SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

 

SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

www.hvacmepcontractors.com SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

TABLE OF CONTENTS

 

INDEX Page#

I. Purpose.............................................. .......................03

 

2. Scope of Work.................................... ......................03

 

3. Reference.......................................................................03

 

4. Responsibilities...............................................................04

 

5. Delivery, Storage, Handling and Preservation ................05

 

6. Qualification of Installer................................................. 06

 

7. Joining Method I Procedure of HDPE Pipes (PE) .............06

 

7.1 Types of Joints (HDPE) ............................................. .....07

 

7.2 Pipes Joining (HDPE) ................................................... ....07

 

8. Installation I Assembling of HDPE Pipes ............................08

 

9. Joining Method I Procedure of PVC I uPVC Pipes .................09

 

9.1 Types of Joints (PVC/uPVC) .................................................09

 

9.2 Pipes Joining (PVC  uPVC) ................................. ................. 10

 

9.3 Installation/Assembling of PVC/uPVC Pipes ....................... 11

 

10. Trench Preparation .................................. ................... 12

 

10.1 Preparation of Bedding Layer. ........ .........................12

 

10.2 Lifting and Installation of Pipes in the Trench............12

 

10.3 Multiple Pipes in one Trench ..................................... 13

 

11. Inspection and Test Plan ............................................... 13

 

) 1.1 Testing Requirements................................ .......... ......14

 

12. Backfilling....................... .... ...... ...... ............ . ............. 14

 

13. Safety Requirements ..................................................... 15

 

1. PURPOSE

To provide the basic technical information to the user in order to achieve the

Accomplishments without any un-usual.

To ensure that all High Density Polyethylene pipe (HDPE) and PVC/uPVC

Piping installation are carry out in an efficient and effective manners, so as to

Provide a product services which conform to all specification, codes and

Standards requirement of the project.

2. SCOPE OF WORK

This procedure covers the field Electro Fusion, Mechanical and Flanged joints

and present general guidelines to field joining process on HDPE & PVC/uPVC

piping for the construction of STP & RO plant. This procedure is applicable to all

HDPE and PVC/uPVC pipe diameters.

3. REFERENCES

Hvac mep contractors Engineering Standards

•           HVAC MEP CONTRACTORS ES-A-004 General Requirements for Pressure Testing

•           HVAC MEP CONTRACTORS ES-L-350 Construction of Plant Piping

•           HVAC MEP CONTRACTORS ES-L-610 Non-metallic Piping

•           HVAC MEP CONTRACTORS ES-S-010 Sanitary Sewers

•           HVAC MEP CONTRACTORS ES-S-020 Industrial Drainage and Sewers

•           HVAC MEP CONTRACTORS ES-S-060 Hvac mep contractors Plumbing Code

•           HVAC MEP CONTRACTORS ES-B-017 Firewater System Design

•           HVAC MEP CONTRACTORS ES-A-104 Wastewater Treatment, Reuse and Disposal

•           HVAC MEP CONTRACTORS ES-A-114 Excavation and Backfill

Hvac mep contractors Materials System Specifications

•           01-SAMSS-024 Pipe Handling and Nesting

Hvac mep contractors Standard Drawings

www.hvacmepcontractors.com SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

•           AB-036155 Supports for Plastic Piping

•           AB-036880 Sleeved Crossing for Restrained Pipelines

Industry Codes and Standards

•           ASME B31.3 Chemical Plant & Petroleum Refinery Piping

•           AWWA C901-08 Polyethylene (PE) Pressure Pipe and Tubing, Y, In. (13

mm) 3 In. Through (76 mm) for Water Service.

•           AWWA C906-15 Polyethylene (PE) Pressure Pipe and Fittings, 4 In.

Through 65 In. (100 mm Through 1,650 mm), for Waterworks

•           ASTM 02321 Underground Installation of Flexible Thermoplastic Sewer

Pipe

•           ASTM 02564 Solvent Cement for PVC Plastic Pipe and Fittings

•           ASTM 02855 Making Solvent Cemented Joints with PVC Pipe and Fittings

•           ASTM F402 Safe Handling of Solvent Cements and Primers Used for

Joining Thermoplastic Pipe and Fittings

•           ASTM F493 Solvent Cements for CPVC Plastic Pipe and Fittings

•           ASTM F585 Insertion of Flexible Polyethylene Pipe into Existing Sewers

The Plastics Pipe Institute

•           PPI Handbook of Polyethylene Pipe

•           Polyethylene Joining Procedures

•           Underground Installation for Polyethylene Plastic Pipe

4. RESPONSIBILITIES

Project Manager

The Project Manager has the overall responsibility of verifying and

Implementing this Method Statement.

