transmitted

to the control centre.



The operating mode shall be managed according to the following principles:

Plant operators shall always be able to force AGC_MODE OFF

Only the plant operator shall switch ON the AGC_MODE (i.e. AGC_MODE is never switched ON automatically)

On error conditions, AGC_MODE shall be switched OFF automatically (the error conditions shall prevent the operator plant switching ON). The typical error conditions shall be as follows:

AGC Faulty signal received

AGC Trip condition

Communication lost with the NLDC

Communication lost with the local RTU

At the application startup, AGC_MODE shall be always OFF unless activated by the operator

At a generator startup, AGC_MODE shall be set to the same state as before the stopping.

“AGC_MODE: ON” Processing - When AGC_MODE is ON, Plant interface shall

validate AGC set-points or raise/lower pulses received from the NLDC, against

static limits (MW) and ramp-rate limits (MW/min), and issues control signals to the

turbine controller, via the local RTU. Control signals to the plant shall be either set-

points (in MW) or raise/lower pulses, depending on the controller type.

“AGC_MODE: OFF” Processing - When AGC_MODE is OFF, Plant interface shall

not take into account the AGC signal received from the NLDC, but shall allow the

power plant operator to specify a local set-point for a generating unit or to issue a

raise/lower signal (depending on the plant controller type). In this mode, there

shall be no validation required. AGC recommended generation set points shall be

displayed to the power plant operator on a separate digital display.

AGC discrepancy - If the difference between the generating unit set-point and the

active output power of the unit is higher than a pre-defined value (in MW), during a

pre-defined time (in seconds), an alarm shall be locally generated (i.e. for the plant

operator). This facility shall be available in both the cases, set-point-controlled

units as well as pulse controlled units.

The Contractor shall supply and install:

A gateway at the Power Plant to provide the necessary IEC-60870-5-104 protocol signals to interface to the NLDC

Fibre optic cable between the power station and the Ashuganj 400 kV substation control building

Optical converters at both the Power Plant and the Ashuganj 400 kV substation

Materials and modifications as necessary to complete the communications circuit between the ICMS and the NLDC communications equipment. Refer also Section 13.14.4

Database/ ICMS/ EMS software modifications, preparation of screens drawings etc. at the NLDC to enable the power plant and switchgear to be monitored and controlled as referenced above.

13.8.5 Engineer’s Workstation

Software maintenance and development facilities for the control system shall be

provided in the form of an Engineer’s Workstation (EWS) located in a room

adjacent to the CCR. The EWS shall consist of a high resolution VDU, keyboard,



input device (e.g. mouse, trackball etc.) mounted on a suitable desk matching the

Operator’s Workstation in appearance. An A4 colour laser printer shall also be

provided. The EWS shall be connected to the ICMS via a data highway to allow

access to system and applications software and to live plant data. Access shall be

password protected. A central configuration master database is to be provided.

All necessary hardware and software shall be provided to allow engineering staff

to trace faults in the system and applications software, to create control strategies,

to monitor VDU screens and all other maintenance activities. Software

configuration and modification shall be done off-line and with the capability for

testing before downloading to the control processors.

The EWS shall allow system configuration, writing and executing of user written

macros, graphics development, report generation, logging specification, system

self-documentation functions, system monitoring functions (which show the result

of self-diagnostic tests), system database load/save etc. In addition it shall be

possible to tune controllers, change limit set-points, view all loop variables,

configure control systems, add and delete alarms.

For the generation of process graphic displays, a standard library of symbols shall

be used. A graphics package should be available on the system. This shall be

able to create user defined symbols and store them in user defined libraries. In

addition standard industrial ISA symbols such as heat exchangers, pumps,

compressors and tanks shall be provided.

Configuration of the control function shall be possible by simply selecting a

programmed algorithm and entering the required attribute information such as

input and output location and tuning constants. Control loop and sequential logic

shall be built by linking the desired control function as they appear on control and

sequential diagram. Modification shall be easily made by revising the attribute

information and inserting and deleting the control function.

The system shall monitor itself continuously for failures by means of self-

diagnostics. Diagnostic routines shall be applied for each control module. Detailed

diagnostic messages shall be displayed on the EWS and group alarms shall be

given at the process operator's desk.

Diagnostic displays shall be available to assist fault location. It is expected that

most faults will be quickly repaired by simple replacement of a card or module.

The diagnostic display should clearly identify the faulty compo-nent, the nature of

the fault and the component location.

If the required diagnostic functions/displays are not available in EWS then a library

of separate diagnostic hardware/software within the ICMS shall be provided.

13.8.6 Plant Manager’s Workstation

One operator console shall be provided for the Plant Manager with provision to

monitor and data compilation/report only. No control command shall be available

to this console. It shall be connected through MIS LAN or other appropriate device

as applicable with the proposed ICMS system. An A4 colour laser printer shall

also be provided.

13.8.7 Condition Monitoring Workstation

This workstation shall be located in a room in the power plant control building and

shall consist of a high resolution 22” TFT flat panel VDU, keyboard, input device

(e.g. mouse, trackball etc.) mounted on a suitable desk matching the Operator’s

Workstation in appearance. An A4 colour laser printer shall also be provided.

Access shall be password protected.



Comprehensive condition monitoring facilities shall be provided for the turbines,

generators, heat recovery steam generator and gas compressors. All necessary

hardware and software shall be provided including field transducers, processing

equipment, cabling, computer, printer and software package.

The system shall be designed to monitor, display and record specific parameter

associated with the general mechanical condition of the plant such as vibration,

temperature including bearing temperatures, turbine loss of flame, winding

temperatures etc. The software package shall be design to highlight deterioration

in the condition of the plant by assessing the changing trends in the plant’s

parameters. The software shall also take into account external influences on the

plant (e.g. number starts, hours run etc.) and raise an alarm when limits are

approached or are about to be exceeded.

The measured parameters shall be recorded and made available for analysis at a

later date and for archiving purposes. Recall of the data shall also be available

either in tabular or graphic (trend) display form. Suitable hardware and software

shall be provided for this purpose.

The condition monitoring system shall be provided fully configured and operational.

13.8.8 Plant Performance Monitoring

This workstation shall be located in a room in the power plant control building (it

may be the same room as for the Condition Monitoring Workstation) and will

consist of a high resolution 22 inch TFT flat panel VDU, keyboard, input device

(e.g. mouse, trackball etc.) mounted on a suitable desk matching the Operator’s

Workstation in appearance. An A4 colour laser printer shall also be provided.

Access shall be password protected.

Facilities shall be provided to enable the performance of the plant to be continual

monitored based on real time data. The equipment shall consists of the

workstation running software designed to calculate, display an report on the

performance of the overall plant and specific plant areas (e.g. gas turbine) heat

rate , net power output.

The system shall be designed to generate reports for analysis by management,

engineering and operating staff identifying/ specifying plant values such as MW,

MVAR, fuel usages, water uses etc. and calculate values such as plant

efficiencies etc.

The facility shall be computer-based and shall include all necessary hardware,

software data inputting and interconnection with other plant equipment to form a

complete and working system. It shall utilize real-time data derived directly from

the ICMS or directly from the individual plant controllers via suitable data

communications medium and shall employ non-linear optimization techniques.

Additional facilities shall be provided to allow operating, engineering and

management staff to carry out on-line and off-line optimization of the power plant.

On-line optimization of the operation of the generating plant and-auxiliary

equipment shall allow the running of a plant computer model in virtual conditions/

real-time using actual plant operating parameters. The model shall represent all

necessary plant areas including fuel system, electrical generator, etc. Information

and data defining the operation of the plant shall be generated directly from the

optimization model and be, capable of being stored later for analysis. Use of this

facility shall not directly affect the operation or control of the power station but will

be used to advise the operator of the current state of the plant and provide him

with operational alternatives. The selection of the operational alternative will be

the responsibility of the operator or engineering staff.



Off-line optimization of the operation of the power station shall provide the facilities

for operating and engineering staff to carry out "What Happens If ?" scenarios to

investigate the impact of operational changes on the efficiency and profitability of

the plant. Use of this facility shall not directly affect the operation or control of the

plant.

The operator facilities provided shall be suitable to allow the operator, engineering

or management staff to access all necessary items of data and to generate reports

as required. All associated hardware and software shall be provided and shall be

designed to match, as far as possible, other equipment located in the CCR in

terms of appearance and functionality. The optimizer shall be complete with its

own printer for generating reports, data schedules, diagrams etc. as required.

The system shall also be capable of connection to a remotely located computer to

allow the optimizer to be operated in a second location (to be selected by the

Client).

A library with standard and proven software for performance monitoring under

different scenario shall be provided by the Contractor at least 3 (three) months

before commissioning of the plant.

13.8.9 Security and Access Control

A password system shall be provided with a unique password for each user.

When "logging-in" to the system, each user shall be given access privileges at a

level set for the workstation that the session was initiated on and for the particular

user. For most users, the lower of the user or workstation privileges shall be

assigned at logon.

It shall be possible to define up to 16 privilege levels from low to full privilege.

Restricted functions in the system shall be assigned a privilege level and only

users with the assigned level or higher shall have access to the particular function.

A number of related functions may be assigned to one privilege level on a system

basis. Only the Supervisor, having logged in at the highest privilege level, shall be

able to display and modify privileges assigned to each user and change the

privilege level of a function.

When accessing privileged functions, the system shall first verify that the user has

the appropriate authority.

The session "log-off" procedure shall cancel the current access privileges of the

particular workstation. The access security “logging in” system shall also apply to

remote access terminals.

13.9 Displays and Reports

As a minimum, the following displays and reports shall be available:

13.9.1 Overview Display

An overview display shall enable the operator to determine the overall operation of

a large segment of the power plant. It shall indicate the alarm status of all loops.

The operator should be able to call up directly any over-view display.

13.9.2 Process Graphics Display

Dynamic interactive graphics of different sections of the power plant configurable

only through engineering environment (i.e. from a console via password access)

and use symbols from a library of standard/user defined graphic symbols.

Different plant sections shall be displayed on different pages.

Graphic displays should be of the interactive type with the possibility of integrating

process parameters ('live' points) through which it should be possible to control



the process. This includes control actions, such as Manual/Auto, On/Off,

Open/Close, set point generation, start of functional groups, etc.

The operation status of individual drives, progress and status of functional group

controls shall be displayed on the graphic pages with different colours being used

to identify different status and events.

Face plate and trending information shall be accessible from the graphic displays

directly through free format windowing facilities. All control parameters shall be

displayed on their respective graphic pages. It should be possible to view the

process variable and alarm points, and to view and change set point values,

manipulated variables, and controller mode, etc. from the graphic display.

13.9.3 Operator Input Windows

It shall be possible to select operator input windows from any of the displays and

to open various operator control windows simultaneously on the screen. When a

particular operator input has been accepted by the ICMS, this condition shall be

indicated to the operator by a change of colour, short blinking, short audible tone,

etc.

Process control operations shall be performed in two steps:

Entering/setting of value

Confirmation/execution of the entry.

In all cases the current and the entered data shall be shown separately.

Standard displays shall be used for adjustment of drives and open/closed loop

controls. All relevant values of the open loop or the closed loop controller (actual

value, manipulated variable, etc.) shall be displayed. All operator inputs shall be

transferred to the automation system only after the 'Execute' key has been

pressed.

13.9.4 Group Display

A group display shall include the status of a smaller number (6 to 8) of control

loops, including:

Bar charts with process variable, set-point and controller output

Numerical values of process variable and set-point, numerical value of output in percentage

Status indication of binary inputs and outputs

Status indication of functional group controls

Control mode of each control loop

Alarm condition in each loop.

The grouping of the control loops shall be done based on the system or equipment

mode of operation and shall be subject to the approval of the Employer.

13.9.5 Loop Display

The loop display shall contain all detail information of the individual control or

measurement loops, including:

Configuration of the loop

Control signals

Control parameters



Status of drive control and functional group control containing trip signals, interlocks, criteria, actual step of sequence and commands

Transmitter range alarm set values

Output limits.

13.9.6 Alarm Summary Display

All activated alarms shall be listed in chronological order. Alarms not yet

acknowledged shall be distinguishable by red and flashing annunciation. The VDU

shall display the message of occurrence and of disappearance.

All new alarm messages shall be displayed on the next available line and shall

flash until acknowledged from the keyboard. Every new alarm shall activate a bell

for 2 seconds to call the attention of the operator. If more alarms are detected

these are to be shown on the VDUs, more recent ones shall be displayed and the

earlier messages shall be shifted to the alarm backlog memory. In this case a

special message on the screen will indicate presence of messages in the backlog

memory. A key facility to recall the backlog messages on the VDU display shall be

provided.

The alarm condition of each point should be displayed on the group display by

colour change and blinking. Alarms acknowledge should be possible only from the

relevant (assigned) operator station. For all alarms a direct access to the

dedicated graphic display shall be provided.

On request the system shall list all the alarms implemented in the system,

grouped by equipment or function (turbine, generator, HRSG, common equipment,

electrical etc.), showing the alarm status of each alarm.

13.9.7 Trend Display

The system shall display both real time and historical trends at a minimum as

follows:

Real time trend: The real time trend shall be for a minimum time of one (1) hour at a sampling rate of 2 seconds and for further seven (7) hours at a sampling rate of 10 seconds

Historical trend: The historical trend shall be prepared from the data in the historian server.

Real time and historical trends shall be possible on any parameter or variable like

measured variable, set point, output, calculated value, etc. The trend display shall

be single line type and bar graph type and shall also display information like loop

tag, engineering units, span, current value, alarm status, etc. of the trended

variable. It shall be possible to display by scrolling or expanding the time base all

of the trend data available on the system. Selection of the tag sampling time for

real time and historical trending should be possible from the operator keyboard.

The system shall also have a multi-trend feature from which it can display the set

point, measured variable and output of any combination of variables on the same

trend variable.

13.9.8 Characteristic Curve

Multi-variable displays shall be provided to show the relationship between

individual process variables (e.g. compressor discharge pressure, load, exhaust

temperature). Actual values and design operating points shall be displayed to

determine whether a component is operating correctly or is likely to exceed one of

its limits.



13.9.9 Logging

The system shall be able to assemble data and print various kinds of standard

reports. The system shall provide the following basic types of reports as a

minimum:

Event lists

Operator action reports

Reports about hours of operation

Custom reports with fixed and variable formats.

The above reports shall use real time data, historical data, or calculated data

generated, by any node in the system or any connected device to the system. All

points in the system shall be available for logging.

Logging of hours of operation shall be performed for all important drives,

aggregates and auxiliary plants.

A report generation function shall be available at the Engineer’s Workstation and

the Plant Manager’s Workstation for free-format report generation of text and data.

The report shall be initiated:

On demand

At a predefined time (hourly, shift, daily, etc.)

Event triggered

Real time events with six hours’ worth of data to help in diagnosing shut-down incidents.

These reports shall be archived for further recall. Schedule assignment for reports

shall be flexible. Demand for immediate output of a report must not affect any

scheduled reports that have been set up previously.

The types or classes of data used by the report generator shall include:

Analogue variables and associated parameters

Operator entered values

Status of multi-state variables

Alarm and event messages

Calculated variables historical data values and status

Other retrievable tagged items.

The report generator shall also be able to incorporate text supplied for report titles,

subheading, messages, etc. Data validity indicators shall be propagated

throughout report production to provide information on the reliability of requested

values.

Math functions to provide more complex reports (more than list of totals and

averages) shall be a standard tool of the report package. The software package

shall be easy to use and not require programming skills.

13.9.10 Alarm Display

Abnormal operating conditions and events in the plant shall be annunciated. For

optimum identification of the cause of faults all alarms shall be displayed on VDU

and printed out in their true sequence of appearance. Corresponding graphic or

loop displays shall be immediately accessible by selection of individual alarm

messages.

The operator shall be able to enable/disable the printing of all or selected alarms.

The design shall include:



Detection of fault and status annunciation in correct time sequence

Changes in annunciation are to be printed out with annunciation tag number, text details, date and time of day

The system shall be self-checking for system faults and shall create its own alarms

Alpha-numeric signal code; at least 12 characters in addition to the print-out of time, status etc.

Sources of alarms shall include:

Status inputs

Analogue or derived variables

Instrument alarms within the ICMS (for example open circuit detection on analogue inputs, bad process measurement, etc.)

Discrepancy alarms (i.e. both limit switches open, etc.)

System fault alarms

Data communication alarms i.e. errors data.

Alarms shall be presented on the alarm display, the first being the newest

unacknowledged alarm. Different selection criteria shall be available for at least

the following:

Acknowledged / unacknowledged alarms

Priorities or states

Period of time

Systems or groups

Sources of alarms.

The display shall list for each alarm:

The time of alarm followed by DAY/MONTH/YEAR

The alarm point tag

The alarm point description

The violation type such as, high, low, deviation, rate of change, "bad" process value (high or low)

Priority indicated by colour

The alarm condition of each point shall be clearly shown in group graphics and individual point displays. Alarms should be displayed as they happen on the correct screen in the allocated area. It shall be easy to determine from these displays if the alarm has been acknowledged (for example, blinking indication for not acknowledgment alarms)

Regardless of its source, a configurable priority shall be able to be allocated to an alarm. For example, priorities could include:

Shut-down safety alarms or fire alarms

Vital alarms (abnormal process conditions which the operator may be able to correct) before protection is activated

Alarms which do not require the operator to be alerted, but which are to be recorded

System alarms.

Process alarms and “return to normal” messages shall be printed with a time

stamp as and when they occur. The operator shall be able to interrupt alarm



printing but the alarm archiving shall continue. Alarm reports shall be available on

request.

It shall be possible to process a selected number of signals in the Sequence of

Event.

13.9.11 Sequence of Events Recording

For Sequence of Events Recording (SER) function, the ICMS shall provide a first

out alarm capability. In the case of an avalanche of alarms, the system should be

able to discriminate between them by time and date in the order of their

occurrence.

The time resolution of the SER function shall be 1.0 millisecond or better, i.e. if the

second event occurs 1.0 millisecond after the first event, then the equipment shall

be capable of resolving the two events.

If alarms transmitted from other control systems (e.g. package systems) to the

ICMS via a serial links are processed in the SER then these alarms shall be

transmitted with the corresponding time tag and the clocks of the two control

systems have to be synchronized. If this requirement cannot be fulfilled then the

processing of these signals in the SER shall not be allowed. In this case the

important alarms from the package control systems shall be hardwired to the

ICMS.

The most important requirement for the SER function is that in case of plant

malfunction, correct time information shall be available for all signals processed in

the SER and that all signals of the plant which can indicate / trigger plant failure

are be included in the SER.

13.9.12 ICMS Configuration Summary

A block diagram of the ICMS system shall be provided showing the major

elements of the system and their operational status.

A display shall show the status and assignment of all printer queues, and the

primary and backup for all printers assigned to each queue. It shall be possible to

re-assign the printers and queues from this display.

13.9.13 Notepad Display

It shall be possible to assign a Notepad display to any of the above displays. The

Operator shall be able to enter free form text or graphics to these displays until

over-written or cleared.

13.9.14 Building Services and Instrumented Protective System Displays

Block diagrams shall be provided showing the major elements of the system and

their operational status. It shall be possible to view all major alarms and status of

equipment as defined in the building services and instrumented protective

systems including fire and gas detection systems.

13.10 ICMS Performance and Capacity

The ICMS shall provide response time during plant start-up of no longer than the following under peak load conditions:

Process alarms: CCR display and audible signal within 2 seconds of plant initiation

Event recording: display within 2 seconds, all points time tagged to 10 milliseconds; for points designated as sequence of events the discrimination shall be 1 millisecond or better.

Analogue updating: CCR display change within 2 seconds of a step change in a transducer output



Command from CCR: signal change at plant within 1 second of operator initiation.

13.11 Instrumentation

13.11.1 General

Instrument housings shall be in accordance with the IEC or other project

designated authority rating for the area in which the instrument is located.

Instruments installed in hazardous areas shall be suitably certified for operation in

the designated zone.

Instruments and transmitters shall be of a type, brand and model that is sold and

supported in Bangladesh.

13.11.2 Thermowells and Protecting Tubes

The selection, construction, and location of thermowells shall be in accordance

with the recommendations and standards set forth in the following references:

ASME PTC19.3 -- Temperature Measurement

ANSI/ASME B31.1 -- Code for Pressure Piping

ASME Boiler and Pressure Vessel Code, Section VIII, Division 1.

13.11.3 Thermocouples and Resistance Temperature Detectors

Temperature measurements for remote use shall be by temperature detectors and

appropriate transmitters. Temperature detectors for high temperature points shall

preferably be thermocouples. Thermocouples shall be of the chromel-alumel type

(ISA Type K) with Type KX extension wire. Thermocouples and extension wire

shall comply with the standard limits of error in accordance with ANSI MC96.1-

1975. The elements as a rule shall be separate from ground (ungrounded).

Resistance temperature detectors (RTDs) shall be of the three wire platinum type.

The nominal resistance of the platinum detectors shall be 100 ohms at 0°C. All

RTDs for measurement of fluid system temperature shall be ungrounded, metal

sheathed, ceramic packed, and suitable for the design temperature, pressure, and

velocity of the fluid system.

13.11.4 Transmitters

Transmitters shall be used to provide the required signals being 4 to 20 mA dc

and/or serial digital bus signals as described in Section13.5.4.

Transmitters shall be designed with provisions for zero and span adjustments, and

shall have accuracy of 0.1 percent of calibrated span. Where necessary,

transmitters shall include mathematical functions or tables to convert measured

value into appropriate engineering units.

13.11.5 Process Measurement Switches

Process measurement switches shall have screw type or compression type

terminal connections on a terminal block for terminating field wiring. Switch set

point shall be adjustable. Contacts shall be of the snap-acting type. Mercury

switches are not acceptable.

13.11.6 Local Indicators

Indicators for local mounting shall have 115 mm minimum dial size. Dial scales

shall be such that the normal operating range is in the middle third of the dial

range.



13.11.7 Solenoid Valves

Solenoid coils shall be Class H high temperature construction and shall be

designed for continuous duty. Three-way solenoid valves shall be designed for

universal operation so that the supply air may be connected to any port. Solenoid

enclosures shall be weatherproof.

13.11.8 Actuators

Smart ("intelligent") actuators with built-in diagnostic and configuration features

should be used where possible.

13.11.9 Earthling

A separate instrument earth shall be provided and all instrumentation cable

screens and instrument earth’s shall be connected to this earth. The

instrumentation earth should be connected to the main station earth at one

location.

13.11.10 Calibration Test Bench / Console

The Contractor shall supply and install a calibration test bench. The details

provided below should be considered as an outline only. The Contractor shall

ensure that the calibration test bench provided is suited to the calibration of all

control and instrumentation equipment provided under the Contract. If at any

stage it is found that some device provided under the Contract cannot be easily

calibrated by the test bench, the necessary calibration equipment shall be deemed

to have been included in the Contract and shall be provided by the Contractor at

no additional cost.

The calibration equipment, instruments and modules will be mounted (where

possible) on a suitable dimensioned and ergonomically designed metallic work

bench / console. A full set of hand tools required for the calibration process shall

also be conveniently mounted on the work bench / console.

Features shall include:

A centrally mounted multi-function calibrator and control centre

HMI consisting of a LCD TFT colour screen (minimum 10.4 inch) with keyboard, mouse and printer as appropriate

Pre-loaded calibration software of all necessary test and calibration procedures to allow the automatic, semi-manual and manual calibration of all devices

The software shall be user friendly and flexible. It shall automate the operation of the calibration of instruments and management of the data. The user shall be able to track the calibration data, as a minimum, based on date, quality and standards. The software shall be able to communicate with calibration instruments of different makes and models

Include login security for multiple levels such as administrator, engineer, technician etc. to ensure security of calibration and calibration data

Store as a minimum the following information as appropriate for the device under test in a database: tag number, identity number, serial number, model number, device type, department, location, calibration date, next calibration date, calibration period, calibration interval, externally calibrated, reason of calibration, procedure name, device under test (DUT) accuracy, accuracy calculation, accuracy units, sensor low range value, sensor high range value, minimum span, scheme name, input function, input range, output function, output range, minimum input, maximum input, minimum output, maximum output, remarks. Detailed structure of the database format should be given at the time of commissioning



Generate calibration test report, repeatability report, linearity report, history report, data report, graphical report, instrument listing, instrument detail, reminder/recall note and user listing report

Report in advance all instruments due for calibration within an operator assigned period selectable between 7 and 30 days

Display calibration acceptance criteria and comparing criteria of the DUT

The software shall eliminate hard copy record keeping but shall allow hard copy reporting if selected by the operator

History card function for recording / reporting servicing, repairs and performance data in a user friendly manner, enabling the operator to decide whether to repair or replace an instrument

The customizing and printing of test certificated

The parallel calibration of different instruments and sensors simultaneously

A data logger with a minimum of 10 channels with inbuilt segment linearizer approximation of each channel

Multi batch trending function

Screen image storage

Allow the customization of menu bar and display functions

Support Ethernet IP addressing

Messaging through web browser

Memory not less than 16 GB

Data conversion to Excel spreadsheets

Back-up device / facilities

It shall be possible to transfer the data from the test bench to a PC loaded with the necessary software and use that software to view the data or use the data for reporting or other purposes (refer PC/Laptop specification later in this section)

Facility to read from the degree centigrade/ temperature look up table for any type of TC/RTD sensors of various standards

Interface with Internet for on-line review and trouble shooting by the manufacturer if / when requested.

Modules / attached test equipment to be supplied and installed by the Contractor

shall include but not be limited to:

Modular Pressure Controller – Pressure Range: 0 to 20 barg, precision 0.01% Rdg + pressure 0.01% FS includes linearity, hysteresis, repeatability and controller temperature effects, long term stability of 0.0 I% of reading per annum, controller stability: Better than 0.003% of span, ¼ VGA wide format Graphics LCD, colour touch screen, readout ±9999999 maximum, update rate 2 times per second, conformity to EN61010, EN61326, PED, ROHS & WEEE CE marked, with interface output to the test bench and a computer for automatic calibration

Modular Pressure Controller - Differential Pressure Range: 0 to 3.5 barg. Precision: 0.01% Rdg + 0.01% FS includes linearity, hysteresis, repeatability and temperature effects. Long term stability: 0.0 I% of reading per annum; controller stability: better than 0.003% of span 1/4. VGA wide format graphics LCD colour screen, readout ±9999999 maximum; update rate: 2 times per second; conformity to EN61010, EN61326, PED, ROHS &WEEE CE marked, with interface output to the test bench and a computer for automatic calibration



Loop calibration module shall include current step response trends, characterizing the first order delay, frequency & time domain response and formation of transfer function, dual zoom function, giga zoom function, dual capture function, wide range of trigger functions, history memory and history search, edge search and zoom, digital signal processing with real time math function, cycle statistical calculation for maximum, minimum average value, standard deviation, X-Y display function memory backup function, snapshot function

A portable source/sink instrument to be provided with accuracy within 0.02% of DC voltage range of source and measure, source/measure to be performed simultaneously, large screen LCD display, sink function, step sweep, linear sweep, program sweep function required. Source unit response time 310 millisecond or better. Built in rechargeable battery, AC adapter for 230 VAC

Dead weight tester - deadweight double piston for better operating resolution, hydraulic tester operated, 1-700 bar range or better with accuracy ± 0.008% of reading for positive pressure and resolution of 0.01 kg/cm2. Built-in lever style hand pump, drain plug (to remove old fluid), hand tight connectors for testing specimens, leveling screws on four corners, flotation indicator, built-in lever style hand pump for priming pump, with output to the test bench and a computer for automatic calibration.

Dry Type furnace - range 150°C to 1,200°C, accuracy ± 1°C at 1,200°C, absolute stability ±0.1°C to ±0.3°C , radial homogeneity ± 0.05°C at 150°C, ± 0.1 at 650°C, ±0.2°C at 1,200°C, heating 100°C to 1,200°C in 20 min, 1,200 to 200°C cooling in 180 minutes, dual display, resolution 0.1°Cover complete range; standard insert with minimum 4 holes of 8 mm each, 33.5 mm diameter by 130 mm deep calibration volume; calibration certificate traceable to international standards, with output to the test bench and a computer for automatic calibration. One set required.

Dry Type furnace, Range 35°C to 650°C, accuracy ±0.l°C , absolute stability ±0.02°C to ±0.03°C, radial homogeneity ± 0.004°C at 50°C, ± 0.022°C at 250°C, ± 0.082°C at 650°C, heating 30°C to 650°C in 20 min, dual display, resolution 0.01°Cover complete range, standard insert with minimum 6 holes of 8 mm each, 35 mm diameter by 148 mm deep calibration volume calibration certificate traceable to international standards, with output to the test bench and a computer for automatic calibration. One set required.

DC Power supply unit - Input 230V AC, 0-60V DC Variable output, 0-2A Variable output, ±0.2% VA accuracy or better.

6 1/2 digit multimeter for DC volts, DC amps, AC volts, AC amps and resistance. Display: LCD/ LED, 1999999 counts of digital display with negative sign; accuracy: ±0.003% of reading ±15 digits, fast sampling at 335 times/s, up to 8000 samples stored in buffer memory, communication interface, Ranges: 200 mV to 1000V DC, 2 mA to 2,000 mA, 200 mV to 700V AC, 200 Ω to 200 MΩ, 230V AC power, panel mounted.

Standard Decade Resistance Box - 0Ω to 111.1110 MΩ. Dial composition: 100 Ω X 10 + 1kΩ X 10+ 10 kΩ X 10 + 100 kΩ X 10+ 1 MΩ X 10+ 10 MΩ X 10. Accuracy: 100 Ω, 1 kΩ, 10 kΩ and 100 kΩ steps, ± (0.05%+0.05 Ω), 1 MΩ and 10 MΩ steps ±0.2%.

Digital manometer: 0-10 kpa differential pressure, readout range -12.0000 to +12.0000 kPa, Accuracy: ±0.01% of reading +0.025% of full scale, readout update interval: within 260 msec, response time 2.6 sec maximum, resolution 0.0001 kpa; temperature effect: zero point: ±0.0016% of full scale/°C; span: ±0.001% of full scale/°C; pressure sensing element to be Hastelloy diaphragm, with output to the test bench and a computer.



Frequency counter with frequency range: 1 mHz to 1 GHz; gate time: 10 ms, 0.1s, 10s. Unit display: mHz, Hz, kHz and MHz. Resolution: ±20 ns or better. Accuracy: ±2 Hz at 1 GHz. Period measurement: 20 ns to 999.999999 seconds. Frequency ratio: 1 mHz to 60 MHz. Time interval: 60 ns to 999.999999 seconds. Pulse width measurement: 20 ns to 999.999999 seconds. Tantalization: input frequency 1 MHz to 50 MHz; count capacity: 0 to 999999999; count error: ±I count. Revolution: 60 Mrpm to 120 Mrpm. Peak voltage measurement: ±5V in frequency range 50 Hz to 20 MHz. Input sensitivity: minimum 100 mv rms. Maximum input voltage: 250V AC for frequency <5 MHz. Input Impedance: I MΩ/45 pF. Display: 9 digits, 7 segment LED. Sampling Rate: 4 mS or greater. Interface to allow two way communications with the test bench and a computer for calibration purposes. Features shall include memory function for storing and recall of data, scaling function, hold-off function, digit masking function, display of trigger-level set point and auto triggering.

Function Generator: number of channels: 2(two). Wave form output: sine square with fixed duty cycle triangle, ramp, pulse with variable duty cycle and their inverted forms simple arbitrary functions. Frequency range: 1 µHz to 15 MHz. Resolution: 1 µHz or 9 digits. Accuracy: 20 ppm%. Stability: 20 ppm for total operating temperature range. Maximum output voltage: ± 10V (maximum amplitude + offset). Amplitude resolution: 2 mV to 20 Vp-p. Amplitude accuracy: ± 1% of set point. Offset voltage accuracy: 0.7% of set point. Harmonic Distortion: 0.3% or less. Square wave rise time: 30 nS or less. Output waveforms: AM, damped waveform, trigger burst, frequency and amplitude sweep, PWM, FSK, VCF, VCA etc. Phase resolution: 0.01 degree. Trigger source: external trigger, manual trigger, duty cycle setting: 0 to 100%. Sweep Type: linear, log, step, log step or arbitrary pattern. Display: 9 Digit, 7 segments LED or better. Interface: to the test bench and a computer.

The above specifications for the modules / test equipment may be varied with the

approval of the Employer. Such approval shall be based on the Contractor proving

to the Employer’s satisfaction that the proposed modules / test equipment meet

the functional and maintenance requirements of the Employer for the calibration of

all instruments provided under the Contract.

The Contractor shall supply and install the following PC/laptop and printer to be

used with the test bench / for calibration and reporting purposes. It shall include all

necessary software.

PC/laptop brand PC, serial MUX card and communication cables as required; Intel Core 2 Duo P8400 (2.2 GHz, 1066MHz FSB, 3MB L2 Cache, Intel Mobile PM 45 Express Chipset); 14.1" WXGA Widescreen/ 3072 MB DDR2 800MHz/ 250GB HDD/DVD RW Dual Layer Drive; wireless LAN 802.lI a/b/g/n and Bluetooth v2.0; Ethernet 10/100/1000; keyboard with touchpad +track point with scroll zone; fingerprint reader; integrated smart card reader; 6 cell Li-Ion battery 55 Whr; ATI Mobility Radon 256MB dedicated graphics; integrated 2MB camera with business card reader; HP Nite Light or equivalent; Windows Vista Business/XP; 90W smart AC adapter; HP Protect Tools Security Manager or equivalent; 8 cell travel battery for 12 hours backup; Microsoft Office Professional 2007; weight approximately 2.2 kg.

Printer Hewlett Packard HP colour laser jet CM2320nf MFP printer or equivalent; resolution up to 600 x 600 dpi, 160MB memory, hi-speed USB 2.0.

13.11.11 Test Instruments

The Contractor shall provide the test instruments as listed below and any

additional test instruments required for the ongoing operation and maintenance of

the power plant in accordance with the system design. If during the course of



installation and commissioning of the power plant, it is found that test instruments

are required that are not included in the contract, then they will be deemed to be

included and shall be supplied by the Contractor at no cost to the Employer.

Variac, variable AC power supply ( 3-phase )

AC test probes

Clamp on ammeters

Digital Storage oscilloscope, transportable 400/MHz, dual trace

Handheld oscilloscope

Transducer injection test set, 3 phase

LAN Test Set

PCB extender cards as necessary

Portable recorder for temperature and humidity (24-hour capability). Includes spares, consumables and paper for 5 year period

Portable multipoint recorder (6 pt). Includes spares, consumables and paper for 5 year period

Digital temperature/humidity meter, portable

Soldering / vacuum de-soldering stations, 1 fixed and 1 portable

Hand tools for electrical/electronic repair & maintenance in lockable cabinet

Appropriate quantity of connectors, plugs, test leads, probes, cables, terminals etc. for workshop start up, including storage trays

High quality electric drill and bits for wood, steel and masonry

Portable battery driven drill plus bits for wood ,steel and masonry

Heat shrink gun

Appropriate cable crimp tools

Angle poise bench lights for electronic work

Lockable tool briefcases fully equipped and provisioned for field work - 2 units

Portable Digital Multimeter

Portable Analogue Multimeter

Clamp on Ammeter - AC and DC

Portable power supply

Portable 0-20 mA Current Source

Re-chargeable torch - 2 units

Logic Analyzer

Crimping Tools for LAN connectors - 2 units

Crimping Tools for Communication connectors - 2 units

Crimping Tools for crimps and lugs used on the wires of twisted pair and multicore cables – 2 units.

Fusion Splicer

Optical Power Source

Optical Fiber Cleaner

Multi-Mode / Single Mode Power Meter

Powered Wire-wrapping Tool for Krone Blocks

MDF Termination tools, patch and test cords, isolating plugs and strips, etc.

Insulation Tester (500V, 1 kV, 2.5 kV and 5 kV)



Earth Resistance Tester.

Flue gas analyzer

PH meter

Portable HART communicator

Conductivity meter.

13.12 Historian Server

The Contractor shall provide two Historian servers that perform the following functions:

Capture and store large volumes of real-time data at fast scan rates while being able to respond to user requests in a timely manner

Present the data to users in a variety of formats without requiring additional developments or applications

Allow end users to retrieve the data directly, rather than being dependent on operator or the software Engineering for its provision

Provide a minimum of 2 years of data readily available on line and a further 3 years from removable storage media

Provide efficient long-term data storage and retrieval.

The Historian servers shall each be arranged as a backup of the other such that failure of one server shall be transparent to the system and shall not cause any loss of data. Reinstatement of a failed or offline server shall cause the reinstated server to be updated with all data missed while it was off line. Bidders may propose alternative redundancy arrangements for these servers.

The data Historians shall have the following capabilities:

(a) Handle the storage and retrieval of numerical, digital and string data

(b) Provide the ability to continuously collect and store data at rates of more than one sample per second

(c) Provide a snapshot database that stores the current data value for each point being monitored, prior to transferring value to the data archive

(d) Provide a historical record of values for each point in a point database, including a time stamped value for all the points in the Point Database

(e) Provide an SQL interface allowing access to the data archive and the point definition file

(f) Provide a point database that allows defining of all points stored in the archive

(g) Provide, as a minimum, storage for the following data types:

Single Digital points whose value can be one of two discrete states such as ON/OFF

Double Digital points whose value can be one of four discrete states

16-bit signed integers

32-bit signed integers

Single precision floating point values (32-bit IEEE 754 format)

Double precision floating point values (64-bit IEEE 754 format)

Strings (strings of up to 255 ASCII characters or more)

Blobs (Binary Large Object being ASCII or binary data of unlimited size)

Timestamps (date and time to a resolution of 1 m Sec).

(h) Provide the ability to define engineering units, scaling and offset for all numerical points



(i) Provide the ability to select compression on or off for each point, and the ability to select the type of compression applied which shall include binary compression, exception filtering of data as it is received and compression filtering of the data that is stored in the archive

(j) Provide data smoothing with the ability to change the time constant of the smoothing filter

(k) Include a flag to indicate quality of data

(l) Provide the ability to perform mathematical functions such as square root extraction

(m) Support at least 50 simultaneous users without degradation

(n) Supports multiple interfaces to other systems including interfaces via standard protocols including DNP 3 and IEC 60870-5-101/104.

The data Historian servers shall collect their data (all I/O monitored or controlled by the ICMS) from the ICMS or directly from the field equipment. Data collection for a point shall be coordinated with the method and frequency of data collection for the equivalent point by the main ICMS scanner.

Methods of data output from the Historian shall include:

(a) Queries using Structured Query Language via TCP/IP

(b) Open Database Connectivity (ODBC)

(c) DDE, OLE or equivalent links to allow users running Microsoft Excel or Access

on Microsoft Windows platforms to exchange information directly with the data historian

(d) Connections to a real-time graphics trending package, running under Microsoft Windows, that includes the following capabilities:

Drawing functions for creating trend graphics

Graphs with values, bars and trends that update dynamically

Access to non-historian data via ODBC

Presentation of multiple data points in the one trend display

(e) Connections to a flexible report creator that allows historian data and graphics of the data to be embedded in reports. The reporting package shall recalculate and regenerate all report data each time the report is run.

The data Historian shall also serve data as Web pages to enable authorized

company users to browse real time and historical ICMS data using a standard

Web browser client on their PC over the internet.

13.13 Station Facilities

13.13.1 Emissions Monitoring

Intermittent manual initiated emission monitoring equipment shall be provided to

monitor the plant stack emissions and waste water discharge from the site in

accordance to Environmental Agency Requirement. Recording of concentration of

gases in the stacks shall include as a minimum:

Flue gas CO2

Flue gas CO

Temperature

Flue gas NOx



Moisture content.

Flue gas O2

Temperature and Chlorine level of circulating water at outfall shall also be

measured continuously or on demand.

The flow, temperature, conductivity, ammonia and PH levels of plant treated waste

waters shall be continuously monitored and displayed by the ICMS. Alarm levels

shall be presented by the operator for action.

The instruments for stack and plant treated waste waters shall be complete and

installed and shall display the instantaneous value of the measurements to the

operator via the ICMS. Local indication shall also be provided for each

measurement at their respective measuring meter. Fault alarm for each instrument

shall be raised in the CCR.

The measurement shall be displayed by the instruments. The ICMS shall display

and record measurements in a format suitable for submission to the local authority

and environmental protection Agency if the Employer desires. All measurements

shall be compensated where necessary according to variation in temperature,

atmospheric pressure, humidity, etc. and the correcting values shall be available

for display by the ICMS.

The equipment shall be of proven reliability and shall be subjected to the

agreement of the Employer. The Bidders will provide details of other sites where

the equipment has been installed. All equipment necessary for the installation,

commissioning, calibration (including calibration gasses) operation and

maintenance of the monitoring equipment shall be supplied.

13.13.2 Station Clock System

A Network Time Protocol server (NTP server) shall provide time synchronization

signals for devices on their respective LANs. It shall synchronise the ICMS and

other systems, for the purposes of synchronizing data acquisition, data login,

alarm and trip events and for all systems employed in such a manner on the site.

This shall include all servers, workstations, ICMS, intelligent protection relays,

intelligent electronic devices and communications devices that maintain a real-

time clock. It is therefore expected that the GPS clocks shall provide both

unmodulated and amplitude modulated IRIG-B signal outputs. The

synchronization interval shall be user settable, and shall initially be set at once per

hour. Overall time synchronization of devices via NTP shall be within 1 millisecond

of Bangladesh time (UTC + 06:00:00.000).

The NTP servers shall be synchronized by a GPS clock that obtains its time

reference from GPS (Global Positioning System) satellites. The GPS antenna

shall be installed on the roof of the building.

The NTP servers shall be managed via the LAN, and shall report status and errors,

such as loss of synchronization, in the CCR.

The station clock system shall also monitor the grid system time and display to the

operator in the CCR the time difference between the station time and grid system

time. Station clocks synchronised to the system shall be supplied and installed in

locations to be approved by the Employer during the detailed design stage.

Closed Circuit Television

A Closed Circuit Television (CCTV) shall be provided for operational and security

monitoring. The Video Surveillance system shall use solid state colour video

cameras mounted at suitable locations to monitor:

Entrance doors



Site entry gate(s)

All fence lines

Critical plant areas

Major items of plant

Store room / storage areas.

Exact locations shall be subject to the approval of the Employer.

The camera pictures shall be displayed at the CCR where the camera view, or

combination of views, selected by an operator shall be displayed on colour LCD

video monitors. A secondary CCTV display station shall be provided at the guard

house.

The cameras shall have a resolution of at least 480 horizontal lines. Each camera

shall have pan, tilt and zoom control to allow the operator to control the camera

direction and magnification. An operating console with controls shall be provided

in the CCR for this purpose.

A digital video recording system shall also be provided to allow a permanent

record to be made from all or selected channels. The system shall store the CCTV

data for at least one month.

13.13.3 Public Address System

A public address system shall be provided for the power plant. The system shall

broadcast announcement throughout the station. Loud speakers shall be

connected on a zone basis with the call station and zone selection facilities

located in the CCR. Sound output level of the PA system shall be designed to

achieve a sound pressure sufficiently higher than the ambient noise in the area to

ensure speech intelligibility.

13.13.4 Revenue Metering

The Contractor shall provide revenue metering including the revenue meter for

grid auxiliary power consumption at high side of 230/6.6 KV Transformer at

Network Control Room (NCR) of ASPCL to monitor the net output of the power

plant in the APSCL 230 & 400 kV substation using CTs and VTs at the substation.

These CT’s and VT’s shall be provided and installed under the Contract. The

revenue meters shall satisfy the following minimum requirements:

A. Energy meter requirement:

1. Programmable Meter

2. Adjustable Different Tariff.

3. 110-400 V flexible input voltage Rating.

4. 1 (100 A Current Rating.

5. Accuracy Class to be ±0.2s for Kwh and ±0.2 for Kvarh.

6. RS 232/485 Port for Modem Interface.

7. Standard Metering protocol for Remote Interface.

8. Data storage of 16 Channel @ 30 min interval and of minimum 90

days.

9. Optical head and software to Upload and Download of meter data.

10. Password protection for Programming and for configuration.

11. Calibration LED for KWh and KVarh Accuracy check.

12. Configurable display, including meter ID, Power Quadrant display

etc. as advised by BPDB.

13. Provision for quick reading scroll, reset etc. (Programmable).

B. Current Transformer (CT) Requirement:



1. CT of ratio --/1A (secondary 1 Amp).

2. Accuracy of ±0.2s class ( with secondary installed burden)

3. Knee Point voltage, Vk < 40V.

4. VA rating should be selected based on the connected VA.

Connected VA burden to be more than 25% of CT rated VA.

