4

Ash discharge pipe and return water system package

4. GENERAL TECHNICAL REQUIREMENTS

Thai Binh 2 Thermal Power Plant

4.1 CODES, STANDARDS AND REGULATIONS

The Work shall comply with Laws, Rules, and Regulations of Vietnam and with the current editions of relevant internationally recognized Codes, Standards, and Regulations. Where the Contractor's Standards differ from those specified but comply with the standards of the country of origin, a complete list of such Standards shall be included in the Schedule of Deviations of the Bid Proposal including a comparison with the specified Standards. The Contractor shall submit five complete sets and one CD of the proposed Standard(s) together with cross-indexed references for each item of deviations with the specified Standard(s) during engineering stage for approval.

In the event of conflict between Standards, the prevailing ruling shall be the one which requires the highest quality of workmanship and materials and the highest degree of safety to personnel, or as interpreted by the Employer, the decision of which shall be final.

Where no Standards or Codes are specified, the Equipment shall be designed, manufactured, installed, and tested in accordance with the best current power station practice.

Where a Standard is specified, that Standard shall be the latest published edition thereof, unless otherwise stated. It shall be the responsibility of the Contractor to adopt the latest editions even if these editions should be published after the award of Contract.

The plant and Equipment shall comply with the local authorities Rules, Regulations, and statutory requirements including but not limited to health, safety, environmental protection, civil, building, and structural works. The fire fighting and protection shall comply with NFPA codes and of local fire authority requirements.

The Contractor shall submit two complete sets and one CD of all Codes/Standards applied to the design, calculation, testing, inspection, etc. for all equipment and piping or each type of equipment for the whole Project to Owner review and approval. This submission shall be made within 60 days after the Contract award.

The Codes and Standards which are preferred over other alternatives codes are listed in Annex 2.

4.2 DESIGN REQUIREMENTS

4.2.1 General Requirements

The Contractor shall be responsible to provide a fully integrated and complete operating plant with the function and performance intended by the Contract. It is understood that design, Codes and Standards, materials and methods specified in this Specification are indicative only of the minimum performance and quality requirements for the plant. This Specification has stated preferred processes for the plant and this shall not relieve the Contractor of his responsibility to meet the Performance and Guarantees of the Contract.

Reliability of the Equipment is of the major importance. Design of the plant and Equipment supplied shall be of proven quality, reliable, and of advanced technology to enable the plant to achieve high availability, reliability, and efficiency. Experimental, prototype, or first of a kind equipment will not be accepted.

The plant shall be easy to operate and maintain and meet the requirements of environmental protection and personnel safety. Plant protection shall be provided that will safely allow the plant to be operated with minimum staff. System stability, operational simplicity, maintainability, convenience, and complete safety of personnel and equipment under normal and abnormal operating conditions shall be essential features of the plant design.

Equipment and materials shall be new and original and of excellent quality to keep maintenance can be kept to a minimum.

The Contractor shall pay due consideration in the design and selection of Equipment and facilities intended for outdoor service, including electrical, instrument and control equipment, pipe and steel structures incorporating effective measures of protection from rain and salty mists contained in the atmosphere.

4.2.2 Site Conditions

4.2.2.1 Site Data

The Contractor shall thoroughly investigate and familiarize himself with conditions of the Site and the surrounding area.

Expenses arising through lack of knowledge or understanding on the part of the Contractor regarding the conditions of the Site shall be the responsibility of the Contractor and no additional payment thereof shall be made by PVN.The site data provided in this Specification and Exhibits or Appendices or Annexes thereto are to assist the Contractor in assessing site conditions in general. Such information is provided to the Contractor in good faith and the Contractor accepts responsibility for interpretation of such data. The Contractor shall decide the extent of additional testing and studies necessary to confirm the site data.

The plant shall be capable of meeting its performance requirements under any combination of ambient conditions likely to be encountered.

The Site ambient conditions are shown in Exhibit 1.

The hydro-meteorological data investigation report is included in Appendix 1.

The topographical investigation report is included in Appendix 2.

The engineering geological condition report is included in Appendix 3.

The geophysics investigation report is included in Appendix 4.

The assessment report on seismic hazards is included in Appendix 5.

The geotechnical investigation report is included in Appendix 8.

4.2.2.2 Seismic Data

According to the seismic investigation and evaluation report produced in March 2008 by the Institute of Geophysics of the National Institute of Technologies and Sciences, the seismic features of the project Site are as follows:

Among the faults (fractures) within a radius of 100km or more from the studied area, the most noticeable the Linh Son Cam Pha fault that runs at a distance of 8 or 9 km northwest of the Site.

The maximum seismic level at the Site is Imax = 7 (MSK-64; MM), and the Peak Ground Acceleration (PGA) amax = 142cm/s2 (amax = 0.145g where g is gravitational acceleration); this is caused by the maximum earthquake intensity Mmax = 5.5, damping depth h = 12km may happen on the Linh Son Cam Pha fault at a distance of 8.1km from the Site.

It is recommended the Maximum Design Earthquake (MDE) be the maximum earthquake at a probability of occurrence of more than 10% in 1,000 years and a repeat cycle of 9,500 years, that translates to IMDE = 7 (MSK-64; MM) and aMDE = 131.63cm/s2; and the Operation Basic Earthquake (OBE) be the maximum earthquake at a probability of occurrence of more than 10% in 50 years and a repeat cycle of 475 years, that translates to IOBE = 7 (MSK-64; MM) and aOBE = 90.85cm/s2.

The detailed seismic investigation and evaluation report is included in Appendix 5.

4.2.2.3 Site Datum

Plant set-outs and elevations shall be referenced to the site datum and grid reference shown in Specification Drawing, Plot Plan, drawing No. TB2-0-DW-000-101 and TB2-0-DW-000-002.4.2.3 Coal, Fuel, and Water Quality

4.2.3.1 Coal and Ash

Coal supply for the power plant is fine dust coal Grade 6B and Grade 5 from mines in Hon Gai and Cam Pha regions. The boilers shall be designed and manufactured so individual coals can be efficiently burned. The coal is briefly described in the following table:

NameSymbolUnitRangePerformance (Guarantee) CoalTest & (Equivalent) Standard

Higher Heating Value, as-received basisHHVkcal/kg4568-52255205TCVN 200 (ISO 1928)

Lower Heating Value, as received basisLHVkcal/kg4406-50925055TCVN 200 (ISO 1928)

Total moistureWar %5-13.008.2TCVN 172 (ISO 589)

Volatile MattersVar %3.55-7.67.5ISO 17 246 for fixed carbon

Ash ContentAar %22.89-31.3528.74TCVN 173 (ISO 1171)

The detailed coal and ash specifications are shown in Exhibit 2.

4.2.3.2Fuel Oil

Heavy Fuel oil Type 2B in accordance with TCVN 6239-2002 will be used as secondary fuel for boiler start-up. The heavy oil is briefly described in the following table:

CharacteristicTypeTest Standard

No. 2B

Density at 15oC, t/m3 0.970TCVN6594:2000 / ASTM D1298)

Sulphur, by weight, (%) 3.0TCVN6701:2000/ASTM D2622/ASTM D129/ASTM D4294

Ash(%) 0.15TCVN6901:1995/ASTM D482

Diesel oil will be used in the auxiliary boiler. The diesel oil is briefly described in the following table:

Property ValueTest Methods

Sulfur Content, mg/kg, max.2500TCVN 6701:2002 (ASTM D 2622)/ ASTM D 5453

Cetane Index, min.46ASTM D4737

Distillation, oC, 90% vol, max.360TCVN 2698:2002/ (ASTM D 86)

Flash Point, oC, min.55TCVN 6608:2000 (ASTM D 3828)/ ASTM D 93

Viscosity at 40 oC, mm2/ s2- 4.5TCVN 3171:2003 (ASTM D 445)

The fuel oil specifications are shown in Exhibit 3

4.2.3.3LimestoneLimestone supplied for the power plant is from limestone mines in Trang Kenh Mountain, Thuy Nguyen District, Hai Phong City. The limestone parameters are briefly described in the following table:

ParameterUnitRangePerformance (Guarantee) Value

Analysis, dry basis

CaCO3

MgCO3

Fe2O3

SiO2

Al2O3

Na2CO3

K2CO3

Otherwt %

wt %

wt %

wt %

wt %

wt %

wt %

wt %96.43 99.12

0.42 2.73

0.18

0.6

0.45

0.035

0.015

0.0297.100

1.600

0.180

0.600

0.450

0.035

0.015

0.020

The limestone specification is shown in Exhibit 4.

4.2.3.4Cooling Water

Cooling water will be taken from the Tra Ly River, through the intake canal to the cooling water pumphouse.

Due to the vicinity of the intake canal to the sea (the plant Site is approximately 3km from the estuary), the flow regime in Tra Ly River at the power plant Site is strongly influenced by tides. Cooling water may be fresh, brackish or totally saline.

Seawater shall be the basis for plant design, of which the quality is shown Exhibit 5.