Site Construction Manager

The Site Construction Manager is responsible for reviewing this procedure of

this method statement and of any subsequent revision. He is also responsible

for ensuring that all works are performed timely, properly, accurately and

completely and aside from making sure that corrective action is taken in case

the work is not done correctly.

QC Manager

The QC Manager is responsible for reviewing this procedure and also has

the overall responsibility of ensuring that works in the field are performed in

compliance with all applicable quality standards, stipulations and procedures

in addition to ensuring that corrective actions are taken in cases where

works are not performed correctly.

Quality Control Inspector

www.hvacmepcontractors.com SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

•           Conducts daily in-house inspections of completed portions of work in

•           Coordination with the Project Engineer and ensures that all corrective

actions necessary from the comments during the inspections are

Performed promptly by the Site Engineer and/or Foreman.

•           Submits the RFI (Request for Inspection) to PIO and coordinates with

them on the relevant inspection required after in-house verification of the

•           completed work by the construction team to ensure compliance to the

specification requirements.

•           Ensures all inspections are performed and all relevant inspection forms are accomplished as per Project Specifications and applicable ITP.

•           Coordinates with the Site Engineer and Hvac mep contractors Representative

during inspections

•           Secure quality documents approval

5. DELIVERY, STORAGE, HANDLING & PRESERVATION

Delivery, Storage & Handling

•           On site pipe storage shall meet all manufacturers' requirements.

•           Solvent cement and primer for thermoplastic piping shall be stored in an air-conditioned building with a maximum temperature of26.rC.

•           Pipe and fittings shall be properly protected from impact, especially on their

ends. They shall not be thrown, dropped, bumped, hit, or dragged and pushed over abrasive surfaces.

•           Adhesive and solvent cement containers shall be tightly closed when not in

use, and shall be returned to the storage facilities to minimize exposure to

excessive temperatures.

•           Transport individual pipe lengths to the job site on padded bunks with nylon

tie-down straps or padded bonding to protect the pipe.

•           Coiled HOPE pipe shall be stored in a manner to ensure safety.

•           Protect the pipe from sharp objects.

•           Anchor pipe securely to prevent slippage.

•           Store individual pipe lengths on earth beams or timber cradles in the

numerical order of installation.

SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

 

•           Stack the heaviest series of pipe at the bottom. Do not stack pipe in excess

of 20-rows high.

•           Protect the pipe from stones and sharp objects.

•           Store fittings in their original cartons.

•           Lift pipes with handling beams or wide belt slings near the middle of joints

as recommended by the pipe manufacturer.

•           Do not use cable slings, chains, or hooks.

•           Before installation, check pipe and fittings for cuts, scratches, gouges,

buckling, kinking, or splitting.

•           Remove any pipe section containing defects by cutting out the damaged

section in a complete cylinder.

•           All the damaged pipe should be stored in quarantine area with identification

marie

PRESERVATION

www.hvacmepcontractors.com SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

•           Solvent cement primer and adhesive containers shall be protected from

direct sunlight.

•           HDPE/PVC/uPVC pipes must be covered with suitable sheet or should

be stored under shade in order to avoid damage the material due to

direct sun light.

•           Material storage area should be visited and inspected all material on

weekly basis.

•           For long term storage, pipe racks should provide continues support, but

if this is not possible, timber of at least 3in bearing width at spacing not

greater than 2ft. centers for pipe sizes 160mm and above should be

placed beneath the pipes and at 1.5m centers at the side, if the stacks

are rectangular.

•           For temporary storage in the field, where racks are not provided, the

ground should be level and free from loose stones. Pipes should not

exceed three layer high and should be stacked to prevent.

•           Stack heights should be reduced if pipe are nested, etc .. pipes stored

inside pipes of larger diameter. Reduction in height should be

proportional to the weight of the nested pipe compared to the weight of

the pipes nonnally contained in such stowage.

•           Any primer, solvent cement, or adhesive that is beyond the stamped

expiration date shall be discarded. Solvent cement that has gelled or

thickened shall be discarded. Leaking or opened containers shall also

be discarded

6. Qualifications of Installers of Plastic Piping

Each operator performing fusion joining shall be qualified in the use

of the manufacturer's recommended fusion procedure(s) by the

following:

Appropriate training or experience in the use of the fusion procedure.