5. Core should be different for Main and Check meter.

6. CT ratio to be selected based on the connected load.

C. Voltage Transformer Requirement:

1. VT ratio ----I 110 V.

2. Accuracy of ±0.2 (with secondary burden).

3. VA rating should be selected based on the connected VA. Connected

VA burden to be more than 25% of VT VA rating.

4. VT output to independent of frequency variation, i.e. pure inductive type

(IVT).

5. Core should be different for Main and Check meter.

D. Additional Requirement:

1. On line Test facility of meter with DB and sufficient Security Sealing

provision.

2. TTB's should be at the suitable accessible Panel front location with

meter.

3. Meter Cabinet should be Exclusive for tariff metering only and have

sufficient Security Sealing provision, provided with 220V, 5A two pin

socket outlet for modem Power, Auxiliary bias power, Testing

Equipment power etc.

4. All Main metering CT, VT should be terminated to metering panel

directly including star point (4 Wire).

5. Backup metering circuit may be shared for other purpose.

6. VT MCB (both Main & Back-up) should be located in the metering

panel. Downstream VT MCB rating should be less than that of

upstream.

7. All CT & VT terminals should have Security Sealing provision.

E. Energy Meter Configuration:

a) Normal Display

1. Complete LCD Test

2. Meter serial Number

3. Present Date

4. Present Time

5. Cumulative Active Energy, Kwh-Del

6. Cumulative Active Energy, Kwh-Rec

7. Cumulative Reactive Energy, Kvarh-Del

8. Cumulative Reactive Energy, Kvarh-Rec

9. Instantaneous KW-Del

10. Instantaneous KW-Rec

11. Phase A Voltage

12. Phase B Voltage

13. Phase C Voltage

14. Phase A Current

15. Phase B Current

16. Phase C Current

17. System Power Factor



18. Line Frequency

b) Alternate Display

1. Complete LCD Test

2. Meter serial Number

3. Present Date

4. Present Time

5. Cumulative Active Energy, Kwh-Del

6. Cumulative Active Energy, Kwh-Rec

7. Cumulative Reactive Energy, Kvarh-Del

8. Cumulative Reactive Energy, Kvarh-Rec

9. System Power Factor

c) Load Profile

Load profile (Cumulative Meter Reading) and Instantaneous Profile

data in the following format should be stored in each 30 minute interval

for at least 90 days.

KWh-Del KWh-Rec KVarh-Del KVarh-Rec P.F

Sample Date 01/05/2016

00:00 0:00 0:00 0:00 0:00 0.89

00:30 0:12 0:00 0:08 0:00 0.85

01:00 0:15 0:00 0:10 0:00 0.86

01:30 0:20 0:00 0:12 0:00 0.85

The meter shall be in accordance with the BPDB’s requirement.

13.14 Communications Systems

13.14.1 General

Internal and external communications systems shall be provided to transport voice,

data, video signals and protection signaling. ICMS internal data communications

requirements are described above in the Integrated Control and Management

System (ICMS) section.

Multi-mode fiber optic communications cables shall be used between rooms and

areas of the power station building and to connect with equipment outside the

building. Copper communications cables may be used within a cabinet or plant

area where isolation is not required.

13.14.2 Communication System Standards

The communications equipment and installation shall conform to relevant

technical requirements of the following standards:

ITU-T International Telecommunications Union - Telecommunications Standardization Sector, particularly parts: G.703, G.707, G.708, G.709, G.772, G.774, G.783, G.784, G.803, G.811, G813, G.823, G.825, G.826, G.828, G.829, G.831, G.957 and G.958.

ITU-R International Telecommunications Union - Radio Communications Sector

IEC 60794 Optical fiber cables



BS 6651 Protection of Structures against Lightning

RFC Applicable Internet “Requests for Comments” (RFC) documents.

13.14.3 External Data Communications

A fiber optic cable loop shall be provided from the Power Station to the Ashuganj

230/400 kV substation and back to the Power Station. The cable shall incorporate

at least 24 fibers and be terminated at each location in a fiber distribution

frame/patch panel provided under the Contract.

The ICMS shall communicate with the SCADA Master Station at NLDC to transfer

the parameters listed in paragraph 13.8.4 above.

Both data and voice communications with the NLDC Master Station shall be

achieved by provision of two E1 data links from the Power Station to the SDH

communications equipment at the Ashuganj 230/400 kV substation. The Contract

scope shall include configuring the RTUs to provide the required data and voice

signals via an Ethernet interface, installing PDH, upgrading the SDH equipment at

the 230/400 kV substation to incorporate two additional E1 multiplexers, and

configuring suitable channels on the SDH network to transport the data to NLDC.

These fiber optic cables shall carry serial data from the RTUs at each substation

and telephone connections as described below.

13.14.4 Optical Cable and Equipment

The fiber and cable specifications shall comply with ITU-T Recommendation G652

and the relevant IEC standards. Each fiber cable shall be supplied with at least

50% spare cores, minimum four spare.

Single mode outdoor optical fiber cable shall be of loose tube, gel filled

construction installed in HDPE cable ducts or direct buried in plastic conduit. The

cable shall have a non-metallic central core sheathed with black polyethylene. An

armoured layer shall surround the inner sheath made up of corrugated steel or

aluminum tape at least 0.2 mm thick followed by an outer polyethylene sheath.

Single mode optical fiber cables shall be designed to optimize transmission of light

at both the 1310nm and 1550nm wavelengths. The core/cladding diameters shall

be 9/125µm.

Multi-Mode indoor optical fiber cable shall be of tight buffered construction

installed in cable ducts or on cable ladder. The cable shall have a non-metallic

central core sheathed with black polyethylene. A non-metallic strength layer shall

surround the inner sheath followed by an outer polyethylene sheath.

Multimode optical fibre cables shall be designed to optimize transmission of light

at the 850nm wavelength. The core/cladding diameters shall be 62.5/125µm.

Suitable fiber optic cable junction boxes, patch panels and patch leads shall be

provided. These shall conform to the following:

They shall support, organize, and protect the optical fibers and the fiber splices whilst ensuring that the optical fibre minimum-bending radius is not exceeded.

The splice tray shall not have any sharp edges or protrusions that may damage the optical fiber cable.

They shall provide entry for all cables.

Include number tags for tube and fiber identification.

They shall provide mounting positions for the bulkhead mounted connectors on which the cable will be terminated.

They shall allow patching of fibers.



Outdoor mounted boxes shall be rated to IP65 in accordance with IEC 60529

The JB/patch panel shall have a fiber capacity equal to the total number of fibers

(connected and spares) for all cables to be connected. Patch panels shall be

designed for 19-inch rack mounting within a standard equipment cabinet.

All unused couplings shall have protective dust covers. The patch area in patch

panels shall be accessible behind a door or removable cover.

Sufficient factory manufactured patch cords with suitable colour coding shall be

provided.

Fiber optic connectors shall be standardized for ease of maintenance. The

industry standard FC/PC type is preferred.

13.14.5 Telephone System

13.14.5.1 Power Station

A modern digital Private Automatic Branch Exchange (PABX) shall be provided at the Power Station for internal and external voice and fax communication. The PABX shall be installed in a dedicated telecommunication equipment room.

The PABX shall be connected to the Bangladesh Public Switched Telephone Network (PSTN) via either conventional trunk lines, via a 2 Mbps E1 multiplexer, or via an ISDN connection depending on facilities offered by the local exchange.

The PABX shall also be connected to the NLDC Operations Telephone System via trunks that are transported through an E1 communications multiplexer.

A digital operator’s console shall be provided for the PABX on the control desk in the CCR. Telephones shall be provided at all major areas of the Power Station and in noisy areas they shall be mounted in appropriate acoustic shrouds. Fifty (50) telephones shall be allowed for. A fax machine shall be provided in the CCR. An NLDC operations telephone shall be provided on the operators’ desk in the CCR and this shall be a distinctly-coloured telephone as designated by PGCB.

Suitable isolation shall be fitted on telecommunication links between the Power Station and other outlying buildings when copper wire is used for telephone extensions.



14. GENERAL TECHNICAL REQUIREMENTS

14.1 Pumps

Particular attention shall be paid to the selection of pumps and their materials of construction. Reliability, ease of replacement of worn parts and maintenance-free bearings are essential requirements. The pumps shall have a well-proven service record.

All pumps shall be capable of meeting their required duty continuously without requiring replacement of impeller or wear rings. They shall be capable of continuous operation without overheating, cavitation, excessive noise or vibration, surging or instability when working singly or in parallel with other pumps.

Pumps shall be designed for maximum efficiency at the design condition and with a head-capacity characteristic which rises steadily from the rated capacity to shut-off.

Particular care shall be taken that pumps pumping fluids with temperatures approaching boiling point or evacuating from vacuum spaces with controlled liquid levels are provided with an adequate margin to ensure operation over the entire range of flows and temperatures without cavitation. No pump shall be supplied with specific suction speeds outside normally accepted ranges.

All the materials in contact with the fluid being pumped shall be compatible and selected to minimize electrolytic corrosion.

Any seal water supply for mechanical seals shall be filtered and provided with means of regulating the seal water flow and pressure to each seal. Seal water quality shall be sufficient to ensure that seal design life is readily achievable with the design maintenance and design maintenance intervals.

All large pumps shall be provided with both impeller and casing wear rings and replaceable gland sleeves. Any priming equipment required shall be provided.

Pumps shall be designed to have adequate margins available in head and capacity to compensate for any normal slow rate of wear anticipated or build-up of deposits in piping. Care shall be taken to ensure that the higher flow rates that may result from such margins do not increase velocities in the associated system to erosion levels. Pumps furnished for each application shall be sized to accept an impeller at least 4 mm larger in diameter than the impeller specified without having to change the pump casing.

Strainers (start-up or permanent) shall be installed in the suction piping of horizontal pumps or sets of pumps. The driver shall be mounted on an extension of the pump bedplate and shall drive the pump through a flexible coupling with OSHA coupling guard.

Pumping systems with variable flow requirement shall have a recirculation line for pump protection. As a minimum, pumps with motors rated for 20 kW and above shall be supplied with a recirculation line for protection. The recirculation line shall normally be routed to the source from which the system takes suction. Modulating or two-position automatic recirculation valves or restriction orifices shall be used as applicable. For the boiler feed water pump, a modulating automatic recirculation control valve or combined recirculation/check valve shall be used.

Vent and drain plugs shall be fitted, where necessary, at suitable points on the pump casing. Oil system pump vents and drains shall be provided with valves. Horizontal split-case pumps shall allow the removable half casing and impeller to be withdrawn without disturbing any of the process piping or valves. Horizontal end-suction pumps shall allow the impeller to be withdrawn from the motor end without disturbing the motor or discharge piping.

Where part-load (e.g., two 50%) duplicate pumps for the same service are provided, they shall be capable of operating in parallel.

Pumps with constant speed drivers shall, where practicable, be capable of head increase by the installation of a larger impeller or a new stage. Motor drivers shall have power ratings, including service factor, at least equal to the following percentage of pump rated power:

Motor Nameplate Rating Percentage of Rated Shaft kW

18.5 kW and less 125%



22 to 55 kW 115%

75 kW and more 110%

Pumps driven at 4-pole motor speed or slower are preferred.

One of each type of pump with motor rating above 75 kW shall be tested in the manufacturer’s works in accordance with ISO 2548 (BS 5316) or equivalent. Other pumps shall have been tested in accordance with the supplier’s normal production procedures.

The electric motor used for driving each item of equipment during factory testing shall, where possible, be the motor to be installed with that item. Performance certificates for the motors used in testing shall be available for checking by the Employer and shall be included in the certification for the equipment tested.

14.2 Valves

14.2.1 Access

All valves shall be arranged so that the hand wheel moves in a clockwise direction

to close the valve. The face of each hand wheel shall be clearly marked with

words “open” and “close” and shall be provided with an arrow to indicate direction

for opening and closing. Valves shall not be fitted with the stems below the

horizontal. An indicator shall be fitted to clearly show the position of each valve

from the hand wheel operating position.

All valves shall be readily accessible for both operating and maintenance and

where necessary for ease of operation the spindles shall be extended and a

pedestal hand wheel provided at convenient operating floor or intermediate floor

level. Chain operators shall not be used.

No thrust from the valve shall be transmitted to the extension spindles and valve

pedestals shall not be mounted directly on floor plating.

Special attention shall be given to the operating mechanism and correct

lubrication of all valves to ensure a minimum of maintenance and ease of

operation, by persons of 1500-1600 mm in height.

Where desirable to protect valve rising spindles against ingress of dirt, or where

the position of the valve may create a hazard to operators when the spindle is

extended, suitable spindle covers shall be provided.

Hand wheels shall be sized to permit operation of valves without using hand wheel

spanners.

14.2.2 Nameplates

All valves shall be provided with name plates showing valve tag number and

service, including automatic valves, relief and check valves - refer Section

14.3.6.2.

14.2.3 Requirements

Certification stamps shall be provided on all equipment.

Materials used shall be ASME type and valve construction shall comply with

requirements of ASME Boiler and Pressure Vessel Code, Division II.

As far as practicable, maintenance or replacement of wearing parts shall be able

to be accomplished with the valves in situ. All valves of similar size, duty and type

shall be directly interchangeable. The internal diameter of all valves and the ends

of connecting pipes shall be of the same internal diameter.

In the case of all welded-in valves, the stub ends of the valves shall project from

the valve body a sufficient length to ensure that the welding process will not affect

the valve seats.



Gate, parallel slide and globe valves shall be of external screw rising spindle type.

Gate valves shall not be used for throttling. Welded end valves shall not be used

for control valves.

Valve packing shall be graphite free. A grease nipple shall be provided for valves

of 200 mm bore and above. Packing shall be capable of being replaced without

removal of the operators and/or without removing the valve from the line. Seals

shall be provided, if required, to retain grease and keep dirt and moisture out of

bearings. Lubricating fittings shall be provided to lubricate bearings, yoke nuts,

bushings etc.

Valve selection and materials shall be appropriate to the fluid and operating

conditions to ensure long life, maintainability and, where applicable, minimum

pressure drop. They shall be well proven in similar service.

Flanged ends of valves shall conform to the dimensions in ANSI B16.10 for the

respective class and shall have end flanges integral with the valve body. Welds on

flanges are not acceptable. Valves 600 mm (34”) and above shall be flanged to

ANSI B16.47 Series A/B.

The preferred direction of flow shall be cast or stamped on the body of the valve.

Shaft bearings shall be made from material rated to operate at a temperature of

150°C.

Hand wheels shall be provided with a corrosion resistant shear pin for over-torque

protection.

All valves 50NPS or larger shall be flanged.

14.2.3.1 Wedge Gate Valves

Unless otherwise stated all valves shall be manufactured to API 600, 602 or 603 standards. 2" NPS valve and smaller shall be manufactured to API 602.

All gate valves shall be the OS&Y (outside screw and yoke) type with rising stem to indicate position of valve. Valve construction shall be carbon steel, low temperature carbon steel, ferritic steel, alloy steel, austenitic stainless steel and nickel base alloys as appropriate for the duty. Trim materials shall be in accordance with API 600 or 603 code whichever is applicable to the valve.

All other valves shall have 100% Teflon braided yarn packing similar to Chesterton Type 1724. Other packing materials may be used subject to satisfactory review by the Employer.

The stem packing shall be designed to allow for in-service packing maintenance and easy access for stem thread greasing. The bonnet shall have a back seating design to prevent leakage past the stem when it is under full pressure and the valve is in the full open position.

Bonnet gaskets shall be in accordance with the requirements of API-600 and shall be stainless steel 316L spiral wound type similar to Flexitallic's "Flexite super" gaskets. The material used shall be suitable for the pressure and temperature rating of the valve except that Asbestos based material, Polytetrafluoroethylene (PTFE) and Perfluoro Ethylene Propylene Copolymer (FEP) are not acceptable.

The stem to gate connection shall not be made with a pin. Valves of 2" NPS and larger shall be supplied with replaceable seats.

14.2.3.2 Swing Check Valves

Trim for swing check valves constructed from carbon steel, low temperature carbon steel, ferritic steel, alloy steel, austenitic stainless



steel and nickel base alloys shall include body and disc seating surface, disc hinge, disc pin, collars and other internal parts in contact with the fluid. These shall be made from materials similar to those in API 600 except that austenitic stainless steel valve trim materials shall be similar to those in API 603.

Valves shall be manufactured to API Spec 6D. Valves shall be able to operate with flow in both the horizontal and vertical (upward) positions.

Valves 6" NPS and larger shall be the type with a tilting disc shaped and designed to close gradually without slamming. The pivot pin shall have an extended external lever arm for showing the position of the disc as well as for stroking the valve. A gland packing capable of in-service packing replacement shall be used for sealing the lever arm.

The disc shall be positively retained in position with stoppers. A port shall be provided for inspection and replacement of seats, disc and pin.

14.2.3.3 Wafer Type Check Valves

Trim for wafer type check valves constructed from carbon steel, low temperature carbon steel, ferritic steel, alloy steel, austenitic stainless steel and nickel base alloys shall include body and disc seating surface, disc hinge, disc pin, collars and other internal parts in contact with the fluid. These shall be made from materials similar to those in API 600 except that austenitic stainless steel valve trim materials shall be similar to those in API 603.

Valve shall be manufactured to API Spec 6D.

Short pattern wafer type check valves are preferred.

A lifting lug shall be provided.

Valves shall be able to operate in both the horizontal and vertical positions.

Valves 6" NPS and larger shall be the type with a tilting disc shaped and designed to close gradually without slamming. The pivot pin shall have an extended external lever arm for showing the position of the disc as well as for stroking the valve. A gland packing capable of in-service packing repairs shall be used for sealing the lever arm.

The disc shall be positively retained in position with stoppers.

14.2.3.4 Ball Valves

Trim for ball valves constructed from carbon steel, low temperature carbon steel, ferritic steel, alloy steel, austenitic stainless steel and nickel base alloys shall include body and ball, seats, seating surfaces and other internal parts in contact with the fluid. These shall be made from materials similar to those in API 600 except that austenitic stainless steel valve trim materials shall be similar to those in API 603.

Valves shall be manufactured to API Spec 6D with dimensions for regular pattern valves.

The ball shall not extend beyond the valve ends.

14.2.3.5 Butterfly Valves

Trim for butterfly valves constructed from carbon steel, low temperature carbon steel, ferritic steel, alloy steel, austenitic stainless steel and nickel base alloys shall include body, disc, seating surface, disc and other internal parts in contact with the fluid. These shall be



made from materials similar to those in API 600 except that austenitic stainless steel valve trim materials shall be similar to those in API 603.

Valves shall be manufactured to API 609 and shall be designed for bi-directional flow.

Valves shall be able to operate in both the horizontal and vertical positions.

The disc shall be eccentric type and shall be positively retained in position with two way axial thrust bearings at the bottom end of the shaft. Shaft bearings shall have lubricating nipples installed to allow in service bearing lubrication.

Packing suitable for the operating temperature shall be used to seal the shaft.

The valve shall be shipped with the disc in a partially open position but contained within the valve body.

The valve shall be designed to enable packing to be replaced without removal of the valve and to allow additional packing to be added by closure of the valve without the removal of the valve actuator.

The disc for butterfly valves shall be eccentric and shall provide the same degree of leak tightness when pressure tested on either side of the disc. The edge of the disc shall be overlaid with material to AISI 316L.

14.2.3.6 Globe Valves

Trim for globe valves constructed from carbon steel, low temperature carbon steel, ferritic steel, alloy steel, austenitic stainless steel and nickel base alloys shall include body, plug, seat ring, and other internal parts in contact with the fluid. These shall be made from materials similar to those in API 600 except that austenitic stainless steel valve trim materials shall be similar to those in API 603.

Valves shall be able to operate in both the horizontal and vertical positions. Valves shall be of the OS&Y design. Valves shall have rising stems to indicate valve position.

Stem packing shall be externally accessible and shall allow additional packing to be installed while the valve is under pressure and in any operating position. Stem threads shall be readily accessible for greasing and maintenance while the valve is in service.

Valves shall have a back-seating design to prohibit leakage past the stem while the valve is under full rated pressure.

14.2.3.7 Full Conduit Slab Gate Valve

All materials of construction used shall meet the requirements specified in the latest edition of the ASME Boiler and Pressure Vessel Code, Section II.

Valves shall be OS&Y type and are to be fabricated according to the latest edition of the American Petroleum Institute (API) 6D Standards.

Valve design shall allow all valve parts, including the seat rings, to be replaced without removing the valve from the line.

All welding required for the fabrication of each valve, including weld overlaying shall be carried out using procedures qualified in accordance with ASME Boiler and Pressure Vessel Code, Section IX.

The valves shall meet established criteria as per API Specification 6D, "Pipeline Valves, End Closures, Connectors, and Swivels", or ANSI



B16.34 "Steel Valves, Flanged, and Butt welding Ends", that pertain to flanged gate valves for pipeline service.

Valve bodies may be cast or plate fabricated. ASTM Grade A515 shall not be

used for plate fabrication.

Through conduit slab gate valves for brine service shall be supplied with a 50 mm

flanged drain valve to allow draining of the fluid from the body during operation.

14.2.4 Corrosion Protection

External and machined surfaces of carbon steel valves not to be painted shall be

coated with a corrosion preventive film suitable for one year corrosion protection in

tropical outdoor conditions.

Threads shall be coated with heavy rust preventive grease or other acceptable

corrosion preventive film that can be easily removed with suitable solvents.

All other items subject to corrosion shall be suitably protected.

14.2.5 Repair of Defects

Casting repairs are not permitted for cast iron, malleable iron or ductile iron.

Surfaces containing defects shall be repaired by welding and re-machined as

required. Repair, chipping, or grinding of welds shall be done in such a manner as

not to gouge, groove, or reduce the adjacent base metal thickness, followed by a

recheck with liquid dye penetrant until all overlaid surfaces are free of defects.

Casting repairs for carbon steel shall follow procedures and welders qualification

to ASTM A488/A488M.

Major repairs in which the depth of cavity prepared for repair by welding exceeds

20% of the wall thickness or the welding area exceeds 10 square inches are not

permitted.

The limit on imperfections, method and extent of required examination for repairs

shall be the same as required for the original castings.

Repair of castings by other means such as peening or impregnation with metallic

or non-metallic materials is not permitted.

14.2.6 Drawings

The Contractor shall submit fully dimensioned and certified drawings of the valves

included within Contractor’s supply showing all accessories to be included with

each valve set.

The Contractor shall furnish, upon request, dimensional drawings showing any

part of the valve.

Other information required on the drawings shall include:

Seat test pressure

Hydrostatic test pressure

Parts list with Material Specification

ANSI Class.

14.2.7 Steam

Materials shall be in carbon steel, with body seat rings, stem and bushings in 13%

Cr. steel, or equivalent.

Isolating valves 200 mm bore and above shall have:

“Flexi-wedge” gate or parallel slide type



Body and disc seats trimmed in Stellite 6 and 8 respectively

Integral drain

Bypass 25 mm bore

Back-seating.

The equivalent eccentric disc valves may be provided as an alternative.

Isolating valves 200 mm bore and below shall have body seats trimmed in Stellite

6 on wedge gate, parallel slide or globe valves.

For all steam valves there shall be a differential hardness of 50 Brinell between

fixed and moving seats, with the harder material on the fixed seats.

14.2.8 Condensate Drains and Air Release

Single valves of wedge gate type shall be used.

14.2.9 Steam and Circulating Water

These valves shall have bolted bonnets, and bolted gland followers.

14.2.10 Filters and Strainers

Filters and/or strainers shall be installed to protect critical system components.

All filters and strainers shall be installed in accessible positions to allow easy

cleaning and removal. Isolating valves shall be installed adjacent to each

filter/strainer. .

The main body shall be of steel construction and the basket shall be constructed

of stainless steel. Drain valves shall be fitted to each filter/ strainer body.

14.2.11 Steam Traps

Use of steam traps shall be avoided as far as possible.

Steam traps shall be of cast or forged steel construction. They shall be sized for

the maximum quantity and minimum discharge pressure.

The Contractor shall select the appropriate type of the steam trap for each location.

Steam traps shall be designed to minimize failure and premature leakage cause

by dirt and other foreign material accumulating in the steam

Care shall be taken to ensure the type of trap and installation arrangement

selected does not permit steam flashing and hammer in the main condensate

return line(s). Thermodynamic traps shall have replaceable seats.

Steam traps shall be Yarway, Armstrong or Spirex Sarco brand or equivalent.

Each trap shall be installed with isolation valves each side of the trap assembly,

together with a strainer, check valve and a blowdown valve. The steam traps shall

be flanged for easy removal.

14.2.12 High Point Vents

High point vents shall be provided at each high point in the pipeline systems.

14.2.13 Low Point Drain

Low point drains shall be provided at each low point and at each point where fluid

needs to be drained for maintenance of the pipeline systems.



14.3 Actuators for Power Operated Valves

14.3.1 General

The initiation of all power operated valves shall be by electrical impulse, but the

mechanical power required for valve operation may be electric motor, compressed

gas or hydraulic fluid. The equipment shall be of proven design and reliability. All

actuators shall have:

A mechanical valve position indicator on either the valve or actuator mounted where it can be easily read from the local operating position

Valve position limit switches, including two sets of clean changeover contacts at each end of valve travel, for remote position indication as required

Additional valve position limit switches for control and interlocks as required.

All electric actuators shall have a hand wheel for opening and closing the valve

which shall be automatically de-coupled when the valve is being power operated.

The actuators shall be suitable for opening and closing each valve against the

relevant differential pressure plus a minimum of 20% extra torque to overcome

sticking which may occur within the valve body, where applicable.

All modulating valve actuators shall include a valve position analogue transmitter

providing a 4 to 20 mA dc signal for remote indication.

All actuator electrical equipment shall be protected against dust and water.

Compressed air actuators utilized in addition to another actuator for emergency

fail safe back up shall be supplied complete with a refillable bottled gas system of

appropriate size. Schemes for the control and interlocking of valves such as main

and bypass valves, and master and martyr drain valves shall be submitted for

review.

When it is required, actuators shall be suitable for remote operation using 125V

DC control signals.

14.3.2 Modulating Valve Control

Modulating valve actuators shall have:

A speed of response to meet the requirements of the control loop in which they are connected

A positional accuracy which is repeatable within the limits required for the control loop in which they are connected

The capability of following the input signal accurately.

Actuators for modulating control valves which must be maintained accurately in an

intermediate position for long periods shall be provided with means for preventing

drift. For pneumatic actuators current signals to the control valves shall be

converted to pneumatic signals by I/P converters. Control valve actuators shall be

identified by colour according to failure-close type or failure-open type. Actuation

time for valves from fully open position to fully closed position and/or vice-versa

shall be within the following limits:

Safety and relief valve < 1 second

Control and isolating valves < 20 seconds.

Valve position shall be indicated on all throttling valves. Remote valve position

shall be provided from a 4-20 mA dc transmitter. Valve position end of travel limit

switches shall be provided on all non-throttling open/close type valves.



14.3.3 Electro Hydraulic Actuators

Electro hydraulic actuators shall be wholly self-contained (either singly or in

functional groups) and shall be complete with all necessary motors, valves,

controls, cut outs, heaters and instruments.

The actuator shall be capable of providing fail safe action appropriate to the

application, and shall include a hand operated pressure equalising valve to allow

hand wheel operation.

The actuator shall be supplied complete with a lockable “remote/off/local” selector

switch, and “open”, “stop” and “close” push-buttons. The “stop” push-button shall

provide overriding control, even if the “open” or “close” push-buttons are operated

and remain depressed.

The hydraulic fluid required shall be of a type readily available in Bangladesh.

14.3.4 Solenoid Actuators

Solenoid operated valves, shall move to the safe position in the event of loss of

power supply.

Solenoid valves shall be protected against water and dust to IP55 of IEC 60529.

They shall have BS 4568 M20 conduit entries and integral terminals.

14.3.5 Electric Actuators

14.3.5.1 General

Electric valve actuators shall be provided with integral contactors. Protection shall be provided for the motor as follows:

The motor shall be de-energized in the event of a stall when attempting to unseat a jammed valve

Motor temperature shall be sensed by a thermostat de-energizing the motor in case of overheating

Lost phase protection

Anti-condensation heaters.

A lockable “remote/off/local” selector switch shall be supplied on each actuator along with “open”, “stop” and “close” local control push-buttons. The “stop” push-button shall provide overriding control, even if the “open” or “close” push-buttons are operated and remain depressed.

The mechanism shall be designed to prevent over running or jamming and shall be fitted with limiting devices capable of accurate and fine adjustment. Torque limiting or other devices shall be provided to prevent damage to the mechanism in the event of the valve jamming.

The actuator shall include a device to ensure that the motor runs with the correct rotation for the required direction of valve travel irrespective of the connection sequence of the power supply.

Reversing contactors and limit switches used for actuator control shall be robust and of proven reliability by both type test and commercial operation. Solid state switching may be accepted where conditions permit.

Each actuator shall be a self-contained unit generally comprising a three phase motor, reduction gearing, reversing contactor starter with local controls, turns and torque limitation with electric logic controls and monitoring facilities.



14.3.5.2 Actuator Environmental Protection

Actuator housings shall have total surface paint treatment to withstand the environmental conditions. Surfaces shall typically undergo a number of surface preparations with the final applied surface being a baked epoxy coating that is weather and chip resistant. The paint finish shall comply with ASTM B117, 35ºC Salt Spray Test for 1,000 hours.

All units shall be suitable for continuous exposed outdoor service, be watertight to a minimum degree of protection of IP68. Ambient temperatures shall range between 10°C and 45ºC.

All actuator wiring shall be tinned throughout, and number ferruled at each end using the "Legrand CAB 3" type or similar cable marking system.

Terminations shall be nickel plated or 316L stainless steel.

Each actuator shall be equipped with an anti-condensation heater which shall be continually energized from the main power supply.

All printed circuit boards shall have a conformal coating and all potentiometers shall be hermetically sealed to protect against the environment.

14.3.5.3 Actuator Local Manual Controls

Each actuator shall be equipped with "Open", "Close" and "Stop" operator manual controls. The "Open" and "Close" controls shall be field configurable as latching or non-latching. In the latching mode of operation, momentary operation of the close/open pushbuttons shall cause the valve to fully close/open respectively. In the non-latching mode, actuator local open/close operation will occur only while the open/close push-buttons are engaged.

Each actuator shall be equipped with a Remote/Off/Local selector switch pad lockable in all three positions. The "Remote" position status of this selector switch is required to be remotely monitored and shall be equipped with either auxiliary voltage free contacts that can be used for a discrete field interface or as inputs to an intelligent actuator field unit that is connected to a serial communications link, as required by the Data Sheets.

Integral indication is required on each actuator for the following:

Valve open position (mechanical pointer)

Valve intermediate position (mechanical pointer)

Valve closed position (mechanical pointer)

Control power on (lamp or flag).

A lockable Hand/Auto lever is required to engage the hand wheel operation in the event of motor power failure. Energisation of the motor shall automatically re-engage power operation. For operator safety, the hand wheel shall be automatically disengaged in the event of actuator motor energisation, the hand wheel shall remain motionless when disengaged.

14.3.5.4 Torque and Travel Limiting

The torque switch mechanism for actuator Open and Close shall be independently adjustable. The torque switches shall be graduated and adjustable so that they may be set to interrupt power to the motor at predetermined output torque levels. The torque setting shall be adjustable 40% to 100% of rated torque.



Open and Close end of travel limit switches shall be coupled to the output of the actuator to ensure correct operation of the limit switches regardless of electric or manual operation of the actuator.

The manufacturer shall factory set both Torque and Travel limits to suit its associated valve and its particular application.

Protection Facilities

Each actuator shall incorporate integral control facilities to provide as a minimum the following protection features. The manufacturer shall provide full technical details of these, together with any other protection facilities to be provided on each actuator.

Note that critical actuator protection features such as motor thermal overload, loss of phase or torque limit and similar shall be independent of microprocessor based electronic controls for operation.

Control circuits shall correct actuator motor rotation irrespective of Employer's supply phase rotation. Incorrect coupling of the 3-phase supply shall not cause actuator or valve damage.

Control circuits shall prevent the energising of motor contactors should one or more phases be lost.

Torque switch hammer in the presence of a maintained control signal shall be prevented from occurring, even if the valve encounters an obstruction in mid-travel. Tripping of the torque switch shall inhibit the re-energisation of the actuator until the maintained control signal is removed.

This feature is required for the protection of the actuator motor when the valve is in the open or closed state. When the end-of-travel limit switches fail to reset within the manufacturer's configured period of time from receipt of a control signal, the contactors shall de-energise. When the valve is in mid-travel position the motor shall be protected in the event of a jammed valve condition by the operation of the torque switches.

A time delay of approximately 0.5 seconds shall occur whenever the motor is instantaneously reversed. This is to protect the motor and contactor from current surges.

This protection shall de-energise the actuator motor if the maximum winding temperature is reached. This protection shall be independent of ambient temperature and motor current.

All actuator inputs and outputs shall be provided with surge protection in accordance with ANSI/IEEE C37-90A-1974.

14.3.5.5 Actuator Analogue and Discrete Inputs/Outputs

Analogue outputs shall be externally loop powered, two wire 4-20 mA capable of driving into a 600 ohm resistance, and have surge protection to ANSI/IEEE specification C37-90A-1974. External loop voltage is nominally 20-28V DC.

Analogue outputs shall each be equipped with facilities for calibration at the actuator.

Analogue inputs shall be two-wire 4-20 mA equipped with surge protection to ANSI/IEEE specification C37-90A-1974. Inputs shall continue to operate in the presence of ±40V common mode voltage.

All discrete inputs shall provide a minimum isolation of 1500V rms, input to logic circuitry.



Input surge withstand protection shall comply with ANSI/IEEE C37-90A-1974.

Inputs shall be equipped with suitable filtering to eliminate spurious signalling from contact bounce. Manufacturer to specify the specific provisions provided.

Discrete Outputs shall provide a voltage free contact output with contact rated at 220V AC, 5 amp or 24V DC 5.0 amp. Output contacts shall be independent and be isolated to the level of 1 kV RMS (output to logic, output to output).

14.3.5.6 Actuator Remote Control and Monitoring Facilities

In addition to local manual controls each actuator is required to be remotely controlled and monitored from a host station. The remote control and monitoring interface shall be by means of a shielded, twisted pair serial communications link implementing the MODBUS protocol.

The actuators shall be equipped with an RS 485 serial communications channel for communication via a twisted pair serial data channel, with a host station. The host station shall be equipped with an RS 485 serial communications port(s) and shall implement the MODBUS ASCII protocol for communication purposes. The manufacturer shall ensure that their serial communications network is fully compatible with and can be directly interfaced to the host station’s MODBUS serial communications port. The communications topology will be such that up to 10 other actuators shall be "multi-dropped" on the same RS 485 channel.

Each actuator on the network shall be assigned a unique network address, the host station (MODBUS Master) shall interrogate the actuators on a polled basis for actuator status and alarm conditions as well as sending control commands. The manufacturer shall supply complete and comprehensive documentation of the MODBUS protocol required for communication between each actuator field unit and the host station.

Electrical connections between the actuator field units and the two-wire network cable shall be made through isolator circuits. Isolation voltages shall not be less than 1,500 volts. Protection against induced voltages such as lightning shall also be included.

14.3.5.7 Actuator Controls, Data and Fault Communications

Comprehensive control data, status and alarm conditions are required from each actuator. Each actuator is required to respond to the following remote control signals:

Signal Function Discrete Interface Detail

Set valve position 4-20 mA signal

Emergency shutdown Contact closure (configurable to open or close valve).

Each actuator is required to provide following indications for remote monitoring:

Indication Function Discrete Interface Detail

Valve position 4-20 mA

Valve fully open



Valve fully closed

Motor running Voltage free contacts closing in the specified condition

Actuator fault alarm

"Remote" selector status

In an emergency condition an Emergency Shutdown (ESD) override signal shall be sent to the actuators. The ESD signal shall override any existing signal with the selector switch in either the Remote or Local position to fully open or close the valve. The selection of ESD control together with the direction of valve operation in an ESD condition shall be easily configurable by switch settings within the actuator. The ESD signal shall also be able to override the motor winding over temperature protection. This feature shall also be user configurable within the actuator.

Where external set point facilities are required actuators shall be equipped with integral adjustable anti-hunt dead-band limits for position control. These dead-band limits shall be adjustable from 1% to 13%.

14.3.5.8 Motor Power Supply

Power supply is 400V AC, 50Hz, 3-phase. Actuator motors shall have a minimum, Class F insulation, be 15 minute per hour duty rated and designed for 60 starts per hour with a maximum of 600 starts per hour. Manufacturer proposed actuator motor power, running and locked rotor currents as well as start and running power factors at the rated power supply shall be stated on the data sheets.

All actuators shall be equipped with all necessary facilities to readily enable the connection of static power factor correction capacitors (if found necessary) external to the actuator. These static power factor capacitors shall only be energized during actuator operation and the actuators shall be internally wired out to terminals accordingly.

14.3.5.9 Seismic and Vibration Resistance

Actuators shall be designed to withstand the following levels of vibration:

Plant induced vibration 0.5g over frequency range 10-200 Hz

Seismic induced vibration 1.0 g over the frequency range 0.2 - 33 Hz, where the actuator is to remain operational.

14.3.5.10 Commissioning Aids

Complete and comprehensive technical, maintenance and commissioning documentation shall be provided including full details of proposed field wiring interface showing terminal numbering and arrangement details.

14.3.6 Pneumatically Operated Control Valves

14.3.6.1 Codes and Standards

Design, selection, materials, manufacture, inspection, testing and installation of the control valves shall comply with the applicable sections of the latest listed standards and codes, such as:

Standard and Practices for Instrumentation



Instrument Society of America (ISA)

American Society for Testing Materials (ASTM)

American National Standards Institute (ANSI)

National Electric Code (NEC)

National Electrical Manufacturing Association (NEMA).

4 (four) set of all Codes and Standards are supplied by the Contractor to review the design documents.

14.3.6.2 Tagging and Name Plate

The following information shall be stamped into the metal of the body or flange:

Manufacturer’s name or trademarks

Body material

Class designation

Nominal valve size.

The valve shall be provided with a stainless steel name plate designating the following:

Make

Class designation/temperature

Service

Body size

Port size

Flow characteristics and Cv

Valve position or power/air failure

Valve travel

Tag number.

Valve Sizing and Selection

The Contractor shall size and specify the valves. The Contractor shall propose the valves to meet the specification.

Valve characteristic shall be equal percentage. Control shall be designed to match the anticipated system pressure and ideally operate at about 70% of the capacity at maximum flow. The possibility of critical flow, cavitation, flashing, and noise shall be considered in control valve selection and sizing.

Noise level from control valves is not to exceed 85 dBA at 1 metre.

The manufacturer shall provide a tabulated data of Cv vs % opening for all control valves.

14.3.6.3 Valve Body

A high-performance disc valve shall generally be used. The inside surface of the body and the surface of the disc shall be hard-faced with Stellite 6.

The shaft bearing box shall be provided with lubrication fittings and the shaft bearings shall be provided with stuffing box and a suitable Teflon packing in accordance with the process temperature and pressure which will protect the stem from process fluid which



contains solid particles such as silica. Shaft bearings shall be suitable for use in a geothermal environment and process fluid.

Control valve leakage rates shall be in accordance with ANSI B16.104. A minimum of Class IV leakage rate shall be specified unless otherwise noted.

Valve shall be capable of handling bidirectional process flow and still having essentially the same performance.

14.3.6.4 Actuators

Double acting piston actuators shall generally be used. The actuator shall have no spring for the fail mode of operation. The fail mode action shall be achieved utilizing check valves, trip valves, volume tank and related accessories. The piston shall be provided with an O-ring or other forms of self-lubrication to prevent a galling effect with the inside surface of the actuator piston chamber.

The valve actuator shall be equipped with a side de-clutchable hand wheel for manual mode of operation. This hand wheel shall be capable of being engaged or disengaged at any valve disc position without necessarily placing the valve in its fail-mode, fully open or fully closed positions.

This hand wheel shall be capable of being mounted in any desired position or angle with reference to the valve body and actuator.

14.3.6.5 Control Valve Ancillaries

Input signal to the transducer shall be 4-20 mA. I/P transducers shall be intrinsically safe. The pneumatic output of 3 ~15 psig or 0.2~1 barg is the input signal to the pneumatic positioner. I/P transducers shall be EMI and RFI immune. They shall have the capability for either direct or reverse valve operation and shall withstand 0.1g vibration. Accessories, including the pilot gauge, shall be made of 316L SS material. Cable entry port size shall be 3/4”. I/P transducers shall be mounted on the manual loader.

Positioners shall be bolted to the valve yoke, and shall be unaffected functionally or mechanically by vibration. They shall be supplied with reversible cams for linear and equal percentage and/or direct and reverse valve operation. All components including cam, cam follower, bearings, screws, bolts and nuts, bracket and gauges shall be made of stainless steel type 316L. No copper or brass components shall be used. The I/P transducer and the pneumatic positioner shall be a separate assembly linked by 316L SS tubing.

Each independent air consuming device such as a positioner, transducer, etc. shall be provided with an air filter regulator fitted with an output pressure gauge. Regulation shall be wrench adjustable and provided with a locking mechanism. The gauges shall be made of 316L SS materials.

Volume boosters, if required, shall be utilized to attain the stroke time for opening or closing the valves as indicated on the data sheets. They shall be capable of handling an input signal of 0.2 to 1.0 barg.

Rotary potentiometer type position transmitters shall generally be used for continuous position indication. The electrical angle of the potentiometer shall match the whole span of the valve travel. Output from the transmitter shall be 4-20 mA. Solid state integrated circuitry shall be utilized and shall be intrinsically safe and EMI and RFI immune. Cable entry port size shall be 3/4”.

Control valves shall be provided with the above accessories required to attain the fail-mode condition (fail-open, fail-close and fail-lock). All



of the above accessories shall be made of stainless steel to withstand corrosion due to H2S laden atmosphere. Changing from one fail mode to another shall be accomplished with minor re-tubing or rearranging of other accessories attached to it.

Therefore all the necessary accessories to achieve the three fail-modes stated above shall be included and attached to the actuator-valve assembly.

A local selector switch shall be provided to enable the control valve to be operated either remotely (control room) or locally. This selector switch shall be capable of providing remote (control room) indication of its position (remote or local). This shall be accomplished by Contractor hardwiring from the selector switch electrical terminal to the digital input module of the ICMS. The I/P transducer shall be mounted on the manual loader station.

A local pneumatic manual station shall be provided to enable the control valve to be locally operated with the selector switch at ‘local’ position. In general the station shall be able to throttle the valve at any desired position.

The local selector switch and the local pneumatic manual station shall be mounted in an instrument stanchion (yoke) support separate from the valve. All internal parts of both the switch and loader station shall be made of 316L stainless steel while the body shall either be made of 316L stainless steel or aluminium coated with epoxy.

14.3.6.6 Technical Data Sheets

The Contractor shall supply a Technical Data Sheet in Instrument Society of America (ISA) standard form for each control valve showing; specific application, rated service condition, special features, etc.

Test Certificates

The Contractor shall provide, as part of Contractor’s Q/A Procedures, materials and test certificates from an independent test authority which shall be reviewed by the Employer. The Contractor shall submit the following certificates to the Employer:

Test Report Certificate

Manufacturer’s Test Certificate

Pressure Test Certificate

Leak Test Certificate

Functional Test Certificate

Ramp Test Certificate.

14.4 Welding

14.4.1 General

All fabrication, erection, installation and testing of pressure containing systems

shall be carried out in accordance with the applicable codes. The requirements for

independent inspection must be recognized and complied with by the Contractor.

14.4.2 Welding Standards

Welding procedure qualifications, welding performance qualifications and

materials and workmanship shall conform to the applicable sections of the

relevant codes and standards. For pressure vessels and pressure piping, the

following applies:



For Pressure Vessels ANSI/ASME Boiler and Pressure Vessel Code

For Pressure Piping ANSI/ASME Codes for Pressure Piping B 31.1 or B 31.3.

14.4.3 Welding Procedure Qualification

The welding procedures shall be prepared and qualified in accordance with the

appropriate pressure piping code. Relevant documentation verifying the

qualification of all welding procedures shall be available for inspection prior to the

commencement of any production welding.

14.4.4 Welder Qualification

All welders shall be tested and qualified in accordance with the appropriate

pressure piping code. Relevant original documentation verifying the welders’

qualifications shall be available for inspection prior to the commencement of any

production welding. The test welds accepted by the testing authority in qualifying

each welder shall be available for inspection at any time prior to completion of the

Work.

