Untitled - Future Pipe Industries

All information was correct at the time of going to press. However, we reserve the right to alter, amend, delete and update 

any product, information or service described in this brochure. 

©2005 By Future Pipe Industries, Inc. 

No part of this brochure may be reproduced in any form, by printing, photocopy, microfilm, photocopies or any other means 

without the written permission of Future Pipe Industries Inc.

Table of Content 

1- Introduction _____________________________________________________________________________________ 

2- Handling ________________________________________________________________________________________ 

3- Excavation ______________________________________________________________________________________ 

4- Backfilling and Installation Selection ___________________________________________________________ 

5- Joints ___________________________________________________________________________________________ 19 

6- Pipe Bedding and Foundation __________________________________________________________________ 30 

7- Hydrostatic Testing of Pipelines ________________________________________________________________ 35 

8- Repair and Replacement of Pipe _______________________________________________________________ 42 

9- Tapping Water Mains ___________________________________________________________________________ 43 

APPENDIX I 

Approximate Weight of Pipe and Joints ______________________________________________________________________ 

APPENDIX II 

Design Consideration for Pipelines - Anchoring ________________________________________________________________ 45 

APPENDIX III 

Air in pipelines, air-valves, and surge control _________________________________________________________________ 48 

APPENDIX IV 

Flange assembly instruction _________________________________________________________________________________ 50 

APPENDIX V 

List of References __________________________________________________________________________________________ 54 

1 

2 

5 

8 

44

1.0: Introduction 

This manual deals with the handling, laying and testing of FiberstrongTM Fiberglass Reinforced Polyester (FRP) pipes manufactured 

by Future Pipe Industries, Inc. (FPI). Pipe diameter ranges from 3” up to 158” with pressure classes of gravity, 100, 

150, 200 and 250 psi, and stiffness classes of 18, 36, 46 and 72 psi. Pipes can be either solid wall type or ribbed. The 

following table (Table 1) shows pipe standard lengths. 

Nominal Pipe Diameter 

(inch) 

Table: 1 

Standard Pipe Length (ft) 

3”-12” 20 

12” & larger 20 & 40 

This manual should be carefully read by the Contractor responsible for laying the pipe, as well as by the design Engineer. 

This information should be considered only as a guide. The Engineers or others involved in pipeline design or installation 

should establish for themselves the procedure best suited to the site conditions. Sound engineering practices should always 

be followed. 

The FPI technical department is available to assist the design Engineer on solutions regarding optimizations of pipeline design 

or its laying. The FPI site service team will assist the Contractor on problems dealing with handling and installation of the 

pipes. For further details, please contact your nearest FPI sales office. FPI in conjunction with 

Dynaflow Engineering also provide engineering services such as surge/water hammer studies, flexibility and stress analysis 

and generation of plan/profile drawings. 

1.1: Responsibilities of the FPI manufacturer site supervisors. 

FPI provides the services of a qualified field representative on all major projects. 

The site representative will: 

• Review FPI’s Handling and Installation instructions with the Contractor and/or the Engineer/ owner prior to the start of 

the installation 

• Where possible he will visit the job site at the time the first delivery of pipe is made and will assist the Contractor I inspecting 

and off-loading the pipe and fittings. If there is any damage during transport, or off-loading, he will inspect the damaged 

products and make arrangements for their repair or replacement. He will also advise the contractor on proper handling 

and storage practices on site. 

• Where possible, he will visit the job site at the beginning of pipe installation to observe trench excavations and pipe laying 

practices on site. He will discuss these practices with the contractor and make recommendations where deemed necessary 

to improve, alter or discontinue the installation practice observed on site. 

• Make periodic visits to the job site throughout the duration of pipe installation to advise the contractor on the proper and 

applicable handling, storage, bedding, laying, jointing, backfilling and site testing procedures necessary to achieve a satisfactory 

pipe installation. These procedures are detailed in this manual. 

• It is the responsibility of the Contractor to make available this installation manual to his crews, and to ensure that they are 

familiar with it, and understand the procedures described therein. 

• It is the responsibility of the Contractor to strictly follow and implement the installation procedures published in this installation 

manual, as well as any additional advice or recommendations given by our field representative. 

• Future Pipe Industries, Inc. shall not be liable for any installation related failures arising from failure of the Contractor to follow 

and implement our written installation instructions and any additional advice or recommendation made by our field representative. 

1

2.0: Handling 

2.1: Receiving 

Generally pipes will be handed over to the Contractor or his representative at the factory or at the job site as agreed upon 

in the Contractor’s purchase order. In the case of an Ex-works delivery, the pipes and fittings shall be loaded on the 

Contractor’s trucks by the factory loading staff. If the loading staff considers the transport unsuitable, they will advise the 

contractor or his representative accordingly. Inspection is thoroughly made by the factory loading staff of the goods being 

loaded. Nevertheless the Contractor or his representative should make their own inspection of the goods during dispatch. 

The Contractor should make the following inspection at the time of the reception of the goods: 

a- Each item should be inspected carefully upon arrival. 

b- Total quantity received of pipes, couplings, rubber rings, fittings, lubricant, etc… should be carefully checked against our 

delivery notes. 

c- Any damaged or missing item must be pointed out to the dispatcher or driver and marked accordingly on the delivery note. 

Materials that have been damaged during transportation should be isolated and stored separately on site, until the material 

is checked by our site representative and repaired or replaced as the case may be. 

Note: Damaged material must not be used before they are repaired (by FPI), or replaced. The Contractor should not attempt 

to repair any damaged item. 

2.2: Unloading pipes 

Unloading at the job site must be carried out carefully under the control and responsibility of the Contractor. Care should be 

taken to avoid impact with any solid object (i.e. other pipes, ground stones, truck side etc.). 

2.2.1: Unloading by hand 

Unloading by hand with two men is only possible for small diameter pipes, not exceeding 100 lbs in weight. This typically 

applies to 20’ sections of pipe up to 8” in diameter. 

Note: See Appendix I for nominal pipe and coupling weights. 

2.2.2 Mechanical unloading 

Mechanical unloading is recommended for pipes heavier than 100 lbs. Flexible slings or straps should be used combined 

with a mobile crane. When unloading is done with a mobile crane, care must be taken that the pipes do not slide off the 

slings. Therefore it is recommended to use two slings or nylon lifting straps to hold and lift the pipes. Steel cables must not 

be used for lifting or handling pipes. Pipes can also be lifted with one sling or strap balanced in the middle with the aid of 

a guide rope. 

Caution: Hooks must not be used at the pipe ends to lift the pipes, nor should the pipe be lifted by passing a rope or sling 

through the pipe. 

2.3: Unloading couplings 

Couplings shall be unloaded with care. They must not be thrown off the truck on the ground. In general, couplings are 

strapped and bundled in the factory and can be off-loaded like the pipes. Couplings may, on certain projects be delivered 

mounted on one end of the pipe. 

2.4: Storing rubber gaskets on site 

Rubber gaskets are delivered in closed bags from the factory and must be stored in a cool shaded area, protected from direct 

sunlight, until they are ready for use. 

2

2.5: Storing pipes on site 

2.5.1 Distribution along the trench 

It is preferable to unload the pipes alongside the trench directly from the truck. If the trench is open, string out the pipes on 

the opposite side to the excavation. Allow sufficient space between pipes and the trench for excavator, cranes, etc. Avoid 

placing the pipes where they can be damaged by traffic or blasting operations. If possible, store pipes on soft level ground 

(e.g. sand), timber bearers, or sand bags. 

Caution: Pipes must not be stored on rocks or stones. 

2.5.2 Storing in stock piles 

Care must be taken that the storage surface is level, and firm, and clear of rocks or solid objects that might damage the pipes. 

Store the pipes in separate stock-piles according to their class and nominal diameter. Pipes are to be placed on wooden timber 

at a maximum spacing of 18 ft. Any extraneous materials are to be removed from the area. Stock piles should not exceed 

the heights shown in table 2. This height is limited for safety purposes and to avoid excessive loads on the pipe during storage. 

Table 2: Storing/stacking height 

DN Up to 16” 18”- 24” 28 - 32” 36 - 56” 60” 

Layers in stock 

pile 

Maximum 

height 

5 4 3 2 1 

< 6.5 ‘ < 8’ < 8’ < 9’ 1 pipe 

Wooden wedges, which are used in order to prevent the pipe stack from sliding, should be placed on both sides of the 

stack on the timber bearers, as shown in figure 1. 

Figure 1: Pipe storage. 

2.6: Handling of nested pipes 

For some projects, pipes may be delivered nested (i.e. one or more small pipes inside a larger pipe). Special handling procedures 

must be followed when handling and de-nesting such pipe loads. 

When handling nested pipes, never use only one sling or strap. Nested pipes must always be lifted using at least two straps 

or slings. A spreader bar will help to insure that the load is lifted at one level. Mobile lifting equipment should move slowly 

when handling nested pipes and all such movements should be kept to a minimum to insure the safety of site personnel. The 

Contractor should insure that the crane operator realizes that the smaller pipes inside the larger nested pipes may slip out 

and fall during movement. All necessary precautions should be taken. 

De-nesting a load is easily accomplished by inserting a forklift fork into a padded boom. The forklift lifting capacity should 

be appropriate enough to handle the weight and length of the pipes being de-nested. Figure 2 shows how this is accomplished. 

Proper padding is essential. Rubber, several wraps of corrugated cardboard sheets, or a PVC or PE pipe slipped 

over the boom are all suitable options to avoid damaging the inside of the pipes. 

3

The Forklift operator should lift the innermost pipe above the pipe around it sufficiently so the pipes do not touch each other 

when the inner pipe is being pulled out. 

4 

Figure 2: Pipes de-nesting

Figure 4: Pipes in the same trench 

Where pipes of the same or different diameters are installed in the same trench, a minimum spacing equal to (ND pipe ‘a’ 

+ ND pipe ‘b’)/4, but not smaller than 12”, is required. 

3.4: Trench depth 

3.4.1: Minimum trench depth 

Generally the burial depth of pipe is specified by the design Engineer. A minimum clear cover above pipes (H min) shall 

always be observed as follows for all stiffness classes. 

• 2.0‘ with no traffic loads 

• 3.3‘ with AASHTO H-20 traffic (4’ for SN 18 psi pipe & all Type IV installations) 

• 5.0‘ with BS 153 HA traffics & ISO HT-60, 3 axle trucks loads. 

• 5.0‘ for road compaction equipment up to 18 Tons (vibrated roller compacter) 

• 10‘ for Cooper E-80 Railroad loadings (12’ for SN 18 psi pipe). 

Note: Minimum cover restrictions may be reduced with special installations such as concrete encasement, concrete protection 

slabs, casings, or other provisions to carry the surface load. In case of high ground water table, a minimum cover depth 

equal to 80 % of the pipe diameter of granular compacted soil must be provided to prevent pipes from floating. Always insure 

that this minimum cover is available before turning off dewatering systems. 