1.         Making a sample joint according to the procedure that passes the following

inspections and tests:

a)         The jOint shall be visually examined during and after joining and

found to have the same appearance as a photograph or sample of an

acceptable jOint that was joined in accordance with the procedure;

and

b)         The joint shall be tested or examined by 1 of the following methods:

•           Pressure and tensile test

•           Ultrasonic inspection and found to be free of flaws that would

cause failure

•           Cut into at least 3 longitudinal straps, each of which is :

•           Visually examined and found to be free of voids or unbonded

areas on the cut surface of the joint, and

•           Deformed bending, torque, or impact and if failure occurs, it must

not initiate in the joint area.

2.         Each operator shall be re-qualified under the procedure if during any 12­

month period:

a)         Operator has not made any joints under the procedure; or

b)         Operator has 3 joints or 3% of the joints made, whichever is greater,

that are found unacceptable by testing according to same procedure.

7. Jointing METHOD I ASSEMBLY PROCEDURE OF HOPE PIPES (PE)

Installation of High-Density Polyethylene Pipe. All high-density polyethylene

(HOPE) pipe shall be assembled, and installed in accordance with AWWA

code, manufacturer's recommendations, and this procedure

1.         Pipe 1/2-inches (13-mm) through 3-inches (76-mm) shall conform to AWWA

C901.

2.         Pipe and Wings 4-inches (102-mm) through 60-inches (1 ,524-mm) shall

confine to AWWA C906.

7.1 TYPS OF JOINTS

www.hvacmepcontractors.com SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES  types of joints

A.         Bun FUSION JOINING

B.         ELECTRO FUSION JOINING

C.         COMPRESSION (Quick Fix) JOINING

D.         FLANGE CONNECTION

E.          MECHANICAL JOINING

Sections of polyethylene pipe shall be joined into continuous lengths on the

job site above ground. The joining method shall be the butt fusion,

Mechanical and Flanged joint method and shall be performed in strict

accordance with the pipe manufacturer's recommendations. The butt fusion

equipment used in the joining procedures shall be capable of meeting all

conditions recommended by the pipe manufacturer.

If a procedure noted below contradicts manufacturer's recommendations,

follow the manufacturer's recommendation.

SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

7.2 PIPES JOINING

A.         Heat Fusion (Butt Fusion) Joint

a) Maintain the proper temperature of the heater plate as recommended by

the pipe manufacturer. Check it with a tempilstik

or pyrometer for correct surface temperature.

b)         Clean pipe ends inside and outside with a clean cotton cloth to remove

dirt, water, grease, and other foreign materials.

c)          Square (face) the pipe ends using the facing tools on the fusion machine.

Remove all burrs, chips, and fillings before joining pipe or fittings.

d)         Check the line-up of pipe ends in the fusion machine to see that pipe ends

meet squarely and completely over the entire surface to be fused. The

clamps shall be tight so that the pipe does not slip during the fusion

process.

e)         Insert the clean heater plate between the aligned ends and bring the ends

firmly in contact with the plate but do not apply pressure while achieving

the melt pattern. Allow the pipe ends to heat and soften. Softening

depths shall be per the manufacturer's recommendation.

£)         Carefully move the pipe ends away from the heater plate and remove the

plate (if the softened material sticks to the heater plate, discontinue the

joint, clean heater plate, square pipe ends, and start over).

SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

g)         The melted ends shall be connected rapidly but not slammed together.

Apply enough pressure to form a double rollback bead to the body of the

pipe around the entire circumference of the pipe about 1I8-inch (3.175­

mm) to 3/16-inch (4.763-mm) wide. Pressure is necessary to cause the

heated material to flow together.

h) Allow the joint to cool and solidify properly. Remove the pipe from the

clamps and inspect the joint appearance.

B.         Flanged Joints

www.hvacmepcontractors.com SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES
FLANGE JOINT

i)           Flange adapters shall be pressure rated the same as the pipe. Flange

adapters shall be heat fused to the pipe as outlined in the heat fusion

section.

j)          Gaskets shall be used between the polyethylene flange adapters when

recommended by the HDPE pipe manufacturer. Sufficient torque shall

be applied evenly to the bolts to prevent leaks. After initial installation

and tightening of flanged connections, allow the connections to set for a

few hours then conduct a final tightening of the bolts.

k)         Lubricate nuts and bolts with oil or graphite prior to installation.