14.4.5 Production Welding

All welding of pipe work shall be performed only by qualified welders using

qualified procedures.

Safety measures in accordance with ANSI Z49.1 requirements shall be

implemented to protect welders and operators involved in welding and cutting of

steel. Welds not conforming to an approved WPS may be rejected.

All valves and other components which could be damaged during the welding

process shall be removed or protected as appropriate.

Fabrication drawings shall use AWS welding and NDE symbols to show where

welding is required, type of weld, welding process examination method, etc.

Welding terms and definitions shall be in accordance with AWS.

Welding may be performed using one or combinations of the following processes:

Shielded Metal Arc Welding (SMAW)

Manual and Automatic Gas Tungsten Arc Welding (GTAW)

Automatic Submerged Arc Welding (SAW).

Except where specifically agreed in writing by the Employer other welding process,

such as Gas Metal Arc Welding (GMAW), Manual Submerged Arc Welding, and

Flux Cored Arc Welding (FCAW) shall not be used. FCAW shall not be used for

pressure vessel and piping not made from carbon steel. If FCAW is approved, all

vertical welding shall be done in the upward progression.

GMAW shall not be used on pressure retaining equipment or components. SAW

shall be performed in multiple layers with each layer not exceeding 1/2” thick. Flux

and filler material used shall be the same as those used for the Procedure

Qualification Record.

Peening, especially on root and cap passes, is not allowed.

Full penetration seal welds shall be used on all joints which are exposed to

process fluids or gases, require special cleaning (pickle and passivation), or

require protective coating or lining. Permanent backing rings or bars are not

permitted.

All joints welded on both sides, except those with a root pass deposited by the gas

tungsten arc welding (GTAW) process, shall have the root of the weld on the

second side removed to sound metal before welding from that side. Contractor



inspection procedure shall be included in the WPS to ensure metal soundness

after gouging and cleaning.

Except for P-1 pipe material, inert gas shall be used on all GTAW root passes.

The gas shield shall be maintained for a minimum of three passes or until 3/16” of

weld metal has been deposited. Gases for purging or shielding shall be welding

grade and have a dew point of at least -40°F or lower.

Unless the welding area is protected by a proper wind shield, welding shall not be

done when air draught or wind velocity is greater than 2.2 m/s and 4.5 m/s for Gas

Shielded Arc Welding and Shielded Metal Arc Welding process respectively.

Welding shall not be performed when the metal temperature is below 10°C or

when the air humidity is 100%. Welding shall not be permitted on wet surfaces.

Tack welds and temporary attachments shall not be permitted on austenitic

stainless steels or corrosion resistant materials. All tack welding and welding of

temporary attachments shall be performed using approved WPS and qualified

welders.

Temporary attachments used during fabrication shall be the same as the base

material. These and tack welds shall be removed after welding (avoid removing

base material) and the attachment area ground smooth and flushed with the

surrounding surface. The affected area shall be visually examined except that for

low-alloy, martensitic stainless or precipitation hardened stainless steels it shall be

examined by magnetic particle or liquid penetrant examination techniques as

applicable.

If PWHT is required for welds, the attachment areas shall also be post-weld heat

treated. If PWHT is not required, the hardness of the attachment area shall be

measured and shall be less than the specified maximum hardness.

Welds shall conform to the hardness limits specified in NACE MR-01-75, except

that the maximum acceptable hardness for welds in P1 base metals is HRC 20

(Rockwell Hardness).

Welding procedures for austenitic stainless steel shall be designed to minimize

sensitization. Unless otherwise approved by the WPS, heat input shall be kept

below 3 kJ/mm, preferably in the range 0.5 - 1.5 kJ/mm. The heat input can be

calculated using the formula:

H = (E . I.)/(V *1000), where:

H = heat input (kJ/mm);

E = arc voltage (V);

I = welding current (amps);

V = welding travel speed (mm/s).

Welding procedures for austenitic stainless steel shall be qualified with the

requirements of ASTM A708.

Wherever possible, starter pads shall be used to avoid arc strikes on the base

metal. Any arc strikes shall be ground smooth and faired into the surrounding

surface and the affected area shall be examined by liquid penetrant or magnetic

particle inspection techniques as required. Defects which reduce the design

minimum section thickness (corrosion allowance included) shall be referred to

Employer. Repair may be made with the same type of electrode or filler wire that

would be used for root pass.

Grinding of completed welds is to be performed only to the extent required for

NDE, including any in-service examination, and to provide weld reinforcement

within the requirements of the fabrication Code. If the surface of the weld requires



grinding, care shall be taken to avoid reducing the weld or base material below the

minimum required thickness. Grinding below the minimum wall thickness shall

require repair welding to restore the lost base metal thickness.

14.4.6 Filler Materials and Controls

Filler material for welding shall be compatible with the base material and shall

comply with those specified in the ASME Boiler and Pressure Vessel Code

Section II, Part C for Welding Rods, Electrodes and Filler Metals. Filler material for

carbon and low alloy steel shall be selected so that the principal elements in the

deposited weld metal are of the same nominal composition as the base metal.

Filler materials for welding low carbon austenitic stainless steel shall be low

carbon type. Austenitic stainless steel filler metal used shall contain 5 to 9 percent

ferrite in the finished weld.

Low hydrogen type electrodes shall be used for SMAW except that EXX10

electrodes may be used for high penetration welds. The finished weld shall have

approximately the same strength as the base material. Low hydrogen filler

electrodes shall be used for joints of dissimilar base materials consisting of carbon

and low alloy steels, (P1) through12chrome (P7). The filler metal shall be

compatible with the composition of either base material, preferably the lower P-

number material.

The Contractor shall avoid joints with dissimilar metal consisting of ferritic alloys

(P1 to P7) and nickel-chrome or austenitic stainless steel (P8) base material. If

such joints are unavoidable, the filler material used shall be AWS A5.4 E 309L-16

type or similar.

If jointing of other type of dissimilar metal or special material is required, the

Contractor shall submit details of the filler electrodes, the composition of the base

material and filler electrodes, together with the WPS for Employer review.

Finished welds from automatic welding process, especially SMAW, shall not

derive any principal elements from any flux used. The flux shall be neutral and the

principal elements shall be derived from the solid filler wires used in the process.

All welding shall be made with at least two passes unless otherwise approved.

Fluxes shall be used according to the manufacturer's recommendation.

Filler wires in specification AWS A5-2 shall not be used when the GTAW process

is used. Only SFA 5.18 filler wire shall be used on P1 type material when the

GTAW process is used.

AWS Electrodes Classes E6012, E6013, E6020, E7014, E7020, E7024 shall not

be used for any pressure retaining or load bearing welds. E7028 may be used in

flat and horizontal position welding contingent upon procedure qualification and

joint configuration.

Welding Rods, Electrodes and Filler Metals shall be locked in a weather-tight,

clean and dry enclosure which is kept at a temperature above ambient dew point,

usually between 15°C and 40°C. The materials shall be stored on perforated

wooden shelves away from the walls and floor of the enclosure to avoid contact

with condensing moisture. The materials shall be identified at all times and shall

be separated to prevent removal of the wrong material. Storage and atmospheric

exposure limits of low hydrogen electrodes for SMAW shall comply with the

requirements of AWS D1.1 Section 4.

Filler materials in the following conditions will be considered damaged and shall

not be acceptable for inclusion in the Work:

Materials that are damaged or pitted

Electrodes which are dirty, damp or contaminated with oil



Electrodes with flux separated from the wire

Bare and flux cored wires with rusts which cannot be removed by light sanding

All flux-cored electrodes contaminated with oil or water

Electrodes which have exceeded atmospheric exposure limits.

Bare and flux-cored wire that becomes dirty may only be used if cleaned and

restored to a bright surface prior to use. Welders shall not be issued or allowed to

carry more than one type of electrode or filler metal at any one time except that

when a qualified welder is specifically assigned to make a weld involving two

processes.

Unused welding rods shall be returned and stored in the proper storage area for

welding electrodes. Damaged electrodes as defined above shall be discarded.

14.4.7 Weld Joint Preparation

Tools used on austenitic stainless steel or non-ferrous materials shall not be used

on carbon or low alloy steels and vice versa. Alumina grinding wheels shall be

used on austenitic stainless steels and non-ferrous materials.

Weld joint preparation may be made by machining, grinding and thermal cutting

provided the prepared weld joint surface shall be uniformly smooth, free of all

loose scale and slag accumulation and preferably ground back to bright metal

finish.

Oxy-fuel shall not be used to cut stainless steel or non-ferrous material.

If preheating is specified for welding it shall also be applied to the material prior to

thermal cutting.

Prior to welding, the surfaces up to 25 mm from the edge of the welding groove for

ferrous material and 50 mm for non-ferrous and stainless steel materials shall be

clean and free from oil, rust, scale, slag, grease, paint, and other foreign material

which is detrimental to welding.

14.4.8 Thermal Treatment

Heating and cooling rates, post-weld heat treatment temperature and holding

times at specified temperature shall be in accordance with the applicable

fabrication code and WPS. PWHT specified in the WPS shall adhere to any steel

supplier's recommendations.

PWHT for shop fabricated piping and equipment, and all duplex stainless steel

castings shall be in a furnace.

PWHT for field fabricated mild steel and low alloy steel piping may be done using

other methods subject to acceptable review by the Employer.

PWHT for pipes shall be performed using four recording thermocouples on NPS

10” and larger pipes. These shall be placed as close as possible to the weld but

no more than 1” away from it, two of these thermocouples shall be place at 12

o'clock and 6 o'clock on one side of the weld and at 3 o'clock and 9 o'clock on the

opposite side. Pipes NPS 8” and smaller only require two thermocouples, one at

12 o'clock and the other at 6 o'clock on the opposite side of the weld.

Batch PWHT shall include hot and cold zones using at least 4 recording

thermocouples on the weld.

Temperature recording charts shall be used with all recording thermocouples and

shall have large enough scale suitable for calculating accurately the heating rate,

holding time and cooling rate. Contractor shall submit for Employer review, a



method for protecting threads and gasket surfaces against excessive oxidation

during heat treatment.

Welding Records

Each qualified welder on the job shall be issued with a distinct identification

symbol. Paint shall be used to clearly mark on the pipe adjacent to each

completed weld the symbol of the welder responsible and the date of the welding.

These markings shall not be removed until the welds have been inspected and

accepted, and the permanent record has been updated accordingly.

The permanent record shall be a set of drawings showing all pipe work. The size,

type, location, welder identification and date of welding of each welded joint shall

be clearly recorded on the drawings. This record shall be maintained by the

Contractor and shall be available for inspection at any time prior to the completion

of the Work. The permanent record shall be handed over on completion of the

Work.

14.4.9 Inspections, Tests and Repairs of Welds

The Contractor shall be responsible for maintaining weld quality consistent with

the requirements of this Technical Specification and the referenced standards.

On steam lines where access is available, the Contractor shall grind the internal

weld surface smooth to assist with NDT examination. Some crowning shall remain

to allow the weld to be located.

The Contractor shall provide all reasonable access for witness tests and

examination of production welds at any stage.

The Contractor shall arrange such inspections as specified. All costs associated

with these inspections shall be borne by the Contractor, regardless of the results

of the inspections. Non-destructive testing, additional to that required by the

fabrication code(s) and the specification, may be requested by the Employer. The

Contractor shall arrange such inspections as appropriate.

All costs associated with arranging such inspection of welds subsequently found

to be defective shall be borne by the Contractor.

Only one attempt shall be made to repair any defective weld, after which it shall be

replaced if still defective.

All costs associated with the repair or replacement of welds shall be borne by the

Contractor.

14.4.10 Weld Repairs

Weld repairs/rework shall be made before any required PWHT. Repair work after

PWHT shall require acceptable review by the Employer.

Unacceptable discontinuities shall be completely removed by chipping, gouging,

grinding or other authorized methods (for the type of material being repaired) to

clean, sound metal, and the excavated area shall as a minimum be visually

examined to assure complete removal.

Weld repairs shall be made using the same WPS used for the original weld, or

other approved welding procedure.

The repaired areas shall be re-examined using the same inspection method which

detected the original defect.

Only two attempts will be allowed to repair any one defective area. If defects are

detected after the second attempt, further repairs shall not be allowed, the faulty



area being cut out and replaced with a section of pipe extending at least 150 mm

either side of the faulty area.

NDT Inspection and Radiography of Pipework and Supports

NDT inspection shall be carried out in accordance with the applicable piping

design code and the special requirements detailed below.

All welds shall be visually inspected for surface defects by qualified inspectors.

Two butt welds out of each welder’s first production butt welds shall be

radiographed and interpreted to applicable piping code. In addition, 10% random

radiography on total no of welds basis is required for all steam piping and 10%

random radiography on total no of welds basis is required for all other piping

greater than or equal to 80 mm bore.

Radiography is to be in accordance with ASME V and acceptance criteria in

accordance with the relevant piping code (ANSI/ASME B31.1 and B31.3). Where

random radiography is carried out, any weld failure will require the further

inspection of the last two entire welds carried out by the same welder.

Selection of welds for radiography is to be carried out by the Contractor’s

independent inspector.

As far as is reasonably practicable, the welds in each piping system and each

piping class shall be subjected to 10% random radiography.

Radiographs, properly indexed and identifiable to welds, shall become the

property of the Employer upon completion. Where radiography is not practicable,

then magnetic particle inspection or ultrasonic flaw detection in accordance with

ASME V shall be carried out.

Magnetic particle inspection shall be carried out on all pipe support attachment

welds for piping in the following categories:

Steam piping at 5 bara and above

All anchors on piping 50 mm bore and above

All pipe support attachments on piping 150 mm bore and above.

Other steam piping

All anchors on piping 80 mm bore and above

Guides on piping 150 mm bore and above except for straight runs between other guides or anchors.

Where spot radiography of supports is required, as specified in ASME Code,

Section VIII, Division 1, paragraph UW 52, the welds selected for examination

shall represent each WPS on the piece of equipment inspected. The evaluation of

such results and the acceptance criteria shall be in accordance with ASME Code,

Section VIII, Division 1 or 2, whichever is applicable.

14.4.11 Welding Stainless Steel

Where stainless steel is to be welded it shall be of the “L” grade. Mild steel

attachments and mild steel tack welding shall not be permitted.

Crevices in corrosive environments shall be avoided, or seal welded.

Care shall be exercised to avoid problems due to high thermal expansion and low

conductivity of stainless steel, such as:

Tack welds not re-melted into the weld pool

Welding heavy and light sections.



Contamination by salt (e.g. perspiration), carbon (e.g. pencil markings) and iron

(e.g. filings, wire brushing, and grindings) shall be avoided.

14.5 Piping Systems


All pipe work shall be designed to ANSI/ASME B31.1 or ANSI/ASME B31.3

14.5.2 Design

Pipe work sizing shall be based on pressure drop calculations to suit equipment

requirements, available fluid pressures and to minimize pumping costs. Pipe work

and equipment shall be sized for the maximum transient flow rates that can occur

in the pipeline.

All steam, water or compressed air drain and vent lines shall be 25 mm internal

diameter or greater. On steam drains clearance shall be provided to enable rod-

out (hot-tap) of a plugged valve.

All sample connections shall be at least 12 mm internal diameter and shall have a

rod-able through isolation valve.

All pipe work shall be designed for applicable ambient conditions, seismic loads,

discharge reactions, dynamic time-force reactions, effect of supports, anchors and

terminal movements/loads.

All pipe work shall be designed to ensure that no harmful vibrations are

transmitted to building elements, pipe work, ductwork, trunking and other plant

and equipment items. Anti-vibration mountings and pipe work isolators shall be

provided as necessary to prevent the transmission of vibrations.

Vertical and horizontal snubbers and/or restraints shall be provided to limit

movement due to machine operation and seismic forces.



The velocity of flow in pipes is not to exceed the following values unless otherwise

specifically mentioned:

Table 18: Velocity of Flow in Pipes

Parameters m/s

Steam

Saturated steam greater than 1.7 Bara (and superheated steam with <14oC superheat

65

Superheated steam (with a minimum of 14C superheat) 75

Low pressure wet steam (including saturated steam up to 1.7 Bara)

40

Water

Condensate piping 3.7

General service piping including potable, fire fighting, raw and service water

3.0

Demineralised water lines 3.0

General pump suction lines 1.0

Feedwater suction 2.4

Feedwater piping 3.3

Air

Compressed air pipelines 25

Gas

Fuel gas supply lines (with insulation to reduce noise levels)

50

14.5.3 Stress Analysis

Piping systems and components shall be stress analyzed, if required, for thermal

flexibility, support, pressure, vibration, seismic, fluid or gas flow reactions, and

environmental factors, including effects on equipment.

Piping flexibility shall be obtained through pipe routing or expansion loops unless

limitations of space or economics dictate the use of flexible connectors. Expansion

loops, when installed in a horizontal plane, may be offset vertically to clear

adjacent piping. Flexible connectors are to be used only when it is not feasible to

provide flexibility by other means.

The piping flexibility analysis shall consider the most severe operating

temperature condition sustained during start-up, normal operation, upsets, or

shutdown. The analysis shall be for the maximum temperature differential. The

effect of installation temperature and solar temperatures shall be considered in

determining the maximum temperature differential. Analysis shall include relief

valve opening and stop valve closure.

As a minimum, computer analysis shall be performed on the following piping

systems:

Main steam from HRSG to the interface points at the steam turbine and surface condenser



HRSG feed water supply from high-pressure feed water pump to HRSG

All piping over 120°C or piping subject to dynamic transients or high-velocity steam flows

All steam and relief piping 150 mm bore and larger.

The pipe support design for turbine steam bypass system(s) will include devices to

restrict pipe dynamic loads, if required by the design.

The Contractor is responsible for meeting all the requirements for pipe

connections established by the manufacturers of the HRSG, ST, the pumps and

other relevant equipment.

The Contractor shall verify proper installation and setting for all pipe supports (1)

before initial heat up, and (2) during initial operation at full plant load or other

maximum operating conditions (where possible).

14.5.4 Material Selection

All steam pipe and fittings less than 600 mm shall be seamless. In general, pipe

and fittings less than 600 mm used elsewhere shall be seamless. Spiral welded

pipe shall not be used for steam. Particular requirements for materials are as

follows:

Steam <420°C Carbon steel

Steam 420 to 530°C Low allow steel

Steam 530°C 2.25% Cr, 1% Mo steel

Demi. water 316L stainless Steel

Seal water 304L stainless steel/ABS

Main and auxiliary Circulating Water FRP/316L stainless steel/ABS

Oil supply 304L stainless steel

Oil return Carbon steel

Condensate 316L stainless steel

Fire main HDPE

Fire suppression Carbon steel

Utility air 304L stainless steel

Instrument air 304L stainless steel

Chemical treatment (except caustic soda) 316L stainless steel

Caustic soda Carbon steel/ABS

Oil transfer Carbon steel

Fuel gas Carbon steel

All buried pipe work other than thermoplastic pipes shall be coated with high

density polyethylene on the outside in accordance with AS 1518.

FRP piping shall be of the reinforced thermosetting resin type manufactured by

the filament wound process using a thermosetting polyester resin reinforced with

fiber glass, generally to ASTM D2996, D2310 designation NTDD105 and AWWA

Standard C950.

14.5.5 Materials

It will be the responsibility of the Contractor to inspect all materials to ensure that

the correct grade of material has been procured, supplied, and installed, and that

identification, dimensions, material quality and end preparations are in accordance



with the requisite standards and specifications. This shall include verification that

all mill certificates are received and checked against materials. These mill

certificates shall be submitted to the Employer for independent review.

The Contractor shall thoroughly check all equipment is clear and free from foreign

matter. Any interior or exterior deterioration, such as rusting or physical damage

shall be remedied by the Contractor.

Any plant found defective in its design, workmanship and/or material, or of

substandard quality, and any damage incurred during its shipment, storage, or site

transport shall be remedied or replaced as necessary by the Contractor.

The Contractor shall account for all materials procured for the project and shall

provide regular reports to Employer, advising quantities required and orders

placed.

The Contractor shall supply all materials including welding rods and equipment

necessary for the completion of the Work as documented and specified. Allow for

all items necessary for the performance of the obligations under the contract

including items not expressly mentioned in these specifications, but necessary for

completion and performance of the Works. All plant and material supplied by

Contractor for incorporation into the Work shall be submitted for review by the

Employer before installation.

Unless otherwise specified all material incorporated into the Work shall be new of

high quality, free from defects and of proven acceptability for the purpose intended.

The Contractor shall use adequate materials, processes and equipment to ensure

that the workmanship is of a standard equal to or better as specified and suitable

for the intended purpose.

The Contractor shall employ only skilled competent tradesmen appropriately

qualified and registered or licensed at the time of carrying out of the site

installation work.

Samples of products/materials shall be submitted for review by the Employer as

and when required.

The Contractor shall not confirm orders requiring Employer’s review until such

review is complete. Retain approved samples on site for comparison with

products/materials used in the Work and remove when no longer required.

Corresponding parts throughout the Work are to be interchangeable and shall

perform in identical manner if fitted in another unit in the Work. Likewise all spare

parts must fit accurately in place without additional machining and shall perform in

no inferior manner to the original part.

The Employer reserves the right to inspect the piping to the extent necessary to

satisfy itself that the Work conforms to the drawings and specifications and to

verify that all the required testing and examinations have been completed to the

satisfaction of the Employer.

The Employer may use any or all recognized testing methods which are deemed

necessary to assist in the accurate determination of weld quality. The Employer

may appoint an Inspection Agency to carry out inspection services and to witness

and verify tests. The Contractor shall liaise and coordinate fully with the Inspector

and take all necessary measures to facilitate testing and verification.

The Contractor shall be responsible and comply with the specification

requirements for radiographic and other non-destructive inspection. The

Contractor shall be responsible, at no additional cost to the Employer, for the

repair of welds, re-inspection of welds and any retraining or re-qualification of

welders or welding operators.



All piping shall be inspected in accordance with the requirements of ANSI B31.1.

Acceptance shall be in accordance with the requirements of the above code,

except where modified or extended by the Employer's specifications.

Identification bands shall be painted on all finished piping in accordance with ANSI

A13.1 or where specified to ANSI B31.3. Bands shall be applied either to the

finished painted pipe or the insulation cladding as appropriate. The identification

bands shall be applied at regular intervals and to both sides of any wall or floor

penetration.

The Contractor shall fabricate and install prior to start-up of equipment, "witches

hat" type start-up strainers on the suctions of all pumps. Contractor shall

throughout commissioning remove, clean and replace the strainers as required.

The Contractor shall remove all start-up strainers upon completion of

commissioning.

The Contractor shall tighten any leaking valve glands as the system is being

tested with steam or hot fluids. Gland packing shall be added to or replaced as

required.

14.5.6 Layout

Piping shall be arranged so that full access is provided for the maintenance of

equipment and so that removal or replacement of plant can be achieved with the

minimum dismantling of piping.

All pipe work shall be carefully set out and installed to ensure that clear access is

maintained to valves, strainers, vents, instruments, plant and through all access

ways.

All valves, strainers, instruments and items requiring operation or maintenance

shall be easily accessible from permanent safe working platforms.

All pipe work shall have, as appropriate, automatic or manual vents and drains. All

horizontal pipe work shall be graded to provide for draining and/or venting as

appropriate. Relief valves and vents shall be piped to discharge in safe locations.

Overflows and drains shall be piped to discharge to the nearest convenient drain.

14.5.7 Handling and Storage

The handling of all materials and plant shall be undertaken safely and in such

manner as to ensure that no damage is incurred. The Contractor shall familiarize

himself with the manufacturer's handling data and shall ensure that the craneage

and handling of all plant, pipes and equipment is carried out in a safe and

workmanlike manner. Manufacturer's lifting instructions shall be followed, including

the use of all specified lifting and jacking points and special lifting frames or

equipment.

Any pipe, pipe coating, fittings, valves or plant damaged during handling,

transportation, stacking, storage and stringing, shall be repaired or replaced by

Contractor.

The Contractor shall provide and maintain in good repair all necessary lifting

equipment suitable for handling line pipe, pipeline fittings, valves and equipment

without damaging bevelled ends, coatings and linings.

The Contractor shall take precautions to ensure that no damage is caused to line

pipe or other materials during loading, hauling and unloading.

Calliper hooks shall be properly padded with non-asbestos brake lining or other

such suitable material. End hooks shall be malleable iron or faced with nickel;

shall be smooth faced and shall properly fit the curvature of the inside of the pipe.

Where end lifting hooks are used, spreader bars shall be provided for the lifting



chains or ropes. In the case of pipes having end caps, the pipes shall be lifted

using nylon, canvas or rubber lined slings.

Coated line pipe shall be lifted, lowered or suspended by special end hooks or by

wide non-abrasive belt slings of rubber or canvas.

The use of tongs, bare pinch bars, chain slings, pipe hooks without proper

padding, ropes, chains or wire cables or any such other handling equipment shall

not be permitted.

Physical separation of different materials shall be enforced and each batch of

materials shall be marked in such a manner that it can be related to the

manufacturer's Test Certificate and Delivery Advice Note.

The conditions of storage shall be as follows:

All fittings, expansion compensators, flanges, valves, instruments, filters, gaskets, bolts, control panels and other mechanical plant shall be stored under ventilated cover

All items listed above shall be stored above grade on material pallets, racks or dunnage such that they may drain

Electrodes shall be stored in hermetically sealed containers as supplied by the manufacturers. Once such containers have been opened, electrodes shall be stored so as to avoid absorption of moisture. Any electrodes exposed to moisture, in any way, shall be scrapped

Protective coverings of pipe bevels shall not be removed until immediately prior to preparation for welding

All gaskets, especially spiral wound type, shall be stored flat on their own backing plate which shall not be removed until immediately prior to its final installation on the pipeline

All pipe coating materials shall be stored in covered, well ventilated stores and handled in such a manner as to prevent damage or contamination which would make them unsuitable for use. Any such material which shows evidence of contamination or deterioration while in Contractor's custody due to weathering or any other cause, shall be rejected

Line pipe shall be stacked clear of the ground and be adequately protected against damage to pipe or coating, and against accidental rolling. Suitable padding shall be provided between pipe tiers

The number of tiers in a stack shall not exceed safe limits for the diameter and wall thicknesses of the pipe and the type of coating. Particularly attention shall be paid to large diameter thin walled pipe. The front and back ends of pipe stacks shall be adequately blocked to prevent any movement. Pipes shall not be nested unless this is agreed by the Employer.

14.5.8 Fabrication, Assembly and Erection

14.5.8.1 Pipe Bends

Welding elbows shall be minimum long radius (1.5D radius) elbows, except for instrument air lines, where short radius butt welding elbows may be used.

Bends may be pulled in pipe of 25 mm nominal size or smaller. Bends shall only be formed with a bending machine using the appropriate dies. The radius to the centre line of the pipe at the bend shall be at least five times the nominal pipe size.

Bends shall be free of racks, wrinkles, bulges, kinks and other defects. The out of roundness, as measured by the difference between the maximum and minimum outside diameters around the



bend, shall not exceed 8% of the outside diameter specified for the pipe.

Where the bend angle is too shallow, generally when the adjacent girth welds in large diameter pipes are less than 100 mm apart at the closest point, a miter bend shall be used in accordance with the requirements of the code.

Each cut bend shall have one factory machined beveled end. That is, each standard pipe bend cannot be used to make more than two bends in the pipeline. No other fabricated bends shall be used unless acceptable to the Employer.

Pipes running along a common route shall be parallel to each other.

Where necessary to fabricate bends and offsets in pipes less than 100 mm diameter, they shall be fabricated by the hot bending process. The temperature shall be sufficiently high throughout the operation to prevent the cold stressing of the metal and the pipes shall be sand-filled to help prevent distortion.

All aspects of the hot bending shall comply with the requirements of ANSI B31.1, or where specified to ANSI B31.3.

No fabrication of bends or offsets shall be carried out on pipe with a diameter greater than 100 mm.

14.5.8.2 Alignment of Welded Joint

Each joint shall be aligned so that the offset between the internal surfaces does not exceed the design code requirements.

Line-up clamps shall be used for aligning pipe ends, wherever possible. Line-up clamps shall remain in position until completion of the root pass.

On no account shall strips, plate sections or cleats be attached to the pipe for alignment purposes unless approved in writing, by the Employer. Where fittings prevent the use of line up clamps, the work shall be set up, properly spaced and supported, and tack welded.

14.5.8.3 Installation of Pipeline Components

The Contractor shall field check all dimensions before preparation of any pipe spools in the shop or field. All fittings including valves and expansion joints shall be positioned in accordance with the drawings and fitted in accordance with the manufacturer's specifications and shall be protected at all times from weld splatter, undue heat, dirt and any pressure, force or deflection in excess of manufacturer's specification.

Flanges shall be installed with the bolt holes straddling the vertical centre line of the pipe. When flanges are to be welded into a line, the second flange of the pair shall be tacked in position. The alignment and rotation shall then be checked before final welding begins. Where flanges connect to valves, expansion joints or other fittings, a similar procedure shall be adopted. The fitting shall be installed and the flanges bolted up before the final joint is tacked and welded.

Butt and socket welded valves shall be in the closed position when welded into pipelines and shall remain closed until the valve has returned to ambient temperature.

All flanged surfaces and grooves shall be clean, dry and unmarked prior to make-up. Gaskets shall be new, clean and free from defects. Stud bolts shall have a full, continuous thread and be long enough to extend a minimum two full threads beyond each nut when tight.



Anti-seize compound shall be used on the threads of all flange bolts and all exposed threads shall be liberally coated with high temperature grease before installation.

Exposed portions of holding down bolts on concrete pads and plinths for supports, anchors and equipment shall be greased and covered before casting into place.

The exposed ends of pipeline instrument connections shall be plugged until the installation of instruments.

Installation of Compensators /Expansion Joints

Expansion joints shall not be installed until line testing, including hydrostatic, testing has been successfully completed on the line section. The expansion joints shall then be installed in the line with the cut short set within ± 1 mm of the length shown on the drawing, and the welds on either side of the compensator will be 100% radiograph tested.

Extreme care shall be taken in setting up the pin angle which shall be within ± 0.2 degrees of the angle shown on the drawings. Contractor shall check the accuracy of the setting before welding the compensator into place.

The angle of the single incline support between the compensators shall be checked and set within ± 0.2 degrees of the angle shown on the drawing. Contractor shall check the accuracy of the setting before welding the compensator into place.

14.5.8.4 Installation and Alignment of Pipes and Pipe Supports

Pipe Installation

Intersection points shall be as shown on the detail drawings, and prior to piping installation shall be pegged out by qualified surveyor, to an accuracy of within a circle of 50 mm radius.

Pipe support positions shall be measured along a straight line between intersection points. The measurement between intersection points shall be cumulative and the tolerance on plan position of any support shall be ± 100 mm except that supports close to bends, valves, compensators and other in line equipment shall be accurate to ± 10 mm. The maximum misalignment of any support shall be ± 3 mm maximum between intersection points.

Pipe levels on supports shall be similarly set up from a straight line between intersection points. The accuracy of the levels shall be ± 3 mm maximum.

Contractor shall make compensation for any cold pull (cut short) in the line.

The saddle positions, size, offsets and direction of offsets shall be shown on the drawings. All welding of saddles to pipe shall be by welder qualified to the requirements of ANSI B31.1, or where specified to ANSI B31.3.

The Contractor shall, at all times, handle and support the pipe in such a manner as not to overstress or cause damage to the pipe or flanges. The piping shall be kept clean internally and all tools and construction materials are removed before the piping is welded.

The longitudinal seam of the pipe shall be at the top of the pipe but offset minimum 50 mm arc length from the vertical centre line so that there is at least 100 mm between the longitudinal seams of adjacent pipes at a circumferential weld joint.



Hot and cold field bending of the pipe to attain alignment of pipe sections shall not be allowed.

Flanged piping connections to pumps, vessels and other rotating equipment shall be aligned so that the flange does not spring upon release of flange bolts.

Screwed joints on instrument airline shall be made using Teflon tape seals.

Buried Pipes

The Contractor shall provide a protective coating for all pipes to be buried. All buried steel pipes shall be adequately protected against corrosion by approved Denso tape, Polyken tape or other equivalent system. The Contractor shall submit the proposed system and procedures for site application for review.

The protective coating shall be applied preferably in the factory prior to stringing the pipes along the pipe route except that site joints shall be wrapped in situ. There shall be at least 1" overlap when wrapping around pipes.

All protective coatings shall be applied and inspected in accordance with the manufacturer's specification.

The bed where the buried pipe is to be installed shall be filled with a layer of sand or stone free soil. Backfill shall be free of sharp objects and stones.

Cold Pull or Cut Short

Pipe shall be at ambient temperature when cold pull (cut short) measurement and set up is undertaken. All work on supports and shoes between adjacent pipes shall be complete prior to the application of cold pull to the superimposed pipe.

Cold pull shall be set up within ± 1 mm of the gap length shown on the drawings and shall be made only after the pipe has been supported as shown in the drawings. Temporary supports may be used to hold up the pipe during the cold pull.

Cold pull techniques shall be used such that the closing force is applied equally to the pipe on each side of the gap. All procedures for cold pull shall be submitted in writing to the Employer for review before proceeding.

14.5.8.5 Pipe Supports, Anchors and Guides

All supports shall comply with the relevant structural steelwork specification. Pipe work shall be supported to prevent any excessive sagging, bowing or bending of the pipe work under normal loading conditions.

The spacing between supports on pipe work shall follow guidelines given in ANSI B31.1 where applicable, and shall not exceed the following limits: Pipe work shall be supported immediately adjacent to all valves and equipment items which are not directly and separately supported.

Pipe supports shall be carefully located to minimize and maintain within permitted limits pipe work stresses and deflections resulting from gravity, thermal, wind, seismic and other loads likely to be imposed on the pipe work. Special care shall be exercised with the location of supports near bends and branches in pipe work subject to significant temperature variations to ensure that the pipe work is not subject to excessive stressing.



The use of springs, constant force supports and other adjustable supports shall be minimized. If provided, the adjustment shall be capable of being locked.

All pipe support components in direct contact with the pipe shall be of materials compatible with the pipe material. Where clips, sliders, rollers, U-bolts or overstraps are not available in, or cannot be made of materials compatible with the pipe, an intermediate material compatible with the pipe and the support clip, slider, roller, U-bolt or overstraps shall be installed to separate the incompatible materials.

Clamp-on supports shall be used for alloy pipe.

The Contractor shall design and supply and install all special and standard supports, anchors and guides for pipes, fittings, valves and other pipeline equipment. This shall include the civil and structural steel work required. Supports can be cast into the foundations.

The Contractor shall ensure that structural steel is primed and fully painted in the fabricator's shop to the maximum extent possible.

Those areas of steel work which require field welding shall be suitably cleaned and primed before painting. These areas and any unpainted steel surface shall be painted with the appropriate paint system in accordance with the paint specifications after welding is complete.

All supports with base plates shall be bolted down on concrete pads or plinths using either approved chemical anchor bolts or bolt pockets formed in the concrete as shown on the drawings. The supports shall be subsequently grouted and the bolts tightened after the grout has cured.

For piping 2” diameter and smaller Contractor shall use an approved proprietary masonry anchor such as Chembolt, Dynabolt or Terrier for fixing to concrete work. Supports of this type shall not support loads of greater than 100 kg. The diameter of any threaded fastener shall not be less than 12 mm.

Should an anchor bolt strike reinforcing, the Contractor shall relocate the anchor to avoid the steel, and make good the concrete work over the reinforcing.

All hangers and supports shall be set during erection such that they carry the design loads. After completion of all tests and installation of thermal insulation, supports and hangers shall be rechecked and the springs adjusted to the design loads in the cold condition.

Before plant start-up and after having verified that the block devices have been removed, the exact locations of the pipes in the cold position shall be recorded on the As-built Drawings. After plant start-up and after having reached the rated temperatures, measurements shall be made again and the position in the hot condition recorded.

14.5.9 Size Changes

Factory made forged reducer fittings shall be used for all changes in pipeline sizes.

In horizontal pipe work, eccentric reducer fittings shall be used as appropriate to

maintain grades for venting and draining.

14.5.10 Flanges

Flanges for piping and valves 600 mm and smaller shall be to ANSI B16.5 Pipe

Flanges and Pipe Fittings. Flanges for piping and valves of 600 mm bore and

above shall be to MSS SP44, or equivalent.



Weld neck flanges shall be used on steel pipes 2" NPS or larger. Socket welded

flanges may be used on pipes 2" and smaller. Threaded flanges shall not be used.

Slip-on flanges may be used for non-steam service, Class 150 and below piping.

Raised face flanges shall be used on class 150 and class 150 flanges. Reducing

welding neck flanges shall not be used:

Flanges shall be carefully fitted to pipes to ensure that correct alignment and

attitude is achieved. Flange faces shall be at right angles to the axis of the pipe,

matching flange faces shall be parallel and flange orientation shall be such that

valves and other flanged components are correctly installed.

Gaskets shall be used to seal all flanged joints. Spiral wound metal gaskets shall

be used in steam service. Additional sealing materials and compounds shall not

be used.

Flanged joints shall be secured with stud bolts and hex nuts and washers. The

bolts shall be of sufficient length to provide between three and five full threads

beyond the crowns of the nuts when tight.

Flanges shall be spot-faced at the back to receive bolts, washers and nuts.

14.5.11 Jointing

All piping 80 mm bore and larger shall be welded or flanged. Threaded

connections shall not be seal welded.

De-mountable joints in piping shall be provided as appropriate to allow

disassembly for cleaning, servicing or maintenance. Flanges or unions shall be

used for making de-mountable joints.

All other joints in the piping systems shall be as follows:

Black steel piping welded joints

Stainless steel piping welded joints

Galvanised steel piping screwed joints on compressed air lines screwed joints or Victaulic couplings or equivalent on water lines.

On small bore piping where welding is impracticable unions or flanges may be

used. Compression fittings may be used for cold pipe smaller than 2" with

pressure less than 350 kPa. Where butt welded or socket welded fittings can be

used, screw connections shall be avoided wherever possible.

Where used for pipes less than 1" NPS, threaded fittings and screw joints shall be

at least schedule 80 for carbon steel and schedule 40 for stainless steel.

Screw threads on pipes shall NPT. Where screw or threaded connections are

used, there shall be at least 4 threads left on the male component when the

connection is completed. Seal welding of thread connections shall not be allowed.

The use of screwed bushings shall be kept to a minimum.

Fabricated stab-in type branch connections are to be used only if the piping

geometry dictates, or where the branch pipe diameter is three pipe diameters or

smaller than the run pipe. Where the branch is within two diameters smaller than

the main, reducing tees shall be used.

Where reducing tees are not readily available, welding fittings such as weldolets,

sockolets and threadolets may be used for connecting 2" diameter pipes and

below to larger pipes. Elbowlets may also be used at connection to a bend. Such

fittings shall be rated for at least ANSI Class 1500.



14.5.12 Floor Collars, Wall Boxes and Weather Hoods

Suitable floor collars or wall boxes shall be provided at all points where pipes pass

through concrete or other similar floors and walls. The floor collars shall have

raised kerbs of suitable height, which shall not be less than 75 mm. The wall

boxes shall be flush fitting and of neat design.

Where pipes pass through roofs, the pipe collar shall upstand not less than 200

mm above the top of the roof and the hood shall shroud it to within 25 mm of the

finished roof level. Where pipes pass through external walls appropriate weather

sealing shall be provided.

Weather hoods shall be provided at the open ends of all upward facing

atmospheric exhaust or vent pipes.

14.6 Thermal Insulation

14.6.1 Design

Thermal insulation shall be in accordance with BS 3958 and BS 5970 or

equivalent.

All condensate and steam piping insulation shall be in calcium silicate.

Lagging shall be asbestos free and non-hygroscopic. Insulation fitted to stainless

steel pipe shall be chloride-free.

Those items with surfaces at 60°C or more at any time shall be insulated.

The following need not be insulated if in areas not accessible to personnel during

normal operation:

Valves, flanges and in-line instruments with surface temperatures below 120°C

Intermittently used plant drains

Steam trap discharge piping

Pipe work, ducts and vessels engaged in the conveyance of hot fluids and gases to waste (indoor: intermittent use, outdoor: intermittent or continuous use);

Lifting lugs, clips and hangers shall be left free of the lagging and cladding

The upper part of valve gland packing shall be left un-insulated

Insulation for cool items shall be provided to prevent condensation and for energy conservation.

Other requirements are as follows:

Cladding for valves and flanges shall be in two halves to facilitate maintenance without disturbing adjacent insulation and cladding

Outdoor clad flat horizontal surfaces shall be cambered to shed water

Cladding shall be designed to prevent ingress of water and dirt

Where it is possible for personnel to contact insulated surfaces, the surface temperature shall not exceed:

50°C for metallic surfaces

45°C for non-metallic surfaces

Parts of plant requiring access for maintenance shall have removable covers in the cladding. Any covers over controls and instruments shall be secured by toggle grips.



Feed water

Mineral wool

14.6.2 Materials

Insulation for piping and equipment shall generally be 50 mm thick and be in

accordance with the following requirements:

Calcium silicate shall be white rigid asbestos-free insulation having thermal conductivity of not higher than 0.072 W/mK at a mean temperature of 149°C and in compliance with ASTM Standard ASTM-C533.

Perlite insulation shall be made of expanded perlite, inorganic binder, and reinforcing fiber suitably bonded together and asbestos-free. It shall have a density of 208 to 288 kg/m3 and a thermal conductivity of not higher than 0.072 W/mK at a mean temperature of 150°C and suitable for a service temperature of not less than 260°C

Fiberglass shall be long, fine, flame-attenuated, asbestos-free glass fiber insulation, having a density of approximately 80 kg/m3 and a thermal conductivity of not higher than 0.065 W/mK at mean temperatures of 150°C and in compliance with US Federal Specification HH-1-558B, Form D, Type III, Class 12. All fiberglass insulation shall be suitable for a service temperature of not less than 260°C.

The cladding material shall be metal jacketing. The finished metal jacket material

shall be polished aluminium alloy 1503 H14 having a minimum thickness of 0.4

mm or acceptable equivalent. One sliding expansion joint in the cladding shall be

provided between pipe supports.

Insulating cement shall be non-hydraulic setting mixture of mineral fibers, clay,

and inorganic binders. It shall be suitable for use at temperatures up to 290°C with

a thermal conductivity less than or equal to 0.123 W/mK at a 150°C mean

temperature. Insulating cement shall be acceptable to the Employer.

Finishing cement shall be non-hydraulic setting mixture of mineral fibers, clay, and

inorganic binders. It shall be suitable for use at temperatures up to 290°C with a

thermal conductivity less than or equal to 0.149 W/mK at a 150°C mean

temperature. It shall meet the requirements of ASTM C449. Finishing cement shall

be acceptable to the Employer.

Wire shall be 16 gauge, 1.6 mm diameter, galvanised steel. The banding material

shall be a suitable aluminium alloy.

All elbows, tees, caps, terminus bevels, equipment and other components shall be

provided with preformed, shop or field fabricated metal cladding.

Screws shall be aluminium pan head or hex head slotted self-tapping sheet metal

screws not less than 10 gauge by 19 mm long.

"S" clips shall either be preformed stainless steel clips or field fabricated out of the

banding material specified above. If preformed clips are used, they shall be 19

mm wide by 0.5 mm thick, type 316L stainless steel.

A high temperature sealant shall be used for sealing joints, edges, and

penetrations in jacketing. It shall be clear silicone, non-shrinking flexible sealant

suitable for use at temperatures up to 290°C

If used, pop rivets shall be aluminium or galvanized steel with both shaft and rivet

heads made of same material. Minimum size is 4 mm diameter by 8 mm long.

Tapes for sealing joints and penetrations in factory-applied/supplied vapour barrier

backings or facings shall be pressure sensitive, vapour barrier types. The tape

facing shall match the backing or facing to which it is applied.



14.6.3 Installation of Insulating Systems

The Contractor shall provide all insulation materials, supervision, labour, fixing

materials, equipment, tools, supplies, security and other requirements to complete

the insulation systems.

The application of insulation shall not begin prior to the commencement of

hydrostatic or pneumatic tests. If circumstances necessitate work to begin prior to

testing, all welds, threads, unions and fittings shall be left uncovered until either

the hydrostatic, pneumatic or in service leak testing has been completed.

All instrument assemblies requiring insulation and attached to hot insulated piping

or equipment shall be insulated with a thickness of 50 mm.

Insulation systems shall account for potential thermal expansion, contraction and

movement of insulated surfaces. Minimum clearance between insulation surfaces

and any obstruction such as stairs, platforms, or piping shall be sufficient to allow

for normal operational movement.

