04-Division 15-Section 15010 Pipework-Version 2.0

ADSSC/GSMW Division 15 Section 15010

Pipework Rev: 02 Jan. 2011 Page 1 of 15

ABU DHABI SEWERAGE SERVICES COMPANY (ADSSC)

GENERAL SPECIFICATION FOR MECHANICAL WORKS

DIVISION 15 MECHANICAL

SECTION 15010 PIPEWORK

General Specification for Mechanical Works Abu Dhabi Sewerage Services Company

(ADSSC)



DOCUMENT CONTROL SHEET

Revision No. Date Revision Description / Purpose of Issue

01 April 2008 First Issue.

02 Jan. 2011 ADSSC new logo

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(ADSSC)



TABLE OF CONTENTS

1. PIPEWORK ..................................................................................................... 4 1.1 GENERAL ............................................................................................ 4 1.1.1 SUITABILITY OF PIPE MATERIALS FOR USE WITH SEWERAGE

AND TREATED SEWAGE EFFLUENT ................................................ 5 1.1.2 GENERAL USE OF MATERIALS IN PIPELINES ................................. 5 1.1.3 SUMMARY OF PROPERTIES OF PIPE MATERIALS: ........................ 6 1.2 PRESSURE RATINGS ......................................................................... 9 1.3 DESIGN ............................................................................................. 10 1.4 VELOCITIES ...................................................................................... 11 1.5 FLANGE ADAPTORS ........................................................................ 11 1.6 CUTTING ........................................................................................... 11 1.7 JOINTING .......................................................................................... 11 1.8 PIPE SUPPORT WORK, HOLDING DOWN BOLTS & BOLTING ...... 11 1.9 INSULATION ...................................................................................... 14 1.10 PIPELINE IDENTIFICATION .............................................................. 14 1.11 STEEL PIPES .................................................................................... 14 1.12 GALVANISED STEEL ........................................................................ 15 1.13 UPVC/ABS ......................................................................................... 15 1.14 FLEXIBLE HOSEWORK .................................................................... 15


(ADSSC)



1. PIPEWORK

1.1 GENERAL

a) Materials and coatings used shall be unconditionally resistant to the conveyed fluids, and any gases derived from that fluid under all operating conditions.

b) Pipework shall be as follows:-

i. Pumped - GRP, MDPE, HDPE, Ductile Iron, coated steel ii. Drainage - uPVC iii. Sludge - Ductile Iron or Coated Steel or ABS iv. Sampling - PVC or ABS, stainless steel

c) Air - Galvanised Mild Steel or ABS.

d) Ductile iron for Potable/Water (including supernatant) shall be cement

mortar lined. e) The following guidelines shall be followed: WRC Pipe Materials

Selection Manual and EN 1295-1 Structural design of buried pipelines under various conditions of loading.

f) General guidelines on the selection of pipe materials and the properties of pipe materials are given in the tables below.

g) This Specification shall be read in conjunction with Section 15001: General M and E Requirements.

h) All pipework fabrications shall be protected against corrosion as

specified in Section 15004 : Corrosion Protection. Pipework internals shall be protected to the same degree and specification as the pipework external structure.


(ADSSC)



1.1.1 SUITABILITY OF PIPE MATERIALS FOR USE WITH SEWERAGE AND TREATED SEWAGE EFFLUENT

Pipe Material

Class Sewerage Treated Sewage Effluent Manufacturing

Base

Relative Cost per m

Gravity Pressure Gravity Pressure

Lined and coated RC

Rigid No No Yes No UAE, Saudi Arabia

Medium

DI Semi rigid

No Yes No Yes Europe, USA High

GRP Flexible Yes Yes Yes Yes UAE Medium

HDPE Flexible Yes Yes Yes Yes UAE Medium

MDPE Flexible Yes No Yes No UAE Medium

uPVC Flexible Yes No Yes No UAE Low

VC Rigid Yes No Yes No Saudi Arabia Low

1.1.2 GENERAL USE OF MATERIALS IN PIPELINES

Material Trunk 300mm Distribution Services Pumping Size up to 2400mm ≥50mm, ≤50mm dia Stations

dia generally300mm to 800mm dia

Sewage , DI, GRP, HDPE, VC

GRP, HDPE, uPVC, VC ,

Not applicable DI , Stainless Steel, Epoxy

Coated Carbon Steel

Treated sewage GRP, HDPE, HDPE,, HDPE, MDPE DI, MDPE, effluent MDPE, VC uPVC, VC , Stainless Steel