I)          Check operation of valves connected to molded stub end flange adapters.

Insert polyethylene spacer if recommended by pipe manufacturer for

clearance

C. Mechanical Joints

m) Wipe the socket and the plain end clean. Lubrication and additional

cleaning should be provided by brushing both the gasket and plain end

with an approved pipe lubricant just prior to slipping the gasket onto the

plain end for joint assembly. Place the gland on the plain end with the lip

extension toward the plain end, followed by the gasket with the narrow

edge of the gasket toward the plain end.

n)         Insert the pipe into the socket and press the gasket firmly and evenly into

the gasket recess. Keep the joint straight during assembly.

0)         Push the gland toward the socket and center it around the pipe with the

gland lip against the gasket. Insert bolts and hand tighten nuts. Make

deflection after assembly but before tightening bolts.

p)         Tighten the bolts to the normal range of bolt torque as indicated in

A WW A C-600 while maintaining approximately the same distance

between the gland and the face of the flange at all points around the

socket.

SPECIAL PROCESS FOR INSTALLATION AND JOINING OF HDPE (PE) & PVC/uPVC PIPES

q)         When connection is being made to HDPE pipe or fittings use a welded

flange to connect to fittings.

NOTE:             Butt fusion joining shall result in joint weld strength equal to or greater

than the tensile strength of the pipe. Socket fusion shall not be used,

Extrusion welding or hot gas welding of HDPE shall not be used,

Flanges, unions, grooved-couplers, transition fittings, and some

mechanical couplers may be used to connect HDPE pipe

mechanically without butt-fusion only where shown in the Drawings,

8. INSTALLATION I ASSEMBLY OF HDPE PIPES

WWW.HVACMEPCONTRACTORS.COM INSTALLATION I ASSEMBLY OF HDPE PIPES

A.         HDPE piping shall be installed as per the manufacturer's instructions in

conjunction with PPI Handbook of Polyethylene Pipe.

B, Underground HDPE sewer piping shall be installed in accordance with

ASTM 02321.

JOINING OF HDPE (PE) & PVC/uPVC PIPES s.s.e.m.

C.         Slip lining of existing sewer pipe with HDPE pipe shall be in accordance

with ASTM F585

D.         Flange adapters with metal back-up flanges may be used for mechanical

joining HDPE pipe to other piping materials, valves, tanks, pumps and

other equipment. In this case, the flange adapters shall have equal

pressure rating as of the HOPE pipe or higher. Such flange adapters shall

be heat fused to the pipe as per paragraph 8.A of this Procedure

E.          Extrusion gun welding, pipe threading, and solvent or epoxy cementing

 

are not permitted for joining of HOPE pipe.

 

F.          HDPE AWWA C901 (112-inch through 3-inch) water and reclaimed

water service connections crossing roads shall be installed in a PVC

casing pipe. PVC casing pipe may be installed by push/pull (reaming)

methods as approved by the County. PVC casing pipe shall be Schedule

40 and meet the requirements of ASTM D 1785. PVC fittings shall be

Schedule 40 and shall meet the requirements of ASTM D2466. Casing

pipe/carrier pipe size shall be as follows:

Carrier Pipe  Casing Pipe (Nominal dia.)

(Nominal dia.) Size 0.0 Wall 1.0

1-inch 2-1/2-inches 2.875 0.203 2.469

1-1 /4-inch 3-inches 3.50 0.216 3.068

1-1/2-inch 3-1/2-inches 4.00 0.226 3.548

2-inch 4-inches 4.5 0.237 4.026

G.        Casing pipe shall be air pressure tested for leaks immediately upon

completion of each crossing at a minimum test pressure of20-psi (.138

MPa).

H.         Following installation of carrier pipe within casing, install a plug in each

open end of casing. Plugs shall be suitable for restraining against

external earth load.

9. JOINING METHOD I ASSEMBLING PROCEDURE OF PVC I uPVC PIPES

9.1 TYPES OF JOINTS

A.         SOLVENT WELD JOINTS

B.         RUBBER RING SEAL JOINTS

SPECIAL PROCESS FOR INSTALLATION AND

JOINING OF HDPE (PE) & PVC/uPVC PIPES

  

Installation of Thermoplastic Pipes. All PVC/uPVC/ CPVC pipe shall be

assembled, and installed in accordance with ASTM code, manufacturer's

recommendations, and this procedure.