All insulation shall be protected from moisture and weather before and during

application. No insulation which has been wetted shall be applied to any surface.

Contractor shall prevent moisture from working underneath partially applied

insulation or collecting on uninsulated surfaces. All non-jacketed insulation shall

be completely covered with plastic to prevent moisture damage at any period of

impending rain. Bare insulation shall be covered with plastic at the close of every

work day.

If the insulation becomes wet after application, it shall be allowed to dry to reduce

the moisture content below 1.0 percent before proceeding with the application of

jacketing or weatherproofing compounds. The Contractor shall provide the

Employer with complete shop drawings detailing all typical and specialised

methods for fabricating and installing all insulation, jackets and weatherproofing

for all items requiring insulation.

The Contractor shall be responsible for making good any damage that occurs to

the insulation systems prior to handover. All insulation on horizontal and sloping

pipes shall have calcium silicate with sufficient strength to withstand the weight of

a person walking on top of the pipe. All cladding shall be installed commencing at

low points and working uphill, irrespective of the steam flow direction. This is to

ensure that laps in cladding are directed away from any surface water runoff.

All metal protrusions through insulation such as pipe shoes, anchors, lugs, drain

valves, etc. shall be sealed with sealing compound. All cut-outs resulting from

protrusions will be made as close as possible to the fitting (3 mm maximum

clearance) to minimize heat loss and to provide a neat appearance. The

Contractor shall install material on pipeline such that the insulation forms a

continuous coating.

Insulation thickness on piping components shall be of the same thickness as that

of the piping.

All bands shall be drawn up by mechanical tightening devices, and the ends shall

be secured by suitable mechanical fasteners of a form which will permit a flat joint

to be made.

14.6.3.1 Application of Full Insulation on Piping

Insulation shall be applied to clean, bare, and dry pipe using staggered joint construction, and shall be secured in place with galvanised wire at 230 mm centers. However, each section shall have at least two (2) wires. The wires shall be tightly twisted and ends embedded into the pipe insulation.



On vertical or inclined pipes, Contractor shall provide bolted, clamp-type insulation supports. The supports shall extend to 13 mm from the outer surface of the outermost insulation layer. Insulation supports will be required for every 5.5m of vertical rise starting at 0.3 m into the vertical run. An insulation support shall be installed a distance above the flange equal to the bolt length.

A metal jacket finish shall be applied with a circumferential and longitudinal seams lapped a minimum of 40 mm. Jacket shall be secured in place with bands as specified. Longitudinal seams shall be placed on the bottom half of the pipe, alternating between 25° and 35° from the bottom centre line so as to shed water. The longitudinal seams shall provide a positive weatherproof seal along the entire length of the jacket.

Aluminium cladding shall be pre-rolled to the requisite diameter, including capillary break crimpings. These may then be sprung over the pipe and the longitudinal seam fastened. Ensure cladding is pulled tight to the insulation.

Longitudinal seams shall be located on the side of the pipeline not normally viewed (away from the road) and be parallel to the centreline. Bands hold cladding around pipe support slippers. Slippers shall have holes or slots for this purpose. Longitudinal seams shall have rivets at 150 mm spacing.

All insulation jacket penetrations such as clips, supports, etc. and all joints except circumferential and weatherproof type longitudinal joints shall be sealed with sealing compound to prevent entrance of moisture and water.

On vertical or inclined piping, bands on permanent jacketing shall be maintained in position with screws. The screws shall be on 150 mm maximum circumferential centers with one screw through the longitudinal seam of jacketing. On vertical pipe two "S" clips shall be used at circumferential laps of jacketing for piping 12” and under; for piping over 12” install three "S" clips. All vertical or inclined pipelines shall have circumferential seams opening downward to shed water and moisture.

Sliding cladding joints shall be provided between supports to allow for thermal expansion.

Bends shall be formed into lobster backs with 15° segments. Each segment shall include one rib. All segments of a single bend shall be pop riveted together at 150 mm centers.

Insulation adjacent to flanges shall be installed in a manner to permit removal of flange bolting without damage to the insulation. The insulation shall be stopped short of the flanges a distance of the stud or bolt length plus 25 mm on each side of the flange.

Metal terminus bevels shall be provided wherever insulation is terminated on piping. Pipe covering shall be beveled to 45°. Metal bevel shall be fabricated to form a 45° angle onto pipe and may be made to cover one or two pieces. Edges shall fit under the adjacent pipe covering jacket. Metal thickness shall be a minimum of 0.4 mm for aluminium.

Cover shall be secured at each end of the terminus bevels with bands as specified.

14.6.3.2 Insulation Surrounding Control Valves

A valve box shall be installed around all control valves. The control valve actuator and wheel for manually operating the valves shall be clear of the valve box with enough room for the personnel to



comfortably work on or operate this equipment. The valve box shall be designed for the purpose of both insulation and noise attenuation of the control valves.

The insulation shall comprise of two layers of Rockwool, of equal thickness, separated by a 5 mm thick sheet of Barium loaded rubber. The rubber sheet shall overlap along one edge by 200 mm, and forms a cylinder surrounding the control valve.

The valve box will separate into two halves along the vertical plane that runs through the centreline of the box.

14.7 Pressure Vessels, Tanks and Heat Exchangers

14.7.1 Pressure Vessels

Pressure vessels shall be designed to ASME VIII standards and in accordance

with state and local requirements. Pressure vessels shall include the following

features and appurtenances:

Process, vent, and drain connections for start-up, operation, and maintenance

Materials compatible with the fluid being handled

A minimum of one manhole and one air ventilation opening (e.g., hand hole) where required for maintenance or cleaning access

Shop-installed insulation clips spaced not greater than 225 mm on centre for vessels requiring insulation

Relief valves in accordance with the applicable codes

Vessel capacity consistent with design requirements of the system and not less than required to absorb the maximum anticipated system transients.

14.7.2 Tanks

Large outdoor storage tanks shall be welded or seamless construction. Drains and

other design features shall be provided as required to prevent damage to the tank

wall during extended outages in subfreezing point weather. Tanks shall be sized

to provide the required storage volume Demineralized water tanks shall be shop-

coated internally with a fused-glass coating. Coated tank material surface profiles

shall be suitable for coating application, Coatings shall extend completely under all

gaskets, and special provisions shall be made at all plate ends to prevent

corrosion (e.g., use of stainless steel edge coat).

Maintenance drains near the tank bottom shall be provided for complete tank

drainage. Containment systems shall be provided for all tanks containing

potentially hazardous liquids, including ammonia. Leak detection systems shall be

provided, as required by regulations or permits. All tank containment areas shall

be furnished with drains and low-point sumps.

Manholes, where provided, shall be at least 750 mm in diameter. Ladders and

cleanout doors shall be provided on storage tanks as required to facilitate

access/maintenance. Provisions shall be included to allow proper tank ventilation

during internal maintenance.

Unless otherwise specified or approved, tanks used for the storage of oil, raw

water, treated fresh water, and condensate shall be carbon-steel-plate stiffened

and stayed in an approved manner where necessary.

Pipe connections for tanks shall be made to welded pads or reinforced nozzles,

the thickness of which shall not be less than 1.5 times the diameter of the joint



studs. Joint stud holes shall not be drilled through the pads. Pipe connections

shall be made with studs and not cap bolts.

Tanks that are to be insulated and lagged shall be provided with external lugs

where necessary.

A corrosion allowance of 1.5 mm for carbon steel and low chrome alloys shall be

used, except for lined or internally coated tanks.

Overflow connections and lines shall be provided and be at least one pipe size

larger than the largest input line or combination of inputs that can discharge

simultaneously.

They shall be designed in accordance with API 650.

14.7.3 Heat Exchangers

Heat exchangers shall be provided as components of mechanical equipment

packages and may be shell-and-tube or plate type.

Heat exchangers shall be designed in accordance with Tubular Exchanger

Manufacturers Association (TEMA) or manufacturer’s standards. Fouling factors

shall be specified in accordance with TEMA or HEI.

Tubular heat exchanger shall have a minimum 10% margin on tubes. Plate type

heat exchangers shall have enough space for addition of plates as per process

requirements.

Thermal relief valves shall be provided for heat exchangers as required.

14.8 Mechanical Plant Erection

14.8.1 General Requirements

The Contractor shall provide suitable, covered fabrication facilities to allow on site

prefabrication of piping and pipe, and steelwork pipe supports.

The Contractor shall erect and maintain all scaffolding, false work, temporary

bracing or support, access stairs and walkways required for the safe execution

and completion of the Work. Contractor shall observe and comply with all safety

and other regulations. Bracing and support shall adequately protect all parts of the

work against damage by wind, water, slips and other causes, and shall ensure

stability during construction.

The Contractor shall ensure that no part of the permanent Work, inclusive of

building structures, is overstressed by loads induced by construction activities.

All construction noise emissions shall comply with the statutory requirements and

shall fit Compressors, percussion tools and other noisy machinery with effective

silencers of a type recommended by their manufacturers.

The Contractor shall take all necessary precautions to promptly prevent nuisance

from water, smoke, dust, rubbish, noise and other causes.

The Contractor shall take all reasonable precautions to prevent loss or damage

from fire. The Contractor shall provide temporary hose reels and fire extinguishers

where appropriate. No fires shall be lit within the boundaries of the project site.

The Contractor shall provide rubbish skips for own use and provide regular

clearing. Employer's rubbish skips on the site will not be available for use by

Contractor.

The Contractor shall provide security guards on the project to adequately protect

the Work and the plant and equipment of Contractor. All security guards for the

project shall be acceptable to the Employer before being brought onto the site.



14.8.2 Sub-Contractors

The Contractor shall accept responsibility for the supervision and administration of

all subcontracts and arrange and monitor a work schedule with each Sub-

Contractor and supplier.

No claim will be considered for the extra cost of cutting away work already built or

for dismantling, or altering or re-erecting work completed in whole or in part in

consequence of neglect on the part of the Contractor who is responsible to resolve

all issues beforehand and to ascertain that the Sub-Contractor's work is done in

accordance with the Contract requirements.

Where Drawings are submitted to the Contractor by Sub-Contractors, the

Contractor shall resolve all conflicts before referring drawings to the Employer for

review.

The Contractor shall co-ordinate the commissioning activities of all Sub-

Contractors and ensure other Sub-Contractors are in attendance where

commissioning of any installation involves a related operation beyond the interface

with such other Sub-Contractors work.

14.8.3 Care of Plant Prior to Installation

Bearing housings, gear reducers and any other lubricated parts of the equipment

shall be filled with flushing oil containing a rust inhibitor.

All equipment in storage shall be inspected at least once a week. Unless specified

otherwise, rotating equipment shall be rotated once every two weeks, whether in

storage or installed on its permanent mounts.

Cleaned, oiled or pickled and passivated pipe shall be stored off-ground, protected

by plastic covers and with pipe caps in place.

14.8.4 Craneage and Scaffolding

The Contractor shall ensure that the craneage and handling of all plant and

equipment is carried out in a safe and workmanlike manner. Manufacturer's lifting

instructions shall be adhered to, including the use of all proper lifting and jacking

points.

The Contractor shall assess and provide for Contractor’s own use such craneage

and lifting equipment as is necessary to complete the Work.

The Contractor shall assess and provide for Contractor’s own use such scaffolding

as is required to safely complete the installation and testing of the Work. All

scaffolding shall be erected in accordance with U.S. Department of Labour

Occupational Safety and Health Administration (OSHA) safety orders and

Bangladesh regulations, whichever provides the greater degree of safety. All

scaffolding shall be installed using safe trade practices and maintained in a safe

condition.

14.8.5 Cleanliness

The inside and outside surfaces of all pumps, valves, dampers, ducts, fittings,

tanks and equipment shall be cleaned of all sand, dirt, and other foreign materials

immediately after removal from storage and before the equipment is to be installed.

14.8.6 Piping Connections

All flanged joints shall be checked and re-tightened after approximately 10 days of

operation at normal operating temperatures.



14.8.7 Alignment and Leveling

Alignment and leveling procedures and results shall be fully documented.

Rotating equipment such as pumps and compressors where driving and driven

shafts are joined by flexible or solid couplings and are shipped fully assembled

shall have the coupling broken and the alignment rechecked and corrected if

necessary, after it has been placed in its final location. The coupling shall be re-

coupled before grouting.

After the grout has cured, the Contractor shall tighten all holding down bolts. The

coupling between rotating equipment shall be uncoupled again and final

equipment alignment check shall then be made and re-adjusted if necessary.

Allow for all alignments to be witnessed by the Employer.

The Contractor shall ensure that the final coupling clearances are in accordance

with the Manufacturer's tolerances. Contractor shall submit detailed alignment

records for each item for Employer’s review.

Prior to final coupling of rotating equipment, the Employer will require the

Contractor to break all flanged piping connections to the driven equipment and

demonstrate the flange set up tolerances are within specification. All flanged

piping connections are to be reinstated with new gaskets.

In cases where motors are connected to driven equipment by gears, the

Contractor shall check all alignment bolts to ensure that the bolts are tight. The

leveling shall be performed as stated for other rotating equipment.

After the rotating equipment has been tested and operated, and its alignment is

shown to be correct, Contractor shall dowel the equipment in accordance with the

Manufacturer's Instructions.

14.8.8 Seal Packing

The Contractor shall check all stuffing boxes for sufficient rings or packing and for

tightness of packing gland draw-up nuts. Pump casing flanges, inlet and outlet

connections shall be checked by the Contractor for tightness of joints. Packing

lubrication shall be checked for cleanliness and supply. Additional lubricant of the

same type as the original shall be added if required.

14.8.9 Welding

Special consideration shall be given to attaching welding equipment grounding

leads to the actual structure being welded so as to prevent internal arcing or

“stray” current from damaging pump and other bearings, controls, instrumentation

etc.

14.8.10 Motors

Each electric motor shall be examined for damage and the insulation tested before

energising.

All motors shall be checked for proper rotation before connection to the driven

equipment. A record shall be kept of all motor rotation checks.

Stainless steel shims, cut to the same size as the motor foot, shall be installed

beneath each motor wherever practicable when aligning shafts so that future

realignment may be performed without grinding the motor base plate.

14.8.11 Lubrication

The Contractor shall provide all lubricants and greases for the protection during

shipment and first filling of equipment at site including flushing oils where

necessary.



The Contractor shall furnish a complete schedule of recommended oils and other

lubricants, available from suppliers in Bangladesh, for all components of the

CCGT facility.

The number of different types of lubricant shall be kept to a minimum. The

schedule shall be incorporated in the Operating and Maintenance Manuals.

Where lubrication is effected by means of grease, a pressure-gun system with a

separate nipple to each point shall be used. Where necessary for accessibility, the

nipple shall be placed at the end of extension piping and, when a number of such

points can be grouped conveniently the nipples shall be brought to a battery plate

mounted in a convenient position. “Hydraulic” nipples in accordance with BS 1486

or equivalent shall preferably be used for normal grease and temperatures up to

120°C. Where special greases are used and where high temperatures are

encountered, then “button” nipples in accordance with BS 1486 or equivalent shall

be used.

14.9 Electrical Construction and Installation


The Contractor shall install all electrical equipment in accordance with equipment

manufacturers and supplier’s guidelines and requirements. Special care shall be

taken to avoid damage during storage and installation. Equipment shall be

properly levelled, aligned and held down. Any damage shall be made good by the

Contractor to at least the manufacturer’s standard. The Contractor shall maintain

the site in a safe, clean and tidy state at all times.

The Work shall be carried out by a qualified and licensed electrical and

instrumentation personnel, specializing in industrial electrical and instrumentation

installations.

Manufacturer’s representatives shall inspect and supervise the installation and

testing of the generator, exciter and AVR.

Electrical connections shall be carefully made with proper cleaning, greasing and

bellville washers as appropriate. All connections shall be made using torque

wrenches and then rechecked and marked.

The Contractor shall provide all facilities necessary for receiving, storing, sampling

and testing insulating oils. Records of all tests shall be handed-over to the

Employer.

The Contractor shall connect temporary power supplies to all anti-condensation

heaters as soon as equipment is installed on site.

The Contractor shall provide smoke and flame retardant sealing around cables

where these pass through openings beneath equipment, walls, floors and roofs

into air conditioned areas and as required by the fire design of the buildings.

14.9.2 Fixings and Supports

The Contractor shall be responsible for providing adequate fixings and supports

for all commodities, plant and other equipment, etc. including support stands and

foundations, adequate for both the specified Service Conditions and earthquake

loadings. Where fixings or supports have not been detailed on the drawings, the

Contractor shall also be responsible for checking that the walls, beams, slabs or

otherwise to which such items are secured, can support the applied loadings

without producing conditions of overstress for their constructional materials.

Securing to masonry and concrete shall be via proprietary stainless steel

expanding masonry anchors adequately sized for their intended duty.



Fixings on structural metal members shall consist of stainless steel bolts, nuts and

washers for outside applications. Elsewhere indoors fixings may be electro-

galvanized.

14.9.3 Cable Trays

The cable tray system shall be designed, fabricated, and installed in accordance

with the latest edition of NEMA Standard Publication Nº VE-1 - Cable Tray

Systems, load/span class designation NEMA Class 12C. Cable tray and cover

material shall be aluminium.

Cable trays and supports shall be manufactured by a specialist manufacturer, and

shall be made of aluminium. Installed cable trays shall, when fully loaded, be able

to support the weight of a person climbing on the racking, without failure or

permanent distortion. Cable tray and conduit shall not be supported off or fixed to

any process piping. The accessories shall include but not be limited to hanger

systems, brackets, holding down clamps, couplers, covers together with all fixings

necessary to complete the work. The accessories supplied shall be of the cable

tray manufacturer's proprietary manufacture. Tray widths and spans shall be

chosen so as to comply with the following conditions:

Manufacturer’s loading and installation requirements

20% spare space capacity for future cable requirements.

All changes in direction both in the horizontal and vertical planes shall be installed

using adjustable couplers, risers, bends etc. and in such a manner that cabling

using the tray route shall not be bent beyond the cable manufacturer's minimum

bending radius for the type of cable being installed.

Adequate separation and segregation shall be provided between power, control,

instrumentation and communications cables, and to other facilities such as pipes

and bus ducts, to avoid interference and consequential damage. Duplicated trip

circuits and power supplies shall have route segregation except at the common

termination points such as circuit breaker mechanisms.

All cable trays shall be bonded to earth over its entire length. Where tray runs are

not continuous, minimum 16 mm2 bonding jumpers shall be run between each run

to ensure electrical continuity. The tinned, stranded copper conductor shall be

used for the bonding jumper.

Each cable shall be neatly laid on the tray and firmly secured to each rung using

the nylon cable ties.

All runs of cable tray shall be fitted with the manufacturer's proprietary covers

when all cabling has been installed, secured, inspected, tested and commissioned

by the Contractor.

14.9.4 Cable Conduits and Accessories

Conduit, accessories and supports etc shall be aluminium or hot dip galvanized

steel, purpose made by one manufacturer who specializes in the design and

manufacture of conduit and accessories. All conduit and accessories shall be

installed to their Manufacturer's requirements and recommendations. The

minimum size conduit allowed is 19 mm.

Above-grade conduit shall be run on overhead pipes or other above-grade

structures and shall be grouped and supported on appropriate conduit supports.

Exposed conduit runs shall be installed in a neat and workmanlike manner,

parallel or perpendicular to structural members. Conduit routings shall be located

as far away as practicable from heat sources or possible fire hazards, such as

pumps and control valve manifolds, sample stations, etc. All above-grade conduits



shall be adequately supported in accordance with applicable Codes and

manufacturer’s requirements and recommendations.

All conduits shall be installed with a minimum number of bends and offsets.

Generally, conduit runs shall be limited to about 50 m between pull points. Where

bends or offsets are required, they shall be made with the manufacturer's

proprietary conduit bending equipment. Uniform circular cross-section of the

conduit shall be maintained at all bends. No single bend shall be greater than 90

deg.

All conduit shall be terminated in threaded hubs or bushings designed to prevent

damage to wire during pulling operation. Grounding-type connections shall be

provided on all conduit runs which in turn shall be bonded to earth.

On steel pipe ways and structures, supplementary supports, racks brackets and

clips shall be installed as required. Conduit shall be attached using the conduit

manufacturer's standard clamps. Scissors clamps or other friction-type holding

devices are not acceptable. Conduit or fittings shall not be welded to any structure.

Arrangements shall not obstruct space assigned to pipes or other equipment

including personal access.

Conduit ends shall be cut square, properly reamed and threaded to engage not

less than five threads. Joints shall be made up tight. Threads shall be coated with

approved conductive thread protective compounds. Thread compound shall not

interfere with grounding continuity of conduit system.

Conduit fittings shall be installed as required to provide a complete installation

meeting the requirements, and to provide a neat workmanlike job. Expansion

fittings, with bonding jumpers, shall be installed every 65 m in straight continuous

runs. Pull fittings, including bends, shall be of adequate size so that the cable can

be installed without bending it on a radius less than the cable manufacturer's

requirements. Conduit fittings shall be Crouse-Hinds Form 8 with cast covers or

similar approved. Crouse-Hinds Type UN union fittings, or similar approved, shall

be installed in conduits entering devices that may require removal for maintenance.

Conduit saddles shall be provided at intervals not exceeding 1000 mm and shall

be screw fixed using stainless steel fixings.

All elbows, bends, tees etc shall be of the inspection type, positioned so that their

covers can be readily removed. All covers shall be secured in place with suitable

fittings.

14.9.5 Cabling

14.9.5.1 General Requirements

The Contractor shall:

install and connect up all cabling required to complete the Work and as listed in the Contractor’s cable schedules and drawings. Cabling shall be of the types and sizes specified

provide the detailed cable route drawings which shall also identify the individual cables for each cable route location

provide the detailed Connection Schedules giving the connections for power, control and instrumentation cabling required to be made between items of plant and equipment

determine the correct phasing and terminations for all power cabling.

Cables shall not be bent beyond the cable manufacturer’s minimum bending recommendations. Bending the wire sharply over the edge



of fittings shall be avoided. Cable lubricants, such as "Wireze" shall not be used without the express approval of the Employer in every instance.

All circular cabling shall be glanded at their point of entry into equipment, switchgear, etc. Moisture proof and corrosion resistant glands shall be used outdoors.

Power cable conductor ends shall be tinned prior to terminating. Soldered connections or terminations are not permitted.

All wire and cable shall be kept in boxes or on reels at the feeding end of a wire pull. Wire and cable spread out on the ground at intermediate pull boxes shall be safeguarded against damage and dirt through the use of tarps, plywood panels or other adequate protection.

The Contractor shall provide all cable glands and compression lugs which shall be selected and installed to the cable manufacturer's recommendations. Lugs shall be tinned copper except for aluminium cables where they shall be aluminium. Aluminium terminations shall be made using a proprietary jointing compound to prevent oxidation or corrosion. Lugs shall be installed using the manufacturer's proprietary compression tools. Ratchet compression tools shall be used for all cables upto and including 16 mm². Hydraulic compression tools shall be used for all other cable sizes.

Cabling entry into plant, equipment, switchgear, etc. mounted outdoors or under shelters shall be from below. Where necessary, provide additional mechanical protection to these cables at low level with galvanized conduits or approved equal.

All cables shall be tested for continuity, identification and insulation. All medium voltage cables shall be field voltage tested after laying at a level recommended by the cable manufacturer. Power and control cables shall be tested with a 1,000 V insulation tester while instrument cables shall be tested with a 500 V insulation tester. Records shall be supplied to the Employer.

14.9.5.2 Direct Buried

As a minimum, direct buried cabling shall be 600 mm deep for instrumentation and control cabling, and 1000 mm deep for power cabling. Cables shall be laid on a 100 mm bedding of sifted soil, then covered with a further 100 mm of sifted soil, then backfilled and compacted. The sand and backfilling material shall be clean, free from rocks, stones, etc. Protective concrete covers shall be located on top of the backfill with the PVC warning strip laid 150 mm below finished ground level.

Supply and install all bedding material, protective concrete covers, proprietary PVC warning strip and cable markers. Excavation, backfilling, compacting and reinstatement of the trench shall be by the Contractor. The removal and disposal of surplus materials are to be included in the QA procedures for Employer review.

All direct buried cable lay down and jointing shall be inspected by the Employer prior to backfilling. The contractor shall mark all the cable routes and jointing on the above ground precisely.

14.9.5.3 6.6 kV and 400 V Power Cabling

Power cabling shall be installed as outlined on approved drawings; cables run on cable trays shall be fixed to each rung of the tray using adequately sized proprietary nylon cable ties.



Cables shall be terminated using heat shrink stress control materials, proprietary cable glands and compression lugs, where stud or bolted connections are required, or shall be terminated directly into the equipment's integral screw-type termination.

14.9.5.4 Control and Instrumentation Cabling

The Contractor shall connect up control and instrumentation cabling between equipment as outlined on the Contractor’s drawings and Connection Schedules.

Where run on cable trays, cabling shall be fixed to each rung of the tray using adequately sized proprietary nylon cable ties. All cores, including spare cores shall be terminated within terminals using proprietary crimp type pre-insulated tinned copper circular solid pin connectors. Crimping shall be carried out using ratchet type crimping tools.

Instrumentation cables shall be continuous between the instruments and point of termination. Multi conductor cables shall be terminated only in designated junction boxes.

All instrument wire shall be stranded and tinned. Minimum wire size is 1.5 mm2. Screens shall be earthed at one end only.

14.9.5.5 Panel Wiring

Where panel wiring is required within equipment it shall be tinned copper, colour coded, selected and sized in accordance with their respective loads, and comply with the relevant standards. It shall be a minimum 1.5 mm2 stranded, tinned, 600V grade PVC insulated to 90°C.

All wiring shall be run in PVC open slotted cable trunking complete with fitted snap on lid. Wiring not run in PVC trunking shall be neatly loomed and supported with nylon cable ties at spacing no greater than 100 mm.

Wiring between panel(s) and hinged doors shall be of sufficient length to enable the door to swing fully open. Provide flexible mechanical protection around each wiring loom and anchor both ends.

All wires shall be number ferruled at each end and shall NOT be joined or teed between terminals. Wire ferrule numbers/letters shall match those shown in the Connection Schedules.

Connections and wiring shall be arranged with special care to prevent overheating resulting from bunched conductors and to give a tidy appearance.

14.9.6 Fibre Optic Cabling

14.9.6.1 General Requirements

General fiber optic cable requirements are:

Supply, termination, and testing of all cores in the fiber optic cable

Provision of fiber optic test results and documentation to the Employer for review

All equipment and cable to be installed to manufacturers’ recommendations and to the satisfaction of the Employer.



The fiber and cable specifications shall comply with all relevant IEC standards and cables shall have at least 50% spare cores after all systems have been commissioned.

Single mode outdoor optical fiber cable shall be steel wire armoured (SWA), suitable for direct burial in a tropical environment.

Indoor optical fiber cable shall be of tight buffered construction and shall be installed in cable ducts or on cable trays. The cable shall have a non-metallic central core sheathed with black polyethylene.

A non-metallic strength layer shall surround the inner sheath followed by an outer polyethylene sheath.

Single mode optical fibre cables shall be designed to optimize transmission of light at both the 1310 nm and 1550 nm wavelengths. The core/cladding diameters shall be 9/125µm.

Multi-mode optical fibre cables shall be designed to optimize transmission of light at the 850 nm wavelength. The core/cladding diameters shall be 62.5/125 µm.

14.9.6.2 Fibre Optic Junction Boxes

A fibre optic cable junction box shall provide the following:

Support, organise, and protect the optical fibres and the fibre splices whilst ensuring that the optical fibre minimum-bending radius is not exceeded

The splice tray shall not have any sharp edges or protrusions that may damage the optical fibre cable

Provide entry for all cables

Include number tags for tube and fibre identification

The junction box shall be rated to IP65 in accordance with IEC 60529

The enclosure shall be lockable

The Junction box shall be mounted on the wall or pedestal at a conveniently accessible height.

14.9.6.3 Patch Panels

Fibre optic cable termination patch panels shall provide the following:

Support, organise, and protect the optical fibres and the fibre splices whilst ensuring that the optical fibre minimum-bending radius is not exceeded

The splice tray shall not have any sharp edges or protrusions that may damage the optical fibre cable

Provide entry for all cables

Include number tags for tube and fibre identification

Provide mounting positions for the bulkhead FC/PC type connectors on which the cable will be terminated

Allow patching of fibres

Have a fibre capacity equal to the total number of fibres (connected and spares) for all cables to be connected. Patch panels shall be designed for 19-inch rack mounting within a standard equipment cabinet

All unused couplings shall have protective dust covers. The patch area shall be accessible behind a door or removable cover



Sufficient factory manufactured patch cords with suitable colour coding.

The Fibre Termination Trays shall be:

19 inch, 1.5 RTC basic cabinet

Fibre net 1.5 RTC fibre trays

12 port ST fibre termination panels

Sliding for ease of access

All Bulk Head Connectors are to be metal

Terminate fibre using ST connectors

Termination Layout in trays:

TX 1 3 5 7

RX 2 4 6 8

14.9.6.4 Fibre Connectors

All optical connectors shall be field installable and perfectly matched to the cable used. The connectors shall provide tight fitting termination to the cladding and buffer coating. Epoxy based or “hot melt” adhesives shall be used to bond the fibre and buffer to the connector ferrule and body prior to polishing the end face. No dry-termination or “quick crimp” connectors are allowed.

After termination with connectors, the fibre ends must be visually inspected at a magnification of not less than 100x to check for cracks or pits in the end face of the fibre. If any irregularities found cannot be removed by further polishing, the entire process must be redone by cutting off and disposing the connector body.

Connectors shall have a maximum allowable connection loss of 0.3 dB per mated pair, as measured per EA.-455-34, without use of index-matching gel (dry interfaces only). Single mode connectors shall be capable of field installation on 9/125 micron fibres with 900µm (OD) buffers.

Each connector shall be of the industry standard ST type, designed for single mode or multi-mode tolerances, and shall meet or exceed the applicable provisions of EA.-455-5, 455-2A, and 455-34, and shall be capable of 100 repeated matings with a maximum loss increase of 0.1 dB. Connectors shall incorporate a key-way design and shall have a zirconium ceramic ferrule.

Connector bodies and couplings shall be made of corrosion-resistant and oxidation-resistant materials, such as nickel plated zinc, designed to operate in humid environments without degradation of surface finishes.

Where a termination enclosure is installed, all fibres of all cables are to be terminated on “pigtails” with a minimum length of 1 m. The pigtail shall be a Kevlar reinforced and plastic coated optical fibre. An ST type connector shall terminate the pigtail.

The connector shall be inserted on the cable side of the bulkhead (feed through) connector in the termination enclosure. All connectors shall be supplied with a removable cap to protect against moisture and dust ingress when not connected.

External optical cable links between site locations shall terminate at the patch panels in the respective site buildings, either directly or via suitable intermediate optical fibre cable. If an intermediate cable is



used then this shall be spliced to the trunk cable with the splices being housed in a suitably located outdoor junction box.

Optical single or double core jumper leads of sufficient length shall be supplied, with ST connectors on each end. Fibre pigtails and jumper leads shall be Kevlar (or aramide) reinforced and plastic coated optical fibre and shall be colour coded depending on function (data, telecom, protection etc.).

14.9.7 Cable and Individual Core Labelling

All cables shall be labelled at both ends with the "Critchley ‘K’ type cable marker

and carrier strip" system, fixed to the cable by means of nylon cable ties at both

ends of each carrier strip. The cable labels shall conform to the Cable Schedules.

Markers shall be white bodied with black lettering.

The cable label shall generally be housed within the equipment.

All conductor cores of control and instrumentation cables shall be labeled

("ferruled") with a suitable cable marker system at both ends of the conductor.

All markers shall be correctly sized for each conductor core, thus ensuring no

movement through gravity or vibration. They shall be neatly lined up, be read from

bottom to top for vertically terminated cables and left to right for horizontally

terminated cables. The visible core shall be made sufficiently long, so that no part

of the marker is obscured by trunking, etc.

Write-on or "Dyno" (impression stamped plastic or metallic type) labels shall not

be used.

14.9.8 Junction and Cable through Boxes

They shall be manufactured from 316L stainless steel sheet of sufficient thickness

to prevent buckling and have a minimum degree of protection to IP65. Boxes

manufactured from high impact polycarbonate, to the same degree of protection,

may be submitted to the Employer for approval.

The junction boxes shall be designed to avoid condensation inside the boxes.

Boxes shall be provided with full size hinged doors on the front which shall be

secured with proprietary locking mechanism. All junction boxes and cable through

boxes shall have the same locking mechanism with common keys. The Contractor

shall provide the Employer ten of the proprietary keys suitable for these locks.

Assemble boxes complete with backplate, terminal mounting rails, terminals,

ducting, ducting covers, labels and all other equipment required. Where mounted

on platforms, fix cabinets to platform handrails with 316L316 stainless steel "U"

bolts, nuts and spring washers to provide as a minimum two points of fixing. Seal

fixing penetrations to maintain the specified IP rating.

Where boxes are to be free-standing, provide and install the support frame and

securely bolt to the concrete foundation.

Digital and analogue terminal blocks shall be fully segregated and mounted on

separate terminal rails.

14.9.9 Terminals

Terminals shall be manufactured from self-extinguishing materials, be rail

mounted and of the self-locking screwed pressure plate type. Metal parts shall be

not less than 85% copper and be nickel plated to prevent corrosion. They shall be

adequately sized to take the conductor(s) which they connect and shall have a

current rating of not less than 20A with the smallest terminals being capable of

taking stranded conductors up to 2.5 mm2 CSA.



The maximum number of cores to be terminated on each side of a terminal shall

be one. If necessary, provide additional terminals to meet this requirement with

looping between being done via terminal manufacturer's standard internal jumper

bars.

Earth terminals shall be green or green/yellow. Other terminals shall not be the

same colour as earth terminals.

Strip connectors shall not be used.

They shall be labelled using the terminal Manufacturer's proprietary labelling

system. “Stick on” adhesive type terminal markers are NOT acceptable. Terminal

numbers shall match those shown on the Connection Schedules.

14.9.10 Labels

All equipment shall be uniquely identified with engraved "Traffolyte" (engraving

laminate) labels. The lettering shall be upper case, black, except for danger and

warning labels, where it shall be red. The background of all labels shall be white.

Labels of the embossed or transfer types shall not be used.

The labels shall be permanently fixed with not less than two corrosion proof, dust

tight fixings, prominently positioned generally over the equipment which they

identify. The method of fixing shall be submitted for approval by the Employer.

The Contractor shall provide the Employer with a list of all proposed labels for

approval prior to engraving. Labels shall be in English language.

14.9.11 Earthing Grids

The earthing system and grid shall be installed as the standard and code requires.

The entire earth grid once installed shall be resistance tested using a specialized

tester. Additional earthing to meet the design requirements shall be installed if

needed. The report shall be submitted to the Employer. Earth resistance testing

shall be carried out in presence of the Employer.

14.10 Instrument Valves and Tubing

14.10.1 Instrument Valves

All connecting lines between tapping points and instruments, transmitters or test

points shall have not less than two isolating valves. One isolating valve shall be

located at the tapping point and one isolating valve located as near as practicable

to the instrument, transmitter or test point.

The instrument valve located at the instrument, transmitter or test point may form

part of an of instrument valve manifold, and be associated with any necessary

vent, test and equalizing valves. The instrument isolating valve or manifold shall

be located such that the temperature on the valve does not exceed 50°C.

Blowdown valves are required in the connecting lines to all transmitters and

instruments used on water and steam services. The method of attaching isolating

valves to instruments shall be such that it is possible to disconnect the instrument

from the connecting pipe without having to drain the pipe.

Isolating valves shall be capable of being locked in the fully open or fully closed

position, and for this purpose circular hand wheels shall be supplied which can

accommodate the shackle of a padlock.

All tapping points isolating and blowdown valves shall have valve labels in

permanent materials. Valves shall be fitted with indicators to clearly show the

position of the valve.



14.10.2 Instrument Tubing and Fittings

All instrument tubing and fittings shall be ½” AISI 316 seamless austenitic

stainless steel, or plastic as appropriate for the duty. Plastic piping is not allowable

for line pressures greater than 2 bar. Blowdown and drain lines shall be provided.

Blowdown pipes shall be included in the connecting tubing to each transmitter or

pressure switch, for all steam services and for all other services in which corrosion

products, suspended solids etc., may block the instrument connecting tubing.

Blowdown connections to a suitable drain shall be made at a point as close to the

transmitter as practicable, while ensuring that the transmitter will not be damaged

by overheating.

Pipe work and tubing shall be neatly run and suitably supported in a manner such

that no air pockets or traps can occur. If either is unavoidable then the Contractor

shall provide a suitable drain or vent valve which shall be easily accessible from a

floor, permanent platform or walkway. Instrument piping used on liquid services

shall be self-venting to the main, while gas and vapour instrument lines shall be

self-draining to the main. Instrument piping containing condensable vapour shall

not be less than 10 mm actual bore from the tapping point to the inlet of the

instrument isolating valve, to avoid the formation of a liquid lock. Movement of the

equipment, where applicable, shall be taken into account to avoid damage to the

piping and/or connected instrument. Siphon condenser seals or pigtails shall be

mounted adjacent to steam pressure instruments to protect the primary element, if

necessary.

Stainless steel instrument tubing shall be connected by AISI 316 compression

fittings. Tubing shall be routed to ensure all compression fittings are accessible

and comply with the manufacturer’s instructions.

All pipe ends for compression type couplings shall be prepared using the coupling

maker’s specialized tools and techniques.

Instrument tapping points on piping or surfaces that are subject to continuous or

intermittent deposition of solid precipitates shall have an access opening for

“rodding” out (hot-tap) deposits across the tapping point. The means of access

shall conform to the piping or vessel design standards. And all instrument pipe

works shall provide access for above hot-tap.

Each pipe shall be identified by individually numbered metal tags or ferrules

spaced not more than ten metres apart.

Adequate junction boxes shall be provided for the termination of multi-tubes

including spare tubes. All tubes shall be fitted with numbered ferrules at each

termination. At points of interconnection between tubing where a change of

numbering cannot be avoided double ferrules shall be provided.

Such points shall be clearly indicated on schematic diagrams. Labels shall be

fitted to junction cubicles to identify each group and each individual tube.

Pipe connections to gas sampling apparatus shall be capable of easy internal

cleaning. Suitable provisions shall be made to facilitate such cleaning.

14.10.3 Instrument Electric Supply Systems

Electric power for all instruments shall be supplied from an Uninterruptible Power

Supply (UPS) system. Dual redundant instrument power supplies shall be

provided and have the capability of being replaced on-line without affecting the

operation of the instruments. The output of the instrument power supplies shall be

24V DC.



14.10.4 Field Instruments Miscellaneous Requirements

Local flow indicators or indicating controllers operating on differential pressure

measurement shall have a separate differential pressure transmitter with its output

connected to the local indicator or local indicating controller.

The make and type of instruments such as transmitters, control valves, analysers,

panel instruments, safety valves and line-mounted instruments shall be

standardized as far a possible throughout the entire plant (including packaged

equipment) for ease of maintenance and spare parts control.

14.10.5 Electronic Equipment

The Contractor shall submit a list of Standards, Codes and Regulations to be used

for the design, manufacture and testing of electronic equipment. This list shall be

submitted to the Employer at least 30 days before design commences.

Electronic equipment offered shall be of a type having proven record of reliability

in thermal power station service conditions.

The design of electronic equipment shall be based on the sub-unit principle, inter-

connected by flexible connectors using high quality plugs and sockets. The flexible

connectors shall be of sufficient length to allow the unit to remain connected when

it is withdrawn for adjustment.

If extender boards are required to facilitate adjustment of any component, they

shall be provided as part of the equipment.

The laminates used for copper foil printed wiring or printed circuit boards shall be

suitable for the climatic and environmental conditions and shall be of an approved

non-hygroscopic base material of high insulation resistance, preferably non-

flammable or flame resistant, and of adequate strength.

Contact-making surfaces of printed circuit board multi-contact plug and socket

connectors shall be of the same or compatible metals. If the contact surfaces are

plated the plating shall be non-porous, free from pinholes and of adequate

thickness to ensure low contact resistance for the life of the equipment. Sockets

shall be preferably of the ‘floating’ type, be tolerant of board thickness and shall

not cause excessive wear on the board connectors.

To minimize the deposition of dust on the surface of the boards they shall,

wherever possible, be mounted in equipment in the vertical plane. The printed

wiring side of the board shall be protected against the effects of the deposition of

dust and moisture by a corrosion retarding epoxy suitable for use under tropical

conditions to ensure the prevention of corrosion.

All electronic equipment shall be housed in cubicles. Components shall have a

temperature/humidity classification of BS 2011 Parts 2.1A, 2.1B and 2.1Ca.

14.10.6 Instrument Cables and Wiring

Power wiring to and from the instruments and power supply units shall be such

that power supply units can be removed without total system shutdown.

Wire and cables of electronic instrument installation shall be single pair not less

than 1.5 mm2 tinned copper conductors with PVC insulation, twisted, with

aluminium shielded Mylar tape separators with drain wire, extruded PVC inner

sheath, wire braid or armour, and overall PVC jacket.

Single pair wires shall be run in separate trays from the various transmitting and

control devices to centrally located field terminal junction boxes in the process

area.



The Contractor shall provide proper wire and cable and its installation works for

digital communication (e.g. Modbus, Fieldbus) that shall be met with the standard

code.

AC power and signal wiring shall be separated by a minimum spacing of 100 mm

in all cases, and shall not under any circumstance be run in the same wireway.

Wiring between terminals shall be point-to-point and free from wire splicing and T

connections.

Cabling and wiring constructions, fixings, ladders, labels, junction boxes,

terminations and other accessories shall be in accordance with Section 14.9.

When shielded cables or wires are necessary, an insulating sheath shall be

included. Provision for termination of shields, or means to maintain the continuity

of isolated shields shall be provided as required. Cable shields shall be connected

and earthed in a manner that prevents circulating currents.

All cables shall be tested for continuity, identification and insulation.

The appropriate compression gland shall be used for glanding the armoured cable.

The gland shall be complete with an integral earthing tag suitable for bonding to

the equipment earthing terminal via an earthing lead with compression lug type

connections.

14.11 Health and Safety


The Contractor shall develop an appropriate safety management plan and take all

necessary safety and other precautions to protect property and persons from

damage, injury or illness arising out of the performance of the work.

The Contractor shall be responsible for providing its employees, Sub-Contractors,

agents and sub-agencies with a safe working environment. The Contractor shall

inspect the working environments where its employees, Sub-Contractors, agents

or sub-agencies are or may be present on the site and shall promptly take action

to correct conditions which cause or may responsible be expected to cause such

working environments to become an unsafe place of employment.

The Contractor shall have policies and rules of personal safety accountability.

Such rules shall apply to anyone working on site. As a minimum requirement,

these policies and rules shall cover the following:

Head, hand, ear and foot protection

Eye protection

Substance abuse

Prohibiting of any kind of weapons

Reporting of unsafe conditions

Use of power tools

Other general rules of behaviour at a construction site.

Prior to starting any field work on each job, the Contractor shall conduct an initial

safety meeting with an authorized representative of his sub-contractors and the

Employer.

The Contractor shall have a written safety work procedure and/or standards to

cover the following types of activities as well as a plan (i.e. training sessions,

weekly training sessions etc.) to communicate all site safety and loss prevention

requirements to its employees and sub-contractors.



As a minimum such procedures and/or standards shall cover the following

activities:

Excavation

Use of ladders and platforms

Work requiring protective clothing and equipment including safety belt

Working at elevated locations

Burning and welding operations

Cleaning and working at confined spaces

Cleaning, tagging and working on equipment that has been energized

Use of motor vehicle on site

Radiography

Electrical works on or near energized circuits

Safe handling and storing of pressurized circuits

Crisis management plan

Reporting of injuries and other safety and loss prevention incidents.

The Employer is entitled to conduct safety audits for compliance with this

specification and also in other related safety areas, at any time during the

progress of the work with or without notice to the Contractor. Safety will be

included as a topic for discussion by the Employer in any regularly scheduled

project meeting that is conducted.

For mitigation of noise impacts the Contractor shall put up temporary noise

barriers during the construction phase and provide special noise protection

devices (to international standards) to all persons on and around the project site

and particularly to school children if required.

Precaution shall be taken by the Contractor to ensure the health and safety of his

staff and labour including all Employer’s personnel. The Contractor shall in

collaboration with and to the requirements of the local health authorities ensure

that medical staff, first aid facilities, sick bay, and ambulance services are

available at site at all times, and that suitable arrangements are made for all

necessary welfare and hygienic requirements and for the prevention of epidemics.