6

3.4.2: Maximum cover height 

The maximum cover height depends on the type of installation, backfill material, its compaction, as well as native soil conditions. 

The figures below are for installation in good and stable native soils, and which provide adequate support for the 

pipes. Detailed selection tables, for each stiffness class, are shown in tables 5, 6, 7 and 8. 

Maximum Cover Depth for pipe installed in : 

Table 3 

Stiffness Class (psi) SN 18 SN 36 SN 46 SN 72 

Fully compacted gravel 46 ft 53 ft 54 ft 58 ft 

Full clean Sand compacted to 90% Std proctor 26 ft 43 ft 44 ft 48 ft 

Full mixed Sand compacted 

to 90% Std proctor 

20 ft 25 ft 26 ft 30 ft 

Clean Sand compacted to 90% Std Proctor to 70 % of pipe ID N.R 16 ft 17 ft 23 ft 

Lightly tamped full clean sand** N.R 4ft 5ft 9ft 

7

4.0: Backfilling and installation selection 

The installation type and choice of pipe bedding and backfill material is normally specified by the design Engineer, based 

on the specified pipe stiffness class (SN), maximum burial depth, vacuum requirements, and native soil conditions. 

4.1: Acceptable pipe foundation, bedding and pipe zone backfill materials 

The following materials are generally acceptable for the pipe foundation, bedding and pipe zone backfill depending on the 

selected installation type. 

A) Crushed stones & rock 

B) Gravel 

C) Clean sand 

D) Mixed Sand 

E) Excavated granular material 

F) Cement stabilized sand (sand - cement mixture) 

** Not recommended in high water table installations. 

A & B) Clean; single grade or well graded gravel and crushed rock/stones containing less than 15% sands and less than 5% 

fines, are an excellent backfill material. These materials are essentially self-compacting and the required density is generally 

achieved when dumped (maximum 12”lifts) with only light compaction required after the pipe haunches have been filled. In 

cases of high ground water table in the trench zone where the possibility of migration with native soils exist, a suitable geotextile 

filter membrane (e.g. Terram® ) should be used to line the trench bottom and sides up to the top of the pipe zone. If 

geotextile filter membrane is required, but unavailable, then clean sand should be used as the backfill material. 

(Unified soils classification: GW, crushed rock) 

Note: See section 4.3 on native soil migration 

C) Clean sand containing less than 5% fines, is good backfill material. Compacted to 90% standard proctor density, using 

hand tamping or plate vibrators (recommended). Maintain moisture content near optimum to minimize compaction effort. 

Place and compact in 12” maximum layers. 

(Unified soil classification per ASTM D2487: SW, SP) 

D) Mixed sand containing less than 12% fines is good backfill material. Compacted to 90% standard proctor density, using 

hand tamping or plate vibrators (recommended). Maintain moisture content near optimum to minimize compaction effort. 

Place and compact in 8” maximum layers. 

(Unified soil classification per ASTM D2487: SW, SP) 

E) Excavated granular material containing more than 12% fines consisting basically of gravel with fines or sand with fines. 

Compacted to 90 % standard proctor density, using hand tamping or plate vibrators (recommended). Maintain moisture content 

near optimum to minimize compaction effort. Place and compact in 6” maximum layer. 

(Unified soil classification per ASTM D2487: GM, GC, SM, SC) 

F) Cement stabilized sand is a mixture of one sack of cement per one ton of clean sand. This backfill material provides excellent 

support for pipe where native soil conditions are poor and would otherwise require a wide trench (up to 4 x DN) excavation, 

or a higher stiffness pipe. This mixture can be obtained dry, from ready-mix concrete suppliers. It should be placed in 

the foundation, bedding, haunches and pipe zone backfill in maximum 8” lifts. Each lift should be wetted with water and 

compacted with plate vibrators before the cement sets. 

8

4.2: Maximum particle size for gravel and crushed rock/stones 

The following limits should be observed with regard to the maximum particle size for the above materials 

Nominal Pipe Maximum 

Diameter (DN) Particle Size 

Up to 12” fi ” 

14 – 36” fl ” 

42” and larger 1 ” 

4.3: Migration 

When backfill materials such as gravel and crushed rocks are placed in a trench adjacent to finer native material, the finer 

material may migrate into the coarser material under the flow pressure force of the ground water table. Migration can also 

occur when selected sand is used as backfill in a trench where the native soil is coarser. 

Significant hydraulic gradients may arise in the pipeline trench during construction, when water levels are controlled by various 

pumping or well-pointing methods. 

Gradients may also arise after construction, when permeable under drainpipes or when the open graded bedding and backfill 

materials act as a French drain under high ground water levels. Migration can result in significant loss of pipe support and 

increasing pipe deflections that may eventually exceed the design limits of the pipe. 

The gradation and relative size of the embedment and adjacent native soils must be compatible in order to minimize migration. 

In general, where significant ground water is anticipated above the foundation or bedding of the pipe, avoid using 

open graded materials such as type A or B backfill material (crushed rocks and gravel) when the native soil is a finer type 

such as sand, unless a geotextile filter media is used to line the trench bottom and sides. 

The following gradation criteria may be used to restrict the migration of finer material into a coarser material under a 

hydraulic gradient. 

• D15 / d85 < 5 where D15 is the sieve opening size passing 15 percent by weight of the coarser material and d85 is the 

sieve opening size passing 85 percent by weight of the finer material. 

• D50 / d50 < 25 where D50 is the sieve opening size passing 50 percent by weight of the coarser material and d50 is 

the sieve opening size passing 50 percent by weight of the finer material. (This criteria doesn’t apply if the coarser material 

is well graded {See ASTM D2487}) 

4.4: Determination of native soil properties 

In order to choose the appropriate installation type and to identify the allowed burial depth limits, it is necessary to determine 

native soil properties. Proper soil investigation along the pipeline route is an engineering practice that should be executed by 

the Contractor in case no soil data is provided by the end user. When no soil data is available, borehole samples should be 

taken along the pipeline route at intervals of not more than 1500 feet. If the native soil properties and appearance are not 

consistent over this distance, shorter intervals for sampling should be adopted. Soil samples must be taken from a representative 

burial depth in order to provide the necessary information of the bedding and pipe zone level of the pipeline. 

Important properties for soils 

• Physical characteristics, appearance, and gradation 

• Water table location 

• Blow counts (N) per ASTM D1586 (Standard Penetration Test) 

• Unconfined compressive strength qu, 

9

4.5: Classification of native soils 

Native soils can be classified into four main groups (1,2 3 and 4) and two sub groups, cohesive and granular as shown in 

table (4). 

Table 4: Soil Groups 

1 2 3 4 

Cohesive soils stiff medium soft very soft 

E’n (psi) > 3000 1500 700 200 

Unconfined compressive 

strength qu (Tons/sf) 

>1 0.50-1.0 0.25-0.5 

Good native soils > Poor native soils 

Granular soils 

Blow counts (N) 

(ASTM D 1586) 

Unconfined compressive 

strength qu (Tons/sf) 

• Installation type I: Full gravel/crushed stones surround, 

compacted. 

(E’b = 3000 psi ) 

0.125- 

0.25 

1 2 3 4 

S 

compact 

• Installation type II: Full clean sand surround compacted 

to 90% SPD. 

(E’b = 2000 psi) 

• Installation type III: Full excavated granular material, 

free from rocks and organic material, 

compacted to 90% SPD. 

(E’b = 1000 psi). 

• Installation type IV: Sand compacted to 90% SPD or 

gravel/crushed stones up to 70% 

of pipe diameter. 

(E’b = 700 psi) 

• Installation type V: Lightly tamped clean sand to 

80% SPD. 

(E’b = 250 psi) 

loose loose 

very 

loose 

>8 5-8 3-4 1-2 

> 3000 2500 700 200 

Good native soils > Poor native soils 

Note: Native soils with a low blow count (N) of less than 2 will generally be unsuitable for installation of 

Fiberglass pipe utilizing standard installation practices. A soil specialist should be consulted on recommended 

alternative installation procedures when this type of native soil is found. 

4.6: Installation selection 

Installation selection, unless otherwise specified by the end user, shall be based on the native soil properties, pipe stiffness 

class (SN), burial depths and any vacuum requirements. Figure 5 illustrates five installation types (I through V). Tables 5, 6, 

7 and 8 are the installation selection tables for pipe with a stiffness class of SN 18, 36, 46, and 72 psi respectively. See figure 

6 for installation schemes in poor soil condition, where a wide trench is required by the installation selection tables. 

Cement stabilized sand (backfill type F) may also be used in a normal trench configuration as an alternative 

to a wide trench construction, and an E’b value of 10,000 psi may be used for deflection calculations. 

10

Installation type I 

ASTM D1586 Blow counts 

Installation type II 


Installation type III 


Installation type IV 

ASTM D 1586 Blow counts 

Installation type V 

ASTM D 1586 Blow counts 

Table 5: Installation selection tables for SN 18 psi pipe 

Trench width requirement (W) 

