installation of off- shore grp pipes

APPENDIX IV TO TECHNICAL SPECIFICATION

PART IV – MECHANICAL WORKS

MATERIAL SPECIFICATION, GENERAL PROCEDURES AND WORK

INSTRUCTIONS FOR OFF-SHORE INSTALLATION OF GRP PIPES

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KUWAIT OIL COMPANY (K.S.C.) (Register of Commerce № 21835) APPENDIX IV -to- TECHNICAL SPECIFICATION

PART IV - MECHANICAL WORKS - for - FIRE WATER SYSTEM FOR NORTH PIER PUMPING AND METERING STATIONS

MATERIAL SPECIFICATION, GENERAL PROCEDURES AND WORK INSTRUCTIONS FOR OFF-SHORE INSTALLATION OF GRP PIPES

1.0 General

This section provides the optimal specifications for GRP pipes used as seawater intakes and outfalls, as found in power generation/desalination plants and petrochemical complex. These specifications are the result of the long and successful experience of Future Pipe Industries in the design, manufacturing and installation of seawater intakes and outfalls through the Arabian Gulf Area.

2.0 Scope This specification includes the minimum requirements for design, manufacture, workmanship, testing, inspection and installation of GRP pipes used for seawater intake and outfall.

2.1 Manufacturer Pre-qualification

GRP pipes shall be manufactured by a manufacturing facility purposely built for the production of GRP pipe. The same facilities shall have at least 5 years experience in the production of large diameter (1.0m and larger) pipe, fittings and related products. Evidence of previous large diameter experience shall be available. All facilities shall have an approved quality management system complying with BS EN ISO 9001: 2000, which shall cover all activities being undertaken during design manufacturing and testing of the pipe, fittings and related products.

2.2 Manufacturer Responsibility

Manufacturer shall be responsible for conducting a full pipeline engineering study, through an ISO 9001 pipe system consulting engineer, including: • Pipeline Layout Drawings • Pipeline Profile Drawings • Hydraulic Design • Detailed Piping Isometric Drawings • Pipeline Connections Details to Pump House / Intake Structure. • Stress Analysis for Critical Areas • Bill of Materials

GRP pipe manufacturer shall also provide an experienced site services team to supervise and assist in the onshore pipeline installation.

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APPENDIX IV` TO TECHNICAL SPECIFICATION


FIRE WATER SYSTEM FOR NORTH PIER PUMPING AND METERING STATION

3.0 Applicable Codes and Standards

The following standards are referenced where appropriate.

AWWA C 950 Glass - Fiber - Reinforced - Thermosetting Resin Pressure

Pipe (2007).

AWWA M 45 Fiberglass Pipe Design (2nd edition).

BS EN1796 Plastics piping systems for water supply with or without

pressure Glass-reinforced thermosetting plastics (GRP)

based on unsaturated Polyester resin (UP).

4.0 GRP Pipe Description

4.1 General

GRP pipe shall be manufactured using the advancing mandrel process and consisting

of a corrosion resistant liner, a structural wall and a resin rich exterior layer.

a) Liner

GRP pipe shall have a resin rich liner reinforced with ‘C’ glass with a low

alkali content and impregnated with isophtalic polyester or epoxy based

vinylester resin. Resin content shall be 70% minimum of the liner weight. The

liner thickness shall not be less than 1.0 mm.

b) Structural Wall

The structural wall shall be as specified in AWWA C 950 for grades 1 through

4. Polyester resins shall be of the Isophthalic type.

c) External Layer

GRP pipes shall have a 0.25 mm thick resin rich exterior surface impregnated

with Polyester Resin (isophtalic).

4.2 Materials

a) Glass Reinforcements shall have a finish compatible with the impregnating

resin used.

b) Resins used shall be commercial high grade thermosetting polyester type as

specified above.

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4.0 GRP Pipe Description (Cont’d)

c) No pigments shall be used. No additives shall be used except for viscosity

control.

d) Fine aggregates may be used and shall be high purity silica.

5.0 System Requirements

5.1 Wall Thickness

GRP pipes up to and including 4000 mm diameter are of the solid wall type. Ribbed

piping shall not be allowed in any case. The wall thickness required for each

size/pressure class is established by the GRP pipe manufacturer to meet the design

requirement. In no case the wall thickness is less than 0.01xDN, where DN is the

nominal pipe inside diameter.

The pipe working pressure class is based on the hydrostatic design basis (HDB) of the

pipe with a design (service) factor of 1.8 as specified in AWWA-M45.