The Contractor shall maintain records and reports concerning health, safety and

welfare of persons and damage to the property and also ecosystem including flora

and fauna under both short and long term effect due to implementation of the

project.

14.11.2 Health and Safety Management at Site

The Contractor shall appoint a qualified HSE specialist at site to be responsible for

maintaining the safety and protection against accidents of personnel on the site.

The HSE specialist shall be qualified and experienced with proven track record

and shall have the authority to issue instructions and take protective measures to

prevent accidents. The Contractor shall provide details to the

Employer of any accident immediately after the occurrence and pay appropriate

compensation including all hospital bills. The selection of hospitals shall be

approved by the Employer.



14.11.3 Staff and Labour Records

The Contractor shall keep and maintain records of all staff and labours engaged

on the project during the contract period and submit updated records each month

to the Employer.

14.11.4 Health and Safety Equipment and Protective Devices

The Contractor shall provide all necessary safety protective equipment and

devices for his staff and labourers including Employer’s staff at site. Equipment

and devices shall be of international standard and approved by the Employer.

14.11.5 Health and Safety Related Signs, Cordons and Training

The Contractor shall hang and maintain health and safety related signs, cordon off

dangerous areas and deploy security personnel for protecting dangerous and

hazardous areas in compliance with international codes and also organize training

for all staff, labours and Employer personnel at site.

In addition, the Contractor shall submit to the Employer training reports and a

training manual.

14.11.6 Health and Safety Responsibility

The Contractor shall be responsible for any damage to the health of his staff,

labourers and also Employer personnel or any project persons engaged on the

project site and shall pay compensation to international level and be acceptable to

the Employer.

14.11.7 Work in Confined Spaces

The Contractor shall provide all necessary health and safety protective equipment

and devices (having international standards) to all supervisors, inspectors and

related personnel who work in confined spaces.

Areas where people may be exposed to excessive noise shall be sign posted as

“Hearing Protection Areas” and their boundaries shall be defined with red lines. No

person will be allowed to enter this area unless wearing personal hearing

protectors.

The confined work spaces shall be provided with sufficient air to avoid any health

risk. Where there is a risk of poisonous or asphyxiating gases being present,

these shall be tested for and confirmed to be at safe levels before entry takes

place. Adequate care shall be taken to minimize stress and ergonomic design

shall be implemented to minimize occupational health hazards.

First aid facilities shall be kept in readiness and evacuation plans for emergency

situations shall be facilitated with adequate drills, instructions and signs. Adequate

firefighting arrangements shall be installed and maintained in good working

condition. In case of emergency, fire-fighters from the district shall be called upon.

14.11.8 Health Records and Hazardous Substances

The Contractor shall submit health records relating to the hazardous substances

in accordance with GOB rules and guidelines including international regulations as

and when applicable.

14.11.9 Storage Facilities for Chemicals, Fuel, Oil and Grease

The Contractor shall follow Government of Bangladesh rules and guidelines

including international regulations as and when applicable for storage of chemicals,

fuels, oil and greases.



14.11.10 Fit for Purpose of Construction and Maintenance Equipment, Instruments and Vehicles

The Contractor shall submit fit for purpose certificates to the Employer for his all

equipment, instruments and vehicles deployed during construction and O&M

phases for the duration of the contract and in case of any irregularity such as

falsified or missing certificates or defects found in any of the above said

equipment/instruments/vehicles, the Employer will request these to be removed

from the site and impose penalties based on national and international standards.

Any delay to the project schedule due to such events and any corresponding

penalties shall be borne by the Contractor.

14.11.11 Labour Laws

The Contractor shall comply with the Bangladesh Labour Law (2006) and all the

relevant labour laws of the Government of Bangladesh and also international

labour rules where applicable and apply them to his employees. The Contractor

shall duly pay and afford these employees all their legal rights. The Contractor

shall require all such employees to obey all applicable laws and regulations

concerning safety at work and on the site. The Contractor shall not, in any case,

employ child labour, which is considered a serious offence and the Employer will

impose penalties.

14.11.12 Working hours

No work shall be carried out on the site outside of the normal working hours stated

in the Labour laws, or on the locally recognized days of rest, unless:

The contract with the employee so provides, with valid documents, provision for overtime payment while following National/international Labour laws or code of practices

The work is unavoidable, or necessary for the saving of life or property or for the safety of the works, in which case the Contractor shall immediately advise the Employee of the situation

The Employee gives his consent.

14.11.13 Facilities for Staff and Labour

The Contractor shall maintain all necessary accommodation and welfare facilities

for his and his sub-contractor’s staff and labour. The Contractor shall also provide

the specified facilities for the Employer’s personnel. The Contractor shall not

permit any of his employees to maintain any temporary or permanent living

quarters within the structures forming part of the works. Refer also to Section 4.6.2

14.11.14 Wages and Employment Conditions

The Contractor shall pay wages and adopt employment conditions not less

favourable than those established for the trade or industry where the work is

carried out. If no such established rates or conditions are applicable, the

Contractor shall pay rates of wages and adopt employment conditions not less

favourable than the general level of wages and conditions observed by Employers

whose trade or industry is similar to that of the Contractor.

14.11.15 Workers Camp and Temporary Construction Facilities

The Contractor shall construct a workers camp, furnish and maintain temporary

construction facilities and provide /obtain safe services such as:

Site office which includes space for the Employer’s personnel and Employer personnel. Refer also to Section 4.6.2

Fire protection



Sewage treatment systems /septic tank facilities

Communication systems

Lighting system

Drainage and dewatering system

Temporary site roads

Facilities for site water distribution

Temporary site parking lot and lay down area

Site entry control facilities

Warehousing and material controls

Materials, equipment, tools, vehicles, lifting facilities and consumables required for the work

Site environmental protection

On-site first aid services.

The Contractor shall prepare a site facilities plan showing the expected location

and arrangement of site facilities and shall submit this to the Employer for

approval before commencing of construction activities.

14.11.16 Housekeeping

The Contractor shall maintain housekeeping practices to ensure a safe working

environment for the workers where waste generation and environmental damage

will be minimized. The house keeping shall include the following:

Minimizing chemical usage

Minimizing erosion

Minimizing emissions

Segregated waste handling with regular collection

Regular site clean-ups with periodic inspections.

14.11.17 Substance Abuse

The use, possession, concealment, transportation, promotion or sale of the

following substances and items by any Contractor and their employees are strictly

prohibited from the site:

Alcoholic beverages

Illegal drugs

Unauthorized controlled substances

Synthetic drugs

Any abnormal substances which may affect the senses, motor functions or alter a person’s perceptions or judgment.

The Contractor must have and administer a formal substance abuse introduction

policy. Such policy must include provision for testing (such as urine drug screens

or blood plasma tests) to determine the use of any illegal or unauthorized

substances prohibited by this policy. The Contractor shall also comply with

Government of Bangladesh rules and guidelines including international regulations

in relation to this issue where applicable.



14.11.18 General Fire Protection Requirements

All plant and buildings shall be designed and arranged to minimise the possibility

of fire hazards originating from them or spreading to them from a fire in the vicinity.

Plant and cables shall be segregated to reduce fire risk, damage and multiple

shutdowns.

Electrical requirement located in hazardous area shall be explosion proof, flame

proof, intrinsically safe or otherwise designed to be suitable for the location zone.

All equipment installed shall comply with NFPA rules and recommendations and

also with Government of Bangladesh rules and guidelines and international

regulations where applicable. The Contractor shall provide certification of

compliance with the NFPA regulations and also Government of Bangladesh

agency/agencies as and when required. Local regulations must be adhered to and

the Contractor must obtain system approval from the local fire authority.

14.11.19 Emergency Response Plan

The Contractor shall prepare a detailed emergency response plan (ERP)

particularly on activities which may cause significant environmental safety

concerns and submit this to the Employer for approval. After approval, the

Contractor shall execute the approved ERP for emergencies arising from activities

carried out within the limits of the project site.

14.12 HAZOP

14.12.1 General

The Contractor shall perform a HAZOP study to demonstrate to the Employer that

where possible all risks concerning safe and efficient construction, O&M (under

Defect Liability period) have been identified and solutions implemented to

eliminate such risks. The Employer will participate in the HAZOP.

In the event that the HAZOP studies identify residual risks which cannot be

avoided, the Contractor shall incorporate measures in the design, implementation

and project documentation (O&M manuals) to ensure that the effects of the risk is

mitigated and the likely effects on Employer personnel, the environment etc. are

minimized and submit a detailed report to the Employer accordingly.

14.12.2 Risk Assessment and Management

The Contractor shall identify potential risks of this project and prepare a risk

management plan to handle those risks and shall submit a report to the Employer

during the initial stage of project implementation. The Contractor shall arrange

proper training of all of his staff and also the Employer’s staff during all phases of

the project (within the contract period) regarding implementation of the risk

handling plan and also report to the Employer a regular basis.

14.13 Plant Identification and Labeling

14.13.1 General

All systems and their component parts including cables and pipes shall be

uniquely identified by means of a comprehensive logical identification system. The

Contractor shall prepare a comprehensive Identification Schedule showing the

name and alpha-numeric number of each item of plant and its respective

arrangement or location drawing number.

Equipment numbers shall be shown on the process and instrument diagrams,

physical piping and general arrangement drawings, system or functional diagrams,

electrical drawings, schedules, civil and structural drawings etc.



This numbering system shall be KKS numbering system.

14.13.2 Signs, Nameplates and Labels

The Contractor shall supply all signs, nameplates, labels, instruction and warning

plates necessary for the clear identification and safe operation of the plant. All

inscriptions shall be in the English language. The size of the lettering used shall

ensure easy reliable identification under all operating and maintenance conditions.

Inscriptions shall include plant item names and/or plant service in addition to the

plant identification number if necessary to ensure easy reliable identification.

All plant buildings shall also be identified with building name painted on the

building. All site erected tanks shall also have their names and tag number

prominently painted for easy identification.

Identification plates and labels shall be non-deteriorating and non-warping under

site conditions.

Stainless steel shall be used on outdoor equipment. A plastic laminate or

equivalent may be used for individual component labels inside panels and desks.

All labels, nameplates, instruction and warning plates shall be securely fixed to

items of plant with stainless steel rivets, plated self-tapping screws or other

permanent mechanical means. Adhesives shall not be used.

Warning plates shall be manufactured from stainless steel with a matt or satin

finish, engraved with red lettering and located in a position which shall afford

maximum personnel safety.

Each circuit breaker panel, control panel, relay panel and the like shall have a

designation label mounted at both front and rear. Corridor type panels shall

additionally have designation labels within the panels. The function of each relay,

control, indicating and alarms device, fuse etc. shall be separately identified.

All pressure vessels and lifting tackle shall have permanently attached to them or

stamped on them, in a conspicuous position, a rating plate giving such details as

the design code, design parameter, test parameter, date of test etc.

Identification of all pipe work shall be by means of intermittently spaced colour

coded bands as per ASME A13.1:2007.

Where possible, valve nameplates shall be circular and fitted under the hand

wheel captive nut. On check valves and small valves the Contractor may provide

rectangular nameplates fitted to brackets on the valve or attached to a wall or

steelwork in a convenient visible position adjacent to the valve.

All valves larger than 150NPS shall, in addition to the above, be fitted a valve

number identification sign. The sign shall be no less than 250 mm by 150 mm.

The sign shall be readable from the normal direction of approach to the valve. The

valve number shall be dark lettering on light back ground.

14.13.3 Instrument Identification and Labeling

All field control stations, instrument junction boxes, cables, cores etc. shall be

uniquely labelled. Instruments shall be labelled with 316 stainless steel plates

engraved with the instrument tag number. Labels shall be mounted adjacent to

equipment which may be removed for maintenance.

Unless otherwise specified, nameplates and legends shall have black characters

on a white background with horizontal text and be of approved materials. Labels of

the embossed or transfer type shall not be used.

The labels shall be permanently fixed with not less than two rustproof, dust-tight

fixings, prominently positioned generally over the equipment which they identify.



14.14 Corrosion Protection and Surface Coatings

14.14.1 General

The entire Project shall be designed to minimise corrosion due to the river

environment. The facility shall be painted or treated with protective coatings to

protect it from corrosion and to provide a neat and pleasing appearance. The

coating system shall be suitable for the environment.

Where corrosion resistant materials (e.g. concrete, stainless steel, plastic and

aluminium) are used, no decorative finish need be applied. All outdoor steelwork

shall be galvanised or painted, and all indoor steelwork shall be painted.

Unlagged piping shall be shop primed and welded joints shall be field primed.

HVAC ductwork shall be unpainted. Equipment and enclosures shall be finish

painted. All items of the plant including equipment, supporting metalwork,

structures, tanks, pipework, lifting tackle and other metallic items, including bolts

and fasteners shall be protected from corrosion and the effects of the environment.

Building exterior finish coatings shall be applied to all roof and wall panels and

decks, wall louvres, flashings, gutters, trim, and other exposed galvanised

surfaces.

All equipment and structures shall be surface-protected, painted and/or galvanised

to protect the steel against corrosion. Surface preparations, paint systems, and

galvanising shall be selected to give a minimum practical life to first maintenance

repainting in no less than 15 and 20 years as noted in Clause 3.3. All surface

preparation, galvanising and painting shall be carried out strictly in accordance

with the paint system manufacturer's recommendations and requirements.

Cathodic protection systems shall be provided for all buried pipe, conduit and

other buried steel materials. See Section 12.17 for detailed requirements for

cathodic protection systems.

All paint systems, paint specifications and other material specifications shall be

submitted to the Employer for acceptance before commencement of field work.

The different paints used for priming, undercoat and finish for the work and site

shall all be mutually compatible.

The coating system and finish used for both internal and external surfaces shall be

suitable for the particular conditions to be experienced in shipping, storing,

erection, commissioning and operation.

Where the surfaces to be coated are subject to heat or attack by chemicals, oil,

acid, fumes, or other corrosive matter special paints having the appropriate

resistant qualities shall be used.

Only high-quality paint products as manufactured by Ameron, Glidden, Sherwin

Williams, or similar reputable international paint manufacturers, shall be used.

Products shall be readily available in Bangladesh.

The painting shall be in accordance with ISO 12944.

14.14.2 Galvanising

All outdoor miscellaneous support steel and gallery work shall be galvanised in

accordance with ASTM A123, or an alternative coating system approved by

Employer. Indoor grating shall be galvanised in accordance with ASTM A123.

Galvanising of iron and steel items shall be carried out by the hot dip process

generally to the requirements of SSPC, ASTM A123 or other approved national or

international standards.



Bolt threads shall be cleaned of surplus spelter by spinning or brushing. Dies shall

not be used for cleaning threads other than on nuts. Nuts shall be galvanized and

tapped 0.4mm oversize and threads shall be oiled.

Excessively thick or brittle coatings due to high levels of silicon or phosphorous in

steel, which may result in an increased risk of coating damage and/or other

features that make the final product not fit for purpose shall be cause for rejection.

Minimum thickness of galvanising shall be 100 microns.

14.14.3 Schedule of Protective Coatings

The Contractor shall submit to the Employer a schedule of protective coatings for

the items of plant provided. The schedule shall be compiled in full co-operation

with the paint and protective coating manufacturers and shall include the following

information:

Protective coating system, compliance standard and colour. Each system shall be identified by a unique identifier

Type of surface or material or plant item to which system is to be applied

Protective coating manufacturer

Protective coating applicator

Surface preparation

Application method and minimum dry film thickness of individual layers

Method of repair of damaged areas

Inspection items, procedure and criteria

Supervision arrangements

Minimum expected life of coating system without recoating

Recommended maintenance procedures

Copy of manufacturer’s specification for storage, mixing, surface preparation and application of coating system.

Technical data on each proposed protective coating system shall be provided with

the schedule.

14.14.4 Painting and Protection

14.14.4.1 Surface Preparation and Inspections

All surface preparation and coating work shall be in strict accordance with Government of Bangladesh safety and health requirements.

Prior to priming, all surfaces shall be visually inspected to ensure that the proper surface conditions necessary for painting exist. This shall include:

Confirmation that environmental requirements for blast cleaning are met

Verification that surface preparation and surface profile are adequate

Verification that cleaned surfaces have been kept free of contamination

Documentation that the dew point conditions have been met

Verification that the storage, mixing, thinning and application of primers are in accordance with manufacturer's instructions



Verification that surfaces not to be coated are masked off or otherwise protected prior to painting of adjacent surfaces.

14.14.4.2 Application of Paint Systems

All paints shall be applied evenly to completely cover the surface. The paint manufacturers’ instructions for paint thickness, overall drying times along with recommended drying times between applications, method of application, and other parameters, must be rigidly adhered to. Successive paint coats shall be of differing colours. It is considered essential that the number of paint manufacturers involved is kept to a minimum. Detailed schedules of painting and protection shall be required at the design stage for all plant components. The schedules shall include all relevant information on the coatings proposed, including manufacturers’ data sheets, the stage of work/completion at which the protective coats shall be applied, and the proposed inspection and repair procedures. No paints or protective materials other than those scheduled and approved by the Employer shall be used. In all cases, the approved paints and protective materials, including decorative and identification paints, shall be applied strictly in accordance with the approved manufacturers’ instructions. All painting and protection shall be carried out by skilled painters with appropriate supervision.

14.14.4.3 Structural Steel and Associated Items

The surfaces of all structural steel, including plant support steel, pipe trestles and associated items, steel stairs, galleries and handrails shall be protected by the same or similar compatible paint systems. Particular care shall be taken to maintain strong paint films on all cleats, bolt holes, bolt heads and similar items. Second and subsequent coats shall only be applied when the previous coats have dried and hardened and the manufacturer's instructions for curing shall be strictly observed. A suitable drying and curing time shall be allowed before packing for shipment.

14.14.4.4 Painting Final Coat Colour Schedule

The colour of buildings and plant structures shall be as selected by the Employer. Final paint colours shall be determined during the implementation stage of the project and shall be manufacturers’ standard colours with the Employer's approval. All paints shall be suitable for the high humidity river area environment.

14.15 Equipment Baseline Monitoring Surveys

14.15.1 Vessel and Pipe Wall Thickness Survey

Within two months of or before steam piping systems are commissioned the

Contractor shall undertake a survey of pipe and vessel wall thickness. The survey

results shall be recorded in an Excel spreadsheet. The database shall record at

least point ID, location, measurement date, results and comments.

All measured points shall be identified with a unique ID number. The ID number

shall be marked next to the point and recorded on a drawing. Where

measurement points are located under insulation cladding, a 50 mm dia. hole with

a 100 mm dia. screwed on aluminium cover shall be made in the insulation. The

ID number shall be marked next to the cover. Trained and certified personnel and

calibrated equipment shall be used for the survey. The baseline monitoring

procedure must ensure measurements are accurate and repeatable.

The following number and location of points are required for pipelines:



Item Location Points on pipe circumference

Elbows Two sets of measurements on each Top, bottom and two sides

Straight pipeline>200NPS

Top, bottom and two sides spacing of no more than 60m

At least one point between elbows and Top, bottom and two sides

Junction points 500mm upstream of the junction point 500mm and 5m downstream

Top, bottom and two sides

Downstream of pressure reductions and control valves

At pipe to flange weld, 500mm and 5m down stream

Top, bottom and two sides

Steam trap pots Above, at and below operating water level

Four points

Nozzles > 150 mm

Neck Four points

Internal plates As recommended by Employer

Internal Piping 1 set at the centre of the pipe length

Four points

Heads Two sets on each head Four points

Shell 30 mm above and below the circumferential weld.

Four points

1 set at the centre between the circumferential weld.

14.15.2 Rotating Equipment Vibration Spectrum Survey

During the functional test of GT, ST and generator and rotating equipment with a

capacity greater than 75 kW, the Contractor shall undertake vibration

measurements which shall include vibration spectrum data, peak displacement,

peak velocity and peak acceleration. A mark shall be made at each measurement

point on the rotating equipment.

All vibration spectrum data shall be included in the equipment function test report.



15. QUALITY ASSURANCE, INSPECTION AND TESTING

15.1 Quality Control, Inspection and Testing

15.1.1 General

The Facilities covered by this Contract will be subject to inspection and test by the

Employer during manufacture, erection and on completion. The costs associated

with all tests and inspection shall be borne by the Contractor.

The Contractor and appointed Sub-Contractors and suppliers are required to

comply with the minimum requirements for quality assurance and quality control

(inspection and tests) to be applied to goods and services as detailed below.

The Contractor and his nominated Sub-Contractors shall work to defined quality

assurance programmes compliant with ISO 9001. The Contractor shall submit to

the Employer for approval, a list of quality level(s) proposed for his own, his Sub-

Contractor's and suppliers’ scope of supply. The Contractor shall supply the

results of any recent audits and approvals held. The Contractor shall undertake in

respect of his subcontractors, where no such acceptable information is available

or where the Sub-Contractor has not been subject to an acceptable external

quality audit within the previous 12 months, the carrying out a quality audit of that

Sub-Contractor to ensure that completion of the work will be compliant with the

Contract requirements.

The Contractor shall have sole responsibility for ensuring compliance with the

overall quality requirements of the Works, and shall ensure that Sub-Contractor’s

implement those quality control activities that are appropriate to the extent and

nature of their supply.

The information supplied in response to the Quality Assurance requirements shall

be deemed as part of the quality assurance arrangement and when agreed and

accepted by the Employer shall form an integral part of the Contract.

The Contractor shall, where required by the Contract or other regulatory

requirements, appoint an approved body to carry out an independent design,

inspection and test audit.

The Contractor shall establish and maintain a documented inspection system

capable of producing objective evidence that all materials; manufactured parts and

assemblies comply with the quality requirements of the Contract.

The Contractor shall establish a written procedure to identify and disposition any

deviations identified during the course of manufacture, inspection and test etc.

The Contractor and his nominated Sub-Contractors may be subject to quality audit

by the Employer.

The Contractor shall give all necessary help and assistance to the Employer in

carrying out such a quality assurance review. Such review/ audits/ verification may

take place during the tender evaluation period.

15.1.2 Employer Review:

The Contractor shall not begin construction work on any activity before the

Employer has reviewed the Contractor's design submittal for that activity and has

no further comments and work not in compliance with established standards and

contract. If the Contractor does begin work prior to such Employer’s review, it

does so at its own risk. The Employer’s review shall not be construed as a

complete check but will evaluate the general design approach and adherence to

Contract parameters. The Employer review is often limited in time and scope.



Therefore the Contractor shall not consider any review performed by the Employer

as an excuse for incomplete work. Upon completion of the review, all comments

will be forwarded to the Contractor.

Design submittals with no comments shall not relieve the Contractor from

responsibility for any design errors or omissions and any liability associated with

such errors, nor from responsibility for complying with the requirements of this

contract.

15.1.2.1 Incorporation of Employer Review Comments

The Contractor will be furnished comments from the various design sections of the Employer, as well as from other concerned agencies involved in the review process. The review will be for conformance with the technical requirements and parameters of the contract documents. The Contractor shall either incorporate each comment or, if the Contractor disagrees technically and does not intend to comply with the comment(s), the Contractor shall clearly outline, with ample justification, its reasons for its non-compliance within seven (7) days after receipt of the comment(s).

Additionally, the Contractor is cautioned in that if it believes the action required by any comment exceeds the requirements of this Contract, that he should take no action and notify the Employer in writing immediately. The disposition of all comments shall be furnished in writing with the next scheduled submittal. The review comments and the submittal material for each design review will become the basis for any ensuing design work. Copies of the design review comments with the action taken on each comment noted shall be bound in all succeeding volumes of the design analysis. All modifications between revision of drawings and documents shall be clearly highlighted (e.g. by a cloud around the change marked with the document revision number). All parts of the drawing or document not highlighted as above shall be deemed to be the same as the previous revision.

15.1.2.2 Design Review Meetings

When the design has achieved sufficient progress, periodic Design Review meetings will be held between the Contractor and the Employer.

In order to shorten the time required for Design Review and to allow the earliest possible time for site mobilization, it is expected that the Employer’s engineering staff will meet with the Contractor’s design staff in the Contractor’s home office on several occasions to expedite drawing/ design approval. The Bidder shall therefore allow in its bid all costs associated with seven (7) of the Employer’s engineers attending three such meetings, each meeting lasting 10 days. Costs shall include the business class airfares, accommodation, transport, meals, medical, incidental pocket expenses for the Employer’s staff of USD 180/ person/ day including travel time etc. The actual number of such meetings will be discussed and agreed during the Contract Negotiations.

15.1.2.3 Design Deficiencies

Design deficiencies noted by the Employer shall be corrected prior to the start of design for subsequent features of work which may be affected by, or need to be built upon, the deficient design work.

15.1.2.4 Design Discrepancies

The Contractor shall be responsible for the correction of incomplete design data, omissions, and design discrepancies which become



apparent during construction. The Contractor shall provide the Employer with a proposed recommendation for correcting a design error, within three (3) calendar days after notification by the Employer. The Employer will notify the Contractor of any detected non-compliance with the foregoing requirements.

The Contractor shall take immediate corrective action after receipt of such notice. Such notice, when delivered to the Contractor at the worksite, shall be deemed sufficient for the purpose of notification. If the Contractor fails or refuses to comply promptly, the Employer may issue an order stopping all or part of the work until satisfactory corrective action has been taken. No part of the time lost due to such stop orders shall be made the subject of claim for extension of time or for excess costs or damages by the Contractor.

15.1.3 Extent of Work

The Contractor shall define in the Schedule the items within his extent of work;

those items to be sub-contracted and proposed quality level attributed to each

together with all items for which quality plans (inspection and test plans) will be

submitted. The Contractor shall identify the names and locations of the suppliers

of all materials, equipment and services including the locations of companies

within his own group of companies.

The Contractor's quality system shall include as a minimum the procedures used

for controlling the following functions:

a) Inclusion on purchase orders of the necessary technical inspection and test details to meet the specified requirements and of the Employer’s right of involvement at the Contractor’s, Sub-Contractors’ and suppliers’ works.

b) Availability at inspection points of applicable drawings, instructions, etc. and prompt removal of superseded documents.

c) Maintenance and calibration of suitable inspection and test equipment.

d) Incoming, in process and final inspection and inspection of packing and marking.

e) Means of identifying inspection status throughout manufacture.

f) Means of identifying and isolating raw materials and components not conforming to the Contract.

g) Provision of a written procedure to identify and disposition any requested deviations to the applicable national standards and specifications mentioned in the contract specification. All such items shall be reported to the Employer via a non-conformance report.

h) Provision of complete inspection and test records.

15.1.4 Document Submission

The Contractor shall submit for review, within 30 days of the Contract award a

quality plan (inspection and test plans) defining the programme of quality control

and inspection activities which he and his Sub-Contractors and suppliers will

perform in order to ensure that the procurement, manufacture and completion of

the materials, equipment and plant complies with the specified requirements.

All submitted documents shall clearly identify the manufacturer and the item/sub-

item of plant to which they apply.

The quality plan may be of any form to suit the Contractor's system, but it shall as

a minimum:

a) Indicate each inspection and test point and its relative location in the production cycle including incoming, packing and site inspections.



b) Indicate where Sub-Contractors' services will be employed (e.g. Sub-Contractor NDT or heat treatment).

c) Identify the characteristics to be inspected, examined, and tested at each point and reference drawings, procedures and acceptance criteria to be used.

d) Indicate the inspection, test and hold points established by the supplier, Sub-Contractor and Contractor, which require verification of selected characteristics of a document, item or process before this work can proceed.

e) Allow for witness, hold and review points to be established by the Employer, which require his verification of selected characteristics of a document, item or process before this work can proceed.

f) Define or refer to sampling plans if proposed and where they will be used.

g) Where applicable, specify where lots or batches will be used.

h) Relevant acceptance criteria.

The Employer will indicate the inspection requirements on the agreed inspection

programme in accordance with the following:

Hold point – requires a mandatory inspection by the Employer. This inspection or test shall be witnessed by the Employer and further progress in manufacture shall not be made until the plant is approved by the Employer.

Witness point – inspection or test of material may be carried out by the Employer at his discretion.

Document review – certification of material and functional test shall be approved by the Employer before despatch from the works.

Independently, the requirements of the Third Party Inspectorate shall be indicated

in a similar manner prior to the submission of the Inspection Plan to the Employer,

for his approval.

The Contractor shall forward for review within 60 days of contract award for

applicable items of equipment identified within quality plans, duplicate copies of:

a) Special process procedures covering the welding, heat treatment and non-destructive examinations of all pressure retaining and loading bearing fabrication welds and major castings including repair procedures. Procedures must include qualification records and acceptance criteria where applicable.

b) Inspection procedures for components and test procedures for sub-assemblies and complete assembly of the turbine shall be submitted to the Employer for approval before assembly commences.

c) Test procedures for the witness testing of generators, excitation system, transformers, motors, frequency converters, HV and MV cables, HV, MV, and LV switchgear, UPS and DC systems, protection equipment and circuit breakers and frequency converters.

d) Test procedures for the witness testing central and local control panels, SCADA and DCS equipment

e) Test procedures for the witness testing pumps, compressors and automated valves.

f) Purchase orders (un-priced) complete with technical specification and data sheets.



15.1.5 Inspection Notification and Right of Access

In order to verify compliance with engineering procurement, manufacturing

requirements and programmes, the Employer shall have access at all reasonable

times, to all places where materials or equipment are being prepared or

manufactured and tested, including the works of the Contractor, Sub-Contractors

or suppliers of raw materials.

The Contractor shall advise the Employer of the readiness of inspection at least

21 days prior to nominate witness or hold points requiring travel outside of

Bangladesh and 14 days prior to a nominated witness or hold point not requiring

travel outside of Bangladesh. Work shall not proceed beyond a hold point without

the written agreement of the Employer. A common form of notification will be

developed and agreed for general use on the contract.

Before giving such notice the Contractor is required to have completed all his

internal controls, including that relative to the notification point and to have

available documentation to that effect for the Employer to review.

Request for waiver from Contract quality requirements shall be made by the

Contractor to the Employer, as soon as it is established that an item of equipment

as designed, or in manufacture, cannot be made to comply with a particular

specified requirement. The subject item of equipment shall not be offered for final

inspection until such waiver requests have been approved by the Employer.

15.1.6 Inspection and Tests

The Employer shall be entitled to witness factory acceptance tests on each of the

major components (or part thereof).

The Bidder shall include in its bid, all costs associated with four members of the

Employer’s engineers, attending and witnessing each of the factory acceptance

tests. When travel outside Bangladesh is required, all costs shall include business

class airfares, accommodation, medical, transport, meals, incidental pocket

expenses for the Employer’s engineers of USD 180/person/ day including travel

time etc. Travel schedules shall be mutually agreed between the Employer and

the Contractor but shall include adequate time for the travellers to recover from

their flights, for the tests / inspections and preparation and review of the test

reports.

Should the equipment or any part thereof fail under these tests, then the cost of

any further tests shall also be borne by the Contractor, including all costs relating

to the Employer attending the retests.

Such inspection/ witnessing of factory acceptance tests shall not relieve the

Contractor from any obligation to perform the Work in accordance with the

Contract documents. Work not so constructed shall be removed and made good

by the Contractor at its own expense.

Major components are:

Gas Turbine

Gas Booster Compressor

HRSG

Steam Turbine

Generators

Transformers

Generator circuit breaker



400 kV equipment

230 KV equipment

Gas RMS

ICMS

Calibration Test Bench

Inspection of materials or equipment may be made by the Employer and could

include the following activities:

a) Evaluation of the Contractor's system and approval of the quality plans.

b) Periodic monitoring to confirm the effectiveness of and the Contractor's, Sub-Contractors’ and suppliers’ compliance with the established quality system procedures, inspection and test plans and inspection and test instructions.

c) Witnessing of inspections and tests and/or verification of inspection records to be carried out at the Employer discretion covering:

Compliance of raw material with specified requirements.

Compliance of manufactured parts, assemblies and final items with Specifications, drawings; standards and good engineering practice.

Periodic inspection of Contractor's design, manufacturing, installation work and the production of progress reports.

Witnessing of inspections and tests.

Packing for shipment including check for completeness of shipment, handling requirements, and case markings and identification.

The Contractor shall keep the Employer informed in advance of the time of

starting and of the progress of the work in its various stages so that arrangements

can be made for inspection and for test. The Contractor shall plan the

performance of inspection and tests so as to avoid the delaying of the work.

All of the required inspections and tests shall be made at the Contractor's expense,

including the cost of all samples used. The Contractor shall be responsible for any

additional costs incurred by the Employer arising from the postponement, re-

inspection or additional inspections or visits attributable to the Contractor, Sub-

Contractors or suppliers’ performance. The Contractor shall also provide, without

charge, all reasonable facilities and assistance for the safety and convenience of

the Employer in the performance of his duties.

If the plant or any portion thereof fails under test to give the required performance,

such further tests which are considered necessary by the Employer shall be

carried out by the Contractor and the whole cost of the repeated tests shall be

borne by the Contractor. This also applies to tests carried out at Sub-Contractor’s

works.

15.1.7 Non-Conformances

Non-conformances identified by the Employer shall be notified to the Contractor

by issue of the Employer Non-Conformance Report. The Contractor shall receive

and action all non-conformance reports and re-inspection shall not be notified until

the completed non-conformance report, together with any applicable re-work or

concession application, have been accepted by the Employer.

Where applicable, rejection of materials, equipment and/or components will be

made as promptly as practicable following any inspection or test involvement by

the Employer. Failure to inspect and or reject materials, equipment and/or

components shall neither relieve the Contractor from responsibility for such items



which may not be in accordance with the specified requirements, nor impose

liability for them on the Employer.

The Contractor and Sub-Contractors quality assurance programme shall identify

and isolate raw materials and components not conforming to specifications. All

such items shall be reported to the Employer via a non-conformance report.

Approval of a concession application is the prerogative of the Employer and

approval of a particular case shall not set a precedent.

The Employer shall have complete authority to accept or reject any equipment or

part thereof considered unsatisfactory and/or not in accordance with the contract

requirements. The witness of any inspection and tests by the Employer of any

components or lots thereof does not relieve the

Contractor of any responsibility whatever regarding defects or other failures which

may be found before the end of the Defect Liability period.

15.1.8 Quality Control Records, Certificates and Certificates of Conformance

At the end of each visit to a manufacturer to carry out quality control activity, the

Employer will complete a Quality Control Record and hand one copy to a

responsible representative of the Manufacturer.

The Quality Control Record (QCR) will identify the item inspected, the stage of

manufacture, and the nature of the QC carried out, and will list all points which

require remedial action by the manufacturer, before the subject item can be

released.

When each item of equipment is ready for despatch from the place of manufacture

and the Employer has verified compliance with specified requirements up to that

point, a Quality Control Certificate will be issued to the Contractor.

The Quality Control Certificate (QCC) will identify the item to which it applies and

will release that item from Employer control only. The QCC does not constitute

any form of acceptance of the item by the Employer.

The Contractor shall provide a Certificate of Conformance confirming compliance

with the Contract requirements and as detailed in the manufacturing record data

book.

Sets of all test records, test certificates and performance curves, whether or not

they have been witnessed by the Employer, shall be supplied for all tests carried

out in accordance with the provisions of this Contract.

Sets of all test certificates shall be endorsed with sufficient information to identify

the material or equipment to which the certificates refer, and shall carry in the top

right hand corner the following reference:

Employer’s name:

Project title:

Employer’s reference number:

All test documentation shall be in the English language.

No materials or equipment shall be shipped to the Site until all tests, analysis and

inspections have been made and the Contractor's Certificate of Conformance has

been reviewed and released by the Employer; or unless otherwise agreed by the

Employer.



15.2 Factory Tests

a) All plant shall be subjected to type, sample and routine tests at the manufacturer's factory in accordance with these clauses and conditions of the Contract.

b) Type, sample, routine tests and factory acceptance tests shall be to the relevant ISO and IEC Standards or other approved standards for equipment where the test requirements are not specified in these clauses.

c) The Contractor may offer type test results for identical equipment in lieu of the type tests specified, in which case the specified type tests may be waived by the Employer. If type test results for identical equipment are offered in lieu of the specified type tests, the Contractor shall also provide evidence as to the similarity of the equipment tested and the Contract equipment.

d) The Contractor shall submit evidence to the Employer that the instruments used for the testing shall have been calibrated at an approved testing laboratory within a period of up to six months for a portable instrument and twelve months for a fixed instrument.

e) The tests mentioned in this section are not intended to form a complete list of the numerous tests which the Contractor would normally perform to ensure equipment quality and reliability of the Facilities.

15.2.1 Gas Turbine

Testing shall be carried out in compliance with sections 6.2 and 6.3 of API

616, as applicable, and ASME Power Test Codes.

The Contractor shall perform full assembly, all tests and inspection necessary

to ensure that the material and workmanship conform to the Contract and

design drawings and that such tests are adequate to demonstrate that the

equipment will comply with the requirements of this Specifications and meet

the guarantees specified. Operating parameters such as vibration,

temperatures, pressures, etc. shall be checked. All measuring, safety and

protection devices on each unit shall be tested.

The Employer shall have access to the Contractor's or Sub-Contractor's

works to determine or assess compliance with the provision of this

Specification or to witness the Contractor's inspection or tests.

The turbine rotors shall be over speed tested at 25% above rated speed for a

period of 2 minutes. Thermal stability tests for the turbine rotors shall also be

performed.

Fracture toughness tests of rotor material as well as for parts subject to creep

and fatigue such as valve castings and forging shall be carried out.

All parts subject to any of the media like steam, water or gas etc. pressure

shall be tested with a hydraulic pressure of 50% in excess of the highest

working gauge pressure to which the component will be subjected.

All equipment shall be tested under simulated working conditions and

conducted in accordance with the appropriate ASME Power Test Code

system so as to comply with the following requirements:

Rub check

Starting to synchronous speed

Rotor balance at full speed

Governing test

Over-speed test

Leak test for fuel, oil, water etc.



Test of all turbine trips, initiation shall be simulated.

Barring

Operation of lube oil system

4 hours run at synchronous speeds including vibration monitoring

Any other test in accordance with manufacturer’s standard practice.

Auxiliary equipment and systems: witnessed tests and/or inspection of auxiliary

including, as applicable:

Radiator assembly

Jack water pumps

Starting air compressor

Exhaust silencers.

Air receivers

Cooling modules.

In the event of a conflict with the specified test codes, this Specification shall

govern.

All pumps and motors shall be tested in the Contractor's and sub-Contractor's

works in accordance with ASME Power Test Code PTC B2 for centrifugal pumps

and the latest IEEE "Test Code for “Squirrel Cage Induction Motors” together with

other relevant codes for other type of pumps and motors.

15.2.2 Steam Turbine

Testing shall be carried out in compliance with paragraph 8.3 of API 611, as

applicable. The Contractor shall perform full assembly, all tests and inspection

necessary to ensure that the material and workmanship conform to the Contract

and design drawings and that such tests are adequate to demonstrate that the

equipment will comply with the requirements of this Specifications and meet the

guarantees specified. Operating parameters such as vibration, temperatures,

pressures, etc. shall be checked. All measuring, safety and protection devices on

each unit shall be tested.

The Employer shall have access to the Contractor's or sub-Contractor's works to

determine or assess compliance with the provision of this Specification or to

witness the Contractor's inspection or tests.

The turbine rotors shall be over speed tested at 25% above rated speed for a

period of 2 minutes. Thermal stability tests for the turbine rotors shall also be

performed.

Fracture toughness tests of rotor material as well as for parts subject to creep and

fatigue such as valve castings and forging shall be carried out.

All parts subject to any of the media like steam, water or gas etc. pressure shall be

tested with a hydraulic pressure of 50% in excess of the highest working gauge

pressure to which the component will be subjected.

All equipment shall be tested under simulated working conditions and conducted

in accordance with the appropriate ASME Power Test Code system so as to

comply with the following requirements:

Rub check

Starting to synchronous speed

Rotor balance at full speed

Governing test



Over-speed test

Leak test for oil, water, etc.

Test of all turbine trips, initiation shall be simulated.

Barring

Operation of lube oil system

4 hours run at synchronous speeds including vibration monitoring

Any other tests required in accordance with manufacturer’s standard practice.

In the event of a conflict with the specified test codes, this Specification shall

govern.

All pumps and motors shall be tested in the Contractor's and sub-Contractor's

works in accordance with ASME Power Test Code PTC B2 for centrifugal pumps

and the latest IEEE "Test Code for “Squirrel Cage Induction Motors” together with

other relevant codes for other type of pumps and motors.

15.2.3 HRSG

The HRSG shall be pressure tested and inspected in accordance with ASME

Division VIII, Boiler and Pressure Vessel Code and referenced codes and

standards.

15.2.4 Gas Booster Compressors

15.2.4.1 Required Tests

The centrifugal, integral gear, fuel gas compressors shall be tested and inspected in accordance with API 617 Axial and Centrifugal Gas Compressors for Petroleum and Gas Service Axial and Centrifugal Compressors and Expander-compressors for Petroleum, Chemical and Gas Industry Services.

The following optional tests from Section 4.3 are to be undertaken or omitted:

Synchronous vibration signatures bat start and end of test run

Tape recordings are not required

Lube oil and seal oil pressures and temperatures to be varied

Shaft end seals need not be removed

Performance test is required

Helium test is required

Sound level test is required

Auxiliary equipment to be tested

Post test inspection of internals not required

Full pressure/full load/ full speed test not required

15.2.4.2 Compressor Tests to be Witnessed by the Employer

The following tests on the compressors shall be witnessed by the Employer:

Hydrostatic testing

Mechanical run test

Performance test



Compressor rotor insensitivity test

Complete unit test

Auxiliary component test

Compressor gas leak test

15.2.4.3 Technical Data to be Provided

Data sheets shall be provided as set out in the following codes:

Centrifugal Compressors – API 617 Section 5

15.2.5 Generator

Generator shall be operated at no-load on the factory test floor with the following

observations and respective data so reported and reference to IEC Standard shall

be made:

a) Measurement of resistance of armature and field windings

b) Mechanical inspection and balance

c) No-load field current at rated voltages and frequency

d) Voltage phase balance and phase sequence

e) Dielectric tests

f) Insulation resistance of field and armature

g) Standard no-load and short circuit tests

h) Characteristic "V' curve test and efficiency tests

i) Generator fixed losses

j) Generator variable losses (at loads available with driving motor)

k) Measurement of vibration

l) Temperature rise test.

15.2.6 Exciter

Each exciter shall be operated at no-loads on the factory test floor with the

following observations and respective data so reported and reference to IEC

Standard should be made:

a) Saturation run

b) Mechanical balance

c) Resistance

d) Dielectric tests

e) Insulation resistance of windings

f) Exciter characteristics tests.

15.2.7 Transformers

The transformers shall be completely assembled at the factory and shall be

subjected to the following tests by the Contractor, in accordance with the latest

revisions of IEC 76 "Power transformers" and 551 "Measurement of transformer

and reactor sound levels".

a) General inspection

b) Measurements of Winding resistance

c) Voltage ratio measurement and check of polarity



d) Measurement of impedance voltages

e) Measurement of load loss

f) Measurement of no-load loss and current

g) Test of temperature rise

h) Induced over-voltage withstand test

i) Separate-source voltage-withstand test

j) Insulation resistance measurement (Megger)

k) Lightning impulse tests

l) Test of protective relays

m) Characteristic test of bushing type current transformers.

Routine tests shall include:

Tangent delta measurement on the insulation

Radio discharge measurement in accordance with IEC or partial discharge test in accordance with IEC.

Gas oil analysis.

Transformer tanks, conservators, oil pipework and cooling plant shall withstand, without leak or permanent distortion, the application for 24 hours of a pressure which is such that the test pressure at any point in the equipment is twice the working pressure at that point, or 0.7 kg/cm2 plus the working pressure at that point, or 0.3 kg/cm2 plus the pressure exerted at that point when the pressure relief valve is opened slowly by oil pressure, whichever is the greater.

15.2.8 Generator Circuit Breakers

Routine Tests

In accordance with the requirements of IEC 56 as applicable together with any

tests carried out as a normal routine procedure by the manufacturer. In addition,

leakage tests shall be carried out on gas filled circuit breakers.

Type Tests

In accordance with the requirements of IEC 56, details of the rate of rise of

recovery voltage to which the circuit breaker will be subjected during short circuit

testing shall be submitted to the Employer for approval.

The Employer may require in addition any of the following tests to be carried out,

the details of which will be agreed between the Employer and the Contractor:

Earth fault interruption tests.

Out of phase switching test to IEC 267

Capacitance switching tests.