Max 

Soil Group Soil Group Soil Group Soil Group 

Cover 

H 

Ft / m 

1 

s. compact / stiff 

12 

2 

Loose / medium 

3 

Soft 

4 

vloose/vsoft 

N>9 N = 5-8 N = 3-4 N = 2 

3.3 / 1 Std trench Std trench Std trench Std trench 

13 / 4 Std trench Std trench Std trench Std trench 

16.5/5 Std trench Std trench Std trench W=2 x ND 

20 / 6 Std trench Std trench Std trench W=2 x ND 


33 / 10 Std trench Std trench W=2 x ND W=3 x ND 



43 / 13 Std trench W=2 x ND W=3 x ND W=3 x ND 


H 

Ft / m 


1 


2 


3 

Soft 

4 

vloose/vsoft 

N>9 N = 5-8 N = 3-4 N = 2 








H 

Ft / m 


1 


2 


3 

Soft 

4 

vloose/vsoft 

N>9 N = 5-8 N = 3-4 N = 2 







H 

Ft / m 


1 


2 


3 

Soft 

4 

vloose/vsoft 

N>9 N = 5-8 N = 3-4 N = 2 

3.3 / 1 Not Recommended Not Recommended Not Recommended Not Recommended 

H 

Ft / m 


1 


2 


3 

Soft 

4 

vloose/vsoft 

N>9 N = 5-8 N = 3-4 N = 2 

3.3 / 1 Not Recommended Not Recommended Not Recommended Not Recommended









Max 


Cover 

H 

Ft / m 

1 


13 

2 


3 

Soft 

4 

vloose /vsoft 

N>9 N = 5-8 N = 3-4 N = 2 





36/11 Stdtrench Stdtrench W=2xND W=3xND 





H 

Ft / m 


1 


2 


3 

Soft 

4 

vloose /vsoft 

N>9 N = 5-8 N = 3-4 N = 2 


16.5 /5 Stdtrench Stdtrench Stdtrench W=2xND 


25 / 7.5 Std trench Std trench W=2 x ND W=3 x ND 






H 

Ft / m 


1 


2 


3 

Soft 

4 

vloose /vsoft 

N>9 N = 5-8 N = 3-4 N = 2 








25 / 8 Std trench Std trench W=2 x ND W=3 x ND


ASTM D1586Blow counts 

Installation type V 


H 

Ft / m 


1 


14 

2 


3 

Soft 

4 

vloose /vsoft 

N>9 N =5-8 N =3-4 N =2 

3.3 / 1 Std trench Std trench Std trench Not Recommended 

6.6 / 2 Std trench Std trench Std trench Not Recommended 

10 / 3 Std trench Std trench Std trench Not Recommended 

13 / 4 Std trench Std trench Std trench Not Recommended 

16 / 5 Std trench Std trench W=2 x ND Not Recommended 

H 

Ft / m 


1 


2 


3 

Soft 

4 

vloose /vsoft 

N>8 N = 5-8 N = 3-4 N = 2 

4 / 1.2 Std trench Std trench Not Recommended Not Recommended









Max 


Cover 

H 

Ft 

1 


15 

2 


3 

Soft 

4 

vloose /vsoft 

N>9 N=5-8 N =3-4 N =2 

14 / 4.2 Std trench Std trench Std trench Std trench 

21 / 6.5 Std trench Std trench Std trench W=2 x ND 







54 / 16.5 Std trench W=3 x ND W=3 x ND W=3 x ND 

H 

Ft 


1 


2 


3 

Soft 

4 

vloose /vsoft 

N>9 N=5-8 N =3-4 N =2 


17.5 / 5.5 Std trench Std trench Std trench W=2 x ND 







44 / 13.5 Stdtrench W=2xND W=3xND W=3xND 

H 

Ft 


1 


2 


3 

Soft 

4 

vloose /vsoft 

N>9 N=5-8 N =3-4 N =2 

5 /1.5 Std trench Stdtrench Stdtrench Stdtrench 

7.5 / 2..3 Std trench Std trench Std trench Std trench 






26 / 8 Std trench Std trench W=2 x ND W=3 x ND


ASTM D1586Blow counts 

H 

Ft 


1 


16 

2 


3 

Soft 

4 

vloose /vsoft 

N>9 N=5-8 N =3-4 N=2 

5 / 1.5 Std trench Std trench Std trench Not Recommended 

7.5 / 2.3 Std trench Std trench Std trench Not Recommended 



17 / 5.2 Std trench Std trench W=2 x ND Not Recommended 

H 

Ft 


1 


2 


3 

Soft 

4 

vloose /vsoft 

N>8 N = 5-8 N = 3-4 N = 2 

5 / 1.5 Std trench Std trench Not Recommended Not Recommended







Table 8: installation selection tables for High stiffness SN 72 psi pipe 


Max 


Cover 

H 

m 

1 

Sl. compact / stiff 

17 

2 


3 

Soft 

4 

vloose /vsoft 

N>8 N = 5-8 N = 3-4 N = 2 










H 

m 


1 


2 


3 

Soft 

4 

vloose /vsoft 

N>8 N = 5-8 N = 3-4 N = 2 










H 

m 

1 


2 


3 

Soft 

4 

vloose /vsoft 

N>9 N=5-8 N =3-4 N=2 

3.3/1 Std trench Stdtrench Stdtrench Std trench 



16 /5 Std trench Stdtrench Std trench W=3xND 


25 /7.5 Stdtrench Stdtrench Stdtrench W=3xND 

28 / 8.5 Std trench Std trench W=3 x ND Not Recommended 

30 / 9 Std trench Std trench Not Recommended Not Recommended

5.0: Joints 

5.1: Joint deflection 

FPI’s Reka Double bell coupling joints, used to join pipes, allows for a certain angular deflection. The maximum allowed 

angular deflection á, distributed equally on both sides of the joint, and the resulting Offset and the radius of curvature (R) are 

given with respect to the pipe nominal diameter and section length, in table 9. 

Nominal Angular deflection at joint 

Nominal Pipe Diameter 

inch 

Table 9: Allowable joint deflection 

Nominal Angular Deflection 

& (Degree) 

Nom. Offset (in) Section 

Lengths 

Figure 7: Joint deflections, offset and radius of curvature 

Nominal Radius of Curvature 

(ft) 

Section Lengths 

10 ft 20ft 40ft 10ft 20ft 40ft 

3 to 6 4.0 8.3 16.5 143 286 

8 to 12 3.5 7.2 14.4 28.9 162 326 653 

14 to 20 3.0 6.2 12.4 24.7 190 383 763 

24 to 36 2.0 4.1 8.3 16.5 286 573 1163 

40 to 48 1.5 3.1 6.2 12.4 383 763 1526 

52 to 72 1.0 2.0 4.1 8.3 573 1146 2289 

78 & larger 0.5 1.0 2.0 4.1 1146 2289 4584 

19

5.1.1: Joint lubricant 

For lubricant, use only a vegetable based soft soap, available for purchase from FPI. In dusty conditions lubricate generously 

the coupling only. The recommended amount of joint lubricant required is shown below. 

DN (inch) 

Table 10 

Amount of lubricant required per joint 

(lb) 

3 – 12” 0.1 

14 – 20” 0.2 

24 – 28” 0.25 

36 – 40” 0.4 

44 – 48” 0.5 

52 – 56” 0.6 

60 – 64” 0.8 

68” – 76” 1.0 

80 – 88” 1.2 

96” 1.6 

104” 2.2 

Larger than Consult FPI 

Caution: Never use petroleum grease, or automotive oils to lubricate the joint, as they may damage the rubber rings. 

5.2: Reka Double Bell Coupling assembly 

Before assembly, inspect each pipe and each coupling carefully and put aside any damaged items. Make sure that all 

required accessories (timber blocks, rubber rings, lubricant, come-along jacks, collar straps, etc.) are available and that the 

installation team (jointer) is well instructed about their job. 

5.2.1: Preparation of the Reka Double Bell Coupling 

In order to avoid its damage, the sealing rubber ring must be fitted into the Reka coupling just before the laying starts. Ensure 

that the grooves of the rubber ring are carefully cleaned with a wire brush and all sand particles are removed. The ring is 

then fitted according to the procedures, which are shown in figure 8. 

• For large sizes lay the coupling horizontally for better control and safety. 

• Fit one end of the ring into the groove. Go on until about three-quarters of the ring is in the groove. Put the other 

end of the ring towards the starting point. 

• The formed loop must then be forced into the groove. For large couplings, several loops are necessary to insert 

the rubber gasket. (The larger the diameter, the more loops are required) 

• Check that the ring is uniformly and regularly seated into the groove, all the way round. 

• For large diameter joints, two to five men are necessary to insert the ring depending on the diameter. 

Figure 8 

20

5.2.2: Mounting the coupling on the pipe 

This operation can be carried out either in or outside the trench. In the latter case it is recommended to lower the pipe with 

the free end towards the laid portion of the line. Clean coupling and pipe ends with a firm brush and inspect them thoroughly. 

Lubricate the pipe end and the coupling rubber ring by means of a dry clean piece of cloth or a sponge. 

For small diameter pipes (DN

Mechanical lowering is used for larger diameter pipes, especially when combined with pipe assembly in the trench. A 

strap or a sling can be used from an excavator boom if no separate lifting equipment is available. 

Caution: Under no circumstance should brute force be applied to mount the coupling. The pipes and couplings are dimensioned 

within close tolerances that allow jointing to be carried out without using excessive force. 

Working with mounting equipment, although very efficient, should not be carried out by unskilled laborers. Risks of damaging 

or dislodging a rubber ring should not be disregarded. It is essential to push the coupling to the home line and not 

more, otherwise the pipes in the coupling will touch each other and will consequently not allow for any expansion or 

deflection inside the joint. Only skilled operators should attempt to use the boom of an excavator to push either coupling or 

pipe, as the direction of the applied force is not under control and might damage the pipes and/or the coupling. No steel 

tools should come into direct contact with the edges of the pipe or its external surface. Pipe edges should be protected with 

a timber. 

Figure 11: Mechanical lowering with excavator 

5.4: Offshore intake and outfall lines 

This installation method is used for the offshore portion of seawater intake/outfall pipes. The pipe joints are normally 

assembled under the water. Steel angle irons lugs will be laminated on the two ends of pipe to allow divers to assemble 

the standard Reka coupling joints under water using stud bolts and nuts (supplied by contractor). It may be possible to 

assemble on the barge up to 3 x 40 ‘ lengths of pipes and to lower the assembled section (total length of 120 ft) into the 

excavated sea bed trench. 

Caution: Standard Fiberstrong FRP pipe is not designed to be assembled on-shore in long lengths and then dragged out 

to the sea. 

Installing pipe under water requires a trench similar to the onshore trench, excepting that the trench width is larger. The typical 

underwater trench width is equal to 2 x DN, but in no case less than DN + 4 ft. The cover over the pipes shall be not 

less than 3.5 ft above the pipes to the normal seabed. 

The divers should backfill with excavated granular seabed material in maximum 12” lifts, paying particular attention to the 

backfilling and compaction of the backfill under the pipe haunches. Backfilling should be made evenly on both sides of the 

pipe to avoid displacement of the pipes. 

Protection shall be provided for the backfilled seabed over the pipe trench. Large stones or rocks (rip-rap) may be used for 

this purpose. 

22

or pushing, however in either case, the contractor must insure that the loads are applied on the spigot end of the pipe and 

not the bell. Some flow in the existing pipe may be helpful to create some buoyancy to reduce friction loads while inserting 

the FRP pipes. A thin plywood spacer may also be placed inside the joint between the two pipe ends to reduce point loads. 

Figure 13 A 

Figure 13 B 

24

5.6: Pipes with locked joints 

For some underground applications, pipes might be provided with a restrained mechanical gasketed joint. Typical applications 

are pipes laid in deep slopes, or where thrust blocks can not be used, and for pipes used as well-casings. In this case, 

special pipe and Reka couplings (or special Bell/Spigot joints), designed to resist the high longitudinal stresses, are provided. 

One locking key (strip), or more, is inserted into the joint to restrain and lock the two-pipe sections jointed. The joint 

assembly shall be done as per the following recommendations: 

• The joint should be assembled in such a way that the position of the hole in the socket (coupling) allows the locking strip 

to be inserted easily. 

• Lubricate lightly the first 6-8” section of the locking key (strip). 

• The beveled end of the locking key should be resting against the inside surface of the socket or coupling when inserting. 

The insertion should be made using a plastic hammer or a piece of wood to tap the key until it resists against the first part of 

the key. See figure 14 for typical joint configurations for rubber seal lock coupler and rubber seal locked joint (restrained bell 

and spigot joint). 

• The Contractor must insure that the locked joint is stretched after assembly and that both the spigot stop and coupling (Bell) 

stop are in contact with the locking key. 

• The maximum allowable joint deflection for “locked” socket joints is 1.5o for sizes up to 24” and 1o for larger sizes. It 

is recommended not to reach these values during installation. 