5.2 Dimensions

Dimensions of GRP pipes, used as seawater intake and outfall, shall follow the

dimensions as mentioned in AWWA-C950 2007 for OD controlled series. For ID

controlled series, the pipe internal diameter should be equal to the pipe nominal

diameter.

5.3 Length

GRP Pipes shall be manufactured in standard laying lengths of 12 meters. Small sizes

(DN<400mm) can have shorter length. Random short lengths; if supplied shall not

exceed 10% of the quantity supplied for each size. The tolerance on the declared

laying length shall be ± 25 mm.

5.4 Stiffness

The minimum pipe stiffness shall be 2500 N/m², when tested in accordance with

AWWA C 950. higher stiffness may be required for pipes where the cover depth

exceed 4 mtrs depending on the site and soil conditions. The manufacturer should

submit design calculation as per AWWA-M45 showing that the offered stiffness class

is suitable for the actual design condition and burial depth requirements.

5.5 Beam Strength

GRP pipes shall meet the minimum longitudinal tensile strength requirements

specified in AWWA C 950 for the appropriate Pipe pressure rating.

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5.0 System Requirements (Cont’d)

5.6 Joints

Standard sea water intake pipe with unrestrained joints shall be filament wound GRP

coupling (double bell couplings), all with confined rubber ring gaskets. Rubber rings

shall be of natural or synthetic rubber conforming to BS 681 or ASTM F477, and

resistant to sea water. Joints deviation, while remaining water tight at 1.5 times the

pipe operating pressure, is as per Table 2. A joint deflection illustration is given in

Figure 1. The rubber rings shall be the sole element depended upon for water

tightness.

Nominal

Diameter (mm)

Maximum Joint

Deflection Offset(mm)

400-500 3o 628.9

600-900 2o 419

1000-1200 1.5o 314.2

1300-1800 1.5o 209.5

1900-4000 0.5o 104.7

Table 2

5.7 Workmanship

a) GRP pipe and joints shall be free from delaminations, cracks, bubbles,

pinholes, pits, blisters, foreign inclusions and resin-starved areas that due to

their nature, degree or extent, detrimentally affect the strength and

serviceability of the pipe. No glass fiber reinforcements shall penetrate the

interior surface of the pipe wall.

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5.0 System Requirements (Cont’d)

5.7 Workmanship (Cont’d)

b) Joint sealing surfaces shall be free of dents, gouges, delaminations, or other

surface irregularities that will affect the integrity of the joints.

c) GRP pipe shall be as uniform as commercially practicable in color, opacity,

density and other physical properties.

5.8 Fittings

a) GRP fittings such as bends, tees, junctions and reducers shall be equal or

superior in performance to the pipe of the same diameter and pressure. All

fittings shall be finished smoothly internally.

b) Large diameter fittings (Diameter greater than 400 mm) are of mitered

construction.

c) For gravity applications no thrust blocks are required at direction changes.

d) For the fittings, the deviation from the stated value of the angle of change of

direction of a bend, tee, junction etc. shall not exceed ± 1º.

e) The tolerance on declared length of fitting, shall be ± 10 mm taken from the

point of intersection to the end of the fitting or ± 10 mm on a straight fitting.

f) All fittings should be manufactured by the GRP pipe manufacturer.

6.0 Design Parameters

GRP pipes shall meet the following minimum design requirements:

6.1 Operating Pressure (Pw) As specified ; Min. 100 kPa

6.2 Additional Surge Pressure (Ps) 40% unless otherwise specified

6.3 Minimum earth cover for 1.0 m

buried pipe.

6.4 Initial Installed deflection 1.5 % Max. for ribbed pipe

for buried pipe

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6.0 Design Parameters (Cont’d)

6.5 Long term installed deflection 3.0 % Max. for restrained pipe

for buried pipe 5.0% Max. for non-restrained pipe

7.0 Quality Control

Quality control testing will include through checks for both pipe and fittings. The

following physical and dimension checks will be made:

Type of Test Each Pipe Once per shift Standard

Reference

Wall thickness x FPI

Visual inspection outside x FPI

Diameter spigot end x FPI

Length x FPI

Stiffness x ASTM D 2412

Barcol Hardness x ASTM D 2583

Loss on Ignition (LOI) x ASTM D 2584

Axial Tensile Strength x ASTM D 638

Table 3

Records of all testing on pipe sections will be maintained in house

8.0 Physical / Mechanical Properties

8.1 Dimensions

Laying Length (IL)

Standard length Random lengths

may be supplied not exceeding

10% of the order

12 – 18 m ± 25 mm

Roundness Deviation Pipe shall be round ±2 mm from nominal

diameter

End Squareness End shall be both square to the

axis of pipe and plane

±2 mm from nominal

diameter

8.2 Stiffness

Minimum specific stiffness shall not be less than 2500 N/m².