Joints shall be made in accordance with ASTM 02855 for PVC and ASTM

F493 for CPVC. Solvent cement shall conform to the following ASTM

Designations:

ASTM 02564 for joining PVC to PVC, and

ASTM F493 for joining CPVC to CPVC or PVc.

Primer and solvent cement shall be handled in accordance with the safety

precautions in ASTM F402 for restrained type joints.

Solvent cement shall not be used past the manufacturer's expiry date on the

label or one year past the date of manufacture if there is no expiry date

specified.

9.2 PIPES JOINING

A. Solvent Weld Joints

Cutting and Chamfering: Pipes should be cut square with proper marking

around the pipe.

Pipes end should be chamfered at an angle of approximately 15°C to about

1/3 of the wall thickness with a coarse file, chamfering tools.

Pipes up to 75mm may be jointed easily with solvent adhesive and larger

pipes required more special techniques.

Mark depth of entry of the size of the pipe into the socket and alignment

mark. Roughen the outside of the pipe and inside of the socket using

Sandpaper or emery cloth up to entry marl<. Clean both surface and remove

all dust & grease using a dry clean cloth and cleaner.

Apply adhesive without delay after cleaning. using a flat clean and proper

brush, where loose fits are found, the pipe should be given a second coat.

Immediately insert the pipe into the socket up to entry marl<. align pipe and

socket. Hold in position for a few second. then wipe off excess cement.

After the joint has been made. the piping shall not be moved until the

drying time listed in Table of this Standard, has elapsed. To limit

movement of a pipe string, the first pipe shall be backfilled with the joint

exposed.

Joint Drying Time before Movement Surface Temperature (I'

Through Hot Weather Mild Weather Cold Weather

Nominal Above 32 ­ 65"C 10 - 32"C Below 10"C

Pipe Sizes (mm)

32 12 min 20 min 30 min

63 30 min 45 min 60 min

110 45 min 60 min 90 min

225 60 min 90 min 150 min

Note 11): These temperatures are pipe surface temperatures and are not air temperature

limitations.

B.         Rubber Ring Seal Joints

WWW.HVACMEPCONTRACTORS.COM Rubber Ring Seal Joints

Ensure that the spigot and socket are free from dust. grit, grease and as

dry as possible. In hot climate joining is recommended in early morning

or in the evening to prevent expansion & contraction in excessive

amount.

Insert pipe into the socket without seal ring in place and mark pipe when

it is fully inserted.

Place seal in groove of socket ensuring that seal is correct way round.

Rubber seal rings should be fitted with tapered section facing the outside

of the socket

Apply jointing lubricant to the chamfer and the end of the spigot of the

pipe or fitting only. Push the pipe firmly into the socket upto the insertion

mark previously made. If an expansion gap is requiring the pipe is then

pulled back by desired amount according the size.

Jointing clamps may be used for ease of assembly.

9.3 INSTALLATION I ASSEMBLING OF PVC/uPVCI CPVC PIPES

•           Field-fabricated, mitered fittings shall not be used.

•           Thermoplastic flanges when used, shall be of flat face. Mating flanges of

different approved material shall also be of flat face. They shall be

assembled w~h full-face elastomeric gaskets, 3 mm thick, and 50 to 60

Shore A Durometer hardness.

•           Flat washers shall be used under nuts and bolt heads on nonmetallic

flanges

•           Flange pressure rating requirements, and bolt tightening procedures and

maximum torque requirements shall be in accordance with HVAC MEP CONTRACTORS ES-L-610.

•           Plastic pipes such as PVC, UPVC, CPVC, HOPE, PP etc shall be

protected from contact with concrete by tape wrapping.

•           At the edges where a thermoplastic pipe or fitting enters or leaves a

thrust block, it shall be wrapped with neoprene wrapping that will

protrude slightly from the block. The thickness and the width of wrap

shall comply with Table 5 of HVAC MEP CONTRACTORS ES-S-070 Standard, unless the

manufacturer requires more than one piece of wrapping.

•           Vibrators shall be kept clear of the piping while casting concrete thrust

blocks.

•           All changes of direction must be anchored. Concrete thrust blocks are

suitable but the unit should only be hunched and a flexible membrane

interposed between the concrete and the unit, to protect it against

damage by abrasion.