4.2.3.5Fresh Water

Freshwater will be taken from the Diem Ho River via pipeline to the power plant.

The freshwater quality is shown in Exhibit 6.

4.2.4 Design Life

The design life of the plant shall be at least 40 years for Civil Engineering and Building Work and 25 years for Equipment and components subject to wear and tear

Design shall consider the likely fatigue effects and the affect upon the life cycle maintenance costs associated with the various modes of operation. Contractor shall assume throughout the design life the whole plant will operate within the intended design parameters and loading limits, without replacement of equipment, other than recognized wear parts that are normally expected to be replaced during routine maintenance.

For plant items operating in the creep range of their constituent materials, the design life shall be at least 200,000 hours. The thickness of such components shall be no less than those required by the approved design Codes and Standards based on 200,000 hour creep stresses and design / calculation pressures based on rated conditions at the highest calculated design temperature.

4.2.5Equipment Redundancy and Design Margin

The plant shall be designed and configured so an outage or failure of any one single component shall not cause reduction of the unit output unless otherwise stated. Critical systems, equipment and components shall be duplicated to provide standby redundancy in either a 2 by 100% or a 3 by 50% duty configuration. The electrical supply for the duty and standby equipment/component shall be taken from two different sources and the latter shall be designed to auto-start on failure of the former. The duty and standby electrical supply cables and raceway shall be physically routed two separate ways. Common auxiliaries including electrical supply shall be provided with sufficient redundancy to allow their outages for maintenance without affecting the total output of the plant.

4.2.6 Plant Layout

The plant layout shall be generally as indicated in the Specification Drawings.The Contractor shall optimize the plant layout taking into consideration cost, constructability and maintainability of the plant and equipment. There shall be a requirement to demonstrate these features by the provision of suitably detailed drawings and walk through presentations by the Contractor during design review stage. Perceived inadequacies shall be rectified by the Contractor at its cost.

The arrangement and handing of each of the two units shall be substantially identical.

Provision shall be made for platforms, stairs, ladders, walkways and maintenance lifting beams to allow for safe, fully accessible operation and maintenance of the plant. Equipment, including valves, shall be positioned to allow unobstructed and safe access for operation and maintenance from access ways or from floor level.

Equipment or components requiring dismantling for maintenance that cannot be physically handled in accordance with governing workplace health and safety requirements shall be provided with lifting and handling facilities.

The Contractor shall include in the layout drawing, the area required during construction phase to house its facilities, which would include offices and amenities, workshops and stores, and assembly yards. The Contractor shall also indicate on the layout drawing the area(s) proposed for laydown of materials, and the estimated duration of occupancy of each area. As other contractors will be working on the Project Site, the allocation of these various areas will be coordinated and determined by the Employer. Use of Thai Binh 2 area for any purpose is not acceptable.

4.2.7Noise

The plant shall be designed and constructed to operate with the least amount of noise. Acoustic treatment shall be provided to ensure required noise is in compliance with the Contract when the plant is operating at any load up to and including its maximum capabilities.

In accordance with QCVN 26:2010 National Technical Regulation on Noise shall be as follows:

Special area Day (06:00 to 21:00 hrs) - 55dB(A) / Night (21:00 to 06:00 hrs) - 45 dB(A)

Common area Day (06:00 to 21:00 hrs) - 70dB(A) / Night (21:00 to 06:00 hrs) - 55 dB(A)

In normal operation conditions, including plant start-up and shut-down, running-up and slowing-down, and load changes, the maximum noise generated by plant equipment shall not exceed the following levels at 1.0 meter distance from the source:

110 dB(A) for immediate noise

85 dB(A) for 24-hour average noise

An exception is made for the boiler start-up operations or for other large pressure reducing devices operating e.g. during emergency periods only and for safety valves.

After commissioning, noise level measurements shall be taken by Contractor in the presence of the Employer in various working areas in the plant, along the boundary of the Site and in the nearest residential area in a manner to be agreed between the Contractor and the Employer in order to verify the noise levels conform to the Contract requirements.

Should the measured noise levels exceed these limitations, the Contractor shall proceed to take appropriate steps to reduce the levels to within acceptable limits.

4.2.8 Environmental Limitations

Plant and equipment for environmental control shall be designed in accordance with the rules and regulations imposed by local regulatory authorities.

Specific care shall also be taken to prevent the discharge or overflow of any toxic or dangerous fluids into the local environment. To this end, dangerous goods shall be suitably bounded and/or trapped to both prevent release and to recover such fluids in the event of a major emergency e.g. chemical spill or major transformer fire.

4.2.9 Standardization and Interchangeability

The Contractor shall provide maximum standardization and interchangeability of equipment and consumables wherever feasible, to simplify maintenance, reduce spare parts inventory, training and support requirements. This includes, but is not limited to valves, piping, flanges, pumps, fans, motors, transformers, switchgear, cables, conveyor belts, instrumentation and controls.

4.3 OPERATING AND PERFORMANCE REQUIREMENTS

4.3.1 HV Connection to GridNot used.4.3.2Boiler and Turbine Operating Requirements4.3.2.1Rated Output

Not used.

4.4 OPERATION AND MAINTENANCE REQUIREMENTS

4.4.1 Maintenance Requirements4.4.1.1Maintenance Isolation System

The Contractor shall install sufficient isolating facilities to allow the safe and efficient maintenance of all items of the plant. This shall allow the complete isolation of any item of the plant that is to be maintained while associated or adjacent equipment is in service. It shall be possible to isolate standby equipment completely while the duty equipment remains in service.

It is a requirement that valves, including drain and vent valves that can be used for isolation shall be able to be locked in the isolated position using standard padlocks or multi-lock devices.

Electrical switches shall be able to be locked in an isolated position so they cannot be closed either manually or remotely. Earth switches shall be able to be locked in the closed position and be unable to be opened remotely.

Current transformers (CT) and voltage transformers (VT) shall also have provision for shorting and isolating as required.

The isolation system shall be designed to allow the isolation of equipment during the commissioning and start up phase to accommodate any phased commissioning of any system or where there is an interconnection with the other units.

4.4.1.2Plant Maintainability

The plant shall be designed and constructed to facilitate routine, periodic, and possible forced outage maintenance. This shall include the provision of facilities such as equipment withdrawal spaces, including access ladders, stairs and platforms, crane access and lifting points, and laydown areas. Isolating facilities shall be provided to allow the safe and efficient maintenance of all items of the plant.

Road access shall be provided to outdoor equipment.

4.4.1.3Maintenance Facilities

The power Plant shall be provided with:

Sufficient capacity (including, laydown areas, crane facilities and crane access) for the efficient execution of the complete overhaul of one unit and associated equipment.

A means of transferring a transformer from its normal secure location to a low-loader trailer of a size readily available, without the need for a large mobile crane. The transformer may be partially dismantled before it is moved onto the trailer.

4.4.1.4Accessibility

The Contractor shall ensure full accessibility is provided for operating and maintaining the plant and this shall include but is not limited to:

Valves that need to be operated during start-up, shutdowns and in emergencies shall have permanent operator access.

Instruments that need to be maintained and calibrated shall have permanent access.

Local indicators shall be placed where they are easily read when standing in a normal position and at a distance that the scale and reading is easily discernible.

Traps and bypasses shall have permanent access; they shall not be placed on the outside (over the rail) of walk ways.

Foot traffic areas including walk ways shall be kept clear of tripping hazards and valves that are at head height.

4.4.1.5 Computerized Maintenance Management System

The Contractor shall provide the initial baseline maintenance schedule for the equipment. Data attributes shall be in a format suitable for loading into a management system.

4.4.2 Operation Requirements

4.4.2.1Operability

The control system for the Works shall be designed and constructed to meet the following objectives:

Operator skill requirements to be minimized by incorporating comprehensive safety features, automatic operation, diagnostics and alarms with alarm prioritizing,

Logical commissioning, start-up and shut down sequences with controls and indications grouped to reasonably minimize staff skill requirements and wasted time,

Comprehensive automatic control of:

Critical and important process conditions (pressures, temperatures, levels),

Starting of standby equipment under fault conditions,

Secure reliable protection of Plant from damage due to fault conditions, operator errors or process excursions. Protection related functions shall only be capable of overriding through keyed interlocks,

Control selection (and related indication) to ensure no item of Plant can be controlled from more than one location at any time,

Indication of significant analogue quantities and Plant status information,

Prioritized indication of Plant alarm and fault conditions so the operators attention is led to the most critical faults first. Conditions leading to unit trip and pre-trip shall be alarmed and be provided with sequence of event monitoring facility to capture the event with one millisecond resolution,

High reliability through appropriate use of features, and

Prompt, effective communications between the operating units

4.4.2.2Start-Up and Loading

The overall system shall be designed with sufficient automation and remotely operated equipment so no more than two operators can safely start-up, shut down, monitor and control the Plant from the control room and, after an initial line up of equipment and valves, require no more than one additional trip from the control room into the Plant for either a "cold" start-up or a "hot" start-up to close manual drain valves.