Epoxy Coated Carbon Steel

HDPE Stainless

Steel, Epoxy Coated Carbon

Steel


(ADSSC)



1.1.3 SUMMARY OF PROPERTIES OF PIPE MATERIALS:

Property DI GRP HDPE uPVC VC

Specification ISO 2531 ISO 8179

ASTM C128 ASTM D3262

ASTM D1447 ASTM D3035

ASTM D1784 ASTM D1785

ASTM C700, BS

65 AWWA C400 DIN 8074 ASTM D2241 BS EN 295 Coating BS

EN 545 BS 486 BS

5480 ISO 4427 ASTM D2665

BSEN 1452-2 DIN 1230

BS EN 548 ISO 11922-1

Maximum Maximum 25 Maximum 25 2.5 Bar to 30 16 Bar 10 Bar operating Bar Bar Bar pressure

Structural type Semi rigid Flexible Flexible Flexible Rigid

Standard 5/6m length 6m max 100m coil up 6m 2m length to 110mm dia > 12m length above 110mm dia

Jointing Push fit spigot and socket,

Flanged joints

Push fit rubber gasket collar joint, Spigot and socket with gasket, Slip on collar

flange

Butt fusion welding,

Electrofusion , Flange

Push fit spigot and socket,

Solvent welding

Push fit with rubber gasket

Anchor Required Required Not required Required Required blocks on welded lines

Fittings DI fittings GRP HDPE fabricated fittings, Standard mechanical joints

PVCu VC limited


(ADSSC)




Deflection allowed

Only on long length

Max 50 More than 50 35D

1 to 50 Up to 200mm 2.90 , For

1000mm 0.60

Trench required

Wide trench Wide trench Narrow trench Wide trench Wide trench

Installation Overground, Underground

Underground Can be laid overground

/underground on slopes

Underground Underground

Corrosion Effected by certain soil chemicals

Resistant to soil corrosion,

Chemically inert


Chemically inert


Chemically inert


Chemically inert

Weight Heavy Lightweight Lightweight Lightweight Heavy

Handling Can be damaged by

heavy handling

Careful handling,

cracks if badly handled

Easy handling, not

easily damaged

Careful handling

because of brittle nature

Careful handling, can

be easily damaged

Hydraulic properties

High frictional loss, High

pumping cost

Low frictional loss, low

pumping cost

Low frictional loss, low

pumping cost

Low frictional loss, can be

susceptible to fatigue, surge failures have been known

Low frictional loss

Abrasion resistance

Lining suspect to abrasion

Good Good Limited Good

Breakage Damaged Impact loads Impact Damaged by Damaged by due to heavy cause cracks resistant, impact impact impact loads unbreakable


(ADSSC)




Installation Easy installation,

Careful installation,

Easy installation,

Easy installation

Easy installation,

larger sizes need

craneage

required Less time required, Only

very large sizes need craneage

but subject to poor

installation methods

many joints due to small

length

Bedding requirements

As dug material

As dug material,

important to support along entire length must be self

Selected as dug material, target 90% standard Proctor

Selected as dug material or

processed granular

materials, target 90% standard

Selected as dug material or processed

granular materials, target 90% standard

compacting Proctor Proctor

Supports, clamps

Supports required

Not applicable,

Above ground installation not

possible

No support required, frequent clamping

Not applicable, Above ground installation not

possible

Not applicable,

Above ground installation not

possible

Maintenance Low maintenance

Low maintenance

No maintenance

No maintenance

No maintenance

Leakages Frequent if corroded

Normal No Leakage Normal allowances for push fit joints

Normal

Surge head High surge pressure

Medium surge pressure

Low wave velocity, Less

surge pressure

Medium surge pressure

Not suitable for pumping

Water supply Depending on water quality

Common Recommend ed all over

world

Commonly used in

distribution

Not applicable

cement internal lining is provided


(ADSSC)