Figure 14: Typical locked joint configurations 

Pipe may also be provided with plain-ends for laminated joints (butt-wrap). 

5.7: Standard short pipe lengths & connections to concrete structures 

Standard short pipe lengths are required to be installed to protect against differential settlement outside structures, such as: 

• Outside rigid structures (i.e. water reservoirs, pumping station, valve chambers, manholes, etc.) 

• To connect the pipes to a line fitting such as bends or tees inside thrust blocks. 

Standard short lengths of pipes shall be planned ahead by the contractor. The recommended length (L) of standard short 

pipe is: 

•L=2to 3 feet for Pipe up to and including 12” in diameter. 

• L = 3.5 – 7 feet for pipe larger than 12” in diameter. 

Note: See figure 15 for typical details. Option (1) is the typical connection details to fittings inside thrust blocks and may 

also be used for connections to manholes. Option (2) is typically used for connections to manholes. 

25

Caution: When pulling the couplings over the insertion piece it is necessary to pull the second rubber ring smoothly over 

the chamfer of the pipe to avoid damaging it. For that purpose, use approved lubricants abundantly. To locate a fitting exactly, 

it is recommended to place it at the required position, to assemble the first pipe in full length, and then to make a closure 

as indicated above. 

Figure 16: Pipeline closure 

5.9: Thrust blocks and anchoring 

Thrust blocks can be used wherever thrust loads are expected, such as at: 

• Changes of direction (bends, Tees, Wyes) 

• Cross sectional changes (reducers) 

• Valves and hydrants 

• Dead ends 

The thrust blocks can be dimensioned and designed according to the resulting thrust load from the working and test pressures 

as well as native soil properties. Thrust block spaces must be foreseen in the design and trench excavations. At vertical bends, 

the line or the bend must be anchored by thrust blocks or other means to resist outward thrusts. Thrust blocks must be cast 

against undisturbed trench walls (native soil) and must completely encase the FRP fitting (except at the joint area). 

The maximum allowable displacement of fittings is 0.5% of the diameter, or ⁄”; whichever is less. The outlet part of the 

encased Fiberglass fitting in the concrete block shall be rubber wrapped with one or more layers as shown in figure 17 (6” 

wide x fl” thick rubber sheet). See appendix II for additional information about thrust blocks. Future Pipe Industries, Inc. is 

not responsible for the design of thrust blocks. 

Note: Gravity lines and buried pipelines with working pressures up to 14.5 psig will not normally require thrust blocks. 

27

Caution: Always provide a standard short pipe length outside thrust blocks (see section 5.8) to protect the pipeline from differential 

settlement. A rubber wrap as detailed on the following drawing must be provided and should protrude about 

1” outside the concrete block. 

Nozzle connections are not necessary to be concrete encased. Nozzles are tee branches meeting all the following criteria: 

1. Nozzle diameter 12” 

2. Header diameter 3 times nozzle diameter 

3. If the nozzle is not concentric and/or not perpendicular to the header pipe axis, the nozzle diameter shall be considered 

to be the longest cord distance on the header pipe wall at the nozzle/pipe intersection. 

Figure 17 : Rubber warp details 

Restrained pipe installations (without thrust blocks) 

FPI can provide special pipe and fittings that allow installation of pressure pipelines without thrust blocks. Pipe joints will typically 

be a gasketed joint with a ‘lock’ to restrain the pipe (see section 5.6 for typical detail), alternatively pipe and fittings 

can be laminated together using a ‘Butt-wrap’ type joint. Bull-wrap joints require skilled and trained technicians to perform 

on site. 

5.10: Flanged joints 

FPI can provide flanged GRP pipe and fittings for use inside valve chambers. Contact your nearest sales office for flange thickness 

before ordering flange bolts as Fiberglass flanges are thicker than steel flanges. 

5.11: Fittings 

One of the advantages of Fiberstrong FRP pipe systems are customized fittings, spools and headers. Our pipe system greatly 

simplifies the valve chamber design and eliminates many unnecessary flanged joints as shown in 

figure 18. Valves must be sufficiently anchored to take the thrust force. 

28

TYPICAL DESIGN WITH CAST / DUCTILE IRON FITTINGS 

TYPICAL DESIGN WITH FRP FITTINGS 

Figure 18 

29

Figure 20 

6.2: Pipe zone backfilling 

The selected backfill material should be placed evenly on both sides of the pipes and compacted as per the requirements of 

section 4.1, depending on the backfill material. Appropriate hand or mechanical tamping shall be carried out by the 

Contractor to achieve the specified degree of compaction required by the selected installation type. During the first one or 

two lifts, special care should be taken to place and to compact the backfill material under the pipe haunches. The best way 

to achieve this compaction is to do it manually with the mean of a wooden board. This is one of the most important 

installation steps and should be executed diligently. Failure to place and to compact the backfill material 

under the pipe haunches may cause ovalization, localized loads and over deflection of the pipes. 

31

Figure 21: Backfilling pipe haunches 

Pipes jointed in the trenches should not be left for long periods without backfilling as some joints may open as a result of the 

daily expansion and contraction of the pipes due to daily night/day temperature fluctuation. Pipes should be backfilled as 

soon as the joint assembly is made in the trench. 

The Contractor should note that the compaction of clean and mixed sand is best achieved when the material is at its optimum 

moisture content. While the wetting of sand is recommended prior to compaction, trench flooding should be avoided to prevent 

pipes from floating. 

Following the first two layers where the backfill has been sufficiently placed, compaction should proceed from the sides of 

the trench towards the pipe. The pipe zone backfill should proceed in 6” to 12” lifts depending on backfill type (see section 

4.1). The pipe zone backfilling and compaction should continue until the backfill reaches at least 6” above the pipe 

crown. For pipes larger than 36” in diameter, backfilling the pipe zone should continue to 12” above the pipe crown. The 

use of plate vibrators is highly recommended to achieve the required proctor density. 

After completion of backfilling in the pipe zone, native material excavated from the trench may be used to complete backfilling 

to final grade. No compaction is required in these final backfilling layers except where specified by the Engineer, or in 

the case of traffic or other high external loads over the pipe are present, and where settlement of the native backfill is to be 

avoided. 

Caution: Sand layers of more than 12” cannot be compacted properly and may result in loss or reduced support for the 

pipes. The best compaction results are achieved with wet sand near its optimum moisture content. Flooding of the trench must 

be avoided as pipe floatation may occur. A minimum of 0.8 pipe diameter of compacted granular backfill above the pipe 

crown is normally required to prevent pipes from floating. 

32

6.3: Backfilling where temporary sheet piles or shoring is used 

Special attention and care from the Contractors’ side is required when the pipes are installed in trenches with temporary 

sheet pipes or temporary shoring. If sheeting or trench shoring is withdrawn after compaction and backfilling of the pipe 

zone, empty spaces may be left and soil pipe support will be lost or reduced. 

CAUTION: Temporary sheet piles or shoring must be withdrawn in stages as backfilling progresses in such a way 

that all hollow spaces left behind the sheeting are filled with compacted backfill material. 

6.4: Deflection measurements 

The maximum allowable long-term deflection of pipe is 5%. Pipe deflection is defined as the percentage reduction in vertical 

diameter after installation, as shown below in figure 22. (Note: For ribbed large diameter pipe the maximum long term 

deflection is 3 %). 

Figure 22: Pipe deflection 

To insure that the long-term deflection does not exceed the maximum allowable limit, the preliminary & initial deflection of the 

pipe must be controlled and checked onsite by the Contractor. Controlling the deflection within the allowable set limits is 

achieved by proper selection of pipe stiffness, installation methods related to the native soil conditions, and maximum burial 

depth. 

Initial deflection limits are set to account for creep and soil consolidation with time (determined by the deflection lag factor). 

Experience has shown that with proper installation, long-term deflections are reached within 6 months from completion of the 

final backfilling to grade, and removal of any de-watering systems. 

Measuring pipe deflections is easy and is the best way for the contractor to check if the installation was executed properly. 

It is recommended to measure the preliminary deflection and the initial deflection. In some cases, the measurement of long 

term deflections may also be required. 

Pipe deflection is measured in the following manner: 

For pipe sizes 32” and larger, where human entry inside the pipes is possible, the installed vertical pipe ID can be measured 

by means of a suitable telescopic micrometer at 10-12 foot intervals. 

For smaller sizes, a wooden disc (‘Pig’) whose outside diameter is equal to the minimum acceptable deflected pipe ID may 

be pulled through the pipes. If the pig passes freely, it means that the pipe deflection has not exceeded the limit set by the 

pig OD. See figure 23 for a typical configuration of a wooden ‘Pig’. 

Note: It is important that pipe deflection measurements are done at the same time of pipe laying operations and not after. 

This will allow for early detection of any installation deficiencies and allow corrective action to be taken quickly in order to 

reduce the time and expenses necessary to rectify defective installations. 

33

Figure 23: Pipe pig 

• Preliminary deflection measurement (Recommended) : 

This measurement should be taken when backfill reaches 12” above pipe crown. At this stage the measured deflection should 

be zero or slightly negative (not less than -2%). A slight negative deflection means the pipe vertical ID has increased slightly 

from the compaction forces coming from good side backfill compaction. 

If a positive deflection is measured at this stage it indicates inadequate compaction in the pipe zone, and improvements in 

the quality of installation and compaction effort are required. Depending on final depth of cover it may be advisable to 

remove the backfill to about 1/3 of the pipe ID from the trench bottom, and to re-compact the backfill in stages up to the top 

of the pipe zone. After this rectification, the preliminary deflection should be measured again. If the backfill compaction has 

been done properly then a slight negative deflection should be observed. 

• Initial deflection measurement (Required) 

This measurement should be done immediately after backfilling reaches the final grade and after all temporary sheeting has 

been withdrawn and all de-watering systems (e.g. well points) have been turned off for two days. The maximum initial deflection 

should not exceed the following limits: 

Table 11 

If the initial deflection exceeds the above limits, the Contractor should re-excavate the trench (by hand from 1 foot above pipe 

crown), remove the pipe zone backfill and start backfilling the pipe once more, paying attention to the pipe haunches and 

backfilling in appropriate lifts to reach the required compaction density. Alternatively if the deflection only slightly exceeds 

the above limits, the pipeline section deflection may be monitored over the following 6 months period with monthly deflection 

measurement. If deflections at the end of the 6 months do not exceed 5 %, the pipeline section may be considered as 

accepted. Any section whose deflection has exceeded 5 % must be excavated and re-backfilled. 

Any recently installed pipe exhibiting deflections equal or greater than 9% (7% for pipes SN 72 psi) must be replaced. Such 

pipe must not be re-installed nor incorporated in any permanent works on site. 