Except for supervision from the Plant Control Room, individual items of the Plant shall be able to operate continuously and unattended. In the event of failure of an item of Plant, it shall be automatically made safe and an alarm generated to the supervisory control system.

4.4.2.3Fault Conditions

Fault conditions shall, where possible, initially provide warnings to the plant operator to permit remedial actions to be taken. A continued or further degrading fault condition shall cause the Plant to automatically fail into a safe condition. Initial assessment will be undertaken by the control room operator who will take corrective action as necessary and possible from the Plant Control Room and call out roving operator/maintenance staff to take local corrective actions.

4.5 DESIGN, OPERATION, AND MAINTENANCE MANUALS

4.5.1General RequirementsDesign, Operation and Maintenance Manuals shall be provided for Systems, Sub-systems and System Equipment.

Manuals containing comprehensive details in the operation and maintenance procedures for items of plant and equipment shall be supplied under this Contract.

Operation and maintenance manuals shall be supplied in separately bound volumes in durable binders bearing the Project Description and shall be suitable for the addition of further information and documents arising from changes or revisions in plant description or procedures.

Procedures in operation and maintenance shall be written in English in a clear and concise manner, and be limited to simple sentences as far as possible. They shall be easy to read and be technically complete and accurate. Adequate space shall be incorporated to allow translation to Vietnamese by users. The procedure shall be developed using vendors and manufacturers drawings and documentation consistent with the format specified herein.

The manuals shall be developed with the objective of providing standardized methods of performing operation or maintenance functions by personnel with different levels of experience. Specific procedures to cope with unusual and critical situations shall also be described with the objective that the plant or equipment in this or connected with this Contract shall not be jeopardized in the process.

4.5.2Design ManualsThese shall include but not be limited to:

Lists of applicable drawings,

System flow/piping and instrumentation diagrams and elementary diagrams,

Heat, material and power balance diagrams,

Pertinent design considerations,

System description including principle and mode of operation, hydraulic gradients,

Equipment description including performance and characteristic curves (eg. head-capacity curve),

Equipment tests itemizing function, number, performance and technical data, power, water, air, steam or other requirements,

Instrument list itemizing function, type, number range with provision for coding by the Employer,

Complete list of DCIS inputs and outputs, including identification, description, action, ranges and setpoints and other information as required for complete description,

Complete list of control system inputs and outputs for autonomous control systems, including information described above,

Complete list of information transmitted between autonomous control systems to DCIS via data links,

Line and valve lists.

List of trips and alarms complete with set points.

The draft design manual shall be submitted 18 months after award of Contract.

4.5.3Operation ManualsThe Contractor shall develop Operation Manuals designed to improve operator skill and knowledge of the specific equipment/system being installed at the Plant. To help meet this goal, the Contractor shall develop plant specific Operation Manuals that will be used in both plant operations and training by the plant personnel. The Manuals shall be developed so their proper use will result in improved performance resulting in higher plant availability, thermal performance and safety.

For each system or piece of equipment supplied under this Contract, the following shall be developed:

A detailed System Description (SD) including descriptions of major flow paths, major components, instruments, alarms,

A detailed Operating Procedure (OP) to give plant operators a specific set of step-by-step instructions on how the plant systems are to be operated, alarm response procedures and valve and power supply check lists,

Procedures and instructions for commissioning, start up, normal operation, shut down, standby and emergency conditions,

Color Coded Flow Diagrams,

Valve operation lists,

Normal range of system variables,

Operating limits and hazards including trip and alarm trip limits,

Routine testing and checking requirements, and

Effect of loss of normal power.

The draft operation manuals shall be submitted 6 months prior to start of first commissioning activities or 24 months after award of Contract whichever is the earlier.

The Contractor shall develop Operations Manuals consisting of System Descriptions and Operating Procedures. The System Descriptions shall be written in a clear and concise manner that is easy to read and at the same time technically complete and accurate. The Operating Procedures shall be clear, concise and limited to one sentence steps.

4.5.4 Maintenance Manual

The Contractor shall develop maintenance manuals for equipment supplied in this Contract.

The manuals shall be developed with the objective of providing standardized methods of performing preventive and corrective maintenance by maintenance personnel with different levels of experience.

For each piece of equipment supplied under this Contract, the following shall be developed:

A step by step procedure covering preventive and corrective maintenance of the specific piece of equipment. Both types of maintenance shall be covered under one procedure, with each having its own relevant section,

Detailed dismantling and assembly procedures with associated routine tests and checks prior to returning equipment to service,

Detailed assembly drawings and illustrations necessary to complement, support and clarify assembly procedures specified herein including parts lists and numbers for replacement ordering,

Setting and running clearances and tolerances,

Cleaning and preservation procedures,

Instrument calibration requirements and procedures,

A Preventative Maintenance Schedule for equipment covered by this Specification,

A Lubrication Schedule showing requirements and Specifications for equipment covered by this Specification,

Printed Circuit Board Schematics and Module Schematics,

Detailed Drawings and method of use of Special Maintenance Tools, and

List of Recommended Spare Parts.

The draft maintenance manual shall be submitted 6 months prior to start of first commissioning activities or 24 months after award of Contract whichever is the earlier.

4.5.5 CD-ROM

As-built Process and Instrumentation drawings, and final Design, Operation and Maintenance manuals shall, in addition to the twelve hardcopies, be provided in CD-ROM format and shall be based on Microsoft software. Two sets of the CD-ROMs shall be submitted to the Employer.

4.5.6TrainingContractor shall provide formal comprehensive training for Employers employees. The training shall cover the operation and maintenance of equipment and systems of the Works. Training shall consist of both classroom training and "on the job" training.

The formal training classes shall be conducted by experienced instructors on equipment comparable to that installed, using course materials prepared by Contractor that have been specifically prepared for the Plant.

The various courses shall be staggered or repeated if required by Employer. The training program shall be structured and shall:

Provide the knowledge and skills required to perform the required operation and maintenance activities,

Demonstrate that each trainee has acquired the skills and knowledge, and

Document that Contractor has tested each trainee to the required level and qualified the trainee to operate or maintain the PlantDetailed training requirements are provided in Annex 9.4.6 INSPECTION AND TEST

4.6.1Inspection and Test PlanWithin 90 days after the award of Contract or before start of fabrication, whichever is the earlier, the Contractor shall submit to the Employer an Inspection and Test Plan for approval that shall include pertinent manufacture and inspection operations. The Plan shall show the Hold Points for inspection by the Employer before the item concerned can be released for further manufacture or shipment.

Contractor shall give Employer at least 14 days prior notice in writing of the date on and the place at which any Works shall reach a Hold Point or shall be ready for independent inspection and testing. Unless Employer advises Contractor not to proceed with the inspection and testing prior to 7 days before the date the Contractor has stated in its notice, Contractor may proceed and any inspection and tests shall be deemed to have been made in Employers presence, and Contractor shall forthwith forward to Employer duly certified copies of the inspection and test results.

Contractor shall provide to Employer full cooperation and assistance in any factory inspection at the premises of Contractor or any other place of manufacture of items supplied hereunder (or components thereof) and Employer shall have the right to request this inspection, provided reasonable written advance notice has been given to Contractor.

Contractor shall at a monthly meeting with Employer, provide the Employer an updated list of tests to be performed in the next month and the date scheduled for these tests.

Contractor shall develop a Construction Inspection and Test Plan to cover construction activities undertaken by Contractor and its Subcontractors. The Plan shall include inspection and test procedures, the applicable item of equipment being tested, equipment used, the standards and method of testing, and shall state a proposed test date. Inspection and test procedures shall be submitted to the Employer for approval.

4.6.2Tests at Manufacturers WorksThe Contractor shall provide as part of the Inspection and Test Plan, a comprehensive list of factory tests for the works.

The Employer shall be given the opportunity of witnessing factory, shop, or manufacturing facility tests, accordingly the Contractor may commence any test after giving at least 14 days prior notice to the Employer.

At least, the tests as listed in Annex 4 shall be carried out before dispatch from the manufacturers works.

4.6.3 Tests at SiteThe Contractor shall carry out site tests to prove compliance with the Specification, independent of tests carried out at the manufacturers works.

The Employer shall be given the opportunity of witnessing on Site testing, accordingly the Contractor may commence any test after giving at least 7 days prior notice to the Employer. Tests/activities that require witnessing by the Employer shall be carried out during the normal working hours. The Contractor shall provide test equipment and instrumentation which, prior to the testing shall be calibrated by an approved authority or laboratory at the Contractors expense. Test and calibration certificates shall be submitted by the Contractor.

The tests shall be carried out in accordance with the relevant ANSI/ASME/ASNT and other Standards as applicable. The tests shall include Vietnamese mandatory codes/standards.

The test schedule shall be incorporated either in the detailed erection schedule and the detailed commissioning schedule.

At least, the tests as listed in Annex 5 shall be carried out before commissioning and start up of the Plant.