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8.0 Physical / Mechanical Properties (Cont’d)

8.3 Thermal Expansion

The approximate axial coefficient of thermal expansion shall be 18 - 27 x 10-6 cm/cm

x ºC (measured according to ASTM D 696).

8.4 Burial Depth

The maximum burial depth per stiffness class shall be as follows:

Burial Depth

m

Stiffness

N/m2

Type of

Backfill

up to 3.0 m 2500 Sand/Gravel



Table 5

Note: All pipes passing Intake Structures and Outfall Structures shall be 10,000

N/m2.

8.5 Poisson’s Ratio

Poisson’s ratio’s due to hoop load 0.3

Poisson’s ratio’s due to longitudinal load 0.25

9.0 Visual Acceptance

GRP pipes shall be free from all defects, including delaminations bubbles, pins, holes,

cracks, pits, blisters, foreign inclusions, and resin starved areas that, due to their

nature, degree, or extent, detrimentally affect the strength and serviceability of the

pipe. The pipe shall be as uniform as commercial practicable in color, capacity,

density and other physical properties.

Visual Characteristics Definition Allowable Limits

Delamination Separation in the laminate None

Blisters Light (straw coloured areas

resulting from too hot a cure)

None to exceed 13

mm in diameter

Haystacks Accumulation glass resin and

sand on exterior surface

None greater than 30

mm Diameter

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9.0 Visual Acceptance (Cont’d)

Visual Characteristics Definition Allowable Limits

Torn Edges End

Delaminations and End

Gouges

Tears and rips the edges of cuts

None which will

affect the integrity of

the joints

Ground Area

Area around lay-up which has

been abraded but lay-up doesn’t

cover or has not been coated

with resin

Not Permitted

Table 6

10.0 On-shore Buoyancy Considerations

Where the pipe is to be installed on-shore within water table level, proper

considerations have to be taken to prevent pipe flotation. In general, a minimum soil

cover equal to one pipe diameter should be kept above the pipe crown to prevent

flotation.

11.0 Highlights of joining GRP pipes for Onshore Operations

11.1 Clean Coupling:

Thoroughly clean the grooves inside the Double Bell Coupler and the Gasket Rings,

to avoid any dirt or oil present.

11.2 Install Gaskets:

Insert the gasket in to the grooves, leaving two to four uniform loops of rubber to

extend out of the groove. With uniform pressure push each gasket in to the gasket

groove. Tapping with a rubber hammer will be helpful in this mission.

11.3 Lubricate the gaskets

Using a clean cloth apply a thin layer of lubricant to the gaskets.

11.4 Clean and Lubricate the spigots:

Clean the Pipe spigot and apply a thin film of lubricant.

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11.0 Highlights of joining GRP pipes for Onshore Operations (Cont’d)

11.5 Fixing of Clamps:

Clamp A is fixed anywhere on first Pipe (refer to Figure 2) or left in position from

previous joint. Fix clamp B on the Pipe to be connected in the correct position relative

to the alignment stripe on the spigot – end so as also to act as stopper.

Figure 2

11.6 Pipe Placement

The Pipe to be connected is placed on the bed with enough distance from the

previously joined pipe to allow lowering the coupling in to position.

11.7 Fixing of the Coupling:

Come-along jacks are installed to connect the Pipe clamps and two 10 cm x 10 cm

timbers or similar are placed between the Pipe previously connected and the coupling.

While these are held in position, the new pipe is entered in to the coupling until it

rests against the Pipe clamp. Come along jack might need protective plank under it in

order not to touch against the Pipe (refer to figure 3)

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11.0 Highlights of joining GRP pipes for Onshore Operations (Cont’d)

11.7 Fixing of the Coupling: (Cont’d)

Figure 3

11.8 Jointing Pipes:

Come along jacks are loosened and the timbers removed before re-tightening the jacks

for entering the coupling on to the previously connected Pipe. Check the correct

position of the edge of the Coupling to the alignment stripe (Refer to figure 4).

After the above step clamp B is left in position and clamp A is moved on to the next

Pipe to be joined.

Figure 4

For example, by using a Crew of 12 skilled technicians with one supervisor, 6

Pipes, DN 3100 mm, can be jointed per day.