• Final deflection measurement (optional) 

Soils Groups 

1 2 3 4 

Blow counts (N) (ASTM D 1586 >8 6-8 3-5 2 

Cohesive soils Stiff Medium Soft Very Soft 

Granular soils S. Compact Loose Loose V. Loose 

max. initial deflection 3% 3% 2.50% 2% 

Good native soils >>>Poor native soils 

This measurement should be done 6 months after the initial test is done, in cases where the initial deflection readings have 

exceed the limits shown in table 10 above and have not been rectified. The deflection reading at this stage can be considered 

the long term deflection and should not exceed 5% ( 6 % for water pipe). Pipes exhibiting deflections in excess of these 

values should be re-excavated and re-backfilled with properly compacted backfill material. 

34

7.0: Hydrostatic testing of pipelines 

7.1: General 

• The length of the test portion should not exceed 1600 ft. This should be controlled at the site. The test section length may 

be progressively increased to 5,000 feet after several consecutive successful tests of 1,600 ft lengths, at the discretion of the 

Engineer or Client. 

Note: While it may be possible to test longer sections, it should be noted that detecting and isolating a leaky joint in a very 

long test section is more difficult, particularly in the case of small leaks. In addition, the expenses incurred in filling and emptying 

the line is substantial in a long test section. 

• The backfilling must be carried out correctly according to section 6.2. Check if the compaction has been properly executed 

in order to avoid displacement of the line during testing. The couplings must be left exposed at their topside for visual 

inspection. The thrust blocks, which are part of the pressure test section, should be of permanent constructions and concrete 

should be poured at least 7 days before testing. 

• Check whether all testing apparatus are available and operational. 

• The opened ends of a line must be sealed temporarily with GRP or steel/Cast iron end- caps. GRP testing end-caps can be 

purchased from the Future Pipe Industries, Inc., with the pipes and the fittings. The end-caps should have an inlet and an outlet. 

The inlet should be placed at the bottom of the end-cap at the low end of the test section, and the outlet at the top of the 

end-cap at the high end. See figure 24 for a typical arrangement of a test section and apparatus. The approximate end thrust 

force is given in table 11 

Note: Test pressure of pipelines are related to the intended working pressure (PW) in the pipes and not to the rated pressure 

class of the pipes (PN) 

35

Table 12: End thrust during pressure testing 

(Values are given in lbs - shaded diameter/ pressure combinations may not be availale) 

End thrust in lbs during pressure testing 

Test Press Test Press Test Press Test Press Test Press Test Press Test Press Test Press Test Press Test Press 

ND psi psi psi psi psi psi psi psi psi psi 

inch. 

50 75 90 112 125 150225 265337375 

3 495 742 891 1,109 1,237 1,485 2,227 2,623 3,336 3,712 

4 905 1,357 1,629 1,2027 2,262 2,714 24,072 4,795 6,098 6,786 

6 1,870 2,804 3,365 4,188 4,674 5,609 8,413 9,909 12,601 14,022 

8 3,216 4,824 5,789 7,205 8,041 9,649 14,473 17,046 21,678 24,122 

10 4,838 7,258 8,709 10,838 12,096 14,515 21,773 25,644 32,611 36,288 

12 6,842 10,264 12,316 15,327 17,106 20,527 30,791 36,265 46,118 51,318 

14 9,193 13,789 16,547 20,592 22,982 27,578 41,367 48,721 61,959 68,945 

16 11,889 17,834 21,401 26,632 29,723 35,668 53,502 63,014 80,134 89,170 

18 14,932 22,399 26,878 33,449 37,331 44,797 67,196 79,142 100,644 111,993 

20 18,322 27,483 32979 41,041 45,804 54,965 82,448 91,105 123,489 137,413 

24 26,140 39,209 47,051 58,553 65,349 78,419 117,628 138,540 176,181 196,047 

28 33,026 49,539 59,447 73,978 82,565 99,078 148,617 175,038 222,595 247,695 

30 40,212 60,319 72,382 90,076 100,531 120,637 180,956 213,125 271,031 301,593 

33 45,396 68,094 81,713 101,687 113,490 136,188 204,282 240,599 305,969 340,470 

36 57,605 86,407 103,688 129,034 144,011 172,814 259,221 305,304 388,255 432,034 

42 77,764 116,646 139,976 174,192 194,410 233,293 349,939 412,150 524,131 583,231 

48 101,341 152,012 182,415 227,005 253,354 304,024 456,036 537,109 683,041 760,061 

54 130,107 195,161 234,193 291,440 325,268 390,321 585,482 689,568 876,922 975,803 

60 149,012 223,518 268,221 333,787 372,530 447,036 670,554 789,763 1,004,340 1,117,589 

64 169,353 254,030 304,836 379,351 423,383 508,060 762,090 897,572 1,141,441 1,270,149 

72 211,915 317,872 381,447 474,689 529,787 635,745 953,617 1,123,149 1,428,306 1,589,361 

78 254,289 381,433 457,720 569,607 635,722 762,867 1,144,300 1,347,732 1,713,908 1,907,167 

84 293,827 440,741 528,889 658,173 734,568 881,481 1,322,222 1,557,283 1,980,394 2,203703 

90 336,148 504,222 605,067 752,972 840,370 1,008,445 1,512,667 1,781,585 2,265,639 2,521,111 

96 381,316 571,973 686,368 854,147 953,289 1,143,947 1,715,920 2,020,973 2,570,068 2,859,867 

102 429,412 644,117 772,941 961,882 1,073,529 1,288,235 1,932,352 2,275,881 2,894,234 3,220,587 

108 480,276 720,415 846,497 1,075,819 1,200,691 1,440,829 2,161,244 2,545,465 3,237,063 3,602,073 

114 533,988 800,981 961,178 1,196,132 1,334,969 1,601,963 2,402,944 2,830,134 3,599,076 4,004,906 

120 590,641 885,962 1,063,154 1,323,036 1,476,603 1,771,924 2,657,886 3,130,399 3,980,922 4,429,810 

132 712,410 1,068,616 1,282,339 1,595,799 1,781,026 2,137,231 3,205,847 3,775,775 4,801,646 5,343,078 

144 845,468 1,268,203 1,521,843 1,893,849 2,113,671 2,536,405 3,804,608 4,480,982 5,698,457 6,341,013 

158 1,015,261 1,522,891 1,827,469 2,274,184 2,538,152 3,045,782 4,568,673 5,380,882 6,842,857 7,614,455 

36

7.2: Bracing test-ends and set-up 

Due to the thrusts occurring at the testing end-caps, temporary blocks must be used to brace the pipe end-caps in order to 

prevent line displacement as indicated in the figure 24. 

Figure 24: Thrust blocking pipe ends and site pressure test set up 

In the gap between the end of the pipeline and the block, jacks should be placed as shown in figure 24. This will keep the 

testing end cap at its original position if the block starts to move. The last pipe length should also be wedged on both sides, 

at the top and at the bottom, in order to prevent lateral and vertical movements. Sandbags can be used for this purpose. 

Note: It may be possible to reduce the size of the concrete blocks by driving into the ground, several meters deep, two or 

more steel sheet piles back to back. Sheet piles so positioned behind the concrete blocks will provide additional bracing. 

7.3: Filling the line with water 

If it is not possible to fill the line from the lowest point, an additional outlet should be added at the inlet end-cap to release 

air. The line should be filled slowly and evenly with water from the lowest end point. At high points, an automatic air release 

will normally be installed, as specified by the design Engineer (see appendix II for additional details). Through these valves, 

the entrapped air will be released. After filling the line with water, the test section should be left for an initial period of at 

least 12 hours under a low static pressure of 30 psig for stabilization. The filling rate of the line with water should be controlled 

such that the water velocity does not exceed 1 ft/second. 

Following the stabilization period and after expelling all the entrapped air out of the pipe test section, the release valves 

should be closed (isolated). 

37

7.4 Volume of water required 

Table 13 indicates the approximate volume of water required in order to fill pipes per 100 feet of pipeline. 

DN 

Inch 

Water volume (gal) 

/ 100 ft of pipeline 

3 39 

4 69 

6 154 

8 270 

10 430 

12 615 

14 840 

16 1,100 

18 1,390 

20 1,700 

24 2,450 

28 3,350 

30 3,850 

33 4,700 

34 4,950 

Table 13 

7.5: Initial test (method 1) 

After the test section is ready, the line shall be filled with water and kept under low pressure (30 psig) for at least 12 hours 

to allow the pipeline to stabilize and to release the entrapped air from the line. After the stabilization period, the pressure 

shall be raised gradually at a rate of 15 – 30 psi every half an hour, until the intended test pressure at the lowest point is 

reached. 

Unless otherwise specified by the Engineer, the test pressure shall be equal to 1.5 times the intended working pressure of the 

pipeline section. Once the required test pressure is reached, the pressure should be maintained for one hour, by pumping if 

necessary. The pump should then be disconnected and no further water permitted to enter the pipeline section for one hour. 

At the end of this one-hour period, the original test pressure shall be restored by pumping water from a graduated water tank 

and measuring the amount of water necessary to restore the test pressure. Unless otherwise specified by the Engineer, the test 

water loss should not exceed .03 US gallons / inch of diameter per mile of pipeline per 24 hours per psig of test pressure 

applied (average test pressure of section). This is equivalent to 4.5 gpd / mile / inch for a 150 psig test pressure. 

During the pressure test, all joints should be visually inspected (where possible), and all visual leaks should be repaired. In 

case the test in not satisfactory, the locations of the leaks shall be determined and rectified, and the line re-tested in the same 

manner as shown above. The test section shall be accepted only after successfully passing the above leakage test. 

Note: The Contractor should note that while pressure testing large diameter pipe on site at pressures generally above 150 

psi, there is a possibility of a slight rotation/pivoting of the Reka coupling. This is the result of uneven pressure against the 

various parts of the coupling, and is inevitable during normal joint assembly where a perfectly centered and aligned joint 

can never be achieved. In the unlikely event that one or more joint starts to rotate or to shift slightly during the pressure test, 

it is advisable to reduce the pressure, and to backfill the joints completely using selected, properly compacted backfill, prior 

to resumption of the pressure test. Any joint that has shifted significantly should be centered again before resuming the pressure 

test. 

38 

DN 

Inch 

Water volume (gal) 

/ 100 ft of pipeline 

36 5,550 

42 7,500 

48 9,900 

54 12,500 

60 15,400 

72 22,200 

80 27,500 

96 39,500 

108 49,950 

114 55,650 

120 61,700 

132 74,500 

144 88,800 

158 107,000

7.6: Final pressure test 

After all backfilling has been completed and the entire pipeline construction has been completed (except at the closing ends 

or tie-in joints of the pipeline), the line shall be subjected to a final pressure test following the same basic procedures described 

in section 7.5. The final test pressure is generally equal to 1.25 times the intended working pressure of the pipeline (unless 

otherwise specifi ed by the Engineer). The duration of this test shall not be less than two hours, or the time to determine by 

visual inspection the closure joints and the overall soundness of the entire pipeline, whichever is greater. 