4.6.4 Factory Witness Tests

The time and duration of visits by the Employers representatives shall be finalized by the Employer after the submission of Inspection and Test Plan schedule.

Key activities to be witnessed by the Employers representatives shall include, but not necessarily be limited to the following:

Low voltage switchgear tests

Motor control centers tests

Other tests as required by the Employer

The Contractor shall submit the Inspection and Test Procedures 3 months after Contract is awarded.

The shop test reports shall be submitted within 1 week after the completion of the test.

4.6.5 General Requirements for Piping

Permanently and legibly mark pipe in general accordance with the guidelines in ASTMA700 and with information required by the applicable ASTM or ASME material specification. Marking shall not result in harmful contamination, reduce the effective minimum wall of the pipe, or create any sharp discontinuities. Marking shall withstand shipping, handling, storage at the job site, and shall remain legible during erection.

Mark each designed and prefabricated pipe section with paint or securely fastened metal tags that refer to the mark number indicated on the pipe erection drawings/spool sheets. Marking shall withstand shipping, handling, storage at the job site, and shall remain legible during erection. Markings shall be 180 apart and located at each end.

Use waterproof materials containing less than 100 ppm leachable chlorides for sealing austenitic stainless steel parts.

Properly protect all openings with watertight coverings to prevent the entrance of moisture, dirt, or debris. Protect projecting parts and machined surfaces with suitable metal or plastic caps, or equal methods. All end/opening protectors shall be sealed with a minimum of two (2) wraps of waterproof tape. Open ends and branches of shop fabricated pipe shall be securely closed as follows to protect the interior cleanliness and end surfaces during shipment.

Submit instructions for any special storage requirements a minimum of 90 days in advance of shipment to allow for necessary preparation. Identify any special materials, equipment, consumables, services, and procedures to properly store all items. The storage procedure shall include recommendations for on-site storage.

Unless otherwise specified, all materials and Equipment permanently incorporated in the Work shall be new, and both workmanship and materials shall be of utility quality. Materials and Equipment shall be as stated herein.

Examine welds in accordance with ASME B31.1, paragraph 136.4.1, Nondestructive Examination or in accordance with ASME B&PVC, Section I, as applicable. Design temperature and pressure for determining nondestructive examination requirements are either defined in the detailed specification or indicated on the Drawings. All non-destructive examinations on ASME P-Numbers 3, 4, 5A, 5B, 6 and 15E material welds shall be performed after post weld heat treatment is performed.

Cold Reheat piping welds shall be examined as follows regardless of the design conditions and wall thickness. Radiograph all butt welds, radiograph branch connections over DN 100, magnetic particle or liquid penetrant branch connections DN 100 and less and perform visual examination for all fillet, socket, and seal welds.

Examine areas where lugs or attachments to power piping are removed or repaired by magnetic particle or dye penetrant methods to meet accepted standards stated in the applicable Code. Remove linear indications and retest the area. Repeat the procedure until no indications are noted.

Re-inspect repaired welds, using the same method which originally detected the discrepancy.

Nondestructive testing personnel shall be qualified and certified in accordance with the requirements of SNTTC1A and CP 189.

Personnel performing or supervising welding inspection shall be responsible for verifying that all aspects of the welding operation are in accordance with the applicable Codes, Standards, welding procedures, and this Contract. All welds shall receive 100 percent visual inspection. Personnel performing the visual inspection of welds shall be qualified as Certified Welding Inspector (CWI) in accordance with the requirements of AWS QC 1.

All NDE results shall be provided in an NDE Report that is evaluated, interpreted, and accepted by Level II or Level III NDE personnel.

At the completion of the work, the Contractor shall submit to the Employer, for record purposes, the complete Documentation Package which shall include, as a minimum:

Shop and/or field records of procedures, tests, inspection, nonconformance reports and other data required by codes and standards as specified herein, to be turned over after last material shipment from the shop and/or prior to de-mobilizing from the site.

Completed ASME data forms for ASME B&PV Code, Section I work and/or boiler external work, including documentation indication the forms have been properly submitted to the required agencies.

One record set of marked-up design drawings documenting all field changes made, to be turned over prior to de-mobilizing from the site.

Weld Procedures and Procedure Qualifications.

Welders Qualifications including Welders symbol traceable to Welders Qualifications.

Material Test Reports and certification of material conformance.

Repair Procedures including method of defect removal, NDE, application of Pre-heat and Welding Procedure to be used.

Visual inspection Reports traceable to welds.

NDE Personnel certifications.

NDE Reports (other than Visual) traceable to weld examined.

Heat treatment Reports including Time Temperature Charts traceable to welds that were heat treated.

Nonconformance report.

The completed documentation shall be submitted in an organized manner preferably in 3 ring binders or as agreed to with the Employer.

The Contractor shall hydrostatically test piping in accordance with the applicable Code and submit the results of testing to the Employer for the record.

Hydrostatically test Boiler External Piping in accordance with the requirements of PG-99 of ASME Section I of the ASME B&PVC. Hydrostatic test shall be performed in the presence of an Authorized Inspector.

Hydrostatically test all new non-boiler external piping or piping systems at 1.5 times the design pressure in accordance with the requirements of paragraph 137.4 of ASME B31.1.

Components subjected to sub-atmospheric pressures shall be hydraulically tested to at least 1.05 bar(g).

Pneumatic testing shall not be allowed, except where approved in writing by the Employer. Requests shall be written and received at least 21 days in advance of the test.

4.7 SPARE PARTS AND SPECIAL TOOLS

4.7.1 Spare Parts

The Contractor shall provide spare parts for turn over to the Employer at Unit acceptance. An independent and complete set of spares shall be provided for each Unit. The spare parts shall include, but not be limited to the following:

Parts listed in the Schedule of Spare parts

Consumable items sufficient for a plant operational period of 24 months

Essential parts to cover the event of a breakdown which will affect the availability or safety of the plant

Spare parts recommended by individual equipment vendors

Spare parts required to perform the first service on equipment

Parts ordered shall be interchangeable and suitable for use in place of the corresponding parts supplied with the Plant. They shall comply with the Specification and shall be marked and numbered for identification and prepared for storage under tropical conditions prevailing at Vietnam.

The Contractor shall submit the List of Spares to be handed over to the Employer. This list should include the tag number, description of the item, a sketch showing major dimensions and materials, the number of items, the price and a cross-reference to the relevant equipment drawing.

The Contractor shall be responsible for the appropriate packing of the spares. The packing provided shall ensure preservation of the spare parts and materials stored within. Spare parts or materials containing electrical insulation shall be delivered in cases for storing the insulation over a period of years without deterioration.

The spares shall be delivered to the Employer's stores where they shall be unpacked and neatly arranged. Relays, meters, transducers and electronic cards or modules shall be tested and calibrated at site before handing over. Empty cases and debris shall be removed from the Employer's stores by the Contractor. Copies of the hand-over certificates shall be prepared by the Contractor for the inspection.

Instruction for the proper storage and maintenance of parts and spares shall be provided in a separate and independent manual to be turned over with the spare parts4.7.2Special ToolsWhere special tools are used by the Contractor's construction team to install and set equipment during the installation stages but is essential for future maintenance of the plant and need to be used during the inspection at the end of the Defects Liability Period, such maintenance tools shall be retained at site as the properties of the Employer. Also, tools for pumps, motors and support stands for rotors are considered as part of special tools and shall be supplied accordingly. Over and above this requirement, one complete set of unused special maintenance tools shall be included for the Equipment supplied under this Contract. The set of unused special maintenance tools shall include the identical set of special maintenance tools used by the Contractor to maintain the equipment.

The scope of special tools to be supplied by the Contractor shall not be limited to the list submitted during the Tender Proposal stage. The Contractor shall be responsible for the supply of other special tools used by the Contractor.

The Contractor shall submit drawings showing details and method of use of the Special Maintenance Tools to be handed over to the Employer. The maintenance manuals shall also make reference to the Special Maintenance Tools.

4.8 PLANT IDENTIFICATION

4.8.1 General

The International System of Units (SI) shall be used. The KKS numbering system shall be adopted for plant component classification and identification system. Numbering shall be from North to South and East to West.

4.8.2NameplatesNameplates, process flow indication, identification labeling and warning signs shall be provided for Equipment throughout the Plant. Nameplates shall be in English with a minimum letter size of 6.4mm.

SI Units shall be clearly stamped on nameplates. Nameplates including electrical panels shall be made of stainless steel and fixed with stainless steel screws or bolts. Lettering shall be of enamel or abrasion resistant paint.

Names and numberings of tanks, vessels, motors, heaters and equipment are to be written in bold sign writing on the respective shells or bodies of the tanks, vessels, heaters or equipment. The size, color and the orientation shall be submitted to the Employer for the record.

4.8.3Pipe MarkingUn-insulated and insulated pipes including insulated pipes in trenches shall have pipe markings on the piping or jacket as applicable, complying fully with ASME A13.1, "Scheme for the Identification of Piping Systems".