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12.0 Off-shore Installation of GRP Seawater Intake Pipes

12.1 Pipe Preparation for Offshore Installation:

Three to Four sections of GRP pipes (each Pipe with 12 – 18 m length) will be

connected together by the above mentioned method, Onshore, taking care to align the

Marine Harness lugs. The Marine Harness Lugs will be jointed by tie rods, which will

fix the adjacent pipes together and will prevent the pipes from slipping out of the

DBC while handling (see figure 5)

A fourth coupler will be placed at the end of the each section. The easiest way will be

by using nylon straps as chokers around the Pipes and then pulling the coupling in to

the Pipe using a come along jack and a 3 or 4 points pulling frame (see figure 6).

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12.0 Off-shore Installation of GRP Seawater Intake Pipes (Cont’d)

Figure 6

Pipes should be placed on pre-formed wooden Cradles, on the Barge, to ensure proper

support.

12.2 Excavation and Bedding preparation:

The trench should be excavated in such a way so as to allow the placing of 15 cm

bedding. The bedding should be reasonably leveled so that the Pipe is well supported.

The maximum burial depth recommended for 2500 N/m² STIS pipes is 3m. If higher

cover depth is required, especially next to the Pump house wall, higher stiffness Pipes

will be given to meet the respective cover required.

12.3 Placing the Pipe in the Trench:

The section of the Pipes joined together, as mentioned above, will be lifted by using

Crane and spreader beams with nylon slings, with, two nylon slings between each

DBC joints. The use of nylon straps tied around the end of the Pipe will be used to

control the movement while in air, particularly in windy conditions. The pipe should

be positioned in the lifting slings GRP pipes are light weight, thus it doesn’t require

heavy mechanical loading equipment. For example to lift a section of 36 m, with a

nominal diameter of 3100 mm, a Crane with capacity of 20 Tons, only, will be

required.

12.4 Special Instruction for the Pipes laying in the water

a) Case of no under current

Pipe Alignment

The trench is prepared to allow the placing of the bedding. As it is difficult to

be in completely level the bedding, the easiest way to align the pipe is to allow

gravel pad at 6 m intervals. The pipes are placed on these pads, as shown in

figure 7.

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12.4 Special Instruction for the Pipes laying in the water (Cont’d)

Pipe connection

The pipes are lowered in the water at an angle of 15°. Once submerged, the

pipe is guided into position by divers. The spigot end of the pipe is placed into

the coupling in the end of the previously laid pipe. The gravel pads mentioned

earlier will help in the alignment of the pipe and provide support.

Draw the spigot end of the pipe into the coupling until the black alignment

stripes on the spigot align with the edge of the coupling. This connection can

be done by means of Hydraulic Jacks or by just tightening the bolts of the

marine lugs.

b) Case of under current

Pipe Alignment

The trench is prepared to allow the placing of the bedding. Guides are placed

in the ground to help in the alignment of the pipe. These guides are placed on

the sides of the pipe (not beneath it) and are left in the seabed after installation.

A Steel frame (holding frame) is connected to hold the pipe while lowering it.

The pipes are lowered at 15° depending on the size of the pipe and the

equipment used. Two sections of 36m up to 48 m can be lowered at the same

time.

In order to ensure a perfect alignment, the H-Beam shown in figure 8 could

coincide with the guides already in the ground.

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12.0 Off-shore Installation of GRP Seawater Intake Pipes (Cont’d) 12.4 Special Instruction for the Pipes laying in the water (Cont’d)

Backfilling works (Stage one)

Figure 8

Pipe connection The spigot end of the pipe is draw into the coupling until the black alignment stripes on the spigot align with the edge of the coupling. This connection can be done by means of hydraulic jacks or by just tightening the bolts of the marine harness lugs.

c) Backfilling the pipe

Stage one Backfill material is placed in the bed area and near the haunches of the pipe. A “Toyo” pump with a discharge hose is used to ensure that the backfill is inserted to the haunches. The pipe creates a vacuum that sucks the material to the haunches. Please refer to figure 8.

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12.0 Off-shore Installation of GRP Seawater Intake Pipes (Cont’d) 12.4 Special Instruction for the Pipes laying in the water (Cont’d)

Stage Two

The backfill material is placed to 75% of the pipe internal diameter. Please refer to

figure 9.

Figure 9

Stage Three

The backfill is completed to the required height. In case the currents are strong, Rip

Rap rock may be placed above the backfill material to secure it and prevent soil

migration. Please refer to Figure 10.

Figure 10

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Note: Before jointing a new pipe section, the previous one should be partially

backfilled (stage 2) in order to allow no deviation in the alignment.

GRP pipes for offshore application are easy to install. For example, a crew of 8 divers

are required to handle pipe sections with a nominal diameter of 3100 mm, under the

water. The crew can perform the installation of 72 m, of the same pipes, per day.