•           The pipeline should be tested initially after a few joints to ensure that

they have been made correctly, and subsequently at convenient

•           Before testing, the line must be backfilled leaving the joints exposed. If

the joints must be covered, it is useful to mark their position.

•           It is very important when laying uPVC pipes for gravity drainage to

ensure that the pipe is laid in accordance with the recommendations of

the manufacturer.

10.0 Trench Preparation

www.hvacmepcontractros.com Trench Preparation

Following points should be considered during trench excavation

o           Take necessary safety precautions to ensure a safe working environment.

o           Prevent water penetration into the trench.

o           During excavation, make sure that trench walls keep vertical position.

o           For a flat bedding, remove all obstacles and sharp edges such as rocks,

gravels, concrete, etc. from the trench.

o           Remove all organic items such as plants, tree roots, etc. from trench

ground.

o           Ensure that trench ground is strong and stable.

o           If the trench ground is not stable enough. Increase trench depth for

Stabilization works.

o           Discharge water (if there is any) from the trench before bedding preparation.

o           When the underground water level is high, it might cause pipes to float. To

prevent floatation, increase the trench depth to increase the height of

backfilling.

o           Ensure that trench width is sufficient enough for bedding and backfilling

compaction works.

o           Ensure that excavated materials are piled at a distance from the trench to

Avoid the possibility of rolling back into the trench

o           Trench walls should be supported with sheet piles if the natural ground soil

is unstable.

o           The minimum trench width from the bottom to 300 mm above the top of the

pipe shall be as shown in below Table

Type of Pipe Nominal Pipe Size Min. Width of Trench

0 (mm)           (mm) s

Thermoplastic 90 and under 300

Thermoplastic 110 and over OD + 300

10.1 Preparation of Bedding

Trench bedding should be flattened, levelled and compacted all along the

trench. Under unstable soil conditions, trench depth and bedding thickness

can be increased.

After trench excavation, bedding should be prepared to provide durable and

stable support for pipe. Pipe bedding should not be less than 15cm in height

and should be prepared with compacted granular material at minimum 90%

Standard Proctor Density or any other suitable bedding material at minimum

%95 Standard Proctor Density.

Bedding depth should be increased if there are unstable, loose or soft soil

conditions. If bedding material is sandy, bedding material should be

moisturized and should be compacted with vibrating compactors. Bedding

should always be flat and levelled with the trench bottom.

A non-woven geotextile with a unit weight of at least 100 g/m2 must be

placed between the crushed stone and the sand bedding layer to prevent

filtration of the sand bedding into the crushed stone matrix.

The trench bottom shall be continuous, smooth, free of rocks, and to the line

and grade shown on the installation drawings.

Bedding material characteristics are very important for a proper support for

the pipes. Generally bedding and backfilling materials are preferred to have

the same characteristics. tf the excavated material is preferred to be used

as backfilling material, characteristics of the excavated soil should be

analyzed for suitability. Another critical point to be taken into consideration

is the possibility of experiencing different soil characteristics along the

pipeline.

10.2. Installation of Pipe in the Trench and Lifting

www.hvacmepcontractors.com  Installation of Pipe in the Trench and Lifting

After completion of trench excavation and bedding, installation can start in

line with the project. Pipes and fittings should be stored along the pipeline

next to the trench according to the daily installation program for a faster and

easier installation. Stored goods should not block the working path of the

construction machines such as crane, excavator, bulldozer, etc

lifting straps should be tied around the pipe from the appropriate lifting

points. While lifting fittings, special lifting and alignment requirements should

be taken into consideration. (For instance, the arm angle of the Tee part).

lifting can be performed with a crane or with the excavator arm and pipe

should be lowered onto the bedding slowly. During lifting and lowering

inside the trench, field teams instruct directions to the excavator operator to

make sure that pipe will be placed at the right location. Pipe should be

lowered closer to the previously installed pipe and should be carefully

aligned 10.3 Multiple Pipe in one Trench.

During installation of multiple pipes in a single trench, distance between any

of the 2 pipes is determined with the formula (r1+ r2) 12 whereas r1 : radius

of the first pipe and r2: radius of the second pipe. Complying with the

formula or Manufacturer recommendation for the distance of pipes in the

same trench.

11.0  Inspection & TEST PLAN

~ Work execution inspection and test shall be monitored and witnessed as per

SSEM ITP and recorded in the SSEM Inspection checklist and QC forms

available in the ITP as applicable.