4.8.4 Floor Level Labeling

Wall mounted signage consisting of 2.5mm solid aluminum plate of minimum 25 micrometers anodizing, and etched with graphics, and coated with paint of approved color shall be provided at floors and platforms to indicate the allowable loadings. The signage shall be provided to indicate the floor levels at 4 prominent locations on every floor.

4.9 PAINTING AND PLANT PROTECTION

Unless otherwise specified, equipment and materials supplied under this Specification shall have protective coatings in accordance with the requirements of this Annex 7. Coating Colors shall be as defined in Annex 7.

4.10 INSULATION AND JACKETING NOT USED4.10.3Piping, Fittings, and ValvesInstall insulation with tight seams and joints using wire loops or straps. Sectional and segmental pipe insulation sections shall be securely wired or banded in place, using no less than three ties or bands for each one meter section. For DN 200 and larger piping, 4 ties or bands shall be used for each one meter section. On piping DN 750 and larger straps shall be used. Cracks, voids and depressions shall be filled with insulating cement suitable for the piping temperature and finish to form. Surfaces shall be made smooth and uniform before application of outer coverings.

Mineral fiber pre-formed pipe insulation and fiberglass blankets on freeze protected piping shall be secured with wire loops, straps or 25 mm wide filament tape on 150 mm centers.

When multiple layers of insulation are installed, longitudinal and circumferential joints of the two layers shall be staggered. Each layer shall be separately wired or strapped as described above. Cracks, voids and depressions in the first layer shall be filled before application of the outer layer.

Stop ends of pipe insulation a sufficient distance from flanges to permit bolt removal clearance.

Insulate where hazardous," or for "personnel protection," is indicated and in locations accessible to personnel. Extend at least 3 meters above the floor, platform or stairway.

Insulation for flanges and flanged valves shall be of a design that shall permit the flanges and bolts to heat up quickly, uniformly and to be maintained as close to the pipe temperature as possible.

Piping and piping components in a system shall be insulated unless specifically excluded by the drawings. Piping components include valves, bends, flanges, strainers, flow nozzles, pipe supports and other miscellaneous specialties.

Steam trap bodies and unions in steam trap piping shall be left un-insulated. Taper the insulation to a neat finish at these points to enable removal of the steam traps without damage to the insulation.

Thermowells shall not be buried. Thermowell lagging extensions shall extend beyond the pipe insulation so insulation will not drop into the thermowell when the temperature element is removed.

Float switches, pressure switches, temperature switches, level controllers, float gages and flow meter caps shall not insulated unless noted on the Drawings.

4.10.4 Steam Drums, Vessels, and Heat Exchangers NOT USED4.10.5 Boilers, Ducting, and Exhaust Stacks NOT USED4.10.6 Jacketing NOT USED4.11 PIPING

4.11.1 General

Where called upon to design, fabricate, supply, deliver to site, erect, test and commission piping systems, the Contractor shall install such systems in accordance with the requirements of ASME Boiler and Pressure Vessel Code (B&PVC), ASME B31.1 and ASME B31.3, unless otherwise specified.

Piping systems shall be designed to have sufficient flexibility to prevent pipe movements from causing failure due to overstress of the pipe material or anchors, leakage at joints or detrimental distortion of connected equipment resulting from excessive thrusts and movements. Flexibility shall be provided by changes of direction in the piping through the use of bends and expansion loops. Swivel, ball joints, corrugated pipe, bellows or flexible metal hose shall not be used to absorb thermal movements.

Overhead pipe including insulation when applicable shall have a minimum headroom of 2.5 meters above floor level.

High piping points shall have vents and low points in the system shall have drains. Intermediate pockets shall be avoided. The drain pipes shall run to the nearest drain sump or trench in a safe and adequate manner.

4.11.2 Material Selection

For piping transporting water and steam with design temperatures up to but not exceeding 427C, carbon steel piping shall be used. Where temperature/pressure ratings permit, the following pipe material and minimum schedules shall be supplied:

Nominal Bore SizePipe Material

Up to and including DN 50ASTM A106 Grade B Seamless, Schedule 80

Over 50mm up to and including DN 300ASTM A106 Grade B Seamless, Schedule 40

Over DN 300ASTM A106 Grade B Seamless, Standard Weight

Pipe that is DN 32, 90, or 125 shall not be used for general system design. However, it is recognized that short segments may be required at connections to equipment.

The use of ASTM A53 piping shall be limited to low pressure and low temperature applications. ASTM A53 shall not be used in applications with design conditions above 10 bar or 100C.

ASTM A106 Grade C seamless piping shall be used for feedwater system piping.

For design temperatures over 426C but not exceeding 565C, ASTM A335 Grade P22 seamless pipe shall be used and with pipe thickness determined in accordance with this Specification.

Where flashing may occur, including heater drains service, ASTM A335 Grade P5 chromium alloy seamless steel piping materials with a minimum of 3.0mm corrosion/erosion allowance shall be used.

Stainless steel 316L piping materials shall be used as follows:

Piping applications requiring a high degree of cleanliness, generally including instrument and service air piping, lubricating oil/sealing oil piping, demineralized water piping and sampling piping after process isolation valves.

Piping generally subjected to corrosive service applications.

Whenever stainless steel pipes are used, the associated fittings and valves shall also be of the same stainless steel material.

Notwithstanding the above, stainless steel material shall be used wherever specifically called for in this Specification.

The fire water spray system piping shall be hot-dip galvanized ASTM A53 Type E or S, Grade B of standard thickness.

Helical seam piping is not acceptable for any service.

4.11.3 Design Requirements

4.11.3.1General

Piping systems shall be checked for correctness of pipe size, dimensional accuracy and choice of material for the specified operating conditions. They shall be designed to function adequately for all modes of operation throughout the life of the plant. Steam systems shall be designed and fabricated to include sufficient pitch in the cold condition to be self-draining under cold and hot conditions to selected drain pockets for condensate disposal.

Minimum wall thickness of straight pipe under internal pressure shall be designed in accordance with the requirements of ASME B31.1, Part 104.

Horizontal drainage lines for steam drains, condensate return and gravity flow drains shall be sloped at a uniform pitch of 6 mm per 300 mm ( 2% slope) where practical, but in no case less than 3 mm per 300 ( 1% slope) in the cold position unless otherwise specifically indicated on the drawings and checked for a positive slope in the hot position based on the movements identified in the stress analysis.

Allowance for variations from normal operation, consideration for local conditions, and transitions shall be in accordance with the requirements of Paragraphs 102.2.4 and 102.2.5 of ASMEB31.1.

The value for allowable stress, SE, shall not exceed that given in AppendixA of ASME B31.1 for the respective material at the design temperature. These values include the weld joint efficiency. For Boiler External Piping and Nonboiler External Piping per ASME B31.1, the minimum wall thickness calculation shall utilize the Allowable Stress Values as shown in Appendix A of ASME B31.1.

The value for corrosion allowance A shall be selected to compensate for material removed in threading, corrosion, and erosion and to provide mechanical strength. The following minimum allowances shall be applied:

Special wall piping DN 65 and larger - The value A shall be at least 0.25mm on alloy steel pipe and 1.5mm on carbon steel pipe.

Schedule wall piping DN 65 and larger - The value of A shall generally be 0.25mm on alloy steel pipe and 1.5mm on carbon steel pipe except when additional thickness is considered necessary for a specific service.

Schedule wall piping DN 50 and smaller - The value of A shall be selected to provide adequate mechanical strength. The minimum A value of 0.25mm on alloy steel pipe and 1.5mm on carbon steel pipe is suggested, but is not mandatory.

Threaded piping - The value of A shall not be less than the depth of thread.

Special Wall Piping is addressed in the Piping Line Specification. The pipe is listed by nominal outside diameter and minimum wall thickness.

Tolerances for all special wall piping shall be in accordance with the applicable standards specified in the Piping Line Specification and this Specification.

The maximum weight of special wall piping shall be in accordance with the requirements of ASTM/ASME A/SA530 and ASTM/ASME A/SA999 as applicable. The permissible variations in outside diameter, ovality, and straightness shall be as stated in the applicable material specification.

The following guaranteed minimum inside diameters shall be provided for the special (minimum) wall pipe on this Contract.

SYSTEMSIZE (OD) in.WALL THICKNESSGUARANTEED MINIMUM I.D. (in.)DESCRIPTIONMATERIAL

Rolled and welded steel plate piping, where allowed by this Contract, shall be of the straight seam welded type unless specified otherwise herein.

The pressure-temperature ratings for seamless and ERW (welded with no filler) schedule wall pipe shall be based on minimum wall values, which are 87percent of the nominal pipe wall thickness per ASME B31.1. This allows for the minus 12percent manufacturing tolerance on wall thickness.

Fittings shall be constructed of materials equivalent to the pipe with which they are used. Unless otherwise specified herein or indicated on the Drawings, steel fittings DN 65 and larger shall be butt welding type and steel fittings DN 50 and smaller shall be socket welding type or threaded type. All fittings used in lube oil and hydraulic oil lines shall be butt welding type regardless of size.