Small inductive breaking current switching tests.

Tests under environmental conditions.

Voltage withstand test after breaking capacity tests.

15.2.9 Disconnectors and Earth Switches

Routine Tests

In accordance with the requirements of IEC 129 and 265 where applicable



Type Tests

In accordance with the requirements of IEC 129 and 265 where applicable, shall

be submitted to the Employer for approval.

If required by the Employer, a complete assembled unit of each type shall be

mounted on its steel structure and operational tests carried out.

15.2.10 Current Transformers

Routine Tests

In accordance with the requirements of IEC 185

Type Tests

In accordance with the requirements of IEC 185, shall be submitted to the

Employer for approval.

15.2.11 Voltage Transformers

Routine Tests

In accordance with the requirements of IEC 186

Type Tests

In accordance with the requirements of IEC 186, shall be submitted to the


15.2.12 Surge Arrestors

Routine Tests

In accordance with the requirements of IEC 99.1

Type Tests

In accordance with the requirements of IEC 99.1, shall be submitted to the


Sample Tests

In accordance with the requirements of IEC 99.1, Clause 68, a residual voltage

test shall be carried out.

15.2.13 Galvanizing

Representative samples, selected by the Employer, of all galvanized material shall

be submitted for galvanizing tests, Galvanized fittings associated with insulators

and steel cores for aluminium conductor steel reinforcing cables shall be tested in

line with the relevant IEC Recommendation. All other fittings, fabrications,

hardware and fixings shall be inspected and tested in accordance with ISO

Recommendations R1460 and R1461.

15.2.14 Structures

Type Tests

If required, one type test of each structure shall be erected in the Works in order to

check the fabrication of the steelwork.

If required, loads corresponding to the assumed conditions of loading shall be

applied to the structures.

15.2.15 Control and Protection System

The following tests for the control and protection system shall be performed at the

factory.



General inspection

Measurement of insulation resistance

Dielectric withstands voltage test

Performance test of relay Error test of meter

Sequential operation test of Control and Protection System

15.2.16 ICMS System Test Requirements

On completion of all subsystem tests to ensure compliance with individual

equipment specifications, the Contractor shall conduct an in-factory System Tests

to verify:

a) Compliance with the functional and operational requirements of the Specification.

b) The units operate correctly when connected in the operational configuration and under all specified operational modes.

c) Hardware and software errors and design weaknesses are identified and corrected before delivery.

d) The system and subsystem availability figures are better than 99.9 % (by extrapolation);

e) All interfaces, in particular the interfaces with and between each of the major equipment suppliers, function correctly.

f) All Contractor furnished software packages are operational.

g) All fail-over and switching functions operated satisfactorily.

h) All alarm functions are verified.

i) All diagnostic routines are verified.

j) ICMS performance and time resolution.

k) The CPU load under worst case conditions;

l) Functional test of man-machine interface.

m) Functional test of facilities for off-line program development; and

n) Test of historical data storage and retrieval.

The Contractor shall assemble all ICMS equipment down to the level of field

controllers, programmable logic controllers and major plant controllers (e.g. the

gas turbine). The Contractor shall simulate plant inputs and shall take such

measures as necessary to ensure factory system tests are realistic and

meaningful. The test shall include the full automatic start-up and shutdown of the

power plant.

The System Tests shall include a 100 (hundred) hour stability test run depending

on the successful completion of the Factory Acceptance Tests. The duration of the

stability test run shall not be less than 100 hours and shall be in periods of not less

than 25 hours each. During the stability test run, no adjustment shall be made to

any equipment without the prior approval of the Employer. Faulty equipment shall

be replaced with spare units without interruptions of the test. The faulty unit shall

be immediately repaired and returned to service. Any period of operation with a

faulty unit shall be regarded as not part of the test. No automatic change-over to a

standby unit shall occur unless the change-over itself is being tested. If a

stoppage of the test occurs due to equipment fault, the test will be deemed to be

invalid and the Employer may require a repetition of the test. At any stage during

the test period the Employer may request a printout of any nominated parts of the



main or auxiliary memory for verification purposes. No additional program or data

shall be read into the system without the prior approval of the Employer.

15.2.17 Piping Specific Requirements

15.2.17.1 Test Certificates

The Contractor shall furnish the following final data as applicable:

Material Test Certificates

Post weld Heat Treatment Charts

Non-destructive and Hydrostatic Testing Reports (Employer will consider exceptions on a case by case basis)

Hardness Readings

Chemical Analyses

Pressure Test Certificates

Manufacturing data report and certificate

Dimensional inspection records.

15.2.17.2 Identification Marks

All pipe, flanges, and fittings shall be identified in full accordance with the requirements of the applicable standard.

15.2.17.3 Pipe Dimensional Tolerances

The dimensions, weights, lengths, wall thicknesses and straightness of the line pipe, including its tolerances and bevel end preparations shall conform to the API-5L code.

Welded pipe larger than 750 mm shall have a manufacturer’s tolerance on pipe under thickness of no more than 5%.

All pipes, flanges and fittings shall be subject to the inspection requirements of ASME, ANSI or API Code, whichever is applicable. Refer also to Section.

15.2.17.4 Manufacturing Inspection

The following are additional inspection requirements for pipes, flanges and fittings to be performed by Contractor or its designated third party inspector.

Pipes:

100% document review on chemical analysis and tensile test

100% document review on hydrostatic test and non-destructive examination

25% dimensional check, 10% weight per shipping lot, per size, type and requisition before shipment

25% end finish and surface finish check per shipping lot, per size, type, and requisition before shipment

100% check on quantity, packaging, marking and loading at final.

Fittings:



100% document review on chemical analysis and tensile tests

5% check on hardness test, 100% document review

In process, random sample, 100% document review on hydrostatic test and non-destructive examination

25% dimensional check, 10% weight per shipping lot, per size, type and requisition before shipment

25% end finish and surface finish check per shipping lot, per size, type, and requisition before shipment

100% check on quantity, packaging, marking and loading at final

25% check on dimensions per shipping lot, per size, type and requisition.

If any item or portion thereof fails under tests to give the required performance, such further tests as are considered necessary by the Employer shall be carried out by Contractor and the whole cost of the repeated or extra tests shall be borne by the Contractor.

15.2.18 Valve Specific Requirements

15.2.18.1 Testing

General:

As part of Contractor’s overall Quality Control Programme Contractor shall furnish reports giving the results of all required tests and examinations that are supplementary to the material specification referenced for manufacture.

Certified test reports of all materials of construction and tests shall be submitted to the Employer. This is required for the body and stem of the valve. At least one valve of each make, type and size shall be tested. Tests shall be made only after all heat treatment and weld repair has been completed and before any painting.

All internal and external surfaces shall be clean and dry before commencement of any test. All water used for testing valves, especially austenitic stainless steel valves, shall be clean and contain as little chlorides as practical. Immediately following tests, valves shall be rinsed with clean water, drained and thoroughly dried.

If the valve cannot be totally drained, it shall be flushed with chloride free water or with alcohol/petroleum distillate (provided it will not damage the valve).

Leakage Test:

Valves shall comply with the degree of leak tightness as specified. For seat leakage tests, valves shall be closed manually with the hand wheel without over tightening. External forces that affect seat leakage shall not be applied to valve ends during testing.

The test shall be in accordance with the requirements of API 598 except that the valve seat shall be subjected to at least a hydrostatic test of 1.5 times the working pressure which shall be applied successively to both sides of the valve to test for sealing. If the permitted leakage rate on a valve is exceeded, all other valves of the same size and type shall be tested.



Hydrostatic Test:

Valves shall only be pressure tested after all auxiliary components or attachments and packing have been fitted. Pressure testing shall be in accordance with API 598 except that the test pressure shall be at least 1.5 times the maximum working pressure and held for a minimum of 10 minutes. Seating surfaces must be dry or coated only with very light oil (no heavier than kerosene).

Valves shall also be subjected to a high-pressure closure test in accordance with API-598. Closure torque during pressure testing shall not exceed that required for manual closing of the valve using only the hand wheel or operator on the valve.

Hardness Testing:

Hardness testing is required for valves 12” and larger on gas, steam and cooling water systems, on the valve shaft, stem, trim and where applicable on the weld overlay. Brinell hardness testing is not permitted for valve stem (or shaft).

Hardness testing shall be performed on the thickest section of each component part selected to be tested, in an area convenient for the specified testing method. Hardness testing shall be performed on the base metal, weld metal, and heat affected zone. If heat treatment is required, hardness testing shall be performed after heat treatment. Hardness testing shall be performed in accordance with ASTM A370.

15.2.18.2 Inspection and Non-Destructive Examination

General:

The Employer reserves the right to witness testing and examination, or to inspect any or all valves at any time during fabrication, manufacture or assembly.

Manufacturing Inspection:

The following are the additional inspection requirements for the valves which are to be performed by the Contractor or a third party inspector assigned by the Contractor:

100% document review on chemical analysis and tensile tests

100% document review on shell hydrostatic and valve closure hydrostatic tests

100% check on finish at final shipping lot

25% check on dimensions at final shipping lot

100% check at final shipping lot on quantity, marking, packaging and loading procedure

25% check at final shipping lot for size, type and requisition, on conformance of valve with purchase order, particularly special features required.

If any item or portion thereof fails under the tests to give the required performance, such further tests considered necessary by the Inspector shall be carried out and the whole cost of the repeated or extra tests shall be borne by the Contractor.

Visual:

Visual examination shall be in accordance with MSS-SP-55.



Radiographic Examination:

Radiographic examination shall be performed in accordance with MSS-SP-54 unless otherwise stated. Limits on imperfections shall be in accordance with MSS-SP-54 or ASME B31.1.

Weld examination methods shall be in accordance with Section V of the ASME BPV Code and the acceptance criteria shall be in accordance with Clause 136.4.5 of ASME B31.1.

Magnetic Particle Examination:

When required, all accessible interior and exterior surfaces shall be examined by magnetic particle examination in accordance with MSS-SP-53 or ASTM E709. Surfaces inaccessible for this method of examination shall be examined by the liquid penetrant examination method. The limits on imperfections shall be in accordance with MSS-SP-53.


Liquid Penetrant Examination:

Liquid penetrant examination where used shall be in accordance with ASTM E165. However, the limits of imperfections shall be in accordance with MSS-SP-53.


Ultrasonic Examination

Ultrasonic examination where used shall be in accordance with the BPV Code, Section V, Article 5. The acceptance criteria for imperfections shall be in accordance with Table 102.4.6 of the ASME B31.1.


Hydrostatic Testing

Pressure testing, including pressure testing at 1.5 times the design pressure (unless noted otherwise), will be specified and performed for pressure components. All pipe joints must be exposed where pipe insulation is installed before the pressure testing. Pressure testing shall include but not be limited to the following equipment and piping systems:

Pump casings

HP/IP steam system

HP feed water system

Fire protection system (test pressure per NFPA)

Fuel gas system

Chemical feed systems

SCR ammonia system

All underground piping (other NDE may be accepted for makeup water and blowdown piping subject to prior written Employer approval). Underground piping or piping that is



otherwise inaccessible after construction shall be pressure tested before it becomes inaccessible.

Condenser air removal system

Closed cooling water system

Potable/Drinking water system

Makeup water system

Condensate system

Demineralized water system

Blowdown system.

Water shall normally be used as the test medium for hydrostatic testing. The water will be clean and will be of such quality as to minimise corrosion of the materials in the piping system. The hydrostatic test pressure will not be less than 1.5 times the design pressure, but will not exceed the maximum allowable test pressure of any non-isolated components, such as vessels, pumps, or valves. Pneumatic testing shall not be used unless approved by the Employer.

15.2.19 Other Materials and Equipment

All other materials and equipment shall be tested at the Contractor's workshops in

accordance with latest IEC, ISO, other approved Standard and/or the request of

the Employer.

15.3 Tests at Site

15.3.1 General

The contractor shall submit the test protocol for all main and auxiliary equipment

for approval by the employer before commencing at site pre commissioning test.

Tests shall consist of:

Pre-commissioning – consisting of:

a. Preliminary tests which are tests performed prior to rotation or energising at normal voltage or admission of normal water or air pressure to the plant under test.

b. Tests on completion which are tests to progressively prove the correct operation of complete auxiliary systems and of the main plant items. These tests shall be carried out in accordance with the conditions of the Contract.

c. Reliability run

Commissioning – consisting of:

a. Guarantee and performance tests

The reliability run and guarantee and performance tests shall be performed first at

completion of to achieve commercial operation date and then at completion of

combined cycle to achieve combined cycle commercial operation date.

The tests mentioned in this section are not intended to form a complete list of the

numerous tests which the Contractor would normally perform to ensure equipment

quality and reliability of the Facilities.

15.3.2 Responsibility for Tests

a) The Contractor shall conduct the tests at the Site in accordance with these clauses and the Conditions of the Contract.



b) The Contractor shall provide all equipment and personnel required to carry out the tests, including the provision, installation and removal of all test instruments, the connection and disconnection of plant items and obtaining of all records.

c) The Contractor shall prepare and submit to the Employer at least three months prior to the commencement of testing, detailed schedules in approved format for each test together with a programs provided by the Contractor. The Contractor shall be responsible for overall coordination and safety control of tests.

d) The Contractor shall submit one copy of the results of each of the tests at the Site to the Employer within one week of the tests being carried out. Four copies of the certificates shall be provided to the Employer within one month of the tests being carried out.

e) The Employer’s staff involvement in the site tests will be as per GC and PC.

f) The Contractor shall submit evidence to the Employer that the instruments used for the tests have been calibrated at an approved testing laboratory within a period of up to six months.

15.3.3 Pre-commissioning

15.3.3.1 Inspection and Checking of Units

After completion of erection and/or installation, and before putting into operation, each unit and all its appurtenances (compressor, gas turbine, steam turbine, generator, HRSG, cooling system, motors, pumps, heaters, fans, piping, valves and all other mechanical and electrical equipment including GIS and material) shall be thoroughly cleaned, inspected and pressure tested etc. in the presence of the Employer to confirm for correctness and completeness of installation and acceptability for placing in operation. The time consumed in the inspection and checking of the units shall be considered as a part of the erection and installation period.

15.3.3.2 Start-up and Trial Operation

Following the satisfactory completion of the inspections and checking of gas turbine, HSRG, steam turbine and generator(s), the same will be placed into trial operation during which all necessary adjustments, repairs etc. shall be made as required, then the unit(s) being shut down as required.

When the equipment is operating properly its characteristics shall be recorded on the start-up report sheets. Start-up reports for all the equipment must be completed before the start of the reliability test period.

The time consumed in start-up and trial operation shall be considered as a part of the erection and installation period.

The following tests shall be carried out on the gas turbine and steam turbine (as appropriate):

Start-up mechanical running test, adjustment of turbine inlet guide vane control and interlocking, etc. The measured data such as pressure, temperature, vibration, adjustable speed range etc. shall be observed and recorded.

Checking of cooling system and lube oil system.

Checking of over-speed tripping devices, protection and interlocking system, start-up and shut-down sequence of auxiliary system.



Noise and vibration level measurement.

Manual and automatic synchronization.

Generator Protection relay testing.

Checking of loading capability.

Load rejection and governor tests.

Preliminary testing of start-up times.

More specifically, functional tests shall be undertaken to demonstrate that key features of the design operate satisfactorily, in particular those associated with plant safety. Functional tests shall include, but need not be limited to:

a. Test and Start-up of Auxiliaries

All auxiliaries shall be tested to verify that they can be operated safely, that their performance is up to the design specifications, and that all protective devices, mechanical as well as electrical, are functioning effectively and at their correct settings. Interlocks which prevent start-up under dangerous conditions, the operation of pressure relief devices, over temperature devices, and over current devices are especially important. Automatic start-up of stand-by auxiliaries upon the loss of running auxiliaries are also required to be tested.

b. Control System

Automatic control systems shall be tested for correct functioning, although it is anticipated that the final trimming of the controls needs to be done at a later stage.

c. Synchronizing Checks

Before the machines are permitted to operate in parallel with other machines, tests shall be performed to ensure that it is safe to do so. These tests shall be witnessed by APSCL/BPDB/PGCB and APSCL/BPDB/PGCB shall be satisfied that all the instruments associated with the synchronizing operation are functioning correctly.

d. Electrical Protective Devices

All electrical protective systems, circuits, devices, and instruments shall be tested on site to prove operation and stability, as well as the compliance of the actual relays and current transformers with the manufacturer’s published information. APSCL shall be entitled to receive from the Contractor full documentation of these tests before accepting any system as operational. This documentation for electrical protection devices will be used as a basis for the system acceptance by APSCL.

e. Mechanical Protective Devices

Tests on over-speed trip and other mechanical protective devices for turbine and HRSG shall be conducted to prove the effectiveness of their operation. The speed governor shall be capable of operating over its range with the droop being adjustable between 4% and 6%.

f. Stability

The automatic voltage regulator (AVR) of the generator shall be checked for proper and stable operation over zero to maximum load at the specified power factor. The HRSG shall be checked for its ability to maintain the steam flow, pressure, and temperature required within the specified load range.



The tests shall demonstrate that the Facility is able to operate at rated voltage, frequency, and specified range of power factors.

The Facility and each unit shall be capable of operation in a stable condition at twenty five percent (25%) of gross rated capacity.

g. Full-Load Rejection Test and Step-Load Change Rejection Test

The Facility shall be able to sustain a full-load rejection and guaranteed step-load change without over speeding to cause the operation of the turbine over speed protection devices. The Facility shall also demonstrate the capability of withstanding sudden loss of demand of ten percent (10%) of gross rated output from any load over the range of forty to one hundred percent (40% to 100%). During any of these tests the Facility must not trip and must otherwise remain in a safe condition.

h. Any other tests required to demonstrate compliance with requirements of the Grid System and, if then in effect, the Grid Code.

15.3.3.3 Reliability Run

Following the satisfactory completion of the start-up and trial operation, the Contractor shall commence the reliability run that will consist of two parts:

Continuous Reliability Test

The Contractor shall be responsible for undertaking a continuous reliability test of the Facilities, including all auxiliaries and controls for the Plant. The Contractor shall operate the units at various loads as specified by the Employer after synchronising the system.

The continuous reliability test shall start on the specified date and shall last for one hundred sixty eight (168) Hours including seventy two (72) hours of continuous operation at MCR load during which time the unit and auxiliaries will operate continuously, uninterrupted without adjustment or repair to the satisfaction of the Employer at all loads up to and including the maximum loads.

Should any failure or interruption occur in the operation of the unit due to faulty design, materials or workmanship under the Contract but not otherwise, sufficient to interrupt the commercial operation of the unit, the continuous reliability test period of one hundred sixty eight (168) hours including seventy two (72) hours of continuous operation at MCR load shall recommence after the Contractor has remedied the cause of the defect.

Cycling Operation, Shutdown and Start-up

On the completion of continuous operation for one hundred sixty eight (168) hours on all automatic and supervisory controls, the Employer will instruct cycling operation, shutdown and start-up during the next seven (7) days.

15.3.4 Commissioning - Performance and Operational Acceptance Tests

15.3.4.1 General

The Start-up Guarantee Tests and the Performance Guarantee Tests (output, heat rate and environmental) shall together constitute the Commissioning Guarantee Tests referred to in General Conditions of Contract Sub-Clause 25. The Performance Guarantee Tests may be conducted during the reliability run. The Noise Test and the Environmental Tests may be undertaken in conjunction with the Performance Test. However, the emission tests shall be performed at the same time as the Performance Tests. The Performance Tests



shall be undertaken with operable and calibrated CEMS (Continuous Emissions Monitoring System) equipment which will be provided by the Contractor for testing purposes. Failure of the temporary CEMS will invalidate a Performance Test.

15.3.4.2 Start-up Guarantee Tests

The CCGT unit shall be started from the cold, warm or hot condition and shall then be shut down. The time elapsed from start initiation to attaining base load for combined cycle mode shall be recorded and compared with the guaranteed maximum start times provided by the Bidder.

15.3.4.3 Performance Guarantee Tests

General

The Contractor shall carry out performance tests to demonstrate that the plant complies with the contractual performance guarantees.

Power output and heat rate of the power plant shall be as defined in Bidding Document Volume 3 Forms, Section 2 and determined in accordance with the appropriate performance test standards such as:

a. PTC 6: Steam Turbines

b. PTC 4.4: Gas Turbine Heat Recovery Steam Generators

c. PTC 22: Gas Turbine Power Plants

d. PTC 46: Overall Plant Performance,

e. PTC 22: For operation

f. ASME PTC 46: For combined cycle operation.

The Contractor shall formulate the testing procedure for carrying out performance tests on the plant with regard to identifying scope of tests, references and definitions, guiding principles, preparation for tests, operating conditions for tests, instruments and methods of measurements, computation of results and test report. The precise nature of the tests together with testing procedures and programmes, accuracy of measurement etc shall be provided by the Contractor and shall be agreed between Contractor and Employer at an early stage in the contract programme but no later than 120 days prior to the expected simple cycle completion date. It is expected that the procedure will include the installation of power totalising meters at the high side of the step up transformers with the net output being determined by direct measurements of the net power output.

The duration of the performance test shall be 6 (six) hours.

Whilst the performance tests shall be carried out on the plant as a whole and not individual plant items, this shall not preclude the Contractor from the responsibility of undertaking the necessary demonstration performance tests on major individual items of plant to either verify satisfactory operation or identify any shortfall in individual plant performance.

Conditions of Test

During the contractual guarantee performance test the plant mode of operation shall be:

The plant shall be operated at the guaranteed loads

All auxiliary equipment that is required for continuous plant operation including, but not limited to gas compressors, river water intake pumps, circulating water pumps, HVAC, etc. shall in operation during the test.



Variations exceeding steady state conditions shall invalidate the test run and shall be repeated

Emissions shall be maintained within guaranteed criterion, throughout the performance tests.

The facility shall be operated in a normal mode which is representative of a long term operating configuration with all equipment operating as designed and within specification and alarm limits consistent with good power generation industry practice. No normally operating systems should be taken out of service including by-passing or suppressing of alarms unless specifically allowed in the test procedure.

Correction Curves

The test results recorded during the Performance Test shall be corrected, as applicable, to those which would have been achieved had the test been carried out at the guarantee basis conditions by using agreed correction curves. Formulas describing the correction curves shall also be provided.

These correction curves and formulas shall be limited to:

Correction for ambient temperature

Correction for humidity

Correction for barometric pressure

Correction for fuel calorific value and C/H ratio

Correction for power factor

Correction for grid frequency

Degradation.*

Net output degradation

Efficiency degradation

Correction for cooling water temperature.

The correction curves and formulae shall be provided in the Performance Test Procedure, and included with the Tender. The calibration certificates older than Twelve months from the date of test shall not be accepted.

*The performance guarantees for combined cycle operation shall make allowance for all fired hours and starts during commissioning. No correction for degradation will be allowed for fired hours and starts by Contractor during commissioning and testing of the Plant in combined cycle. The number of fired hours and starts and correction for degradation due to Plant commercial operation in combined cycle shall be agreed by the Employer and the Contractor prior to commencement of the combined cycle performance test.

Metering

The net Combined Cycle Gas Turbine plant output (as defined in Volume 3 Section 2) for the performance guarantee tests shall be measured using tariff meters. The meters shall be capable of displaying kilowatt hours for the duration of the test. All auxiliary loads that would normally be operating at the Guarantee Point shall be in operation during the tests. A list of auxiliary loads shall be provided with the bid and in the Test Procedure. The fuel meters provided shall be of suitable accuracy for performance testing according to the appropriate test code.



Procedures for measurement of other parameters such as ambient temperature, barometric pressure, relative humidity etc. shall be fully detailed in the Performance Test Procedure. No test-measuring orifice plates, nozzles or venturi tubes shall be installed without the approval of, and witnessed by the Employer.

Fuel Analysis

The Contractor shall ensure that an analysis of the fuel before, during and after the test is performed and that this data shall be submitted with other relevant test information in the Final Test Report.

The Contractor shall supply the necessary apparatus for taking and containing the fuel samples. Three separate samples shall be taken at each of the three sampling periods. One of each set of three samples shall be analyzed by an independent authority and the costs of these analyses shall be borne by the Contractor. One sample of each set of three shall be properly labeled and handed over to the Employer. One set shall be maintained by the Employer in case of dispute of the results.

Instrument Test Measurement Uncertainty

Just prior to the Performance Test every test instrument required for the measurement of test data shall be checked and recalibrated if necessary.

All instruments used in the Performance Test shall be of the standard, quality, and accuracy suitable for performance testing as detailed in the Performance Test Procedure.

A pre-test uncertainty analysis shall be carried out to confirm that the selected instruments and test design shall provide test uncertainties on corrected heat rate and power no greater than those given in the Test Code. A post-test uncertainty analysis shall also be carried out to validate the test, the results of which shall be included in the test report. The details and results of the pre-test and uncertainty analyses shall be included in the test procedure.

Instruments for critical measurements shall be calibrated using standard reference sources or shall have been previously calibrated and certified by independent nationally or internationally approved calibration authorities.

Calibration certificates shall be provided for the test instruments at the time of test. The costs involved in preparation of calibration certificates will be to the Contractor's account.

The corrected test result of net heat rate and net power output shall have no measurement uncertainty correction applied. The Contractor's guaranteed performance figures shall be quoted accordingly.

Performance Tolerances

The corrected test result of net heat rate and net power output shall have no tolerance correction applied. The Contractor's guaranteed performance figures shall be quoted accordingly.

Performance Testing Procedure

A Performance Test Procedure document shall be prepared by the Contractor for approval by the Employer and shall be submitted to the Employer in its final form not less than six months prior to the programmed Test Date.

The Performance Test Procedure shall be a full and detailed procedure based on ASME PTC 22 or ISO 2314 and in accordance with the procedures, scope and details contained in this Specification.



Curves and correction factors to be used for the Performance Tests shall be based on the equipment bidder's standard correction curves. The curves used shall be those included in the Contract.

The Performance Testing Procedure shall be in accordance with the pre-Contract Performance Test Procedure and will be mutually agreed between the Contractor and the Employer at an early stage in the contract programme. The Performance Test Procedure shall include all calculations showing the use of all correction curves and factors for each parameter. The Performance Tests shall be witnessed by the Employer and the evaluated test results submitted to the Employer for approval. The format for the Performance Testing Procedure will generally be as follows:

Scope of tests

Guiding principles

Test dates and timetable

Preparation for tests

Method of tests

Plant mode of operation

Testing conditions

Operating conditions

Constancy of test conditions

Maximum permissible variations in plant operating conditions

Duration of tests

Instruments and method of measurement

Define plant test parameters

List Of test instruments

Calibration of test instruments (class of accuracy)

Instrument test measurement uncertainty

Commercial panel instruments

Computation of test results

Data acquisition system log sheets

Commercial panel instrument log sheets

Frequency of readings

Observers and labour

Specified requirements and guarantees

Fuel calculations

Correction curves and data

Net output correction curves

Heat rate correction curves

Instrument list and diagram of test measuring points

Diagram of electrical test measuring equipment

Instrumentation for electrical output

Current and voltage transformers.



Environmental Performance Guarantee Tests

During the output and heat rate performance tests and the reliability test, the Contractor shall undertake witnessed noise level tests to prove that the plant meets all relevant noise requirements.

Measurement of noise levels at the site boundaries shall be measured in accordance with the approach defined in ISO 6190:1999 “Acoustics - measurement of sound pressure levels of gas turbine installations for evaluating environmental noise - survey method”.

Prior to testing, a measure shall be made of the background noise levels without the power plant operating. Measurements shall preferably be made at night in a period of low background noise levels from other sources and minimum off-site vehicle movements.

The measurement equipment shall comply with ANSI S1.4 precision standards. The test method shall be in accordance with BS 4142:1007 or equivalent.

For work area noise acceptance tests, equivalent continuous levels shall be obtained at a minimum distance of 1 m from the surface of equipment, acoustic enclosures, or room boundaries.

The results of the tests shall be fully reported together with operating conditions of the equipment, meteorological conditions, noise measurements, instrument locations and instrument details.

Any increase in noise levels above that allowed in the Contract shall be investigated and should these be shown to be because of noise emanating from new plant, then the Contractor shall remedy the source of the emission at his own cost by the installation of sound attenuation measures. Repeat tests shall then be carried out to demonstrate that the remedial works have been successful in eliminating the noise problem.

15.3.5 Civil Inspections and Testing

A programme for testing soils during earthwork and when underground utilities

and foundations are installed shall be carried out. The minimum moisture and

density testing requirements for structural fill shall be one test per 75 m3 at least

one test under each foundation greater than 1.5 m2.

In-place representative field density tests shall be performed, preferably at the

frequencies specified below in accordance with ASTM D 1557. The following

frequencies shall be increased in areas where apparent difficulties exist:

Fill Class Testing Area Cubic Metres per Test

A Structural Foundations 250 (or 160 m2 of each lift or once per work shift, whichever is more frequent)

B Backfill Surrounding Structures

(Same as Class A)

B Roads, Shoulders, and Parking Lots

650

C General Backfill 1800

If a compacted area fails to meet the specified compaction requirements, two

additional tests shall be performed for that area. If the results of either of the two



additional tests-prove unsatisfactory, the area shall undergo additional compaction

and testing until test results meet the minimum compaction requirements.

Records of inspection and testing of soils to ensure compliance with design

assumptions shall be turned over to the Employer and shall comply with good

engineering and construction practices as well as the requirements of the local

authority regarding notification and inspection. If pile supported foundations are to

be used, the Contractor shall conduct a pile load test program. The trial pile-

testing programme shall be submitted to the Employer for review at least two

weeks before the start of the pile testing.

Testing and inspections of structures shall be in accordance with the Bangladesh

National Building Code or equivalent and other licensing requirements.

Concrete test cylinder sets shall be taken at the minimum rate of one set per day

but not less than once for each 150 m3 for slabs, foundations, or walls. Concrete

test cylinder sets for paving shall be taken at the minimum rate of 1 set per day

but not less than once for each 150 m3, nor less than once for every 500 m2. As a

minimum, one set of cylinders shall be taken for each equipment foundation, with

exception that one set of cylinders may be made for each concrete truck load

where multiple small foundations are poured from a single load. Test and

sampling procedures shall be in accordance with the appropriate ASTM standards

or equivalent. Copies of test data shall be provided to the Employer.

The Contractor shall utilise a system to validate type and grade of high-strength

bolts by sampling and metallurgical testing. A testing programme of high-strength

bolts and nuts shall be conducted by the Contractor to ensure that each bolt

shipment meets the appropriate ASTM standards or equivalent for dimensional

tolerances and material quality.

All structural welds shall be subject to inspection in accordance with weld quality

requirements provided in AWS D1.1. Critical welds shall be inspected as required,

and all other welds shall be subject to random NDT.

15.3.6 Field Inspections and Tests on Switchgear and Equipment

The following site tests shall be performed by the Contractor.

15.3.6.1 Protection, Control, Alarm, Measurement and Indication Equipment

Wiring

Insulation resistance test using 500 V Megger shall be carried out on all AC and DC protection, control, and alarm and indication circuit.

The insulation of all circuits shall be checked before proceeding with other tests and it is also essential that all AC wiring is correctly connected relay contacts, auxiliary contacts, etc., being closed, as necessary, to verify this. Checks shall be made on cable glands, cable jointing, fuse or circuit breaker and small panel items, such as indicating lamps. Static equipment which may be damaged by the application of test voltage shall have the appropriate terminals short circuited. Inter relay, inter unit and cubicle wiring carried out at the Site shall be checked to the appropriate circuit and/or wiring diagram.

Where it is found necessary during pre-commissioning work to effect site modifications to the secondary wiring, site copies of the appropriate schematic and wiring diagrams shall be suitably marked as agreed with the Employer before the circuit is commissioned.

Loop resistance measurements shall be made on all current transformer circuits. Separate values are required for current transformer circuits.



Mechanical Check

All relays shall be examined to ensure that they are in proper working condition and correctly adjusted, correctly labeled, and the relay case, cover, glass and gaskets are in good order and properly fitting.

Secondary Injection

Secondary injection shall be carried out on all AC instruments and relays, using voltage and current of sinusoidal waveform and rated power frequency.

15.3.6.2 Current Transformer Magnetizing Tests

The magnetization characteristic of all current transformers shall be checked at the minimum of two points to identify the current transformers with reference to the manufacturer's estimated design curve, and to determine the suitability of the current transformer for its intended duty. It may be noted that it is not normally necessary to check the characteristic up to the knee-point for this purpose. Special measures may have to be taken to ensure that the core is fully de-magnetized before commencing the test.

Primary Injection

Primary current injection tests shall be carried out by the Contractor. The primary injection methods employed for a particular installation shall therefore be agreed with the Employer.

Tests shall be carried out as follows:-

Local primary injection to establish the ratio and polarity of current transformers of similar ratio.

Overall primary injection to prove correct inter-connections between the current transformer groups and associated relays.

Fault setting tests to establish, where practicable, the value of current necessary to produce operation of the relays. If not practicable, these tests are to be carried out by secondary injection applied at the wiring close to the current transformer.

15.3.6.3 DC Operations

Tests shall be carried out to prove the correctness of all DC polarities, the operating levels of DC relays and the correct functioning of DC relay schemes, selection and control switching, indicating and alarms.

15.3.6.4 On Load Tests

In view of the hazards inherent in these tests, they shall be carried out under the direct supervision of the Employer.

An operation and stability test shall be carried out for on load commissioning of unit type protection.

Test for restraint shall be carried out to prove the characteristics of protective systems with directional/differential characteristics.

On load checks shall be made after the protection gear has been placed in service to ensure that all connections and test links have been replaced and test leads removed, as well as to confirm the integrity of the current transformer circuits. Where necessary voltage readings shall be taken at the terminals on each relay and meters to ensure that loop connections between the relays and meters are complete. Special attention shall be paid to broken delta voltages and residual current circuits where zero voltage or current respectively may not be proof of the completeness of the circuit.



15.3.6.5 Transformers

Tests shall include but not limited to:

General mechanical checks.

Core and winding insulation tests.

Ratio and HV magnetization current tests.

Vector group check.

Motors overload protection tests.

Buchholz device tests.

Temperature instrument calibration and tests.

Operational tests on tap change equipment.

Dielectric strength tests of insulation oil.

The above tests shall be recorded on approved test sheets, two signed copies of which shall be forwarded to the Engineer immediately after a test or series of tests has been completed.

First Inspection

The First Inspections (combustion inspection), as specified in the Particular Conditions of Contract, shall be undertaken by the Contractor after the completion of the recommended hours of operation, but , in any case, before the expiry of the Defects Liability Period of twenty four (24) months. It shall be carried out according to a programme agreed between the Contractor and the Employer. It shall be undertaken by the Contractor and the costs of corrections, repairs and replacements made by him shall be entirely at the Contractor’s cost.

For the first inspection the Contractor will provide the supervisors with any required special tools and the Employer will provide labour, normal tools, and a crane with driver placed under the responsibility of the Contractor.

15.4 Government and Third Party Inspections

The Contractor must be fully conversant with the Government of Bangladesh inspection regulations and certification requirements. The Contractor shall be responsible, at its cost, for obtaining all necessary certificates and licenses to permit operation of the Facilities. The Contractor shall, at its cost, retain the services of a single Government of Bangladesh approved Third Party Agent who shall perform the required Government of Bangladesh certification for all Plant and Equipment.

Such Third Party Agent shall be approved by the Employer. The request for the Government of Bangladesh approval of this Third Party Agent shall be prepared by the Contractor on Employer’s letterhead and submitted to the Employer for approval and signing.

The Contractor is responsible for the arrangement and costs of transportation and lodging of all Third Party Agent(s) and Government of Bangladesh personnel, as required for all inspections and tests.



16. Definitions and General References

The following terms shall have the following meanings when used in this Agreement:

“Accepted Industry Practices” means those practices, methods, and acts engaged in or approved by a significant portion of the electric power industry during the relevant time period, which a prudent owner and/or engineer would, at a minimum, follow (or in exercise of reasonable judgment in light of the facts known at the time a decision is made, could have been expected to follow) in connection with operating and/or maintaining electric power generation facilities and equipment similar to the Combustion Turbine lawfully, reliably, safely, and in a manner consistent with good business practices.

“Balance of Plant” (BOP) means all plant equipment located on the site other than the combustion turbine, comprises the heat recovery steam generator (HRSG), the steam turbine, the electric generator(s), the synchronous clutch (if applicable), the boiler feed pumps, the fuel gas compressors, and the main step-up transformer(s).

“Calendar Year” means a period of time beginning on 01 January, 24:00 hours, and concluding on 31 December, 24:00 hours.

“Turnkey Work” shall mean design, engineering, manufacturing, inspection, testing, supply, delivery to site, construction, erection, testing and commissioning including all other works to complete the project for ready to operate.

“Combustion Turbine” (CT) means the combustion turbine supplied by the EPC vendor per the proposal and located at the Site. For the purposes of this project the Combustion Turbine is synonymous with Gas Turbine (GT).

“Combustor Inspection (CI) Scheduled Outage” or “Combustor Scheduled Outage” means the type of Scheduled Outage and its associated Services as described more fully in Section 16.6 and the Proposal Forms.

“Commercial Operation” means, with respect to the Combustion Turbine, that such Combustion Turbine (and its associated Generator and other BOP equipment) is operated or capable of being operated by the Employer (or any agent, contractor, lessee, assignee or affiliate of the Employer) at its requirement for continuous dispatched operation at between base load factors for the unit.

“Day” means a full calendar day, comprising the complete period beginning at 24:00 hours and ending at 24:00 hours.

“Equivalent Base Load Hours” (EBH) means the calculated result of equivalent base load hours determined in accordance with the combustion turbine OEM’s guidelines.

“Equivalent Starts” (ES) means the calculated result of equivalent starts determined in accordance with the combustion turbine OEM’s guidelines.

“Hot Gas Path Inspection (HGPI) Scheduled Outage” or “Hot Gas Path Scheduled Outage” means the type of Scheduled Outage and its associated services as described more fully in Section 16.2 (d) and the Proposal Forms.

“Major Combustion Inspection” has the meaning as described in Section 16.2 (c) and in the Proposal Forms.

“Major Overhaul Inspection” (MOI) has the meaning as described in Section 16.2 (e) and in the Proposal Forms.

“Major Scheduled Outage” means the type of scheduled outage and its associated services as described more fully in the Proposal Forms.

“Minor Combustion Inspection” has the meaning as described in Section 16.2 (b) and in the Proposal Forms.

“Miscellaneous Hardware” means miscellaneous hardware items that are required to remove and/or install the programme parts.

“Monitoring System” has the meaning set out in Section 5.

“Non-Programme Parts” means all parts and components of a combustion turbine (other than programme parts, miscellaneous hardware and all instrumentation, control devices and wiring maintained by the Employer); provided that such parts or components are located on or inside of the



applicable combustion turbine within the following boundaries: (a) from the Combustion Turbine side of the inlet bellmouth flange to and including (b) the Combustion Turbine side of the exhaust cylinder and (c) the Combustion Turbine side of all flanges and/or connections located directly on the Combustion Turbine proper.

“Original Equipment Manufacturer” (OEM) means the manufacturer of the Combustion Turbine.

“Employer” means APSCL and includes its permitted successors and assigns.

“Period” means, with respect to the Combustion Turbine, the interval from the start of one scheduled outage on such Combustion Turbine, and ending upon the start of the next scheduled outage of such Combustion Turbine.

“Programme Management Services” means all of the services to be provided by the LTSA Provider as described in Section 2 and identified in the Proposal Forms.

“Programme Part(s)” means and includes all (a) part(s) of the Combustion Turbine that are listed in the Proposal Forms.

“Running Inspection” (RI) means the analysis conducted during operation of the covered equipment as described in Section 16.2 (a).

“Scheduled Outage Services” means, with respect to the Combustion Turbine, the periodic inspection, testing, maintenance, repair, overhaul and/or replacement of programme parts and miscellaneous hardware of such Combustion Turbine as may be necessary as a result of wear and tear based upon the guidelines of the OEM and consistent with the Contractor’s Defect Liability obligations and includes without limitation performing the work scope described in Section 16.6 and the Proposal Forms.

“Scheduled Outage Technical Field Specialist Services” means all of the technical field specialist services to be provided by the Contractor hereunder during the applicable scheduled outage.

“Scheduled Outage TFA Services” means all of the TFA services to be provided by the Contractor hereunder during the applicable scheduled outage.

“Scheduled Outage” means a planned outage of a combustion turbine to perform the applicable scheduled outage services

Programme Parts, other parts, and Miscellaneous Hardware, in Employer’s possession and being stored by the Employer, then on site available to the Contractor’s Scheduled Outage personnel. The Scheduled Outage will end when the Contractor has released the Combustion Turbine to the Employer for turning gear operation by the Employer for operation.

“Serviceable” means, with respect to a programme part, that such programme part is suitable for operation in the Combustion Turbine until such programme part’s next scheduled outage.

“Services” means any and all services to be provided by the Contractor under this Contract

“Site” means the real property located in Ashuganj where the Combustion Turbine will be located.

“Sub-Contractor(s)” means any licensor, Sub-Contractor or supplier of any tier supplying material, equipment, labour, goods or services in connection with its obligations under this Contract.

“Unscheduled Outage” means any outage of the Combustion Turbine other than a scheduled outage.

16.1 Project Description

The Project shall consist of a combined cycle plant in 1:1:1 (single shaft without bypass stack) configuration with all BOP and site development included in the scope of the EPC Contractor. The primary power block for the plant will consist of:

One gas turbine, one HRSG and one steam turbine with associated generator and auxiliary equipment with a total net capacity between 400± 5% as measured at the high side of the step-up transformers at site reference conditions at (35°C, 1.013 bar, R.H. 98%).

The combined cycle Plant will be equipped and designed for prolonged combined cycle operation. The Plant will also include pumps, water treatment plant and circulating water system, unit step-up transformer(s), and high voltage (HV) underground/overhead cable for power evacuation. Provisions for firing with fuel oil will not be included. The gas turbines will not be equipped with inlet cooling. Duct firing for load enhancement will not be included.



16.2 Operating Regime

The unit is expected to operate as a base load unit in combined cycle operation for the majority of the time. Forced outages due to system stability are anticipated and a rapid return to service is a design consideration. Refer to Section 2 of this volume (Volume 2) for plant operating conditions.

a) Running Inspection

The running inspection is performed while the unit is operating. This inspection involves monitoring various engine operating parameters to identify changes from a new or clean/overhaul condition. Engine monitoring includes, but is not limited to:

Blade path temperatures, spreads, and trends

Exhaust temperatures

Disc cavity temperatures

Vibration levels and trends

Bearing temperatures and oil pressure

Compressor fouling

Combustor shell pressure.

b) Minor Combustor Inspection

The minor combustor inspection includes removal, cleaning, and inspection of the fuel nozzle assemblies, and the inspection of the interior surfaces of the combustors and transitions through the nozzle openings. On units that have man-way access, a crawl through should be performed. The inspection is to verify that the nozzles are clean, and free of debris and leaks; and that the combustor baskets and transitions are clean and free of distortions and distress.

c) Major Combustor Inspection

The major combustor inspection includes removal of all combustor and turbine end components that are accessible without performing a cover lift. These parts are thoroughly cleaned and inspected in accordance with the appropriate service bulletin information. Components that are not removable without a cover lift are inspected in place. Turbine Row 1 vanes are inspected at this time and repositioned to minimise wear resulting from combustion hot spots.

d) Hot Gas Path Inspection

The hot-path inspection includes a major combustor inspection, plus inspection of the remainder of the turbine hot-gas path. Access requires removal of the appropriate cylinder cover and blade rings. All blades and associated parts are removed from the rotor, cleaned, and inspected. Turbine disc blade root serrations are also cleaned and inspected. Vanes and ring segments are removed from the blade ring as required for cleaning and inspection; and inter stage vane seals and baffles are inspected before disassembly.

e) Major Overhaul Inspection

The major outage inspection is the most comprehensive inspection carried out on the Combustion Turbine. It includes a hot-path inspection plus the lifting of the inlet, compressor, compressor combustor cylinder, and torque tube housing covers. Compressor diaphragms are removed, cleaned, and inspected. Compressor blades and discs are cleaned and inspected in place. Compressor and turbine bearings and bearing seals are also inspected. The rotor may be removed or inspected in place.



17. SPARES


The Contractor shall guarantee that all spare parts shall be available during the operational life of the plant.