7.7: Testing according to method type 2 (using a joint tester) 

Field testing using method type 2 is applicable only for diameters of 36” and above. This method is recommended in the 

case of: 

• Non availability of a suitable water supply source 

• Unstable soils, which pose a potential problem in the case of use of test method 1 

• Very Large diameter pipelines where traditional pipe section pressure test is not feasible 

7.7.1: Preliminary test (method 2) 

As laying proceeds, each coupling is tested for its water tightness by applying internal hydrostatic pressure by means of a 

mobile joint testing apparatus fitted internally and designed to straddle the gap between the pipe ends. Through the pressure 

applied, a high thrust results, and the pipes must be solidly anchored and wedged laterally. 

The last pipes laid must be at least 2 pipes ahead of those to be tested. Prior to the test, the pipe sections must have at least 

0.5 x D of cover above the pipe crown, with a minimum of 12”. It is not essential to leave the joints exposed to ambient 

atmosphere in this test method. The test pressure shall be 1.5 times the intended working pressure of the pipes. 

Caution: Pipe joint testing shall be performed in well ventilated pipelines only. The safety of the operators inside the pipe 

must always be assured. For safety considerations, the operators must work at the free end of the joint tester (near to the pipe 

open access). All operators must be securely hooked to a guide rope to other workers terminating outside the pipeline to 

allow pulling them out from the pipeline in the case of an emergency. Safety personnel must review the proposed testing procedures 

to insure the safety of the workers inside the pipe. All possible causes of trench flooding must be identified and 

appropriate safeguards taken. 

39

7.7.2: Final test (method 2) 

After the completion of the hydrostatic test on each individual coupling and after backfilling has been achieved, a final hydrostatic 

test shall be applied to the whole length of the pipeline in accordance with section 7.6 

7.8: Pipeline commissioning 

After completing the hydraulic test, the line must be thoroughly flushed out and disinfected (in case of potable water lines), 

as specified by the engineer or local regulations. In the absence of any such regulations, the following guidelines may be followed. 

Disinfecting potable water lines is normally performed using either of the following chemical mediums: 

• Liquid Chlorine 

• Sodium Hypochlorite solution 

• Calcium Hypochlorite granules or tables 

This gives a solution containing at least 20 to 25 mg/l of free chlorine initially. The disinfecting period is normally 24 hours 

after which the residual chlorine should not be less than 10 mg/l. After the 24 hour disinfecting period, the line is flushed 

and filled with potable water. 

When commissioning a pipeline, first ensure that all air valves are fully opened to release entrapped air. Fill the line very 

slowly and evenly at velocities not exceeding 1 ft/s. Do not open valves quickly and fully during filling. After releasing all 

air, close air valves and hydrants and open inlet valve fully. If the line is coupled to a pump, the inlet valve should be closed 

when the pump starts running. Later on, the inlet valve shall be opened slowly. The discharge valve should be closed slowly 

before shutting down the pump. 

7.9: Pressure testing gravity lines 

Two methods are available for testing gravity lines, a low-pressure air test or a low head water test. 

7.9.1: Air test 

The Contractor should plug both ends of the pipeline section (between two manholes) with suitable plugs. The plugs should 

have connections for air and a manometer or air pressure gauge. Air shall be pumped into the line until a pressure of 3.5 

psig is indicated on the manometer or air pressure gauge. After a 5 minute stabilization period, air may be added to restore 

the pressure up to 3.5 psi gage. During the test period shown in table 13 (in minutes), if the pressure drop does not exceed 

0.5 psi, the line shall be considered as having passed the air test. 

Table 14 - Test time for low pressure air test 

Test time (hours) 

DN (In) 

/ 100 ft 

4 0.3 

6 0.6 

8 1.0 

10 1.4 

12 1.8 

DN (In) 

Test time (hours) 

/ 100 ft 

14 2.0 

16 2.2 

18 2.3 

20 2.8 

24 3.0 

Note: In cases where the pipes are laid below the ground water table, the test pressure shall be increased by 0.5 psi for 

every 1 foot of ground water above the pipe crown. If the resulting air test pressure exceeds 5 psig, the air test method 

should not be used and the infiltration method is recommended. 

Caution: Testing with air can be dangerous if the line is not prepared properly and safety precautions are not taken. It is 

very important to install the test plugs properly and brace them to prevent blowouts. Air pressure must always be relieved 

before attempting to remove the test plugs. The test equipment should include a pressure relief valve designed to release air 

and prevent pressure from exceeding 6 psig. 

40

7.9.2: Low head water test 

The Contractor should plug both ends of the pipeline section (between two manholes) with suitable plugs. The test section 

should not exceed 650 feet. The plugs should have connections for a standpipe (typically 2” or 3” in diameter) connected 

to the pipe plug with a 90º elbow. At the upstream manhole, the standpipe shall extend 4 feet above the crown of the gravity 

pipe, or 4 feet above the existing ground water level. This level is called the test level. The test section shall be filled slowly 

from the upstream manhole while releasing the air out. Allow the water to stand for about 1 hour for stabilization, after 

which add water until the water level again reaches the test level in the stand pipe at the upstream manhole. Start the test, 

and over the next 30 minutes, the amount of water necessary to maintain a constant test level water head shall be measured 

using graduated containers of water. The line shall pass the test if the ex-filtration amount does not exceed 10 gallons per 24 

hours per inch of pipeline diameter per mile of pipe. A typical test setup is shown in figure 25. 

Figure 25: low head water test installation detail. 

41

8.0: Repair and replacement of pipe 

The flow in the pipe section should be stopped by closing the appropriate valves in the system, or plugging the pipe ends 

and then draining the line. 

The replacement of a pipe or a fitting is similar to that of a closure (i.e., laying of the last length of pipe or fitting which closes 

or completes the line or a section of the line). 

To completely replace a damaged pipe, the couplings are first carefully removed by cutting them off with a circular blade 

saw. The pipe, and the rubber rings from the pipes adjacent to it, is then removed from its location in the line. Insert the new 

pipe as indicated below: 

• Carefully measure the gap where the replacement piece has to be fitted. The replacement piece must be well centered, and 

an equal clearance of 3/4” must be left between the inserted pipe and the adjacent ones. 

• Use a pipe on site with a constant OD, if necessary cut the pipe with a circular saw square to the end and bevel 

the pipe end with a grinding disk. 

• Pull the coupling into the pipe ends of the new pipe after abundantly lubricating the ends and the sealing rings. It will be 

necessary to gently help the second sealing ring over the chamfered (beveled) end of the pipe. 

• After cleaning them thoroughly, lubricate the ends of the two adjacent pipes well. 

• Insert the pipe in its final position and pull the coupling over the adjacent pipes up to the home line with the mechanical 

equipment described in section 5.2. 

To replace a damage pipe section 

• Carefully measure the gap where the replacement piece has to be fitted. The replacement piece must be 1 1/2” shorter 

than the length of the gap. The damaged section should be cut using a circular saw (taking care of electrical hazards when 

working in a wet trench). 

• Use a pipe on site with a constant OD, cut the pipe with a circular saw square to the end, to the required length and bevel 

the pipe end with a grinding disk. The new pipe section must be well centered, and an equal clearance of 3/4” must be 

left between the inserted pipe and the existing ones. 

• Pull the coupling into the pipe ends of the new pipe after abundantly lubricating the ends and the sealing rings. It will be 

necessary to gently help the second sealing ring over the chamfered (beveled) end of the pipe. After cleaning them thoroughly, 

lubricate the ends of the two adjacent pipes well. 

• Insert the pipe in its final position and pull the coupling over the adjacent pipes up to the home line with the mechanical 

equipment described in section 5.2. 

• Alternatively for sizes 16 through 64”, two standard ductile iron mechanical couplings may be used to join the new pipe 

sections. Care must be taken not to over-tighten the mechanical coupling bolts. Tighten enough to seal the joint and no more. 

42

9.0: Tapping water mains 

Pressure pipes, which require tapping, should have a minimum stiffness of SN 36 psi. 

‘Live’ water pipe can be tapped while pressurized and in service to obtain service connections to consumers. Typically, 

3/4” service connections are made. 1” service taps are also available. 

Wide band gunmetal saddles or HDPE saddles may be used to tap FRP pipes. Saddles are normally provided with a threaded 

outlet of the required size (e.g. 3/4”). 

The following general procedure should be adhered to: 

• The outside surface of the pipe, where the saddle will be mounted, in particular where the outlet will be located, should be 

cleaned and all soil, sand, etc. should be removed by a brush, before mounting the saddle. 

• Insert the stopcock into the threaded outlet of the saddle before mounting on the pipe, using Teflon tape where necessary. 

Screw the stopcock in until a tight seal is obtained. 

• Attach a rubber or PE hose/pipe to the outlet of the stopcock. The hose should be sufficiently long so that water run-off will 

be outside the trench area. 

• The saddles should be assembled in accordance with the manufacturer’s instructions, making sure that the rubber O ring 

seal is well seated and centered between the threaded outlet and the outside surface of the pipe. Do not over-tighten the saddle 

to avoid damaging or distorting the FRP pipe. 

• Using a commercial tapping machine, attach the correct hole cutting tool into the tapping machine and screw the assembly 

quickly into the open stopcock. 

• Follow the tapping machine operating instruction and after drilling is complete, use the hose and pressurized water to flush 

out any debris. 

• Unscrew the tapping machine and close the stopcock, then connect the permanent house connection pipe (typically PE) to 

the stopcock using a male adapter. 

• Backfill the pipe following the standard instructions making sure that the backfill material is placed and compacted under 

the pipe haunches. 

43

APPENDIX I: 

APPROXIMATE WEIGHT OF PIPE & JOINTS (FOR HANDLING 

PURPOSES ONLY) 

Nominal pipe weight; lb/ft 

Coupling 

weight 

DN (Inch) SN 18 psi SN 36 psi SN 46 psi SN 72 psi 

lb/pc 

14 7 

9 

10 

11 

26 

16 

18 

20 

24 

28 

32 

36 

40 

9 

12 

15 

21 

28 

36 

45 

55 

11 

15 

18 

25 

34 

44 

56 

69 

44 67 83 90 103 123 

48 79 98 106 127 147 

52 92 115 124 142 168 

56 107 134 144 164 176 

60 122 151 164 186 187 

64 139 171 186 211 205 

68 156 193 209 241 216 

72 175 216 234 270 233 

76 194 242 262 317 249 

80 213 267 289 333 268 

84 234 293 318 367 286 

88 258 322 349 403 306 

92 281 351 380 456 326 

96/98 305 384 415 496 345 

100/102 341 416 450 535 365 

104/104 366 449 486 577 387 

108/110 394 491 514 621 409 

112/114 422 527 551 665 431 

116/118 452 565 591 711 583 

120/122 482 603 630 711 607 

128/130 545 683 713 860 631 

132/134 578 726 757 914 658 

136/ 

138 

612 

765 

800 

682 

140/ 

142 

649 

809 

847 

708 

144/ 

146 

685 

856 

894 

735 

148/ 

150 

722 

903 

943 

761 

152/ 

154 

759 

950 

788 

156/ 

158 

799 

1000 

814 

Note: Pipe sizes larger than 96” may be ribbed and will weigh less. 