Fittings shall be seamless unless specifically specified otherwise on the Drawings.

Safety/relief valve nozzles on the piping systems shall be set on weldolet or forged nozzle types. All nozzles shall be designed for the control of flow-induced vibration. Nozzles shall be designed in accordance with the requirements of ASME B31.1 Appendix II Rules for the Design of Safety Valve Installations including area replacement requirements per ASME B31.1. Nozzles shall be designed for dead weight and dynamic loading associated with safety/relief valve discharge and the design conditions provided in the Data Sheets. The internal geometry and dimensions as shown on the drawings shall be adhered to. A summary of the calculation results for the safety valve nozzle design including area replacement and drawings of nozzles shall be submitted for review to the Engineer.

The maximum allowable fluid velocities shall be as follows:

SERVICEVELOCITY

STEAM:

LP saturated ( 200 kPa35 m/s

LP superheated ( 200 kPa61 m/s

MP saturated ( 1400 kPa51 m/s

MP superheated ( 1400 kPa71 m/s

HP superheated v 0.062476 m/s

HP superheated v < 0.062471 m/s

Sub-atmospheric150 m/s maximum

Intermittent turbine bypass200 m/s maximum

Where v = specific volume, m3/kg

Heater Drains2.5 m/s maximum

Extraction Steam:

Superheated Steam (Any pressure)100 m/s maximum

Saturated Steam (Any pressure)60 m/s maximum

WATER:

General service 3 m/s

HP boiler feedwater6 m/s

Pump suction - low NPSH1.8 m/s

Pump suction - high NPSH3 m/s

Salt Water3.6 m/s

AIR:

Compressed air ((700 kPa)23 m/s

LIMESTONE SLURRY

30 wt%1.5 m/sec to 3 m/sec

30 wt% to 50 wt%1.5 m/sec to 3 m/sec

51 wt% to 70 wt%6 m/sec to 3 m/sec

GYPSUM SLURRY

0 wt% to 10 wt%1 m/sec to 3.7 m/sec

10 wt% to 30 wt%1 m/sec to 3.7 m/sec

31 wt% to 50 wt%4 m/sec to 3 m/sec

51 wt% to 70 wt%6 m/sec to 3 m/sec

HEAVY OIL:2.4 m/s

HEAVY OIL, PUMP SUCTION0.9 m/s

4.11.3.2Vent and Drain Piping Design Criteria

Vent and drain piping through design shall be consistent with the piping for the main piping system.

Vent connections shall be provided at high points in liquid piping and high points in other piping, including steam lines, that will be hydrostatically tested.

Drain connections shall be provided at non-drainable low points in liquid piping and other piping that will be hydrostatically tested.

Drain and vent connections shall be provided between the isolation valves for inline equipment such as pumps and strainers if not already included on the equipment.

Piping systems such as steam systems may have the high point vent valve omitted following hydrostatic testing, with the vent connection plugged by welding a cap/plug in place on the vent valve.

Vent and drain connections that require frequent operation shall be piped to a suitable drain away from walkways or work areas. Vent or drain connections that normally require operation with hot fluids shall be piped to a safe termination point (drain funnel or floor area discharge) away from walkways or work areas. Other connections shall terminate with the isolation valve.

Piping high point vents shall be valved and shall be DN 20 minimum size for piping sizes being vented that are equal to or greater than, DN 20. Vent and drain valves shall be provided with a chained cap/plug.

Vent and drain valves requiring frequent operation shall be readily accessible from walkways, platforms, or permanent man-ladders. Other less frequently used vents and drains may be accessed via temporary ladders, man lifts or temporary scaffolds. This would include vents required solely for system hydrostatic testing, filling, and, draining and manual drains from the bottom of steam drip pots.

Unless shown otherwise on the Drawings root connections on horizontal or sloping lines shall not be located below the centerline of the pipe. Root connections for service on steam and condensable vapors or wet gas shall be taken from the top side of the pipe or from any point between the top and the side. Root connections for service on liquids shall be taken from the side or top of the pipe, with the root nipple horizontal. Root connections for service on dry gases shall be taken from the top of the pipe. Double block root valves on high energy systems shall be supported from the header the line is tapping in order to reduce stresses at the connection.

4.11.3.3Pipe Design Pressure and Temperature

The design pressure for piping shall be consistent with conditions established for the design of the associated system.

The design pressure of a piping system generally shall be based on the maximum sustained pressure, which may act on the system during normal or upset operating conditions plus 175kPa, unless otherwise noted in the specific design parameters for the system. The piping system design pressure values shall be rounded up to the next 100kPa increment, unless otherwise noted. On systems with pumps, the maximum sustained pressure is generally the pump shutoff head at the maximum possible suction pressure based on cold water.

4.11.3.3.1High Energy Piping Design Pressure NOT USED4.11.4 4.11.3.3.1.1Piping Joints

4.11.4.1General

Joints in carbon steel and alloy steel pipes shall be made by butt welding for pipe sizes DN 65 nominal bore and over, and by socket welding for the smaller sizes.

Joints in the control oil and turbine lube oil piping shall be made by butt welding for all pipe sizes. Socket weld joints in the turbine hydraulic control oil, turbine lube oil and boilerfeed pump and turbine lube oil systems will not be accepted.

Butt welded joints shall be made without the use of backing rings. For pipes conveying steam , feedwater, condensate, oil (control oil, lube oil), and all stainless steel butt welds the root pass weld shall be by the tungsten inert gas process, the balance of the weld being completed using the shielded metal arc process. For other services butt joints can be by the shielded metal arc process throughout. Consumable insert rings may be used where considered necessary.

Electrode, filler wire and consumable insert materials shall be selected to match the mechanical and chemical characteristics of the parent pipe.

Butt-weld profiles shall be in accordance with ASME B16.25.

The proximity of adjacent welds shall be no less than 6 times the thickness of the material being welded. In the case of two different thickness of material to be welded, the thicker material shall govern.

4.11.4.2Flanges

Flanges shall be in accordance with the details and pressure-temperature ratings specified in ASME B16.5.

Flanges shall be constructed of materials equivalent to the pipe with which they are used.

Unless otherwise required, steel flanges DN 65 and larger shall be of the weld neck type and steel flanges DN 50 and smaller shall be of the socket type. Steel flanges shall have raised face flange preparation except when mating with valve or equipment where either material or manufacture results in a flat face flanged connection.

Carbon steel flanges shall not be used for temperatures exceeding 427 C.

4.11.4.3Gasket Material

The jointing material used for flanged joints shall be selected to accommodate thermal cyclic stresses and movements that will occur during all conditions including cyclic operation of the unit.

Compressed fiber gaskets shall be used with flat face flanges and slip-on raised face flanges. Spiral wound gaskets shall be used with raised face flanges other than slip-on flanges. The use of asbestos is forbidden.

Compressed fiber gaskets shall be in accordance with ASME B16.21 and materials shall be suitable for the maximum design pressure and the maximum design temperature of the service. Gaskets shall be dimensioned to suit the contact facing. They shall be full faced for flat face flanges and shall extend to the inside edge of the bolt holes on raised face flanges. Gaskets for plain finished surfaces shall be no less than 1.6mm thick and for serrated surfaces shall be no less than 2.4mm thick.

Spiral wound gaskets shall conform to ASME B16.20 and shall be constructed of a continuous stainless steel ribbon wound into a spiral with non-asbestos filler between adjacent coils. The gasket shall be inserted into a steel gage ring whose outside diameter shall fit inside the flange bolts properly positioning the gasket. The gage ring shall serve to limit the compression of the gasket to the proper value. Compressed gasket thickness shall be 3.3mm 0.13mm.

Rubber gasket materials shall be cloth inserted sheet rubber and shall conform to ASME B16.21. Gaskets shall be full face and 1.6mm thick unless otherwise required.

Ring joint gaskets shall be octagonal in cross section and shall have dimensions conforming to ASME B16.20. Material shall be suitable for the service conditions encountered and shall be softer than the flange material.

4.11.4.4Screwed Connections

Screwed ends shall have thread dimensions in accordance with the Pipe Threads, General Purpose, ASME B1.20.1 and be limited to DN 50 and smaller pipe sizes. Screwed connections are not permitted for underground piping.

4.11.4.5 Branch Connections

Branch connections shall be made by attaching the branch pipe directly to the run pipe by welding. If this procedure warrants the use of branch reinforcement as determined from ASME B31.1 then a branch fitting manufactured by a qualified supplier with successful experience shall be used, that shall provide a branch having a bursting strength equal to that of the unpierced run pipe.

4.11.4.6 Grooved Connections

Grooved end connections in accordance with AWWA C606, Grooved and Shouldered Joints are acceptable for water service and air supply.