The list of OEM recommended spare parts shall consist of spare parts in accordance with the manufacturer's maintenance guidelines and shall be based on experience and expected life time of the recommended spare parts concerned. The spares provided shall include all necessary spares for the gas turbine generating set as well as necessary spares for all the ancillary and auxiliary systems supplied under the Contract. During the Defect Liability period of 24 months, the Contractor shall supply all necessary equipment, spare parts, materials/ consumables including normal wear and tear spares etc. at his own cost and whether it is listed or not in their list. In preparation of the lists the tenderer have to consider plant factor as 85%.

The Contractor shall submit a full inventory requirement of essential spare parts inclusive of OEM Part No. with consumables such as greases, air & oil filters, chemicals, cleaning agents and lube oil that shall be necessary for maintenance procedures of the Gas Turbine Generator unit and any other plant equipment inclusive of any emergency usage that may be required during the course of Plant Operation during the 24 months Defect Liability. The Contractor shall also submit the Manufacturer’s recommendation letter of spare parts.

In addition of the above Defect Liability period Spares & consumables, the Contractor shall supply spare & consumables for schedule inspections of GT during equivalent 24,000 operating hours.

Bidders shall have to submit GT manufacturer’s guideline for schedule inspection interval, details list of spares & consumables for each type Schedule inspection from GT manufacturer along with GT manufacturer’s covering letter. Otherwise, tender may not be considered for further evaluation.

These spare and consumables will be used only at the time of scheduled inspections of GT during Defect Liability period and after Defect Liability period. These spares and consumables cannot be used against Defect Liability claim or as wear and tear spares for installed GT components.

The cost of each item shall be priced as per mentioned in volume 1 of 3 delivery to the Employer's storage at site. The Contractor shall furnish with the bid proposal an itemised list of priced spares, the total of which shall be included into the total Contract Price.

The Bidder shall state in their proposal a guaranteed delivery schedule for all recommended and mandatory spares.

All spares to be supplied shall be strictly interchangeable with the parts for which they are intended to be replaced and shall be packaged suitable for the storage period under the climatic conditions specified for the Site. Each spare shall be marked clearly or labelled on the outside of its packing with its description and purpose and when more than one, spare is packed in a single case or other container a general description of the contents shall be shown on the outside of such case or container and a detailed list shall be enclosed within the case. All cases, containers and other packages shall be marked suitable and numbered for purpose of identification.

All such cases, containers or other packages are liable to be opened and witnessed for such examination as Employer may require by the Contractor. All such openings and subsequent repackaging shall be totally at the expense of the Contractor. All parts shall be packaged in containers, labelled for identification and suitably packed and inhibited to prevent deterioration due climatic conditions and subsequent handling.

17.2 Mandatory Spares

The Contractor is to supply the mandatory spares as listed in the Price Schedules in Volume 1 of the Bidding Document. The Contractor shall provide in the Contract for all spare parts and consumables required during the Contract period including the Defect Liability period whether it is listed in price schedule. It is the Contractor’s responsibility to ensure that there



is an adequate supply of consumable items and spare parts available on site to fulfil the contractual requirements.

In addition of the above Defect Liability period Spares & consumables, the Contractor shall supply spare & consumables for schedule inspections of GT during equivalent 24,000 operating hours.

17.3 Recommended Spares

In addition to the contractual spare parts the Contractor shall provide before issuance of the Operational Acceptance Certificate as part of the Contract a complete list of all Spare Parts based on the experience and according to the selected design and operation for a further period of three (3) years. The spare parts proposed shall be itemized with individual prices and delivery schedules for each item.


17.4.1 Spares

The Contractor shall include in the scope of supply for all spare part requirements

considered essential and as advised by the OEM’s for the Defect Liability period

operation a total of two (2) years effective from the Commercial Operation date.

In addition of the above Defect Liability period Spares & consumables, the

Contractor shall supply spare & consumables for schedule inspections of GT

during equivalent 24,000 operating hours.

Any spare parts required prior to Operational Acceptance Certificate being issued

shall be replaced at no cost to the Employer.

The proposed spare parts by the Contractor shall be in the form of an itemised

inventory and individually priced to the conclusion of a lump sum price. The

Contractor shall use for this purpose Price Schedule.

The above inventory shall be reviewed and clarification sort from the Contractor if

required and shall be subject approval by the Employer.

17.4.2 Logistics and Acceptance of Spares

It shall be in the interests of the Contractor to schedule all logistics and storage of

spare parts prior to hot commissioning of the Power Plant to avoid post erection

issues and delays.

All spare parts shall be inspected and witnessed when opened by Employer along

with the OEM representative's presence. On completion of witness and inspection

of parts all packaging shall be replaced as per original delivery state. Any special

storage requirements shall be identified and actioned by the Contractor, i.e.

instrumentation and electrical equipment.

Any spare parts procured and delivered for use by the Contractor under the

contract shall be deemed fit for purpose and they shall be guaranteed to be free

from manufacturing defects and upon any failure occurring within the Defect

Liability period shall be replaced at no cost to the Employer.

The individual spare parts must be labelled with an identification number, easily

legible from the outside. The Contractor shall follow a system of designating and

tagging each and every spare part for ease of store keeping. The final

consolidated spare parts list shall bear sufficient tagging particulars as required for

convenient identification of the spare part -without undue loss of time.

When the final spare parts inventory is complete the Contractor shall present to

the Employer five hard copies and two soft copies of said inventory.



The Contractor is required to provide a Material Management System such as

Systems, Applications and Products in Data Processing (SAP) or similar. The

Contractor shall also provide the training the Employer's personnel for the use of

this software material management system.

17.4.3 Long Term Availability of Spares

The Contractor shall guarantee the long term availability of all spares to the

Employer for the full life of the equipment covered under the Contract. The

Contractor shall guarantee that before going out of production of spare parts of the

equipment covered under the Contract, the Contractor shall give the Employer a

minimum of twelve months advance notice so that the Employer may request a

bulk consignment of required spares, if the Employer so desires. The same

provision shall also be applicable to the Sub-Contractor. In case of any

discontinuance of any manufacture of any spares by the Contractor or his Sub-

Contractor, the Contractor shall provide the Employer with two years advance

notice and the issuance of full manufacturing drawings, material specification and

technical information required by the Employer for the purpose of the ability to

manufacture such items.

Further, in case of discontinuance of supply of the spares by the Contractor or his

Sub-Contractor, the Contractor shall provide the Employer with complete

information to allow for replacement of such spares with other equivalent makes, if

so required by the Employer.

The Contractor shall provide the Employer with a "directory" of his Subcontractor

giving the addresses and other particulars of his Subcontractor. The Employer, if

so desired, shall have the right to procure the spares directly from the Sub-

Contractor.

17.4.4 Tools

The Contractor shall supply within this Contract all necessary maintenance and

inspection tools including special tools required for the disassembly, assembly,

maintenance inclusive but not limited to, alignment tools for all rotating equipment,

rotor removal equipment, flexible borescope inspection equipment or videoscope,

torque wrenches capable of meeting all torque tightening requirements.

The workshop should comprise all equipment and tools suitable for all

maintenance activities including but not limited to spanner sets, socket sets,

wrenches, precision taps & dies, slings, wire ropes, power / air operated hand

tools including impact wrenches, masonry and metal drill bit sets various sizes,

chain hoists various sizes, portable electrical / electronic instruments (covered by

the Test Bench Section 14.11.10).

Tools shall be of a suitable brand, new and unused and shall be stored in the

correct manner and appropriate locations.

All Precision and Special Tools shall be required to be accompanied with a

Certified Calibration document for twelve months The Bidder shall allow for all

tools in the Volume 2 Price Schedules. The Contractor shall furnish a list of tools

to the Employer for approval. All tools not listed in the inventory list and found to

be necessary for maintenance of the works shall be deemed to be included in the

Contract price.”

17.5 Storage of Spare Parts

All spare parts supplied as part of this Contract shall be suitably protected and packed in cases or crates suitable for long-term indoor or outdoor storage on the site or in a warehouse without deterioration of the contents. The method of protection and packing to be employed shall be inspected and approved by the Employer.



17.5.1 Locking Devices (Permit to Work)

During commissioning and outages the Permit to Work system shall require

padlocks or other approved locking devices for, but not limited to circuit-breakers,

isolating devices, and control switches, valves, marshalling kiosks, cubicles,

screened enclosures, shall be supplied under this Contract.

All padlocks and other locks shall be provided with three identical keys with

engraved or durable identification label. All padlocks shall have three master keys

and shall not be able to be opened or unlocked with any other key under this

Contract. Locks shall be in suites provided with master-key facilities. Each key

shall be attached to an individual durable identification label. Keys and locks shall

be impressed with the manufacturer’s serial number. Wall mounting cabinets

suitable for the accommodation of padlocks and keys while not in use shall be

provided and mounted in approved positions and shall be suitably labelled.

The turbine water washing system shall include lockable valves. All isolating

valves on the gas fuel and diesel systems shall be lockable. The firefighting water

system shall also have valve lock out capabilities. In addition, the Contractor shall

advise and recommend all lockable equipment based on the Contractor's

experience.

17.5.2 Packing Lists

A complete description and fully itemised inventory shall be prepared of the

contents of each packing case and placed inside the case. Where appropriate,

drawings showing the erection markings of the items concerned shall be placed

inside the case. In addition, a separate copy of the packing inventory contained

within a waterproof envelope shall be placed inside a metal holder securely fixed

to a protected part of the exterior of each case.

17.5.3 Gas Turbine Generator

Having completed final factory tests and prior to shipment the GTG shall be

packaged appropriately as per OEM Procedure and a copy of which shall be

issued prior to shipment and the opportunity shall be given to the Employer to

witness this procedure at no cost to the Employer.

17.5.4 Receipt and Storage

All items, packing cases, containers and packages received at Site shall be

recorded against the shipping schedule and immediately inspected for signs of

damage. All signs of damage shall be investigated and the extent and nature of

the damage recorded. The contents of each packing case, container or package

shall be checked against the contents list and any discrepancies noted.

Photographic evidence would be advised. All special packaging shall remain intact

until the last moment, however if it is necessary to access or remove special

packaging then it shall be replaced as it was prior to removal.

Each item shall be carefully unpacked and checked for physical damage and/or

damage to the corrosion protection. All such damage shall be recorded both in

document form and photographic evidence and the necessary actions or

procedures shall be completed. No item shall be accepted for storage on site until

all required inspections, witnessing, approvals have been signed and cleared.

The Employer shall be informed of all received items and given appropriate time to

witness any opening, etc.

It is emphasised in the respect of any damage which may affect the life or function

of the component will require a full report and procedure for the proposed

refurbishment or complete replacement of the component concerned.



The following measures are to be taken to protect the equipment from the effects

of inclement weather:

Covered storage is to be provided for all electrical, instrumentation, valves ad small items including special climate controlled areas for some items

All equipment shall be stored on wooden pallets or wooden sleepers and not on the ground

A suitable fence is to be provided around the storage compound.

All items stored at Site are to be inspected regularly and adequate recourse of

inspections, cores on protection and any rectification carried out are to be kept. All

such records and the items in store will be subject to periodic audit and inspection

by the Employer who may require additional work to be done to ether restore the

condition of an item or to ensure that deterioration does not occur.

The cost of all recording, inspection and rectification shall be borne by the

Contractor who shall also be responsible for any necessary insurance claims

against shippers and/or other parties in respect of the damage to or loss of any

item or component.

On withdrawal from store, each item or component shall be prepared for erection

by removal of temporary shipping and site storage protection. Immediately prior to

erection an inspection shall be carried out to ensure that all such protection has

been properly and completely removed as necessary, unless the protection is to

be used for additional protection during erection. All such protection must be

removed prior to commissioning the plant unless it is specifically approved by the

Employer that they can be removed during testing and/or commissioning without

detriment to the plant or associated plant and equipment. All descents and vapour

phase inhibitors must be removed prior to erection even though semi-completed

systems and/or vessels may subsequently require re-protection by similar means

to prevent deterioration during erection and standing prior to commissioning.



18. ENVIRONMENTAL

18.1 General Introduction

The key design criteria that were used in the development of the Ashuganj CCGT power plant design are summarized below, and follow the 2008 World Bank Guidelines and the Environmental Conservation Act, 1995 and the Environmental Conservation Rules (ECR), 1997 of Bangladesh.

18.2 Information

This section provides excerpts from key environmental documents for information and reference only. The final environmental requirements shall be the most stringent of the limits indicated in all applicable environmental standards to the Ashuganj CCGT power plant, and as indicated below and finalised in the project’s final Environmental Impact Assessment (EIA) and approved permit.

The Ashuganj CCGT shall comply with both the national environmental standards, as well as, the standards established by the World Bank.

For complete sets of the above referenced standards, refer to the following publications:

The Environment Conservation Rules, 1997, Government of the People’s Republic of Bangladesh, Ministry of Environment and Forest, Date: August 1997

Thermal Power: Guidelines for New Plants, Effective July 1998, Pollution Prevention and Abatement Handbook, The World Bank Group

Pollution Prevention and Abatement Handbook, Toward Cleaner Production, The World Bank Group, 1999

Performance Standards on Social and Environmental Sustainability, International Finance Corporation / World Bank Group, April 30, 2006

Environmental, Health, and Safety (EHS) Guidelines General EHS Guidelines, International Finance Corporation / World Bank Group, April 30, 2007

Asian Development Bank (ADB) Safeguard Policy Statement-June 2009. And Mitigation Measures for Construction prepared by Safeguards Unit, Central & West Asia Department, Asian Development Bank (ADB) which includes (vegetation removal, erosion and sediment control, air quality, water quality, noise & vibration, waste management, Oil, Grease & Fuel management, closing of borrow pits and site closure etc.)

Further, excerpts from the applicable standards follow in Section 18.4 for information only. The Contractor is responsible for ensuring the design(s) complies with all the applicable standards.

18.3 General Environmental Requirements and Permit Compliance

The Ashuganj CCGT shall be designed by the Contractor and constructed to comply with the requirements of the EIA and the 2008 WB Guidelines, the Environmental Conservation Act, 1995 and the Environmental Conservation Rules, 1997 that are in effect, before the time of the EPC contractor’s contract signing.

In Bangladesh, the Department of Environment (DoE) is the government agency responsible for environmental planning, management, and monitoring according to the Environmental Conservation Rules (ECR), 1997 issued under the Ministry of Environment and Forest (MoEF). According to Schedule 1 of the ECR, the Project falls under the Red Category classification. Obtaining environmental clearance from the DoE for projects in the Red Category involves three steps. The first step is to obtain a Local Clearance Certificate if required and an Environmental Clearance Certificate (Form #3) to permit preconstruction and construction activities. The second step is to submit the Environmental Impact Assessment (EIA) report, along with the Layout Plan, Time Schedule and a detail design of the effluent treatment plant (ETP) within three months of receipt of the Site Clearance Certificate and obtain approval of DoE. After temporary environmental clearance from DoE has been received, the Employer may precede with importing of ETP equipment for construction of the plant. As per the terms of the clearance, the Employer can proceed with the installation of ETP and procurement of a Contractor for design and construction of the



plant within 60 days after the Environmental Clearance Certificate is issued. Upon final approval the Employer may proceed with importing of equipment for construction of the power plant.

18.4 Environmental Limits and Permit Compliance

The Contractor's design of the Ashuganj CCGT shall meet all statutory environmental regulations which shall be adhered to during the operational phase of the Project. The final plant design and operation shall comply with the final EIA report and the environmental permit. The Contractor shall cooperate with the Employer in providing inputs, as needed, for completion of the EIA report and permit application.

18.4.1 Air Emissions

The air emissions from the Ashuganj CCGT are the gaseous products of

combustion and particulate matter (solids from combustion are low as the fuel is

natural gas). The pollutant of concern with firing natural gas is nitrogen oxides

(NOx). The typical chemical composition of the natural gas as given does not

contain sulphur; therefore, sulphur dioxide (SO2) emission is not produced and the

need for flue gas desulphurization is not relevant. The Ashuganj CCGT is to

comply with stack emissions standards and the ambient air quality guidelines of

the 2008 World Bank Guidelines and the Environmental Conservation Rules, 1997

and appropriate DOE schedules.

The 2008 WB Guidelines limit for NOx are 51 mg/Nm3 (25 ppm) dry at 15%

excess oxygen and PM limits are not applicable to natural gas fired turbines at all

loads, Presently the WB does not limit CO and CO2. In Bangladesh, the natural

gas contains a significant portion of carbon, which reacts with oxygen to produce

CO2 and heat.

18.4.2 Ambient Air Quality

Excerpts from the applicable standards follow, for information only. The Contractor

is responsible for ensuring the design complies with all the applicable standards.

Table 19 provides the ambient air quality standards applicable to the Ashuganj

CCGT.

Emissions of particulate matter are very low because of natural gas firing. The

Contractor shall perform an ambient air quality study for stack emissions design,

and is responsible for verifying the actual ground level concentration calculation

analysis at the site. Further, the Contractor is responsible for ensuring the design

criteria complies with all the applicable standards.

Table 19: Applicable Ambient Air Quality Standards

Pollutant Averaging

Period 2008 WBG (µg/m3)

DOE (µg/m3)

PM 24 hours N/A -

1 year N/A 500

NO2 1 hour 200 -

1 year 40 100

18.4.3 Noise Level

The Contractor is responsible for verifying the current GoB-DoE noise category for

the site and determining the appropriate design criteria to meet the controlling

standards. Permissible noise levels at Project boundary as per 2008 WB and

GoB-DoE ECR guidelines are indicated in Table 20.



Table 20: Permissible Noise Levels

Land Use

2008 WB Sound Level Limits, dB(A) (hourly Leq)

DOE Sound Level Limits, dB(A) (hourly Leq)

Day Time

07:00-22:00

Night Time

22:00-07:00

Day Time

06:00-21:00

Night Time

21:00-06:00

Sensitive Areas (e.g., schools)

N/A N/A 45 35

Residential Areas 55 45 50 40

Mixed-Use Areas (predominantly residential areas mixed with commercial and industrial)

N/A N/A 60 50

Commercial Areas

70 70 70 60

Industrial Areas 70 70 75 70

The Contractor is to be aware that mitigation measures are to be incorporated in

the design of the Project where it is determined that noise emissions could result

in an impact on the adjacent receptors. The Contractor shall comply with the GoB-

DoE strict noise provisions when designing the Project mitigation measures.

According to World Bank Noise Criteria, noise from all sources shall be reduced

such that the total noise level when the facility is operational under any conditions

from minimum to maximum and with all auxiliaries in use does not exceed 70

dB(A) daytime and 70 dB(A) night time, at the site boundary. The Contractor shall

ensure meeting these requirements by incorporation appropriate noise mitigation

measures in its design.

18.5 Effluent Discharge

Effluent discharges shall not exceed the discharge limits for industrial/power plant effluents specified by Bangladesh or the World Bank guidelines, whichever are more stringent, as such discharge limits are in effect thirty (30) Days prior to the Bid Date. The Bangladesh guidelines for wastewater are provided in the Environment Conservation Rule 1997. The effluent discharge quality requirements are summarized in Table 21 below:

Table 21: The Effluent Discharge Limits for Thermal Power Plant

Parameter Maximum value

PH 6-9

Total Suspended Solids (TSS) 50 mg/l

Oil and grease 10 mg/l

Total residual chlorine 0.2 mg/l

Chromium (total) 0.5 mg/l

Copper 0.5 mg/l

Iron 1.0 mg/l



Parameter Maximum value

Zinc 1.0 mg/l

Lead 0.5 mg/l

Cadmium 0.1 mg/l

Mercury 0.005 mg/l

Arsenic 0.5 mg/l

Temperature increase at edge of the mixing zone

Site specific requirement to be established by EA. Elevated

temperature areas should be minimized

Regardless of the dilution of the aqueous environment, the temperature of the effluent discharged must not exceed 40°C in winter and 45°C in summer.

Table 22: Indicative Values for Treated Sanitary Sewage Discharges

Pollutants Units 2000 WB Guideline Value

GoB-DoE2

PH 6.5 – 8.5

BOD mg/l 10 or less

COD mg/l

DO mg/l 5 or more

Total Nitrogen mg/l

Total Phosphorus mg/l

Oil and Grease mg/l

Total Suspended Solids mg/l

Total Coliform Bacteria MPN/100 1,000 or less

1) MPN = Most Probable Number

2) GoB – DoE Water Used for Irrigation

18.5.1 Sanitary - Domestic Wastewater

Plant Sanitary wastewater from the anticipated 130 plant member staff shall be

collected and treated within a septic tank on the project site and shall comply with

the 2008 WB standards for effluent water presented in Tables 33 and 34. The

Contractor shall ensure that the discharge treated domestic wastewater is

compliant with current GoB-DoE standards. The treated sewage water or sanitary

waste water will be finally released to another ground septic tank. Treated sewage

water is strictly prohibited to be released to neighboring river, canal or any surface

water body. Treatment of all wastewater must be consistent with the standards

and measures in the EHS guidelines on wastewater and ambient water quality.

Septic systems should only be used for treatment of sanitary sewage, and are

unsuitable for process wastewater treatment.



18.5.2 Plant Wastewater

The Contractor shall provide treatment of all plant liquid wastes in compliance with

the GoB-DoE environmental standards requirements, prior to discharge. Such

plant liquid wastes shall include, but are not limited to:

Demineralizer waste

Oily water and chemical area drains

Sanitary waste

HRSG blow down.

The Contractor shall provide adequate sanitary facilities during the Project

construction and operations. The oily waste stream from the Ashuganj Project

shall be kept to a reasonable minimum and should be removed from the collection

of rainwater from areas that are not at risk of contamination by oil.

All plant process wastewater and all industrial wastewater effluents shall be

collected and treated by chemical neutralization, physical, chemical, and biological

treatment methods to comply with the effluent discharge limit criteria set forth in

the GoB-DoE’s Environmental Conservation Rules, 1997 Schedule 12 and

appropriate DoE schedules, and will also conform to the requirements of the

General EHS Guidelines for environmental wastewater treatment operations

presented in Tables 33 and 34.

The Contractor shall formulate and provide as part of the plant’s quality assurance

(QA) programme a system to monitor the quantity and quality of the treated plant

wastewater. The programme shall provide for the submission of monthly reports

summarizing the previous month’s results of the plant wastewater treatment

programme.

18.6 Solid Wastes

The proposed Ashuganj Project may generate small quantities of solids and unit process wastes during the construction of the plant and its operational phases. The staff working at the plant and the plant’s water/wastewater treatment processes will produce some solid wastes such as paper, packaging materials and food wastes, and process sludge from the water treatment facilities, etc. All such solid waste would be non-toxic in nature and may not require any special disposal requirements. The Contractor is to provide for these materials and they should be transported to a designated off-site landfill area for final disposal in an environmentally sound manner during plant construction and commissioning. The landfill methods shall comply with the GoB-DoE’s Environmental Conservation Rules, 1997 Schedule 12 and appropriate DoE schedules, and will also conform to the requirements of the General EHS Guidelines.

The Contractor shall provide for the disposal method and means for the recovered oil from the plant equipment that will be captured and sent to a recycler for reprocessing or to a processor for fuel application in a brick kiln.

18.7 River Water Temperature

The Contractor is to of a river greater than 3°C of the ambient temperature at the edge of a scientifically established mixing zone from the plant’s outfall discharge. GoB-DoE guidelines state that ambient river temperatures should not exceed 40°C during the summer and 45°C during the winter. There will be no increase in the temperature of the thermal discharge above the existing discharge temperature, and no increase above 3 degrees C of the upstream background become knowledgeable and comply with the current GoB-DoE environmental standards for plant water guidelines for Thermal Power Plants, cooling water discharge shall not cause an increase in the ambient temperature at the edge of the mixing zone in both winter and summer.

There will be no increase in the temperature of the thermal discharge above the existing discharge temperature, and no increase above 3 degrees C of the upstream background temperature at the edge of the mixing zone in both winter and summer,



18.7.1 Mitigation Measures

The Contractor’s design and construction of the water system for the Ashuganj

CCGT plant shall ensure that no contamination or waste is carried into the

Meghna River and that the river water will remain free from any sort of negative

impact originating from the power plant’s processes and the power plant site.

18.8 Environmental Monitoring

The following environmental issues should be monitored, according to EMP:

NOx emissions

PM ( SPM, PM2.5, PM10)

Noise

Plant treated wastewaters

Discharge water quality and temperature change.

The Contractor shall also provide a continuous emission monitoring system (CEMS) for NOx, O2, CO, CO2, SOx measurements of flue gases. The Contractor shall provide sampling ports on the plant stack for periodic and continuous air emissions monitoring. These ports will allow the monitoring of exhaust stack emissions by portable Flue gas analyzer.

Monitoring for noise and water quality is able to be carried out by the Contractor at the source or point of discharge.

A NOx ground level concentrations calculation was performed with a proposed 50 m stack height and indicated that concentrations may be above the acceptable limit. In addition, for high load power station operations the potential for exceedances may exist. This situation is considered a potential environmental problem and the Contractor may use these values for design; however it is required and the responsibility of the Contractor to conduct their own study to ensure that the Project is properly designed and is compliant with 2008 WB Standards and GoB-DoE Standards.

18.9 Environmental Management Plan

18.9.1 General Introduction

By their very presence, power plant projects have the potential of creating

environmental impacts during both construction and operation, particularly in

terms of air emissions, noise pollution, and discharge of liquid wastes. Energy

projects can also have some positive effects, particularly in terms of socio-

economic benefits. The Environmental Management Plan (EMP) is related to the

implementation of the measures prescribed in the EIA to reduce the adverse

impacts to acceptable levels and to enhance the beneficial effects. The objectives

of the EIA cannot be achieved unless the mitigation and benefit enhancement

measures, identified in the EIA, are observed properly. For the Ashuganj CCGT

project, all the measures will be said to be successful if they comply with the

Environmental Quality Standards (EQS) as specified in the Bangladesh-DoE

Environmental Conservation Rules of 1997. The general objectives of the EMP for

this project are as follows:

Implementation of the mitigation measures to reduce or eliminate negative impacts

Implementation of enhancement activities in order to maximize positive impacts

Identifying monitoring requirements and monitoring indicators.

The site EMP will be used to demonstrate that the Ashuganj CCGT project is operated with the minimum impact. The EMP presents the project information and examines the following:

Work plans and schedules



Resources necessary for implementation

Emergency procedures

Training requirements.

The EPC Contractor has to follow strictly the EMP suggested in EIA report that is approved by Asian Development Bank (ADB) and published in ADB’ website both for construction and operational phase. The plant designs have to comply all the environmental requirements.

18.9.2 Work Plans and Schedules

18.9.2.1 Air Quality Management

During plant construction, dust is generated from construction activities and the movement of transport vehicles. Construction Management shall attempt to minimise dust generation during the construction works; water shall be spread on exposed surfaces regularly during the dry season to keep the soil wet, thereby minimising dust generation.

Guaranteed emission levels for the plant at full-load capacity will be used in the design to predict the expected atmospheric emissions from the power plant, once it is operating. These levels are based on the temperature and excess oxygen concentrations prevalent within the combustion chamber.

Emission monitoring will form part of the plant operation procedure. During operation, stack emissions will be continuously monitored using fully automated gas analysis equipment (CEMS) for NOx, SOx, CO2, CO, O2 & SPM. The EPC contractor will provide proper emission monitoring on behalf of the Employer. Oxides of nitrogen and sulphur and particulate matter will be monitored.

Oxides of Nitrogen

Flue gases will be analysed for NOx. The data will be continuously recorded over a 24-hour period and reported monthly in terms of concentrations (hourly average and 24-hour average) and tonnages (monthly and year-to-date). Continuous monitoring of combustion emissions will be conducted for the operational life of the plant.

Oxides of Sulphur

Typically the sulphur content of natural gas being supplied by BGDCL is very low, almost nonexistent, leading to a negligible or no discharge of SO2 into the environment. Stack sampling of the gas turbine is proposed for measuring SOx bi-monthly and upon request for the operational life of the plant.

Particulate

Natural gas does not produce any significant concentration of suspended particulate matter (SPM) in the exhaust. Any particulate in the exhaust gas is likely to be dust drawn in through the air intakes. Proper maintenance of the filters on the air intake will prevent this problem if it should occur and will be carried out as part of the maintenance schedule. Quarterly stack sampling of the GT is proposed for monitoring the concentration of SPM in the flue gas.

18.9.2.2 Water Quality Management

Make up water will be withdrawn from the Meghna River during the entire period of project life and discharged back to the river with consideration to minimize wastage. The volume of wastewater discharged from the power plant will consist of boiler wash water,



boiler blow down, jacket water and other occasional releases. It will be passed to a treatment facility for treatment prior to river discharge to maintain GoB-DoE standard effluent quality.

The discharge of oily water shall be prevented by the plant’s treatment system, through which all the process wastewater discharge will be conveyed, treated, and sampled before release to the Meghna River. Any oil leakage from the tanks shall be transferred to the waste oil tanks. Surface water runoff shall be collected by the site drainage system and passed into the oily water treatment system before discharge to the sewer. Correct labelling of drains, operator training, and monitoring of effluent shall also be maintained.

To minimize waste, treated and cleaned water shall be reused (recycled) as much as possible within the power plant. Water that cannot be reused shall be discharged via an existing sewerage system and returned to surface water after treatment.

The effluent discharged from the neutralizing tank shall be continuously analyzed before release to confirm that it complies with 2008 World Bank and GoB-DoE standards regarding discharge limits.

Ground water samples, surface water samples and drinking water samples from existing drinking water system of APSCL and Jar/bottled mineral water if it is used shall be collected for routine analysis on a monthly and quarterly basis as determined by the environmental manager. If an incident occur, additional monitoring shall be conducted immediately following an incident such as a spillage in order to document that there has been no contamination of the ground water by accidental spillages, leakages, or as a result of surface-water run-off from the plant site.

18.9.2.3 Solid Waste Management

There shall be a plant solid waste management system in place to handle plant solid wastes and recovered solids from wastewater treatment. Solid wastes, insulation materials, oily rags, used fuel and lube oil filters shall be collected in leak-proof and fire-proof containers that shall be taken off the site for proper disposal. Sufficient number of labeled dustbin (for paper, plastic, glass, food/organic waste, toxic, hazardous waste etc.) of different color codes to segregate waste and spittoon shall be kept at various locations of the plant site. The solid waste, oily rags and filters shall be collected in a designated place and handled in a safe and sanitary disposal manner in an off-site landfill, or if deemed appropriate for recycling, incinerated in a brick kilns.

18.9.2.4 Fuel Management

The Ashuganj CCGT will be fired on natural gas. There is no need for a comprehensive fuel management plan as in the case of a dual-fuel plant firing heavy fuel oil and natural gas.

18.9.2.5 Lubricating Materials and Chemicals Management

Lube oil shall be brought in barrels and supplied to the system. A portion of the lube oil system will be cleaned by means of oil purifier/recycling and will be returned back into the system. The dirty oil from the system shall be collected in drums and sold to approve oil recyclers for further cleaning and recycling, or to brick kiln operators for final destruction as a kiln fuel.

18.9.2.6 Health and Safety Management

Construction and operational activities shall be carried out in accordance with relevant health and safety procedures. The



procedures of the 2008 World Bank Health and Safety Guidelines will be followed in this regard. These are briefly described below:

Workplace Air Quality

The workplace air quality shall follow the 2008 World Bank’s General Guidelines for

Environmental, Health, and Safety as furnished by the 2005 American Conference of Governmental Industrial Hygienists (ACGIH). Protective respiratory equipment shall be used in areas where employees are exposed to welding fumes, solvents, and other material present that exceed accepted standards or the World Bank - ACGIH threshold limits. In the control room there should be calibrated handheld hygrometer or system to monitor daily temperature and humidity of the control room. The store or warehouse will be dust free system and temperature and humidity will be controlled. Air-conditioning system will be must where needed. Smoke detector and Firefighting system with display of evacuation plan will be also present in the store. The safe walkway also should be marked in the store.

Workplace Noise

For limit noise levels within the allowable H&S Guideline limits, sound-insulated equipment and control rooms shall be employed in normal work areas. Plant equipment shall be well maintained to minimize noise levels; canopy system and turbine inlet silencers shall be used to reduce plant noise. Hearing protection shall be worn in areas where personnel are exposed to noise levels above 85 dB (A).

Electrocution Avoidance

To reduce the risk of electrocution, a formal permit-to-work system shall be operated. Strict procedures shall be followed for de-energizing and checking-securing electrical equipment with appropriate lock-out and tagging before maintenance work commences. Strict safety procedures must be implemented in the case of energized equipment, including constant supervision. Full training shall be provided on the respiratory revival techniques for electrocution of personnel.

Work in Confined Spaces

Confined spaces such as tanks, sumps, sewers, and excavations areas shall be tested for the presence of toxic, flammable, and/or explosive gases or vapours and for the lack of oxygen before entry. Employees shall use approved full-face mask air-supplied respirators in areas that may be contaminated or are potentially deficient in oxygen during any period of time they are in a confined area. Furthermore, adequate ventilation shall be provided before entry and during occupancy of confined spaces. Proper safety signage will be installed or displayed clearly in large and sufficient number.

General Health

In order to maintain sound health and safety for the plant personnel on a routine basis, the following general procedures will be undertaken. All kinds of Personal protective equipment (PPE) shall be provided for the use at the plant site. Personnel will use special footwear (steel toe shoes), safety glasses, ear plugs and/or muffs, masks, and clothing for work in areas with high dust levels or contaminated with hazardous materials. Safety equipment will be supplied where applicable, particularly in areas where exposure to elevated area, confined space, high temperature or chemicals is likely.



Shield guards and guard railings will be installed at all belts, pulleys, gears, and other moving parts

Elevated platforms and walkways, stairways, and ramps will be equipped with handrails, toe-plates, and non-slip surfaces

All electrical equipment will be grounded and well insulated and will conform to all applicable codes

Oil drum and greasy materials will not be in direct contact of soil and will be stored on Oil spillage tray for prevention of rust, soil and water contamination.

Two LED based Accident Free Record Boards (displaying accident free days number, date from, hours or time etc.) will be set by EPC Contractor at APSCL sites selected by HS&E manager of APSCL.

One or two safety corner will be established by EPC contractor during construction phase at APSCL main gate and other place selected by HS&E Manager of APSCL for plant visitors’ safety. The safety corner will be furnished with Fiber glass or by others with key and lock system with sufficient number of safety tools (PPE) like safety shoe, safety helmet, safety jacket, ear plug, ear muff, anti-dust musk etc. The safety corners will be smart in design to distribute or receive PPE in disciplined manner or walk way.

Both all kinds of filled and blank Gas cylinder used for welding and other activities will must be safely carried with trolley (both during construction and operational phase). Earth rolling of gas cylinder is strictly prohibited. All fabrication works will be done at safe site of the project.

Safe walkway will be marked by color in respective areas such as in Turbine hall, store etc.

Emergency eyewash and showers will be installed in sufficient number in areas containing corrosive material, chemical handling and relevant hazardous working areas.

Adequate and large safety signage and pictorial safety instructions will be clearly displayed or installed in respective areas and main gate of APSCL.

Safety Instruction brochures will be provided by Contractor according to guidance of HS&E Manager of APSCL.

Adequate number of first aid kits with required items shall be kept and maintained at various locations of the plant site.

Robust Drinking water purification system with Reverse osmosis or UV and hot and cold water system will be installed at various locations in adequate number at the plant site for operational phase. The filter accessories (RO/UV filter) for at least one year for plant operational period also should be provided. During construction phase this water purification system in few locations should be installed to provide safe drinking water for construction workers also.

Erect all kinds of relevant signs regarding safety, emergency & waste minimization in respective places of the project and main gate of APSCL.

Erect adequate number of large pictorial safety instructions in front and entry point of all buildings of 400 MW East project like all floor and entrance points of Turbine hall, Warehouse, control building, Waste Water treatment plant, and main entry point of this project etc.



During construction phase bamboo scaffolding will not be allowed at construction site. High quality and sufficient number of all kinds of Personal Protective Equipments (PPE) and new safety shoes with socks will be provided by EPC Contractor and ensure for all project related personnel of APSCL (Maximum 10 persons of APSCL, during commissioning the number may be more than 10 or as required), project related employees and construction workers of both EPC Contractors and Subcontractor. Subcontractor will provide all kinds of new Personal Protective Equipments (PPE) and new safety shoes with socks to their all employees and construction workers. It will be liability of EPC Contractor to ensure and monitor Subcontractor for these safety materials, otherwise EPC Contractor will have to provide these.

The EPC Contractor must have the Occupational Health and Safety policy that shall be submitted to HS&E Division of APSCL and APSCL authority to execute all kinds of project activities safely. The EPC Contractor will provide all kinds of treatment facilities and pay compensation according to Bangladesh Labor Law 2006 (amended in 2013) for any kind of human accident, injury, near miss or casualty and asset damage. The EPC Contractor will also ensure the compensation policy regarding these types of incident for Sub-contractor’s workers. It will be better for EPC Contractor to engage Sub-contractor if needed having this types of policy complying Bangladesh Labor Law. Otherwise EPC Contractor will provide treatment cost and pay the compensation for employee or worker of Sub-Contractor. Any kind of accident, near miss or injury will must be reported to APSCL’s HS&E Division and APSCL authority. The compensation policy for injury, accident or casualty of both EPC Contractor and Sub-Contractor will must be submitted to HS&E Division of APSCL and APSCL authority

The EPC Contractor shall be engaged a strong Health, safety and Environmental team during construction phase. Sufficient number of HS&E personnel of Subcontractor (One HS&E supervisor with two or three skilled person) for 40 workers will be must at the project site to provide safety to all, monitor and prevent any kind of accident. Daily Toolbox meeting or safety instruction meeting with project workers before starting of work is must during construction period.

There should be a furnished pantry beside or near control room with a freeze, micro oven, electric tea kettle, drinking water purifier with RO/UV system and hot/cold water dispenser, crockeries etc, smoke detector for plant operational phase.

There should be a prayer room beside or near the control room. A dress change room will also be near or beside control room with shoe rack and cabinet where employees can keep their safety shoes and other safety materials safely. Similar change room will also be in other place of the plant where employees will get this facility.

Use of asbestos as insulation material or in other scope of this project is absolutely forbidden

Record Keeping and Reporting

Records will be maintained of significant environmental matters, including monitoring data, accidents, training, daily toolbox meeting or safety instruction meeting with project workers with relevant



photographs, employees’ health checkup and occupational illnesses, spills, fires, traffic movement and other emergencies. The information will be reviewed and evaluated to improve the effectiveness of the environmental, health, and safety programme. Safe work permit and ID card of project related employees and workers of EPC contractor will be provided by EPC Contractor with the permission of Security and Discipline Division of APSCL and APSCL authority. EPC Contractor will also manage the safe work permit and ID card for workers of Subcontractor by themselves or own responsibility with the permission of Security and Discipline Division of APSCL. During construction period, a standard temporary medical center will be established for providing first aid and necessary treatment to project employees and all workers in the project site. Two LED based smart accident free record boards will be set at the designated sites (selected by HS&E Manager of APSCL) to display record of no injury or accident according to guideline of HS&E division of APSCL. A pictorial safety guideline or notification display board will also be established in the plant premise. Sufficient number of good sanitary toilets (1 for 50 workers) will be made at construction site for the use of workers during construction period.

Training

Training is essential to maintain the employees' health and safety. Both theoretical and practical training will be conducted for the employees on the hazards, precautions, and procedures for the safe storage, handling, and use of all potentially harmful materials. Training procedures will incorporate information from the Material Safety Data Sheets (MSDS) for potentially harmful materials. Training will include instruction on the following:

Use of personal protective equipment and first aid tools.

Prevention of accident

Emergency preparedness for fire, earthquake etc.

Safe chemical handling practices, waste minimization and safe disposal.

Safety awareness for no smoking in plant area and sensitive locations.

Location and proper use of emergency equipment, fire extinguishers etc.

Procedures for raising the alarm and notifying emergency response teams

Proper response actions for each foreseeable emergency situation

Proper usage of lock-out and safety tagging before work orders are issued.

Use of safe drinking water and sanitary toilets for safety and hygiene.

Emergency response spill plan and train personnel in its use.

Maintenance

Maintenance of the plant will be undertaken to minimize releases to the environment. Equipment specific maintenance will be carried out in accordance with the manufacturer's guidelines.

18.9.3 Compensatory Measures and Emergencies

18.9.3.1 Resources, Implementation and Training

Resources



In order for proper operation, maintenance, and environmental safety, the power plant operational workforce shall include a designated Environment Manager Specialist who will be a senior manager with executive responsibility for environmental matters.

Implementation

The Environment Manager Specialist shall be responsible for establishing that the environmental management plan is effective. He will be responsible for initiating any necessary programme improvements, via direct reporting to the Plant Manager.

Training

The Environmental Specialist shall be responsible for conducting following environmental training:

Environmental protection procedure

Promotion of environmental awareness

Specific training for staff working in sensitive areas

Updating staff on changes to environmental standards

Reporting to staff on plant environmental performance.

Training on installed environmental management technologies in the new plant.

18.9.3.2 Compensatory Measures

If any specific problem areas are identified in relation to the plant's environmental performance, mitigation measures will be adopted if deemed to be appropriate and included in the improvement plans for the plant. This enhancement in the environmental performance of the plant may arise through the normal operating performance of components of the plant or through changes in legislation.

18.9.3.3 Emergencies

To ameliorate any environmental risk, there shall be an Emergency Action Plan in place so that in case of an emergency, all plant personnel are aware of their responsibilities. Fire protection equipment and facilities will be available at suitable locations within the power plant and will include the following:

Fixed fire protection systems and automated sprinkler system.

Fire hydrants

Fire blankets

Alarm enunciators

Portable fire-fighting equipment /fire extinguishers will be wall mounted at standard height (28 inches- 30 inches) at all respective places.

Automatic fire vents

Fire compartments

Smoke detectors in all rooms and sensitive points with alarm system

PA and Buzzer system from control room to turbine hall and other risky and noisy areas

Display of Instructions of firefighting systems in respective points

Sufficient large LED Fire exit & Emergency exit signs

Spill prevention-response equipment. Safe and wide emergency exit way directed with large LED Sign



Sufficient number of emergency evacuation plan in large size should be displayed in sufficient places by wall mounted frame.

All the entry and exit points and also from corridor should be directed with Large LED signs.

Clear marking and direction of emergency assembly point and plant location.

Visualize all danger, safety and precaution signage and pictorial instructions in big size and sufficient number in all applicable points, confined space, stairways, lift points (if lift is used) and water intake and outfall areas.

Will set big and smart nameplate of all of the buildings, turbine hall, control room, warehouse etc. of the project. Mark all doors with standard and visible Push and Pull sign. Separate male and female toilets with sign.

Display all emergency numbers provided by APSCL in respective locations.

Will provide all kinds of new and relevant personal protective equipment (PPE) sufficiently for plant operation during operational phase.

The plant buildings and floors, turbine hall, store and project area will be covered by sufficient number (15-16 sets) of high resolution and visible range CCTV camera with warning signage.

The hose adjustment or attachment system with the main valve system of all the fire hydrant points (both indoor and outdoor) will be of coupling system (not screw or thread system) in the project facilities. The door system of all hydrant points and hose cabinet system will be of single door system with stainless steel built in door side lock and push system. EPC contractor will also provide a set of Master key by which all hose cabinets and hydrant points lock system can be opened with a single key for rapid and smooth operation during any emergency. The system will be compatible with present APSCL’s Fire system (Like from Unit 1 to Unit 5). The hydrant point and hose cabinet will be clearly marked with printed/painted letter.

Provide portable hose ventilation system for work in confined space during operational period

In case of an emergency, the Environmental Specialist will be available to provide special advice on the environmental aspects of the situation and its potential for pollution incidences. Advice will also be provided on the use of fire equipment on site and on the assembly sites for plant personnel not assigned to fire equipment response duty.

In order to provide 24-hour coverage, either the Environmental Specialist, or a member of staff appointed for those times not covered by the full-time Environment Manager Specialist, shall be accessible 24 hours a day.

18.10 Environmental Monitoring Programme

18.10.1 General

Environmental monitoring is the repetitive and systematic collection of data of

specific environmental parameters or resources over a time to achieve some

objectives. The term monitoring is defined in the context of environmental impact

assessment as an activity undertaken to provide specific information on the



characteristics and time. Environmental monitoring is a very useful tool for the

management of environment and natural resources and for the safe and efficient

operation of the plant. Environmental monitoring may be broadly classified into

baseline monitoring, impacts or effects monitoring, mitigation monitoring, and

compliance monitoring.

A crucial part of the environmental management plan is the monitoring scheme,

which is carried out during operation of the plant. This section considers the

environmental monitoring plan for the proposed power plant, together with the

institutional requirements for its successful execution. The monitoring programme

will be designed so that up-to-date records of the environmental parameters are

maintained during construction and operational period to allow timely intervention

in case of unacceptable environmental impacts.