44 

12 

16 

19 

27 

37 

48 

61 

74 

14 

19 

23 

33 

42 

57 

72 

85 

29 

33 

37 

64 

73 

81 

88 

101

APPENDIX II: 

Design considerations for pipelines anchoring 

The anchorage of pressure pipelines with rubber gasketed joints is an important consideration for the safe and reliable operation 

of pressure pipelines. 

If pressure pipelines are not anchored properly, the thrust loads can lead to the displacement of pipes and fitting sections. 

Thrust loads occur in pipelines wherever there is a change in diameter (e.g. reducers), a change in direction (elbow, tee, and 

wye, etc.), or at dead ends (e.g. blind flanges, closed valves, bulk heads). 

The determination of the thrust occurring in these situations is relatively simple. The figures and formulas in the following sections 

show the values of thrust occurring in various types of fitting configurations, common to all pressure pipelines. It is not 

the intention of this section to provide the design methods of thrust blocks. Specialized engineers should do these kinds of 

studies. The main design considerations of thrust blocks are as follows: 

• The pressure is assumed to be acting on the joint area, and not on the internal pipe cross sectional area. 

• Where concrete thrust blocks are used, they should be poured against undisturbed native soil. This is required to ensure 

proper load distribution, and that pressures induced by the surrounding soil do not exceed the maximum design bearing 

capacity. A soil investigation is recommended to establish the proper soil bearing capacities. 

• Upward thrust forces can be absorbed by a combination of pipe weight, water in the pipe and the soil on top of the pipe. 

If these restraining forces are not sufficient, concrete blocks can be used to provide additional weight on top of the pipe. 

• In the case of a horizontal thrust (the most common case), concrete blocks, both non-reinforced and reinforced are 

typically used. Pilings may also be used where native soils are unstable. It may also be possible to provide special axially 

reinforced pipes and to tie several sections of pipe together on both sides of an elbow for example. Tied pipe sections plus 

the weight of water plus the soil weight provide support which resists by friction the thrust forces in the pipeline. Tying of pipe 

and fitting sections is normally done by laminated (butt-wrap) joints or alternatively by rubber gasketed locked joints. 

• The ground on which the pipes are laid normally absorbs downward thrust forces. The designer should note that 

where unstable soils are present, a proper foundation and bed constructed with good granular material shall be provided. 

• The typical coefficients of friction (f) used for design purposes are the following : 

- Concrete on concrete 0.65 

- Concrete on dry clay 0.50 

- Concrete on wet clay 0.33 

- Concrete on gravel 0.65 

- Concrete on sand 0.40 

45

• The table below provides typical soil bearing capacities (horizontal) which may be used for the design of thrust blocks. 

The designer should note that proper evaluation and identification of native soil is essential to determine the proper soil 

bearing capacity values. 

Soil type Bearing capacity (strength) (lb/ft) 

Soft clay 1,000 

Silt 1,500 

Sandy silt 3,000 

Sand 4,000 

Sandy clay 6,000 

Hard clay 9,000 

Figure II-1: Thrust in Fittings 

46

APPENDIX III 

AIR IN PIPELINES, AIR-VALVES, SURGE AND HAMMER CONTROL 

Air in pressure pipelines can cause major operational problems. Typical problems induced by the presence of such air are 

the reduction in flow capacity because of reduced cross-sectional areas, and fluctuation in flow caused by expansion and 

contraction of the air pockets in the line. High surge pressures can result from the flow fluctuations, which cause sudden movements 

of the air from one location to another, followed by the slugs of water. Also, surge (water hammer) can occur in 

pipelines from opening and closing valves and from the start-up and shutdown of pumps. 

Air can enter a pipeline from many locations: 

• On draining the line 

• Negative surges (vacuum) causing air to enter at air valves in the pipeline 

• At the intake source. 

• Release of dissolved air from the water by temperature and pressure variation 

• Draining parts of the pipeline or the pipe system during normal shut-down 

In the first instance, air shall be prevented from entering the line. This will reduce operational difficulties. 

Suggested solutions for controlling entrapped air in pipelines are the following: 

• The intake point should be provided with low water level pump cut-off. 

• Release of air: Air dissolved in the water at the intake and released due to temperature and pressure fluctuations cannot 

be prevented. However, the quantities of such air are not large and provisions for releasing the air can be made by the means 

of air valves. Proper selection of air valves is essential. 

• While draining the line, air cannot be prevented from entering the line. Large orifice air valves should be provided for 

exhausting the air during refilling. Long filling times will allow the complete release of air. 

• Negative surges (vacuum) - Large volumes of air may be involved here and can cause serious operational problems. The 

best way to prevent air from entering under these conditions is by proper design to eliminate the possibility of water column 

separation. 

Studies have shown that suddenly released entrapped air under apparently static conditions creates a situation similar to a 

water hammer. Generated pressures can be of the order of several times the pipeline test pressure. Any pipeline material can 

be seriously affected by the quick increase in the magnitude of pressure loads. 

Remedial actions against entrapped air and water hammer are the following: 

1- Lay the pipeline essentially to grade wherever is possible, avoiding major slopes. It may be advantageous to create 

artificial high points by providing a small slope of around 0.01” to 0.02” per foot to facilitate air collection at high points. 

2- Automatic continual acting air release valves should be used at all major high points. Almost all the air release valve manufacturers 

limit the maximum distance between air release valves to around 2500 feet. 

3- Air should be sucked out from the pipeline slowly. 

4- Filling velocity of the pipeline should be limited to 1 ft/sec. 

5- Use d/D = 1/10 to 1/15, where: 

d = diameter of air release valve 

D = pipe diameter 

48

6- Using motorized actuated valves is an effective means of limiting positive surges to an acceptable level by controlling the 

rate of opening and closing of the valves. 

7- Flywheels on pump motors allow the pump to keep on running for a short period of time after any power shut down, before 

it gradually stops. 

Note: For water hammer calculations, a value of 17,500 MPa (2,538,000 psi) may be used for the pipe. Modulus of 

Elasticity E’ for continuous filament wound pipe. 

Surge Control Device 

49

APPENDIX IV 

FLANGE INSTALLATION INSTRUCTIONS 

1. Scope 

Installation instructions and use of fiberglass ( RTR ) flanges. 

Tools 

Tools necessary for assembly of Flanges are: 

• Ring spanner with required bolt-head size 

• Torque wrench with required socket size. 

Note: Fiberglass flanges are substantially thicker than steel flanges. The contractor should contact FPI for actual thickness of 

flanges supplied to order the correct flange bolt lengths. 

Bolts and Nuts 

Bolts should be wire brushed and lubricated before being used. Failure to clean the bolts will result in insufficient initial tension 

in the flange bolts which could result in movement of the flange during operation conditions. Washers and nuts should 

be clean and well lubricated before being used. It is important to use washers with all fiberglass flanges. ALWAYS USE A 

TORQUE WRENCH. 

CAUTION: Fiberglass flanges must always be installed tension free, therefore flanges must be accurately aligned. Pipelines 

must never be pulled by means of the flange bolts. If a fiberglass pipeline is connected to a steel line, this steel line must be 

anchored at or near the interface point to prevent any movements or loads being transmitted to the fiberglass line. 

2. Connection against raised Face Flange: 

Fiberglass flanges are flat faced and must be connected against flat faced flanges. If this is not possible, special precautions 

should be taken. 

• The gap between the raise face and the flat face must be filled with a stainless steel washer or a hard gasket (e.g. Asbestosfree 

CAF-equivalent type) of a thickness equal to: 

the raised face ‘t’ + gasket ‘t’ – ⁄”. 

• A second alternative is to fit a steel back up ring behind the fiberglass flanges. Through 12” diameter the connection of 

fiberglass flat faced flanges is possible provided that the torques is limited. On the fiberglass side of the flange joint the bolts 

and nuts must be provided with washers to avoid exceeding the allowable surface pressure. 

• When assembling a wafer-type butterfly valve, the bolts should be tightened first by hand. At pressure testing if leakage 

occurs, the bolts can be tightened up to the maximum valves. 

To avoid over stressing of the flanges, spacers can be placed between the GRP flanges. 

3. Tightening sequence of fiberglass flanges 

• Tightening of the bolts of a flange connection must be done according to the diagonal sequence shown below. 

• Bolts in the flanges must be placed straddle to the centerline unless differently specified. 

• The flange must be connected perpendicular on the axis of the pipe. The maximum allowable deviation is as follows: 

For pipe diameter through 12” : 1 mm (0.04”) 

For pipe diameter 14” through 24” : 2 mm (0.08”) 

For pipe diameter 28” mm and larger : 3 mm ( 1/8”) 

50

4. Gaskets and torques 

For sealing fiberglass flanges, several gaskets types may be used, depending on the diameter, system pressure or specific 

requirements of the client. 

IMPORTANT NOTE ON MAXIMUM TORQUE 

When assembling fiberglass flanges, bolts should be tightened by hand first, then using a torque wrench up to 30% or the 

max torque value shown below and on the following pages. If flanges are not leak tight, torques should be increased up to 

60% of the max torque values shown. After all the bolts have been tightened to the recommended torque, recheck the torque 

on each soil in the same sequence, since previously tightened bolts may have relaxed. Max torque values shown are 

‘Ultimate’ and should be avoided under normal site conditions. Always follow the correct torqueing sequence specified. 

Consult FPI for more assistance. Excess torque can prevent sealing and can damage flanges. 

a. Asbestos-free CAF type (equivalent to compressed asbestos fibers) 

Sized type : full face t = 1/8” 

Application : DN 1” through 12”, up to 300 psi rating. 

Torques if assembled against flat faced flanges 

51

Table 1a 

If connected to raised faced flanges, used 50 % of above torque values 

*see important Note on maximum torque 

b. Neoprene flat gasket 

Sized type : full face t = 0.125”, Shore A hardness 60 + 5 

Application : DN 1” through 14”, PN through ANSI 150 # rating. 


*see important Note on maximum torque 

Max* Torque 

lb-ft (N.m) 

Table 1b 

c. Neoprene flat gasket with steel inlay 

Sized type : full face t = 1/4” to 3/8” 

Application : DN 1” through 48”, up to 250 psi rating. 


Table 1c 

f. Assembly of large diameter flanges with rubber ‘O’ ring seals 

Max* Torque 

lb-ft (N.m) 

Max* Torque 

lb-ft (N.m) 

ID (inch) DIN 2501 PN 10 ASA 150# ASA 300# 

1” 52 (70) 52 (70) 74(100) 

1 1/2” 74 (100) 74 (100) 110 (150) 

2” 74 (100) 74 (100) 110 (150) 

3” 74 (100) 74 (100) 110 (150) 

4” 74 (100) 74 (100) 185 (250) 

6” 110 (150) 110 (150) 185 (250) 

8” 110 150) 110 (150) 220 (300) 

10” 110 (150) 220 (300) 370 (500) 

12” 110 (150) 220 (300) 405 (550) 

ID (inch) 

Max* Torque lb-ft (N.m) 

ASA 150 # 

1-3” 40 (55) 

4-6” 40 (55) 

12” 74 (100) 

14” 92 (125) 

ID (inch) 

Max* Torque lb-ft (N.m) 

225 psi max 

1-12” 40 ( 55) 

14-24’” 74 (100) 

28-32” 222 (300) 

36-42” 295 (400) 

Large diameter flanges (generally 36”and larger) are supplied with a groove in the flange face for sealing using a neoprene 

‘O’ ring supplied by FPI. The following assembly instructions are applicable. 