4.11.5 General Fabrication Requirements

Circumferential butt welds shall not be located in the arc of any bend. Bends shall be smooth, without buckles, and truly circular. Allowable flattening, as defined by the ASME B31.1 Code, shall not be greater than 5 percent of the average measured outside diameter of the pipe before bending.

The Contractor shall provide allowance for thinning of the pipe wall, in accordance with its experience, its bending procedure, and the requirements of ASME B31.1, to ensure that the minimum wall thickness after bending is not less than the wall thickness as permitted by ASME B31.1 paragraph 102.4.5(B) utilizing the design conditions specified, the corrosion allowance specified, manufacturing tolerances, and bend thinning as applicable.

Pipe bending may be by the hot or cold bending method and to any radius that will result in a bend surface free of cracks or other defects and meet the design requirements for minimum wall thickness.

Where sand filled hot bending of pipe is utilized the pipe inside diameter shall be sand filled, tamped, and the pipe ends capped except where the wall thickness prior to bending is sufficient to ensure that no buckling of the bend will result when no interior sand packing is used.

Hot bending or other hot forging operations shall not be carried out on piping outside the temperature range of 899C to 1093C.

After bending, the Contractor shall verify the minimum wall thickness requirement for the pipe. Pipe bend thickness measurements shall be taken along the tension side of the bend arc, beginning at either tangent location and recorded for minimum wall thickness verification.

Hanger lugs, connections and structural attachments welded to the piping shall be of the same chemical composition to the piping and shall be in accordance with ASME/ASTM Standards. Such attachments shall be carefully designed to ensure the presence of sharp edged stress raisers is eliminated. Attachments (e.g. welded lugs and ears) for support of piping systems which shall be stress relieved shall be shop welded on fabricated pipe prior to stress relieving.

Thermal insulated pipes are to be supported by steel sleeves attached to the pipes. The outside diameter of these sleeves shall be covered by insulation.

Each fabricated pipe component shall be identified with its piece mark number painted on each end 180 apart. The same number and the location of the pipe to which it refers shall appear on the finalized piping arrangement drawings.

4.11.6 General Welding Requirements

The Contractor shall be responsible for the welding performed by its organization and shall establish its own welding procedures. The Contractor and its subcontractors shall be responsible for the development and qualification of all Welding Procedure Specifications, welders, and/or welding operators required to perform the Work including the supply of all testing materials and filler material required for the qualification of these procedures.

Welding shall be performed with qualified welding procedures which comply with Section IX of the ASME B&PVC.

Welders/welding operators shall be qualified in accordance with the test requirements of Section IX of the ASME B&PVC. Welders to be engaged for site work shall pass the welder qualification test at the site. Welder qualification from a previous employer is not acceptable.

Any welder who fails to meet the requirements of the Code shall not be accepted for a retest within the period of six months.

When welding with a gas shielded process, the wind velocity in the weld area shall not exceed 5 mph.

The welding filler metal shall have a chemical composition as similar as possible to the base metals to be welded. The finished weld as deposited, or after post weld heat treatment (PWHT) when required, shall be at least equal to the base metal as to strength, ductility, notch toughness, corrosion-erosion resistance, or other physical or thermal properties.

Shielded metal arc welding (SMAW), gas-shielded flux-cored arc welding (FCAW), submerged arc welding (SAW), gas metal arc welding (GMAW), or the gas tungsten inert gas welding (GTAW) process shall be employed in the Work. Other welding processes may be used only if specifically accepted by the Engineer/Owner. Requests to utilize other welding processes shall define where and to what extent the Contractor would propose to use the procedure.

Use Argon gas of purity at least equal to that of commercial welding grade as a purge to the reverse side of all GTAW welds, except for ASME P Numbers 1, 3, and 4 materials. Maintain this inert purge on the root pass and subsequent passes as necessary to prevent oxidation on the reverse side of the weld joint. The argon gas shall have a dew point of minus 40 degrees C.

Welding filler metal chemistry shall match that of the base material. Similar metallurgical properties, i.e., yield strength equal to or greater than base metal, equal or better corrosion-erosion resistance, and equal or better thermal properties, shall be produced.

As-welded surfaces are permitted, provided the surface of the weld/ welds shall be sufficiently free from course ripples, grooves, overlaps, abrupt ridges and valleys to permit the proper interpretation of radiographic and other nondestructive examinations as required by the Code.

Store welding filler metal and welding flux in their original unopened containers and in such a manner to ensure no moisture accumulation occurs in the weld rod. Storage, handling, and drying of SMAW electrodes and SAW flux shall, as a minimum, be in accordance with the manufacturers recommendations. In addition, SMAW low-hydrogen type carbon and low alloy steel electrodes shall be stored in ovens at 121C minimum after the hermetically sealed or vacuum packed container is opened. Bare rod in straight lengths shall be individually flag tagged, stamped, or otherwise identified with the AWS classification or product classification. Each spool of solid or cored wire shall be tagged, labeled, or otherwise identified with the AWS classification or product classification. Any SMAW low-hydrogen type electrodes that have been wet or have damaged coatings shall not be used. Any welding filer metals or fluxes not readily identifiable shall not be used. Reconditioning of electrodes is prohibited.

When electrodes are removed from the storage ovens they shall be issued in portable ovens to mitigate the possibility of the electrodes being exposed to moisture.

A maximum inter-pass temperature of 315C shall not be exceeded when welding carbon steels and low alloy steels.

Shop and Field personnel not qualified and certified as welders or welding operators are prohibited from performing any welding activity on materials designated for permanent or temporary installation by the Contract, such as tack welds or temporary welds.

4.11.7 Post Bending Heat Treatment

A post bending or post forming heat treatment is required on all carbon steel materials with a nominal wall thickness greater than 20 mm unless the bending or forming operations are performed and completed at a temperature of 899C or greater.

Ferritic alloy piping with a nominal pipe size of 100 mm and larger or with a nominal wall thickness of 13 mm or greater which has been heated for bending or other forming operations shall receive a tempering heat treatment.

All stainless steel pipe subject to bending shall be solution heat-treated in accordance with the requirements of the ASTM specification applicable to that pipe material.

Cold bending and forming of carbon steel having a wall thickness of 20mm and greater shall receive a stress relieving treatment.

Cold bending of carbon and ferritic alloy steel pipe in sizes and thicknesses less than those specified above may be carried out without the need for post heat treatment.

4.11.8 Pre-Heat of Welds

Butt weld joints in carbon and alloy steel piping shall be pre-heated to requirements specified in ASME B31.1. The base metal temperature prior to welding shall be at or above the specified minimum temperature in all directions at a distance as specified in ASME B31.1. Preheating shall be applied prior to any welding, cutting, or gouging operations.

Preheat treatment shall be performed with electric resistance, induction heating, or air-fuel gas torch heating methods. The use of oxy-fuel heating sources that introduce oxygen gas are prohibited such as gas rosebuds, welding or cutting torches is prohibited. Preheat and interpass temperature shall be monitored and checked by temperature indicating crayons, thermocouples, thermometers, or surface contact pyrometers.

Austenitic stainless steel components shall have a maximum interpass temperature of 177 C. Heat input for welding shall not exceed 55,000 joules per inch. Minimum preheat shall be 10 C.

Where preheating above 10 C is required, the interpass temperature shall be maintained at least equal to the preheat temperature.

4.11.9 Post Weld Heat Treatment of Welds

Post weld heat treatment of welds shall be in accordance with ASME B31.1.

When post weld heat treatment is performed in a furnace or locally, sufficient thermocouples shall be properly attached directly to the materials to accurately indicate the metal temperature uniformity throughout the heating, soak, and cooling cycle. Post weld heat treatment recorders shall be calibrated in accordance with the manufacturers standard or other suitable standard to ensure the accuracy of the recorded temperatures.

Thermocouples and thermocouple wire shall be Type K chromel/alumel. Thermocouple wire may be temporarily attached directly to materials by using the capacitor discharge method of welding. The capacitor discharge method of welding shall be performed in accordance with the requirements of the applicable Code.

Shop welds shall be stress relieved in a furnace, by local electric induction coils or by radient heating coils. Site welds shall be stress relieved locally by means of electric induction or electric radiant heating coils.

The proposed post heat treatment procedure including the time temperature chart for piping that is heat treated shall include the heating rates, cooling rates, holding time and holding temperature and shall be submitted to the Employer for the record.

Upon completion of post heat treatment of welds, shop and field piping welds shall be further examined by radiography or 100% ultrasonic testing where required by Table 136.4 of ASME B31.1.

4.11.10 Cleaning

Upon completion of fabrication and prior to shipping, all scale, weld spatter, sand, oil, dirt, and other foreign matter shall be removed from the inside and outside of piping by a pickling process or an approved method and grade of shot blasting.

Immediately following the pickling process, the outside of the piping shall be painted with a rust inhibiting paint to protect it from corrosion during shipping and storage and the inside protected from corrosion by an application of an approved rust inhibitor. Piping ends shall be provided with plastic or metal end-caps that are taped on to protect the internal surfaces from corrosion and foreign matter during transportation and site storage.