18.10.2 Institutional Capability and Requirements

To help the project achieve its desired goals with minimal environmental risks, a

proper institutional setup will be established by the project environmental manager

so that close coordination is maintained between the Employer and GoB-DoE,

representing the national government agency with overall responsibility for

environmental monitoring.

The GoB-DoE will specify environmental guidelines regarding monitoring and

examine levels of compliance either on a regular or an ad-hoc basis. Therefore,

the project Employer shall maintain the appropriate staff, skills, tools, and

equipment in order to undertake a surveillance programme capable of satisfying

the GoB-DoE national monitoring regulatory requirements.

It shall be the responsibility of the Environment Manager Specialist to implement

the Site

Environmental Monitoring and Environmental Management Plan and to encourage

general environmental awareness at site. The Environment Manager Specialist

will be suitably trained and shall be responsible for the following actions:

Provide that all environmental protection procedures are followed

Co-ordinate environmental monitoring

Liaison with members of the public, local organizations, and governmental and nongovernmental organizations

Direct that all data on environmental aspects of plant operation be continuously updated and available in the form suitable for immediate inspection by authorized personnel

Monitor hazardous substances on-site to minimize that the possibility of accidental release

Promote on-site environmental awareness

Liaison with other industry

Promote reporting of near misses for environmental and safety incidents.

The EMP may also require the employment of a laboratory technician to analyze

air and water samples and report results to the Environment Manager Specialist.

The Contractor shall provide onsite laboratory facilities for carrying out all of the

required chemical analyses for proper monitoring.

18.11 Environmental Monitoring Plan

18.11.1 Parameters to be monitored

The plan will consist of on-site monitoring for the following parameters:

Air quality



Fuel quality

Stack emissions

Water quality (surface water, ground water, drinking water from existing drinking water system of APSCL and bottled/jar mineral water provided to project workers) and liquid discharges

Noise levels (external and internal to the plant)

Chemical wastes

Socio-economic characteristics

Public complaints.

Workers health

The monitoring plan’s goal is that the Ashuganj CCGT continually meets all

relevant DoE operating standards. The programme employed to carry out this

monitoring will employ standard internationally recognized and accepted

procedures. In addition to quantitative analysis, a number of qualitative monitoring

steps will also be included. Post-construction monitoring of the impacts on the

local community and economy will also be included within the monitoring

programme so that all the mitigating measures have been successfully undertaken.

The proposed detailed monitoring plan, including estimates, will be developed

during design phase of the project. Monitoring will track compliance with any

current and future established DoE standards.

18.11.2 Target Media and Monitoring Schedule

Atmospheric Emissions

Emissions from the proposed power plant will be maintained at a reasonably

constant level through combustion control and the homogeneous fuel quality of

natural gas. Table 23 summarises the scope and details of flue gas monitoring for

emissions from operation of the turbine(s).

Table 23: Flue Gas Monitoring

Monitoring Method

Air Pollutant

NO2 SO2 SPM PM2.5 PM10

Continuous monitoring by surrogate parameters

Yes Yes Yes Yes Yes

Annual stack test of one GRT operating on natural gas

Yes Yes Yes Yes Yes

To assess ambient air quality after plant commissioning, continuous air quality

monitoring will be carried out with the help of a suitable institution or monitoring

agency. Monitoring will be conducted for NOx, SOx, and SPM at sites and in the

surrounding area. Locations typically include at least three monitoring points within

the study area, including one at the expected point of maximum impact. An

additional monitoring point will be located within the existing plant boundary. This

information will provide the DoE with a better understanding of the ambient NOx,

SOx, and SPM.

Water Quality and Discharge

Water will be continuously taken from and returned to the Meghna River for the

plant’s water supply needs and cooling water system. The sources of wastewater

from the power plant will consist of oily water, boiler blow down, boiler wash water,

jacket water, and other occasional discharges. These shall be passed to a

chemical neutralizing tank for treatment. Water flow diversion system and screen



system will be required for safety and preservation of aquatic organisms & fishes

from inflow water at Water intake point area.

The effluent discharge from the neutralizing tanks shall be continuously analyzed

before release to document that it complies with GoB-DoE discharge limits (or as

they may be so revised). Table 24 presents the proposed monitoring plan for the

water discharged from the plant.

Table 24: Monitoring Plan for Water Discharge

Monitoring Method PH Temperature Total

Suspended

Oil and

Grease

Monthly monitoring

by instrument Yes Yes Yes Yes

Quarterly analysis

by sampling Yes Yes Yes Yes

Surface water samples shall be collected weekly for routine analysis. Additional

monitoring shall also be conducted immediately following an incident such as a

spillage in order to document that there has been no contamination of the ground

water by accidental spillages or leakages or as a result of surface-water run-off

from the site.

Noise

A noise survey within operational areas at the site boundary and at sensitive

receptors shall be undertaken before construction begins and during plant

operation. Additional monitoring may be required at various times in response to

public complaints, in order to verify that ambient noise level limits are reasonably

consistent with historical measurements and permissible limits.

Socio-Economic Characteristics

The project’s impact on the social and economic status of the stakeholders shall

be assessed. If the adverse impacts of the power plant are perceived to be

insignificant and public complaints attributed to the power plant are few, then the

required monitoring will be conducted semi-annually.

Public Complaints Procedure

Any complaints by the public that are lodged in writing shall be noted on a

complaint register. The register will include the name and address of the

complainant, including the time and date that the complaint is registered, and the

details of the complaint. The Environment Manager Specialist or other designated

representative shall then personally visit or telephone each complainant in order to

discuss the details of the complaint and to establish how the complaint can be

rectified in the interests of all concerned parties. EPC Contractor will keep

complain box as grievance mitigation measure and maintain a register in project

gate and main gate according to guideline of HS&E division of APSCL.

18.11.3 Reporting Procedures

There shall be a proper reporting system at the Ashuganj power plant site. The

Employer will need to delegate the responsibility for environmental issues to a



senior member of its existing staff. The Health, Safety and Environmental

Manager of EPC Contractor will submit the monthly and other scheduled

Environmental reports complying all the set parameters (According to ADB

Environmental Safeguard guideline, IFC Thermal Power Plant guideline and DoE,

Bangladesh guideline) to Project Director/APSCL authority and Manager (Health,

Safety and Environment) of APSCL.

Implementation of the Environmental Monitoring Plan will be the responsibility of

the appointed Environment Manager Specialist who will be responsible for

arranging and reporting the results of all emissions, ambient air quality, noise, and

water quality monitoring. The Environment Manager Specialist will also be

responsible for obtaining, reporting, and maintaining all environmental data

records and for the correct implementation of the public complaints and

emergency procedures. The project proponent shall also comply with the

requirement of the regulatory body, namely, GoB-DoE, in maintaining reporting

procedure.

The laboratory technician shall be responsible for conducting all in-house

analyses and for reporting all in-house analytical results direct to the Environment

Manager Specialist, who will in turn be responsible for compilation of all monitored

results and for informing the plant manager of any possible nonconformity.

There may be occasions where outside individuals or consultants are required for

specialist monitoring or training. The Environmental Specialist shall be responsible

for coordinating any monitoring conducted by outside individuals or consultants.

All monitoring results obtained by outside individuals or consultants shall be

reported directly to the Environment Manager Specialist.

It is the responsibility of the Environment Manager Specialist to check calibration

procedures and to verify the authenticity of the results.

The EPC Contractor has to follow the following Follow mitigation measures set out

in this EIA and the EHS Guidelines on Construction phase and has to ensure the

design to comply all environmental parameters during operational phase

according to EMP in EIA report approved by Asian Development Bank (ADB) that

is published in ADB’s website for this project.

Ambient air quality monitoring at sensitive receptors within the zone of maximum deposition. Notably the settlement and PDB high school and Hazi Jalil high schools to the west, plus the APSCL dormitory to the east and the local settlement to the south of the project. Identified sensitive receptors within 2-5km west of the project site must also be monitored.

Seasonal 24hr noise monitoring at nearest sensitive receptors (in absence of construction work)- Notably the settlement and PDB high school and Hazi Jalil high schools to the west, plus the APSCL dormitory to the east and the local settlement to the south of the project.

Daily monitoring of the existing discharge temperature at the point of discharge on all three outfall channels.

Seasonal monitoring of river water temperature 500m upstream and downstream of the discharge point (away from the influence of the outfall channel).

Detailed design for 400 MW CCPP (East) power plant to incorporate mitigation

measures set out in the EIA and the EHS General and Thermal Power Plant

Guidance.

Detailed design to demonstrate:

i. emission standard of 51mg/m3 (25ppm) NOx will be met through adoption of dry low NOx burner (catalytic removal will be retrofitted if necessary



following review of annual ambient air quality data) with dust filters on air intake to ensure no particulate or SO2 emission,

ii. noise level of 70dB can be achieved at the site boundary and that there will be no increase in background noise levels greater than 3dB at the nearest sensitive receptors,

iii. there will be no increase in the temperature of the thermal discharge above the existing discharge temperature, and no increase above 3 degrees C of the upstream background temperature at the edge of the mixing zone in both winter and summer,

iv. structural engineering meets the applicable seismic design standards for location of the power plant, and

v. H&S measures per the EHS onshore oil and gas development guidelines are incorporated, undertake quantitative risk assessment of gas-related elements to demonstrate there will be no increase in risk level at the nearest sensitive receptors from gas leak, fire or explosion.


this EIA and the EHS General and Thermal Power Plant Guidance to minimize

fish entrainment including reduction of maximum through-screen design intake

velocity to 0.5 ft/s.

Finalize IEE for associated facilities including grievance redress mechanism and

to address hazardous materials including SF6 and waste management.

Prepare Construction Environment Management Plan incorporating site waste

management plan and emergency response procedures, Construction Health and

Safety Plan incorporating emergency response procedures, and Construction

Traffic Management Plan.

Follow mitigation measures set out in this EIA and the EHS Guidelines on

Construction. Emissions must be within prescribed limits of National Ambient Air

Quality Standards.

Mitigation practices including:

appropriate sitting and maintenance of stockpiles of materials so as to minimize dust blow (seek to achieve a distance of at least 500m from nearest sensitive receptors);

minimizing drop heights for material transfer activities such as unloading of materials;

construction phase to begin with construction of access roads;

roads will be kept damp via a water browser;

provide wheel wash for all vehicles leaving the project site;

do not permit any open burning on the project site;

roads will be compacted and graveled if necessary;

site roads will be maintained in good order;

regulation of site access;

sheeting of lorries transporting construction materials and soil;

enforcement of vehicle speed limits on nonmetal roads to <10 km/h.

A continuous daily visual inspection by trained staff of the Contractor is needed.

Weekly monitoring and supervision by APSCL will be done to ensure the

implementation of good site management practices by all Contractors during

construction.

Measurements and analysis of different pollutants to be made on a continuous

basis (at least monthly) by a third party consultant and the report to be submitted

to the APSCL authority. Monitoring to be carried out on site and at the settlement

and PDB high school and Hazi Jalil high schools to the west, plus the APSCL

dormitory to the east and the local settlement to the south of the project.



River water quality must be within prescribed limits of the national ambient water

quality standards for classification as source of drinking water as it will be used to

provide potable water for the construction workers (for standards see

http://faolex.fao.org/docs/pdf/bgd19918.pdf).

Construction Method Statement to be produced by the Contractor;

coffer dam to be used during in-channel works to minimize downstream sediment release;

inlet structure construction in river should be undertaken outside the breeding season of fishes;

dredged areas limited to minimum area required;

disposal of dredged sediments to an agreed site;

all works will be made clearly visible using flags, beacons and/or signals;

bank area will be reinstated following construction.

Continuous daily visual Inspection by trained staff of the Contractor. Weekly

monitoring and supervision by APSCL will be done to ensure the implementation

of good site management practices by all Contractors during construction.

During dredging and in-river works sediment discharge and surface water quality

will be monitored (at least weekly) at three locations (upstream, adjacent to works

and downstream) by a third party consultant. During other times river water

sample should be collected monthly from three locations, 500m upstream and

downstream of works and at the works site-outfall, if preliminary monitoring

campaign shows strong variations in water quality additional locations may be

required.

no discharge of effluents into the river- all effluents shall be collected and removed off site for treatment by approved firms or disposed after proper treatment at site (records of effluent transfers to be maintained);

no discharge of surface water runoff direct into the river - development of a temporary site drainage plan which reduces flow velocity and sediment load by passing discharge through a sediment pond;

protection of temporary stockpiles of soil from erosion by using a reduced slope angle where practical, sheeting and by incorporating sediment traps in drainage ditches;

at least 100 m safe distance for stockpiles to water body to be achieved;

maintenance of well-kept construction site.

all fuel, oil and chemicals should be stored in bounded area 110% volume.

impermeable surface should be used for refueling

regular training of all workers in spill response

provision of spill equipment at easily accessible locations around the site.

Treatment of all wastewater must be consistent with the standards and measures

in the EHS guidelines on wastewater and ambient water quality. River water

sample should be collected monthly by a third party consultant from three

locations, 500m upstream and downstream of works and at the works site-outfall,

If preliminary monitoring campaign shows strong variations in water quality

additional locations may be required.

No employee should be exposed to a noise level greater than 85 dB (A) for a

duration of more than 8 hours per day without hearing protection. And no

unprotected ear should be exposed to a peak sound pressure level of more than

140 dB(C). The use of hearing protection should be enforced actively when the

equivalent sound level over 8 hours reaches 85 dB(A), the peak sound levels

reaches 140 dB(C), or the average maximum sound level reaches 110 dB(A).



Hearing protective devices provided should be capable of reducing sound levels at

the ear to at least 85dB (A).

Emissions at the site boundary and nearest sensitive receptors must be within

prescribed limits of the EHS Noise Guidelines.

Monitoring of 24-hr noise levels to be made on a continuous basis (at least

monthly) by a third party consultant at the site boundary and nearest sensitive

receptors and the report to be submitted to the APSCL authority. Monitoring to be

carried out on site and at the settlement and PDB high school and Hazi Jalil high

school to the west, plus the APSCL dormitory to the east and the local settlement

to the south of the project.

provision of noise barrier around the project site to reduce off-site noise levels; enforcement of vehicle speed limits;

strict controls of vehicle routing;

diesel engine construction equipment to be fitted with silencers;

limited noisy construction activities at night;

prohibition of light vehicle movements at night;

use of protective hearing equipment for workers.

Good site management practices will be observed to ensure that disturbance of habitats off-site are minimized.

Specific mitigation measures include restricting personnel and vehicles to within construction site boundaries, lay down areas and access roads.

development of effective site drainage systems designed to include allowance for climate change;

restriction of access only to construction site areas;

disposal of waste materials unsuitable for reuse on-site, (e.g. for landfilling) at appropriately licensed sites;

provision of oil and suspended solid interceptors;

management of excavations during construction to avoid the generation of drainage pathways to underlying aquifers;

provision of impermeable bases in operational areas to prevent absorption of spillages.

No septic tank will be installed within 500m of a deep or shallow tube well used by

the community for drinking water. Septic tank will be installed in well drained and

permeable soils well above high groundwater level and where sufficient soil

percolation exists for design wastewater loading rate. It will be properly designed

to prevent hazard to human health or contamination of land or water. Regular

maintenance required. No overflow of septic tank permitted. If monitoring of tube

wells identifies contamination (exceedance of national drinking water standards)

provide community users with an alternate source of drinking water.

Public access to the site must be restricted.

Ensure H&S measures per the EHS electric power and distribution guidelines and

EHS onshore oil and gas development guidelines are incorporated

Continuous daily visual inspection will be conducted by trained staff of the

Contractor to ensure the implementation of good management practices during

construction. Weekly inspection and supervision by APSCL will be done to ensure

the implementation of good site management practices by the Contractor during

construction. Quarterly monitoring of drinking water in tube wells within 1km of a

septic tank location by third party consultant to confirm that national drinking water

standards are met.

No forced or child labor (under age 18) to be employed. All employees to be legal.

Regular talks on communicable diseases including HIV to be held for all workers.



The Contractor will be responsible for relevant temporary water / toilet facilities

during construction and the need to provide appropriate services will be specified

in their contracts. Provide adequate supplies of drinking water that is compliant

with the national drinking water quality standards to all workers.

Provide adequate sanitation facilities as outlined in the EIA. Toilets and

bathrooms must be properly equipped including hand washing facilities with hot

water and with separate facilities for men and women.

Regular talks on sanitation to be held for all workers to encourage cleanliness.

Standard good practice measures will be implemented as follows:

adherence of abnormal load movements to prescribed routes, outside peak hours and advance publication of movements if required;

construction shifts will be staggered;

scheduling of traffic to avoid peak hours on local roads;

routing of transport to avoid residential areas;

provision of adequate signage and flagmen along transport route and at site entrance;

transportation of construction workers by contract bus. Ensure all roads and bridges used by construction traffic are maintained in at least their current state during construction with any damage immediately repaired.

Daily monitoring of traffic entering the site during morning & evening peaks to

ensure the implementation of good site management practices by trained staff of

the Contractor. Weekly inspection and supervision by APSCL will be done to

ensure the implementation of good site management practices by the Contractor

during construction. Quarterly monitoring of road and bridge condition by third

party consultant to ensure maintenance being kept up.

Good engineering design will incorporate the following mitigation measures:

drainage system designed to direct flood water from main plant areas into the river and direct potentially contaminated waters through the oil interceptor.

Good practice measures such as the following:

a. all waste taken off-site will be undertaken by a licensed Contractor and APSCL will audit disposal procedure;

b. collection and segregation of wastes and safe storage;

c. recording of consignments for disposal;

d. prior agreement of standards for storage, management and disposal with relevant authorities.

It is of highest importance that final disposal of wastes shall be strictly adhered to

environment friendly disposal Contract.

Regular H&S training will be conducted for all construction staff, including training

on good housekeeping, cleanup of debris and spills, and working in confined

spaces and at height. Measures include:

implementation of EHS procedures as a condition of contract of the Contractors and Sub-Contractors;

clear definition of the EHS roles and responsibilities for all construction companies and staff;

management, supervision, monitoring and record-keeping as set out in plant’s operational manual;

pre-construction and operation assessment of the EHS risks and hazards;



completion and implementation of Fire Safety Plan prior to commissioning any part of the plant;

provision of appropriate training on EHS issues for all workers;

provision of health and safety information;

regular inspection, review and recording of EHS performance;

appointment of site nurse and provision of free on-site medical care for all construction staff;

pest and vector control;

maintenance of a high standard of housekeeping at all times.

provision of first aid equipment at easily accessible locations around the

site

provision of a noise barrier around the project site to minimize off-site

noise levels.

Sanitary discharges to meet national wastewater treatment standards.

Good site management practices including the following will be implemented:

proper treatment of contaminated water or cooling water before discharge to natural water body.

no disposal of solid wastes into the discharge structure;

regular maintenance of site drainage system to ensure efficient operation;

all discharges will comply with local and World Bank guidelines.

i. all fuel, oil and chemicals should be stored in bunded area 110% volume

ii. regular training of all workers in spill response

iii. provision of spill equipment at easily accessible locations around the site

Daily inspection is required to ensure the implementation of EHS Policies, plans

and practices during construction. Record all fatalities, accidents and near misses

that occur during construction work and implement corrective action to ensure

such incidents are not repeated in future.



Table 25 presents the monitoring programme in a summarized form.

Table 25: Environmental Monitoring Plan

No. Monitoring

Item Process and Methodology Frequency Responsibility

1. Construction Dust (from at least four sampling points)

Sheeting of lorries carrying friable materials, damping exposed earthen surface, and control of vehicle movement with speed limit at 10 km/hr inside the plant area. Continuous spray of water is the mandatory at the construction site, roadway used for project activities and area of influenced during construction phase.

Daily

Contractor

2. Construction Noise (from at least four sampling points)

Major work to be undertaken during normal working hours. Nearby residents to be warned of any unusual noisy operation. Batching plant will be away from the plant site and locality. Fine-tuned equipment should be used. Cranes, forklifts, roof hoist, other heavy equipments, vehicles and their accessories must be fine-tuned and fit with conducting of regular fitness test. Faulty, old, black exhaust generating and unfit equipments are strictly forbidden at the construction site and plant premises. PPE will be used during noisy and all other construction activities.

Daily

Contractor

3. Air Quality Stack velocity and height to be designed to maintain air quality. Air quality monitoring (SOx, NOx, SPM) survey to be undertaken during plant operation.

Continuously w/24hr averaging. Annual stack test 3 yrs.

Contractor (During construction phase and Defect Liability period)/ Employer (after Defect

Liability period)

4. Fuel Quality Analysis by sampling Weekly and upon plant operator complaint


Liability period)

5. Stack Emission Dry low NOx control, NOx emissions monitoring

Continuously w/24 hr averaging.


Liability period)



No. Monitoring


6. Water and Liquid Discharge

Analysis by sampling (for oil and grease, pH, TDS and temperature). Cr, Cd, Pb, oil & grease in soil sample will be analyzed for once in 12 months. Asbestos test for soil and air will also be needed if required.

Continuously, before release

Contractor (During construction phase and Defect Liability period) / Employer (after Defect

Liability period)

7. Noise Level Plant to meet design values Ear muffs, ear plug to be provided for designated areas where Warning signs are appropriate for Noise monitoring.

Surveillance before first exposure, monitor at

regular intervals

Contractor (During construction phase and Defect Liability period)/

Employer (after Defect Liability period)

8. Chemical Waste Effluent from neutralizing tank to be analyzed by sampling

Before release following treatment


Liability period)

9. Socio- Economic

By periodic social survey Semi-Annual Contractor (During construction phase)/

Employer

10. Public Complaints

Complaint will be noted by maintaining register and providing complain box in project gate and main gate of APSCL.

As soon as complaint is

received

Contractor (During construction phase)/

Employer (During Operational period)

11. Terrestrial Ecology (from at least four sampling points)

Air quality to be monitored for NOx, SPM, PM2.5 and PM10.

Continuously w/24 hr

averaging


Employer (During Operational period)

12. Aquatic Ecology Effluent discharge to be monitored for pH, BOD, oil and grease, temperature and other applicable parameters as per IFC/World Bank and DoE, Bangladesh guidelines. Water diversification system and screen system will be required for safety and preservation of aquatic organisms & fishes from inflow water at Water intake point area.

Continuously


Employer (After Defect Liability period)

13. Plantation and beautification

Greenery layout, gardening and beautification will be done sufficiently at entry point of the project and whole project site by EPC Contractor own design. Plantation in plant premises and outside of plant will be done

During construction

phase

Contractor

(During construction phase)



No. Monitoring


during construction phase by instruction of HS&E division of APSCL. Gardening and beautification will be made in front of APSCL main gate/entrance area (both inside and outside) and other places required according to instruction of HS&E division of APSCL.

14. River water quality analysis (from at least four sampling

points)

River water quality for Temperature, DO, BOD5, COD, Oil & Grease, Total Cr, Cd, Pb will be analyzed monthly to check the influence of project activities.

During construction

phase

Contractor


15. Drinking water quality analysis (from at least four sampling

points)

Drinking water quality for pH, Ammonia, Nitrate, Phosphate, As, Fe, Mn, Total Coliform & Faecal Coliform will be analyzed monthly.

During construction

phase

Contractor


16. Ground water quality analysis (from at least four sampling

points)

Ground water quality for pH, TDS, Ammonia, Nitrate, Phosphate, As, Fe, Mn, Total Coliform & Faecal Coliform will be analyzed monthly.

During construction

phase

Contractor


17. Workers health Quarterly health check of employees with respect to EMF exposure and other occupational hazards.

Quarterly Contractor




19. DOCUMENTATION

19.1 General

19.1.1 Language

All documents, correspondence and submissions shall be in the English Language.

19.1.2 Control

The Contractor shall, for all work to be performed under the Contract, establish

and maintain a comprehensive computer-based document control system

ensuring that, at all phases of the work the identification, revision, status and

location of documentation is determined. The Contractor's system shall also

provide for all Subcontractor' and Bidders’ documents.

At the end of each reporting period the Contractor shall provide to the Employer a

complete hard and electronic record and electronic copies of all drawings,

submissions, documents and correspondence delivered in both hard and

electronic form during that reporting period.

19.1.3 Identification

The Contractor shall develop and maintain an identification system for all project

documentation for permanent inclusion in the Works which shall enable the

Contractor to control the documentation in the live phase of the project and enable

the Employer fully, efficiently and to the standards required by the Contract,

operate the Plant by providing ready access to the system. The Contractor shall

therefore develop a method to identify documents to their specific

process/pressurized system and any interfaces appertaining thereto. This

philosophy shall be maintained in the assembly of the required Engineering, Plant

Operations, Maintenance, spares and Quality Records.

The Contractor's adopted computer based system shall be transferable to

standard personal computers (IBM compatible) and transferred to the Employer at

the completion of the Works as part of the documentation handover.

Provision shall be made by the Contractor to provide full training in the use of the

identification system by the Plant operator in readiness for handover of the system.

19.1.4 Organization of Documentation

All documentation shall be organised in a logical manner and all contents shall be

properly indexed.

A revision status record sheet at the front of each document shall facilitate

recording of amendments in a logical manner. Revision indication and issue dates

shall also appear on each amended sheet. All submissions, except drawings, shall

be housed in durable loose-leaf folders suitable for the addition of amendment

data. The cover shall identify the contents, and carry the Contract reference

number.

19.1.5 Quantity

Four hard copies and one soft copy of all documents and drawings shall be

provided at all stages of the Contract. Document distribution will be advised.

19.1.6 Quality

Paper used for documentation shall be suitable for long term storage (minimum 80

gIm2). All drawings shall comply with the relevant standards.

All drawings shall be stored in electronic format in AutoCAD.



19.1.7 Size

With the exception of drawings and certain other forms such as certificates, all

other documents shall be size A4. The maximum sheet size for drawings shall be

size A1. Documents sized A0 are not acceptable.

Except in instances where the original drawing is size A4, drawings for inclusion

for technical manuals should be size A3, double folded to size A4, title visible with

the drawing folded and bound along the left-hand side. If drawings of size larger

than A3 are required to facilitate clarity they shall be folded and placed into plastic

wallets, with each wallet clearly identifying the enclosed drawing. The wallets shall

be secured in the manual cover and permit easy access to the enclosed drawing.

All documents greater than size A3 must be capable of reduction to size A3 with

no loss of symbol, and lettering legibility, etc. Such drawings shall also have a

minimum left-hand margin of 25 mm at size A3 to ensure that no information is

obscured by binding.

The Contractor shall provide electronically versions of all bidder documentation

and drawings.

19.1.8 Symbols

Symbols shall comply with relevant international standards for Construction

Drawing Practice Graphical Symbols for General Engineering and Electrical

Power, Telecommunications and Electronics Diagrams. This includes, but is not

limited to:

ISO 1000; The International System of Units (SI) and its Applications.

19.1.9 Units and Scale Ratios

All drawings shall be supplied in SI metric units using one of the following scales

1:1, 1:2, 1:5, 1:10, 1:25, 1:50, 1:100, 1:200, 1:500, 1: 1,000, or 2,500. Third angle

projection shall be used throughout. All drawings shall be provided with a scale

bar.

19.2 During Contract

19.2.1 Documentation Schedule

The Contractor shall provide a detailed schedule of documents to be produced

during the Contract in accordance with the Document Schedule for submission to

the Employer. The schedule shall indicate, by generic type, those supplied for

review and comment (specifications, procedures, etc.) and those for information.

Typical documentation to be provided shall include, but not be limited to, the

following:

Copy of topographical and soil investigation results and interpretation

List of design codes to be followed (include with Tender)

Detail of all loadings, both actual and assumed, incorporated into the designs. Where an interpretation of codes of practice is necessary, e.g. for wind and seismic loading, the assessment and conclusion shall be clearly stated

Material data to include strength of materials and source of manufacture of all structural elements (include details with Tender)

Calculations for all structural, civil, and building work

Drawings

Manufacturer's test certificates.

Equipment sizing calculations.

Design criteria and system descriptions



Hydraulic study, risk assessment, CW intake model study and other reports.

Control philosophy, control loops and protection systems.

O & M Manual

QA test reports, welding x-ray reports etc.

The schedule of documentation shall also indicate to the Employer those specific

design, safety and related elements required for third party verification and, where

possible, the proposed third party.

The sequence of submission of all drawings and calculations shall be such that all

information required for review shall be available. A letter of transmittal shall

accompany each submittal.

The Contractor shall allow at least twenty one calendar days, plus appropriate

transit time, for each review by the Employer unless otherwise stated in the

Contract.

Review of, comments on, approval of, or expression of satisfaction with the

Contractor's drawings or calculations by the Employer shall not relieve the

Contractor of any of its obligations to meet all the requirements of the Contract or

relieve the Contractor of the responsibility for the correctness of such drawings.

The Contractor shall make any changes that are necessary to make the work

conform to the provisions and intent of the Contract.

19.2.2 Calculations

The Contractor shall submit two copies of all Project calculations under

Contractor’s letterhead.

Such submittal shall be made not less than thirty calendar days prior to the time

that the materials represented by such calculations are needed for incorporation

into any work. Calculations shall be subject to the option of review by the

Employer and material dependent upon such calculations shall not be

incorporated into any work without any such review.

Calculations shall clearly identify the subject of the calculation and shall include

but not be limited to providing the following information:

Contractor’s name

Project name

Designer's name

Checker's name

Contract number

Name of the item

Assumption used for design purposes

Specification section reference

Codes used

Loadings used

Date of calculation

Calculation

Reference sources

Manufacturers' names and literature

Reference to the appropriate drawing.

Where necessary, Supplier Statements shall be obtained and provided by the

Contractor for all relevant plant.



All calculations shall be on A4 size paper and shall be bound in stiff-backed ring

binders. The covers shall show the Contractor's name, the Contract name, and the

title of the calculations, the date of submission and the revision letter of the

calculations. Electronically scanned copies of all calculations shall be provided.

All computer printouts shall be bound into an appropriate binder with a cover that

shall show the Contractor’s name, the Contract name, the title of the subject, the

date of submission and the revision letter of the printout.

Where the use of a computer and design software packages are proposed, details

shall be given in the Tender of the design programmes proposed, including any

certification of approval by independent authorities for the computer programs

proposed.

19.2.3 Construction Procurement Records

The Contractor shall generate records as required by the Contract and the Quality

Requirements, Quality Procedure and Quality Plan.

All records, including those generated by Subcontractor or suppliers, shall be

concisely compiled, indexed and uniquely identified with the Contract reference

number and where relevant, subcontract or order numbers. They shall be clearly

identifiable to the individual parts and assemblies to which they refer.

The Contractor shall ensure that all Site and Works documentation is maintained

and stored in accordance with the Quality Requirements, the Quality Procedures

and the Quality Plan.

For items of Plant or equipment that are being delivered to Site, the Contractor

shall ensure that all records required by the Employer pertaining to such

equipment arrive on Site with the plant or equipment. Such records shall include

reports and certification in respect of, for example, pressure containing

components together with all traceability records.

The compilation and storage of records during the Contract shall be controlled to

ensure adequate security, verification and traceability prior to Taking Over. The

storage conditions shall provide resistance to damage and deterioration.

Copies of all records generated during the course of the Contract by the

Contractor, its Subcontractor and suppliers shall be retained by the Contractor for

a minimum period of ten years.

These records shall be made available to the Employer on request. Before final

disposal by the Contractor at the end of this period, these records shall be offered

at no cost to the Employer.

The Contractor shall submit a monthly Drawing and Documentation Schedule for

review by the Employer and shall maintain the schedule throughout the Contract

to show the up-to-date status and revision of each document. The transfer of this

information should be achieved by electronic transfer (disk) from the Contractor’s

Central System.

The Contractor shall submit documents for review by the Employer in accordance

with the Documentation Schedule and the Quality Requirements, Quality

Procedures and Quality Programme. Review of, comments on, approval of, or

expression of satisfaction with any drawing, document or the Drawing

Documentation Schedule by the Employer shall not relieve the Contractor of any

of its obligations under the Contract.

Prior to Taking Over, final documentation shall be handed over to the Employer in

such numbers and formats as is laid down elsewhere in the Contract.



19.2.4 Welding Procedures

The Contractor shall submit copies of all weld procedures and supporting weld

procedure qualification data to the Employer for review not less than 30 days prior

to the commencement of welding. Unqualified weld procedures may be submitted

before this time for approval in principle.

Number of copies shall be as required in Clause 19.1.6

The Contractor shall include in the above submission, a register, weld map or

similar document showing the application of each weld procedure submitted.

The Contractor shall submit copies of heat treatment procedures for review not

less than 30 days prior to the commencement of welding, preferably with the weld

procedure submission.

The Contractor shall submit copies of non-destructive examination (NDE)

schedules for testing on all pressure equipment, including piping and pressure

retaining components. The schedule shall contain the following information, as a

minimum:

Weld identification or system

Description

Pressure and temperature applicable

Dimensions

Material specification(s)

Joint type

Reference drawings

Weld procedure reference

NDE method, percentage and sensitivity

Applicable acceptance code.

The NDE schedule may be in a form that incorporates the weld procedure and

heat treatment information above.


The Contractor shall develop and maintain a current certification schedule for all

items of plant and equipment requiring periodic inspection/testing in accordance

with the respective mandatory codes and applicable standards, e.g. pressure

vessels, rigging and lifting appliances, pressurized systems, etc. Procedures shall

be individually developed for each item, forming part of the certification manual

presented at Taking Over. Such procedures shall also be identified in accordance

with the project identification procedure.

The Contractor shall provide a ‘Written Scheme of Examinations’ for third party

design and inspection verification for all Pressure Vessels and Piping Systems to

be carried out by the Employer.

19.2.6 Erection Procedure

The Contractor shall submit copies of the erection procedure for all Plant,

equipment and systems to the Employer for information prior to such erection

being carried out on the Site.

19.2.7 Pre-Commissioning Procedures

The Contractor shall prepare detailed stand-alone pre-commissioning procedures

necessary to cover mechanical and electrical completion, testing and pre-

commissioning of equipment and systems to a state of readiness for start-up and

operation in accordance with the procedures, test details and criteria contained in



the Conditions of Contract and the Technical Specifications. The Contractor shall

review equipment systems and provide for specialist bidder personnel to assist as

required.

Pre-commissioning shall be carried out on a system by system basis. The

Contractor shall, in accordance with the procedures, test details and criteria

referred to above, prepare a separate procedure for each system to be pre-

commissioned, bound in an A4 size file. It is important that where Contractor

packages/equipment pre-commissioning procedures are written that all relevant

Contractor drawings and documentation are included in the relevant procedure file.

Each system pre-commissioning procedure shall contain:

Title and system number to which the procedure refers

Index

Status/approval signature sheet

Equipment test record sheets including pre-commissioning test records.

The Contractor shall submit each system commissioning procedures and all

documentation for review by the Employer not later than three months before the

commencement of pre commissioning of that system. Each system pre-

commissioning procedure shall contain all correction curves and tables necessary

for the pre-commissioning and testing of that system. Pre-Commissioning

procedure will be completed after continuous operation of the plant for 168 hours.

19.2.8 Commissioning

The Contractor shall submit copies of the Procedure for Commissioning to the

Employer for review not later than six months prior to the Commissioning.

19.3 Submission of Final Documentation

19.3.1 Timing of Final Documentation

All final documentation, not limited to those documents described below, shall be

delivered to the Employer in its final version not later than 90 days after Taking

Over of the Works.

19.3.2 Quality and Format

All final documentation which shall be used or referred to by the Employer's

operation and maintenance staff shall be in the English language.

The Contractor shall submit to the Employer, all drawings in master hard copy

format and electronic format. All scripted documents, A4 manuals, etc. shall be

provided in hard copy format from the master and electronic format.

All documents produced specifically for the project shall be in Microsoft Office

2007 format, i.e. Word, Excel and Access. Drawings shall be produced using

AutoCAD 2009.

Standard and reference documents not already available in electronic format shall

be converted to rasterized computer files in a standard world-wide compatible

format.

19.3.3 Storage at Site

The Contractor shall provide a permanent library of the hard copy master copies

within the permanent Site offices ensuring that the area is sufficiently protected

and equipped with viewing and printing facilities. The atmospheric storage

conditions within this facility shall be such as to prevent deterioration of the data.

The facility shall provide secure storage of the data.



The masters in electronic format shall be submitted to the Employer in CD ROM

read/writable format.

19.3.4 Hand-over

The Contractor shall progressively pass to the Employer final documentation for

the Works in accordance with the Documentation Schedule.

19.3.5 Types of Manuals

The Contractor shall provide the manuals listed below in accordance with the

Conditions of Contract.

The format of the data included shall be of two specific types; those documents

that apply to the construction and commissioning activities for a single system, e.g.

materials, tests, inspections, etc., and those not system specific, i.e. welder

certificates and procedures. The Contractor shall therefore produce the manual in

distinct parts per system or generic type.

For weld procedures, welder qualifications, NDT procedures, etc, the levels of

approval for each shall be scheduled and included as part of the index.

For all system related documents the Contractor shall include a system/book

index for the total submissions and inclusion within all volumes.

Commissioning Manual: This manual shall be developed from the individual

plant items and assembled by system in accordance with the plant start-

up/shutdown maintenance and operational philosophy.

The manual shall include the agreed commissioning procedures within the

appropriate sections. The manual shall be accurately indexed to facilitate retrieval

of information by plant system in accordance with the operational philosophy.

Spare Parts Manual: A separate volume, cross-referenced to all tagged items of

equipment, detailing the spares recommended by the Contractor for

commissioning, operation and insurance purposes. This manual shall also include

a schedule of required lubricants and any special requirements relating to the

handling and storage and disposal thereof.

Operations Manual: A fully descriptive manual of the functions and logic used in

all aspects of the operation of the plant, including all safety features. It shall also

include a description of the various modes of operation.

Operating and Maintenance Manual: To contain full and explicit instructions in

respect of the methods for operating the plant in all conditions of operation and the

routines to be established to maintain the plant for optimum performance.

This manual shall be divided by process, utility, power or other systems, as

appropriate, into individual sections. All sections shall be clearly indexed and sub-

sectioned as necessary.

The details contained therein shall be derived from the design, Contractors’ and

commissioning data without need to cross-reference to other documents i.e. stand

alone. The sole inclusion of standard Contractors’ published material shall not be

accepted.

All sections shall contain an introductory description of the particular item/system

including its function, operational criteria and any special features appertaining

thereto.

Each section shall contain a sub-section entitled Safety which shall contain all

standard and special safety precautions for operating and during maintenance of

the system.



In addition to the other copies four copies of this manual shall be presented in

durable plastic or plasticised card to enable use at the workface. These copies

shall further have the ability to be cleaned by a water/soap solution without

deterioration or loss of clarity.

The timing of submission of all of the above manuals by the Contractor shall be in

accordance with the Documentation Schedule.

19.4 Implementation Schedules

19.4.1 General

After Bids close they will be evaluated and followed by contract negotiations with

the lowest ranked compliant Bidder. The estimated timeline for the above activities

is shown in Table 26

Table 26: Estimated Timeline for Bid Documents

Activity

Duration Estimated

Date Duration

Estimated Date

1st Stage 2nd Stage

Release of Bid Documents by APSCL

15 days 10 days

Bid Period 60 days 45 days

Bid Evaluation 60 days 45 days

Contract Negotiations 30 days

Notice of Award 10 days

EPC Contract Execution

35 days

19.4.2 EPC Contract Schedule

The EPC contract duration shall not be more than 1080 days for both demolition,

disposal of the existing plants & all over ground, underground structure/foundation

of the plant area & all underground structure/foundation from the rest of the

Project area, Site preparation and Construction of combined cycle power plant

from the EDOC.

19.5 Progress Reports

19.5.1 Progress Measurement

The Contractor shall, for the duration of the Contract Period, develop and maintain

systems and procedures for the measurement of progress against the

Contractor’s Programme and Document Schedule.

Progress achieved shall be measured concurrently at all Work locations. Unless

otherwise stipulated in the Contract the measurement cut-off date shall be the last

Friday of each calendar month.

Progress measurement at the Site shall be carried out on a weekly basis.

Prior to the formal issue of progress statistics to the Employer, the Contractor shall

establish within its own organization the accuracy of the monthly measure.



Detailed risk analysis shall be carried out on the programme and submitted to the

Employer on a monthly basis.

19.5.2 Progress Reporting

The Contractor shall submit to the Employer a detailed progress report for each

month up to the cutoff date. The monthly report shall contain, but not be limited to,

the following:

Listing of activities more than two weeks late

Listing of all items on the critical path and next sub critical path

Explanations for late activities which are having, or are likely to have, impact on the project schedule

Details of measures proposed to bring late activities back on schedule

Outstanding interface data and measures proposed to expedite the issue of critical interface data

Confirmation of the achievement of near term milestones

Confirmation of the achievement of the completion date

Detailed risk analysis of the programme.

In addition to the activities referred to above the monthly progress report shall also

include, but not be limited to, the following:

Covering letter and executive summary

Details of any accident or injuries during the reporting period and overall accident, safety and injury statistics for the construction phase, in the reporting period and to date. Management report on, and status of compliance with, the Health and Safety Plan

Management report on, and status of compliance with, the Environmental Management Plan

Details of any industrial relations issues

Details of any complaints or comments made by external bodies or individuals

Problem areas (and details of measures being taken to resolve problems)

A statement of the number of site personnel engaged in the work during the reporting period and, where relevant, details of erection equipment in use or held in readiness

Document Index marked up to show document status

Purchasing schedule marked up to show status of procurement activities

Copies of those inspection and test reports which identify any deviations from the quality standards in the Contract and a statement of corrective actions

A Schedule of all other inspections and tests performed

Copies of quality assurance audit reports which identify the need of corrective actions and evidence of the implementation of corrective actions

Progress on compilation of manuals

Colour photographs showing the progress of construction

Update of manning histograms

Update of progress ‘S’ curves.

The Project Master Schedule shall be marked up, on a monthly basis, by the

Contractor to indicate the progress achieved against each activity and submitted

as part of the monthly progress report which shall be issued to the Employer

within 10 working days after the cut-off date (one week prior to the monthly

progress meeting).



The progress curves developed from the Project Master Schedule shall include

planned and actual progress status. The progress curves shall be produced using

the manhour content of the network activities factored to achieve a percentage

weighting for each activity. The weightings, once agreed, shall not be varied

during the course of the Project unless otherwise agreed by the Employer.

The progress report, six copies of which shall be provided, shall address each of

the following project phases, as appropriate:

Engineering

Procurement

Expediting

Inspection

Manufacturer and fabrication

Construction and erection

Testing and pre-commissioning

Commissioning

Reliability testing, performance testing and taking over.

19.5.3 Photographs

Twelve colour photographs showing progress on site shall be provided with each

monthly report. Each photograph shall not be less than 240 mm by 180 mm and

shall carry description, serial number and dates.

Soft copies in jpg format of all photographs shall be handed over to the Employer

at the completion of the Contract at which time the Contractor shall also hand over

three sets of photographs in separate albums.

In addition to still photographs, the Contractor shall provide four digital videos

taken at key dates during the construction programme. Two copies of each video

file on a DVD shall be provided to the Employer.

19.5.4 Data for Asset Management System

The Employer is purchasing an asset management system under another contract.

In addition to the above documentation, the Contractor shall provide on DVDs

(four sets), electronic versions/copies of the following key plant reference

documents:

Plant Equipment List

Equipment Name Plate Data

Plant Spare Parts and Inventory List

Equipment Operations Manuals

Equipment Maintenance Manuals and Bill of Materials

Plant System Design and As-Built Drawings (AutoCAD)

Plant System Design Specifications

Plant As-Built Equipment MTBF and During Startup/Testing Equipment Failure Data.

The information is to be provided in a machine readable/searchable format.



20. END USER’S PLANT VISIT

The Contractor shall arrange site visit of four personnel of the Employer to the premises of the power plant as mentioned in experience data sheet. All living, accommodation, food, transport expenses of the personnel during the period of visit including airfares, incidental expenses, medical expenses, medical insurance etc. will be covered by the Contractor including pocket allowance of US$ 180/ day/ person including travel time. The visit shall be arranged immediately after the effective date of the Contract Agreement.



21. Annexure (Technical)

Annexure-1: Existing Ashuganj Power Station complex showing site for proposed 400 MW CCPP



Annexure-2: Single Line Diagram of 400KV and 230 KV Sub-station for Power Evacuation and Grid Auxiliary Power Supply for proposed 400 MW CCPP



Annexure-3: Basic Wind Speed Map of Bangladesh



Annexure-4: Seismic Zoning Map of Bangladesh