Sewage Common in Common in New to UAE Common in Common pump mains Middle East UAE throughout World

Test pressure 1.5 times operating

pressure or 1.25 times max surge pressure,

whichever is greater

1.5 times operating



1.5 times operating



1.5 times operating

pressure or 1.25 times max

surge pressure,


Air/gravity test

Design life 35 years depending on environment

50 years 50 years minimum

50 years (without brittle

failures)

50 years

Deterioration Corrosion Joints Nil Joint Joint with time encrustation deteriorate deterioration deterioration etc encrustation etc

Availability Imported UAE Local up to Commonly Saudi Arabia 1200mm dia available up UAE to 400mm dia

UV light Not affected Deteriorates in UV

Stabilised Deteriorates in UV

Not affected

Cost High Moderate Moderate Low Low

1.2 PRESSURE RATINGS

a) Pipework and fittings shall be suitable for a safe working pressure equivalent to the maximum working pressure of the system.

b) The safe working pressure of pumping mains shall be the closed valve

head of the pump plus the maximum suction static head plus the maximum surge pressure.

c) Pipework and fittings shall be suitably rated to withstand intermittent

surge pressure transients specified in the technical schedules. d) Ductile iron pipework and fittings shall have a minimum pressure rating

of 16 bar.


(ADSSC)



e) Tests shall be carried out to ensure the pipework systems are correctly

levelled. f) Upon completion of the installation, the whole of the pipework, valves etc

shall be tested to 25% above the max. surge pressure. 1.3 DESIGN

a) There shall be a sufficient number of mechanical joints to enable mechanical plant and valves to be disconnected from built-in pipework. Such joints shall be tied, and shall not be allowed to sustain the weight of any pipework.

b) All machinery stations shall be provided with flexible joints, flange

adaptors or unions such that upon renewal of plant minimal disturbance of pipework is required.

c) Flanges shall be drilled off centres and shall be to BS EN1092-1. d) Pump suction bell mouths shall be standard castings in either cast iron

or ductile iron. e) The use of gusseted bends shall only be permitted upon approval by

ADSSC. f) All bends shall be even curvature manipulated bends where space

allows and the use of carbon and alloy steel welding fittings to BS 1640 Part 3 or equivalent shall be permitted where short radius bends are required.

g) Carbon and alloy steel welding fittings to BS 1640 Part 3 or equivalent

shall be permitted where short radius bends are required. h) Tee pieces on pump manifolds shall have a radial branch to enable a

more streamline flow from branch to body. i) Short radius tee pieces are permitted where there are space limitations

and the consequent head loss is insignificant. Due allowance shall be made for reinforcement in the vicinity of branches etc.

j) Puddle flanges shall be provided on all pipes where they pass through

pumping station walls and the Contractor shall provide and ensure a gas tight seal at the penetration.

k) Pump suction and delivery manifolds shall be provided with a drain valve

and a station isolating valve.


(ADSSC)



1.4 VELOCITIES

Allowable velocities shall be as stated in the Design Guidelines Document. 1.5 FLANGE ADAPTORS

a) Thrust shall not be transmitted through the flange adaptor, but through suitable ties across the adaptor to the adjacent pipework an each side, and alignment shall be within the manufacturers tolerance.

b) Where "tying" of flange adaptors is impractical fixed slip-on flanges are

permitted. 1.6 CUTTING

a) Pipes shall be cut by a method which provides a clean square profile, without splitting or fracturing the pipe wall, and which causes minimum damage to any protective coating.

b) Where necessary, the cut ends of pipes shall be formed to the tapers

and chamfers suitable for the type of joint to be used, and any protective coatings shall be made good to the original specification.