Clean all austenitic stainless steel piping, shop and field/job site, with rotary turbine cleaner, using new austenitic stainless steel rotary elements, after which piping shall be blown out with compressed air free of moisture and halides.

All tools used in fabrication of stainless steel shall be protected in such a way as to prevent contact with steel alloys or free iron. For wire brushing, bristles shall be stainless steel. Brushes shall be identified and controlled. Grinding shall be performed with resin or rubber bonded aluminum oxide or silicon carbide grinding wheels which are identified and controlled for their use on these materials only. Antispatter compounds, marking fluids, marking pens, tape, and other tools shall have a total halogen content of less than 200 parts per million.

Thoroughly clean all external carbon steel and alloy steel pipe and pipe support surfaces of loose dirt, rust, and mill scale in accordance with the requirements of SSPCSP6/NACE No. 3, and apply a primer coat(s) of inorganic zinc silicate paint to within 75mm of field weld connections to obtain a total dry film thickness (DFT) of 3.0 mils minimum. Surface preparation shall be in accordance with the paint manufacturers recommendation if more stringent than the requirements of SSPC SP6/NACE No. 3. Mix and apply coating in accordance with the requirements of SSPC-PA1 and the paint manufacturers recommendations. Omit paint from all areas of field welding, contact surface of field bolted connections, stainless steel, copper, plastics and other corrosion-resisting surfaces, and all nameplates.

Machined parts shall be covered with a rust inhibiting grease and openings shall be protected and sealed to prevent damage to weld ends and contamination of the pipe bore during handling, shipping and storage.

Following site erection, water piping system shall be flushed through with clean water to remove rust. The velocity of the flushing water shall be maintained at 60% above the normal operating velocities until no improvement in the cleanliness of the cleaning agent is observable. Air piping shall be blown with compressed air while steam and fuel piping shall be steam blown to remove foreign matters. The Contractor shall submit the details of steam blow to the Employer for the record.

4.11.11 Pipe Flexibility and Stress Analysis

The Contractor shall ensure the piping systems meet the requirements of ASME B31.1 with respect to thermal expansion and flexibility.

Where it is required that a comprehensive stress analysis be undertaken, those systems should be analyzed for the following conditions:

Pipe (and equipment) cold with full account being taken of cold spring incorporated in the line and due allowance being made for the dead weight of the piping. Tabulate maximum cold terminal reactions.

Pipe hot with two thirds of actual cold spring incorporated in the line and due allowance being made for the dead weight of the piping. Tabulate maximum hot terminal reactions.

Pipe hot with no allowance for cold spring and with due allowance for dead weight. For this calculation, the modulus of elasticity shall be the "cold" (i.e.; as erected) value for the material being used. Tabulate position and magnitude of maximum expansion stress and compare with the allowance stress range as defined in ASME B31.1.

The following information shall also be tabulated from the above calculations:

The displacement of pipe elements from the "as erected" position to the post cold spring position and from the post cold spring position to the final hot position.

The dead weight of the system to be supported at each hanger position.

The Contractor shall perform complete pipe flexibility and stress analysis using reputable, verified computer software.

Flexibility and hanger and load calculations shall be based on nominal pipe dimensions.

Flexibility analyses shall be made for each mode of operation of the equipment and the piping shall be designed for the worst case.

When requested for specific cases, the results of the analyses shall be submitted to the Employer in the form of tabulations and isometric sketches for the record. The location and magnitude of loads to be shown on the drawings together with pipe movements at support positions from the "as erected to "cold pull condition and from the "cold" to "hot" condition. The reactions at terminal points due to the restrained thermal expansion of the pipe shall also be included in the isometric drawings.

The main steam piping system and feed water piping system shall be designed to safely withstanding the stresses under normal operating condition as well as stresses resulting from on-load testing and rapid load changes. Similarly, the piping system shall withstand the stresses resulting from rapid valve closure on steam turbine trip under any load conditions. Systems shall be designed in accordance with the operating cycles as specified elsewhere in this Specification and shall also be capable of withstanding the normal piping stress reversal cycles that will occur during the life of the unit.

4.11.12 Hanger Design and Construction Requirements

Piping systems shall be supported in accordance with the requirements of ASME B31.1. The hangers and accessories shall be designed to avoid interference due to pipe movement and shall support the pipe under conditions of operation, allow unrestricted expansion of the piping and prevent excessive stress resulting from transferred weight being induced into the pipe or terminals. Supports shall be designed in accordance with the rules of MSS SP-58. Angle iron hangers and brackets shall not be used. A schedule for hangers shall be submitted by the Contractor before site erection. It shall contain hanger types, settings, maximum spacing between hangers, loading and travel for hot and cold condition. Locations of hangers shall be included on piping drawings, which shall be submitted to the Employer for the record prior to site erection.

The hangers shall be supplemented where necessary by spring type dampeners to eliminate pipe sway.

Hangers shall be designed with linkages to permit lateral and axial movements of pipe due to normal thermal expansion. Where these movements are excessive, the hanger assemblies shall be offset in the "as erected" condition to ensure proper vertical alignment when the piping system is in operation.

The use of constant load type hangers shall be indicated when the maximum vertical movement of the pipe at the support position exceeds 63mm. The supporting force exerted by constant load hangers shall not vary over the range of travel by more than 2 per cent from the rated load and they shall embody a suitable means for field adjustment of the supporting force through a range of 10 per cent of the rated load.

Spring and constant load supports shall have a total travel range of at least 25mm in excess of the specified maximum movement of the supported load. Travel scales shall be provided to indicate the position of the supported load and fitted with Hot and Cold indicators.

In determining the actual travel range of each supported load due recognition shall be given to load movement due to cold pull as well as that due to thermal expansion.

For hydrostatic tests, hangers shall be furnished with a removable travel stop, thereby preventing excessive pipe deflections due to dead weight.

When riser clamps are utilized stops or lugs shall be shop installed. Conventional pipe covering protection saddles shall be supplied for the cold reheat and feed water piping.

For alloy steel piping, alloy plate pipe covering protection saddles shall be supplied for use on under pipe and trapeze type assemblies.

Supports shall have screw adjustments workable when loaded. Threaded members shall have a true and complete depth of thread. Nuts, clevises, sleeves and turnbuckles shall have their full length of thread in complete service while in use, and the amount for available adjustment plainly visible. Sight holes are to be provided for visibility of parts where necessary to permit inspection.

Locknuts or other locking devices shall be furnished where necessary for adjustment, in which case, the locknuts should be on the right hand thread end if possible.

Hanger rods shall be designed with a minimum safety factor of 5, based on the ultimate strength of the material. Hanger rod diameters shall be compatible with the other component parts of the hanger assembly.

Notwithstanding the above, horizontal pipe clamps for rigid hangers shall be heavy duty 3-bolts construction fitted with locknuts as a minimum. Band and ring-type hangers for horizontal pipe runs shall not be used. The beam bracket for the hanger rod and welded/attached to the structure steelworks, if used, shall be one-piece construction.

Where additional supporting steel is required for the proper support of the pipes, this steel shall be indicated on the hanger sketches and shall be provided by the Contractor. Slight inaccuracies in punching shall be corrected by reaming, but unfair holes shall not be enlarged by drifting. Critical connections shall be assembled with high tensile steel bolts and set by torque wrench.

4.11.13 Rubber Lining NOT USED4.11.14 Field Run Piping

Piping DN 50and under shall be field run. Pipes shall be provided with spacing between pipes, doors, hatches, equipment, manways, structures, etc. to facilitate inspection and maintenance. Free access for valves and other in-line equipment operation and maintenance shall be provided, to permit unrestricted operation, component removal and sufficient maintenance letdown area.

4.11.15 Buried Piping

Underground carbon steel piping shall be complete with insulating flanges, wrapping/coating, and cathodic protection.

4.12 REQUIREMENTS FOR GRADE 91 Material (9Cr-1Mo-V) NOT USED4.13VALVES

4.13.1General

This section of Specification shall be read in conjunction with other relevant sections to enable a proper application and selection of valves to suit the equipment and system requirements.

Valves shall be designed in accordance with the requirements of ASME B16.10, ASME B16.34 and ASME B31.1.

Connections DN 65 and larger in nominal size shall be butt welded. Connections DN 50 and smaller in nominal size shall be socket welded. Weld ends shall be in accordance with ASME B16.25 Figures 4, 5B, or 6B for GTAW root pass in piping systems requiring a GTAW root pass.

The type of valves selected and supplied shall be suited to perform their respective system functions including the following:

Isolation with tight shut-off on closure

Minimum flow restriction when open

Regulation of flow

Back flow prevention

Pressure regulation

Pressure relief

Valves, except otherwise specified, shall be rising stem, outside screw and yoke. Non-rising stem designs may be used where space limitations dictate and compliance with code requirements are mandatory (such as NFPA), in which case a valve position indicator shall be installed.

In this Specification, ASME valve ratings have been specified. The Contractor may supply valves in accordance with the ra