52

Notes: When assembling two flanges, only one flange must have an ‘O’ ring groove. The other mating flange must be 

flat faced. 

• ‘O’ rings like all rubber products should be stored in a cool shaded area away from sunlight. 

• Clean the ‘O’ ring groove with a hard brush to remove all dirt and sand, then wipe clean with a damp cloth. 

• Clean the neoprene ‘O’ ring with a damp cloth thoroughly check the ring for cracks by stretching the gasket all around 

to about 30% over its normal length. Never use used cracked or otherwise damaged ‘O’ ring gaskets. 

• Insert the ‘O’ ring in the flange groove and secure in position using several small strips of double sided adhesive tape 

placed between the ‘O’ ring and the groove surface. 

• Align the two flanges and insert the bolts, nuts, and washers after cleaning and lubricating in accordance with section ‘a’ 

of this appendix. 

• Tighten the nuts and bolts using a torque wrench following the sequence shown in section ‘c’ of this appendix, to a torque 

of 25 lb-ft (35 N.m) 

• Re-torque all nuts and bolts in the correct sequence to 48 lb-ft (65 N.m). This torque is normally sufficient to achieve the 

required sealing during the hydrostatic test and normal operation. Maximum torques must not exceed 74 lb-ft (100 N.m.). 

5. Assembly and disassembly of flanged equipment 

When assembling flanged parts (equipment, valves, orifice flanges, etc.) that may need to be disassembled in the future, a 

mechanical flange adaptor or a dismantling joint must be placed on one side of the flanged joint, to allows some displacement 

in the axial direction. 

6. Trouble shooting 

If an assembled flanged joint leaks, loosen and remove all bolts, nuts, washers, and gaskets. Check for alignment of assembly 

and correct alignment as required. Check the gasket for damage. If damaged, discard and replace with a new gasket. 

Check flanges for seal rings. Flanges with damaged inner seal rings must be removed and new, undamaged flanges installed. 

If leak occurs as a result of deficiencies in non-fiberglass components of the piping system, consult the manufacturer of the 

defective components for recommended corrective procedures. 

Clean and lubricate old threads and washers before rejoining. Repeat the rejoining procedure outlined above. After corrective 

action has been taken retest the joints to see if a water-tight seal has been made. 

53

APPENDIX V: LIST OF REFERENCES 

The following standards and publications provide a good source of information on the design, installation and testing of 

FRP pipe and other pipe materials. 

• Fiberglass Pipe Institute Fiberglass pipe Handbook – 1989 

• ASTM C924 Standard Practice for Testing Concrete Pipe Sewer Lines by Low-pressure Air Test 

Method 

• ASTM C969 Standard Practice for Infiltration and Exfiltration Acceptance Testing of Installed Precast 

Concrete Sewer Lines 

• ASTM D1586 Standard Method for Penetration Test and Split Barrel Sampling of Soils. 

• ASTM D2487 Classification of Soils for Engineering Purposes 

• ASTM D1586 Standard Method for Penetration Test and Split Barrel Sampling of Soils 

• ASTM D 3839 Standard Practice for Underground Installation of “fiberglass” Pipe. 

• AWWA C950-02 Standard Specification for Fiberglass Pipe 

• AWWA Manual M45 Fiberglass Pipe Design - 1996 

• BS 8010 Part 1:89 Pipelines on Land - General 

• BS 8010 Part 2.5:89 Pipelines on Land - Design, Construction & Installation - GRP Pipelines. 

• BS 8010 Part 3:93 Pipelines - Sub-sea: Design, Construction & Installation. 

54

Texas, USA 

Future Pipe Industries, Inc. 

11811 Proctor Road, 

Houston, Texas 77038, USA 

Tel: +1 (281) 847 2987 

Fax: +1 (281) 847 1931 

Email: houston@future-pipe.com 

Beirut, Lebanon 

Future Pipe Industries (S.A.L.) 

Akkar, North Lebanon 

P.O. Box 13-5009 


Tel: +961 (6) 875 102 

+961 (6) 875 103 

Fax: +961 (6) 875 101 

Email: lebanon@future-pipe.com 

Doha, Qatar 

Future Pipe Industries (Q.C.J.S.C) 

P.O. Box 24678 

Doha, Qatar 

Tel: +974 431 5290/2 

Fax: +974 431 5298 

Email: qatar@future-pipe.com 

USA & Latin America 

Future Pipe Industries Inc. 

11811 Proctor Road, Houston, 

Texas 77038, USA 

Tel: +1 (281) 847 2987 

Fax: +1 (281) 847 4216 

Email: sales-spoolable@future-pipe.com 

sales-houston@future-pipe.com 

Puteaux, France 

Future Pipe (S.A.R.L.) 

Tour Arago 5 Rue Bellini, 

La Défense 11 92 806 

Puteaux, France 

Tel: +33 (1) 4767 6869 

Fax: +33 (1) 4767 6870 

Email: sales-france@future-pipe.com 

Dammam, KSA 

Future Pipe Industries (L.L.C.) 

P.O. Box 8513 

Al-Khobar 31492 

Dammam, Kingdom of Saudi Arabia 

Tel: +966 (3) 812 3454 

Fax: +966 (3) 812 3453 

Email: sales-saudiarabia@future-pipe.com 

Mississippi, USA 


12450 Glascock Drive, 

Gulfport, Mississippi 39503, USA 

Tel: +1 (228) 604 0060 

Fax: +1 (228) 604 0051 

Email: gulfport@future-pipe.com 

6th of October City, Egypt 

Future Pipe Industries (S.A.E.) 

P.O. Box 96 

6th of October City, 

Arab Republic of Egypt 

Tel: +20 (2) 834 1610 

Fax: +20 (2) 834 1608 

Email: egypt@future-pipe.com 

Dubai, UAE 

Gulf Eternit Industries (L.L.C.) 

P.O. Box 1371 

Dubai, United Arab Emirates 

Tel: +971 (4) 210 1234 

Fax: +971 (4) 210 1299 

Email: info@gulf-eternit.com 

Calgary Alberta, Canada 

Representative Office 

2900 First Canadian Center, 

350 - 7th Avenue S.W., 

Calgary Alberta, Canada T2P 3N9 

Tel: +1 (403) 668 5522 

Fax: +1 (403) 668 5523 

Email: sales-canada@future-pipe.com 

Hardenberg, The Netherlands 

Future Pipe Industries bv 

J.C. Kellerlaan 3, P.O. Box 255 

7770 AG Hardenberg 

The Netherlands 

Tel: +31 (523) 288 911 

Fax: +31 (523) 288 441 

Email: sales-netherlands@future-pipe.com 

Rusayl, Sultanate of Oman 


P.O. Box 213 

PC, 124 Rusayl, Sultanate of Oman 

Tel: +968 (24) 449 164 

Fax: +968 (24) 446 217 

Email: sales-oman@future-pipe.com 

Bangkok, Thailand 

Future Pipe Industries Limited 

44th Floor, CRC Tower, 

All Seasons Place, 

Bangkok, Thailand 

Tel: +66 (2) 685 3290 

Fax: +66 (2) 6853289 

Email: sales-thailand@future-pipe.com 

Manufacturing Facilities 

Sales Offices 

Texas, USA 


Spoolable Pipe Division 

8641 Moers Road, 

Houston, Texas 39502, USA 

Tel: +1 (713) 941 6639 

Fax: +1 (713) 910 8819 

Email: spoolable@future-pipe.com 

Dammam, KSA 


P.O. Box 8513 

Al-Khobar 31492, 

Dammam, Kingdom of Saudi Arabia 

Tel: +966 (3) 812 3454 

Fax: +966 (3) 812 3453 

Email: saudiarabia@future-pipe.com 

Dubai, UAE 


P.O. Box 62501 


Tel: +971 (4) 210 1200 

Fax: +971 (4) 210 1200 

Email: dubai@future-pipe.com 

London, United Kingdom 

Future Pipe Limited 

Whitlock House, 6 Earls Court Road, 

London W8 6EA, United Kingdom 

Tel: +44 (20) 7938 4942 

Fax: +44 (20) 7938 4962 

Email: sales-uk@future-pipe.com 


Future Pipe Industries (S.A.L.) 

Ain Mreisseh, John F. Kennedy Street 

P.O. Box 13-5009 


Tel: +961 (1) 369 870 

Fax: +961 (1) 369 860 

Email: sales-lebanon@future-pipe.com 

Dubai, UAE 

Gulf Eternit Industries (L.L.C.) 

P.O. Box 1371 


Tel: +971 (4) 210 1200 

Fax: +971 (4) 210 1222 

Email: sales@gulf-eternit.com 

Singapore 

Future Pipe Industries 

No.30 Woodlands Loop # 02-01, Nobel 

Design Building, 

Singapore 738319 

Tel: +65 757 5312 

Fax: +65 757 5317 

Email: sales-singapore@future-pipe.com 

Hardenberg, The Netherlands 

Future Pipe Industries bv 

J.C. Kellerlaan 3, 

P.O. Box 255 

7770 AG Hardenberg, 

The Netherlands 

Tel: +31 (523) 288 911 

Fax: +31 (523) 288 441 

Email: netherlands@future-pipe.com 

Rusayl, Sultanate of Oman 


P.O. Box 213 

PC, 124 Rusayl, Sultanate of Oman 

Tel: +968 (24) 449 164 

Fax: +968 (24) 446 217 

Email: oman@future-pipe.com 

Abu Dhabi, UAE 


P.O. Box 29205 

Abu Dhabi, United Arab Emirates 

Tel: +971 (2) 551 0777 

Fax: +971 (2) 551 0666 

Email: abudhabi@future-pipe.com 

Madrid, Spain 

Future Pipe (S.L.) 

Edificio Lexington 

c/ Orense, 85 28020, 

Madrid, Spain 

Tel: +34 (91) 567 8463 

Fax: +34 (91) 567 8464 

Email: sales-spain@future-pipe.com 

Giza, Egypt 

Future Pipe Industries (S.A.E.) 

34 El Riyad Street Mohandessin, 

Giza, Egypt 

Tel: +20 (2) 302 2234 

Fax: +20 (2) 302 2206 

Email: sales-egypt@future-pipe.com 

Abu Dhabi, UAE 


P.O. Box 29205 

Abu Dhabi, United Arab Emirates 

Tel: +971 (2) 627 0008 

Fax: +971 (2) 627 0009 

Email: sales-abudhabi@future-pipe.com

Untitled - Future Pipe Industries

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