~ Request for Inspection (RFI)QC inspector shall issue a RFI 24 hour and 48

hours for weekend inspection and remote area location as per Schedule Q

in advance of test I inspection to permit SAPMT to verify the readiness of

the test I Inspection and to inform HVAC MEP CONTRACTORSI PID QC inspection in

advance.

11.1 TESTING REQUIREMENTS

• Visual inspection

All HDPE & PVC/uPVC pipe and fittings shall be visually inspected for

scratches, damaged ends, cracks, delamination, crushing, weathering, and

cracked O-rings and gaskets.

Each piece of thermoplastic pipe and fitting shall be exam ined for cuts,

scratches. gouges, kinks, buckles, and ultra-violet (sun) damage. Damaged

lengths of pipe shall be cut out and discarded. Damaged fittings shall be

discarded. Thermoplastic pipe and fittings that show ultra-violet damage and

weathering effects shall not be used.

•           Hydro test

Hydro test will be performed as per SSEM hydro test procedure # JEC-P01­

QA-Q02-0007.

12.BACKFILLING

www.hvacmepcontractors.com BACKFILLING

When the pipe installation and hydro testing is completed and successful,

backfilling of the pipe will follow. However, partial backfilling prior to hydro - testing

is permitted provided that the coupling joints or lamination joints are exposed.

During backfilling the following are to be followed:

»          Proper selection, placement and compaction of the pipe zone backfill are

important for controlling the vertical deflection and are critical to the pipe

performance.

»          Attention must be paid so that the backfilling material is not contaminated

with debris or other foreign materials that could damage the pipe or cause

loss of side support.

»          During backfilling, the granular material should flow completely under the

pipe to provide full support.

»          A blunt tool maybe used to push and compact the backfill under the pipe.

»          Proper backfilling should be done in 150 mm to 300mm lifts depending on

the backfill material and compaction material. 300 mm lifts will be adequate

for gravel because it is easy to compact.

»          Compaction of sandy backfill is most easily accomplished when the material

is near to its optimum moisture content. When backfilling reaches pipe

spring line, all compaction shall be done first near the trench sides and

proceeds towards the pipe.

»          It is recommended that placing and compacting of the pipe zone backfill is

done in such a way as to cause the pipe to overlies slightly in the vertical

direction.

The clean sand bedding shall be compacted to 70% Relative Density (ASTM

D4253/ASTM D4254). The clean sand from the bottom of the pipe to 300 mm

above the top of the pipe (sand cover) shall be compacted by water flooding

and hand tamping only. No compaction testing is required in this section of the

trench.

Within 300 mm of the top of the pipe, backfill shall be hand tamped, or a board

shall be used to protect the pipe from damage from vibratory plate compactors

 

Backfill above 300 mm sand cover in Non-Traffic area shall be on site

excavation or borrowed materials that meet the following conditions:

Minimum Cover over Top of Pipe

www.hvacmepcontractors.com Minimum Cover over Top of Pipe

Type of Pipe              Nominal Pipe Size and Minimum Cover (mm)

Service

Thermoplastic Sewers. gravity flow 900

Thermoplastic Pressure pipe under 100 600

mm size

Thermoplastic Pressure pipe 100 mm 900

and larger sizes

Thermoplastic Irrigation. under 90 mm 300

size

Thermoplastic          Irrigation. 90 mm and 600

larger

13. SAFETY REQUIREMENTS

•           All works shall be done in accordance with the CLINT Project HSE

Manual and all individual activities shall be set up in an orderly manner to

ensure compliance with the requirements.

•           Work permit shall be secured by the Site Engineer prior to carrying out any

work and work shall proceed in accordance with the specific measures

itemized in the permit

•           Relevant information on the permit shall be made available to all operative

•           performing the work by providing a copy to the Bulletin Board nearest or

adjacent to the work area.

•           The Safety Supervisor I Safety Officer is responsible along with the Site

Engineer for ensuring that all operations are being done with due regard for

the safety of personnel property as well as the general public.

•           All PPEs shall be worn by personnel performing the work at all times in full

compliance to safety rules on PPE ·s. Additional PPE's like respirator.

rubber hand gloves and disposable coveralls shall be provided during

lamination and grinding works.

•           Barricades shall be provided to isolate the work area but proper access

shall be provided to all operatives.

•           The worksite shall be maintained in a clean and tidy condition.

for any inquiry or help or for project selling please contact on following email

contact@hvacmepcontractors.com    

QUOTATION@HVACMEPCONTRACTORS.COM