12.5 Intake Structure

The intake pipe is normally connected to a concrete intake structure. This structure is

provided with a suitable wire mesh to prevent foreign matter (fish, debris,…) from

entering the pipe. More details are shown in figure 11.

Typical Intake Structure

Figure 11

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12.6 Access Manholes

The offshore portion of the pipeline is provided with access manholes. These are

suitable sized and placed unequal tees that provide access to the pipe interior. A

typical manhole is shown in Figure 12.

13.0 GRP Chlorination Pipe

13.1 General

This section covers the minimum requirements for GRP chlorination pipes.

13.2 Product Description

a) General

GRP pipes shall be machine-made filament wound consisting of a corrosion resistant

liner, a structural wall and a resin rich exterior layer.

Liner

GRP pipes shall have a resin rich liner reinforced with ‘C’ glass and impregnated

with

Epoxy based vinylester. The liner thickness shall not be less than 1.0mm.

Structural Wall

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13.0 GRP Chlorination Pipe (Cont’d)

13.2 Product Description (Cont’d)

The pipe structural wall shall be as specified in AWWA C 950 for Grades 1

through 4.

Epoxy-based Vinyester resin should be used in the structural wall of the

chlorination line.

External Layer

Pipe shall have a 0.25 mm thick resin rich exterior surface impregnated with resin.

b) Materials

Glass reinforcements shall have a finish compatible with the impregnating resin

used.

Resins shall be a commercial high-grade thermosetting type as specified above.

No pigments shall be used in the GRP pipe or joints. No additives shall be used

except for viscosity control.

13.3 Requirements

a) Wall Thickness

The wall thickness required for each size/pressure class shall be established to

meet the design requirements but in no case shall the wall thickness be less

than 3.5 mm. The pipe working pressure class shall be based on the

Hydrostatic Design Basis (HDB) of the pipe with a design (service) factor of

0.5.

b) Length

The pipe shall be manufactured in standard laying lengths of not greater than

12 meters depending on diameter. Random short lengths: if supplied shall not

exceed 5% of the quantity supplied for each size. The tolerance on the

Manufacturers declared laying length shall not exceed ± 25mm.

c) Stiffness

The pipe stiffness shall be in no case be less than 5000 N/m2, when tested in

accordance with AWWA C950 or BS 5480.

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d) Beam Strength

The offered pipes shall meet the minimum longitudinal tensile strength requirements

specified in AWWA C950 for the appropriate Pipe pressure class.

13.4 Joints

a) Flexible Joints

GRP pipes, used for chlorination, shall be joined with a restrained rubber seal lock

joint. The rubber ensures the sealing while the fixation rods secure the restrain. The

joints have to be stretched during installation.

Figure 13

b) Rigid Joints

Flanges

GRP flanges are filament wound and drilled to standard ANSI B16.5 (150 lb Flanges)

dimensions depending upon pipe size. These flanges are designed to be used in pipe

systems, which incorporate thrust blocks. GRP flanges can be drilled to other

standards (DIN, ISO, BS etc...)

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Figure 14

13.5 Workmanship

a) GRP pipes and joints shall be free from delamination, cracks, bubbles, pinholes,

pits, blister, foreign inclusions and resin-starved areas that due to their nature, degree or extent detrimentally affects the strength and serviceability of the pipe. No glass shall penetrate the interior surface of the pipe wall.

b) Joint sealing surfaces shall be free of dents, gouges, delaminations or other

surface irregularities that will affect the integrity of the joints.

c) GRP pipe shall be as uniform as commercially practicable in color, capacity, density and other physical properties.

13.6 Fittings

a) GRP fittings such as bends, tees, junctions and reducers shall be equal or

superior in performance to the GRP pipe of the same diameter and pressure. b) For the fittings, the deviation from the stated value of the angle of change of

direction of a bend, tee, junction etc. shall not exceed ± 1º. c) The tolerance on the manufacturers declared length of fitting shall be ± 10mm

taken from the point of intersection to the end of the fitting or ± 10 mm on a straight fitting.

d) All fittings when mitered shall be fabricated by the GRP pipe manufacturer.

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13.7 Fixation

The chlorination pipe shall be fixed in the intake pipeline on cradles with Fiberglass

bolts. The cradles shall be fixed at 120º from vertical position.

13.8 Maintenance Requirements

For flushing the line a double flange piece is supplied at the manhole location. This

will allow to dismantling this part to flush the line for any residual flakes.

installation of off- shore grp pipes

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