1.7 JOINTING

a) Pipe jointing surfaces and components shall be kept clean and free from extraneous matter until the joints have been made or assembled. Care shall be taken to ensure that there is no ingress of grout or other extraneous material into the joint annulus after the joint has been made.

b) Gaskets for flanged pipe joints shall be of the inside-bolt circle type. c) Flanges shall be properly aligned before any bolts are tightened. d) Jointing compounds shall not be used when making flanged joints,

except that, to facilitate the making of vertical joints, gaskets may be secured temporarily to one flange face by a minimum quantity of clear rubber solution.

1.8 PIPE SUPPORT WORK, HOLDING DOWN BOLTS & BOLTING

a) Pipework shall be designed and installed so that no dead weight loads are transmitted to machinery casings and pipes shall not be sprung into place.

b) Riser pipework shall be supported independently of connected horizontal

pipework.


(ADSSC)



c) During site erection the Contractor shall take particular care to ensure that none of the component parts are stressed due to misalignment of the pipes or other items.

d) The Contractor shall provide all fixing brackets and holding down bolts

for the plant and pipework supplied within the scope of his works. e) Pipes shall be installed to provide a minimum spacing of 13mm between

finished covering and adjacent work. f) Prior to tightening all bolt threads shall be treated with graphite paste or

"copperkote". g) Nuts shall be tightened evenly in diametrically opposite pairs. h) An expanding grout shall be used for grouting in any duck foot bends

and the Contractor shall comply with the appropriate period stipulated by the manufacturer before any equipment is equipment is run on this grout and shall in any case not run any equipment for at least two weeks.

i) The same stipulation shall apply for all other holding down bolts and

brackets fixed by grout. j) All holding down bolts, pipe and support brackets within the works shall

be sheradised or electro-galvanised before any painting is carried out of these items.

k) Contact between dissimilar metals shall not be permitted. Suitable

isolation washers/gaskets/ shims shall be used l) For auxiliary pipework, pipe hangers and supports shall be provided

according to the following schedule:


(ADSSC)



System Pipe Size Material Features

Fire Protection Systems, Hydronic Systems, Refrigerant and Plumbing Systems

Hanger – 9 mm rod

13 – 38 mm

Malleable Iron /Carbon Steel, Stainless Steel

Adjustable, swivel, split ring @ 2 meter maximum spacing, and at 1.8 m for uPVC pipe.

Hanger – 9 mm rod

> 38 mm

Carbon Steel, Stainless Steel

Adjustable, Clevis @ 3 meter maximum spacing, and at 1.8 m for uPVC

Multiple or trapeze Hanger

All

Steel, Stainless Steel

Steel channels with welded spacers and hanger rods spaced at: < 38 mm Dia- 2 meters > 38 mm Dia – 3 meters and at 1.8 m for uPVC pipe

Wall Supports 13 – 75 mm Cast Iron, Stainless

Steel Hook spaced at: < 38 mm Dia – 2 meters > 38 mm Dia – 3 meters

Vertical Support All Steel, Stainless Steel Riser clamp Floor Support All Cast Iron, Stainless

Steel Adjustable pipe saddle, lock nut, nipple, floor flange, and concrete pier or steel support.

Copper Support All Carbon Steel, copper plated Stainless Steel

Adjustable Ring, spaced at < 38 mm Dia – 2 meters > 38 mm Dia – 3 meters

Hanger > 100 mm diameter pipe

> 100 Galvanised Steel, Stainless Steel

New – Hooked rod to concrete reinforcement. Refurbishment – drill through concrete from below and provide through bolt, spaced at 3 meters, and 1.8 meters for uPVC

Flanged uPVC & ABS Pipe Systems

All uPVC proprietary systems, Stainless Steel

Spaced at maximum spacing of 1.8 meters.

Accessories

Hanger Rods All Mild steel Galvanised, Stainless Steel

Threaded


(ADSSC)



1.9 INSULATION

a) Where heat gain or heat loss affects process conditions, and where specified, pipework shall be provided with a flexible weather and vermin proof system of non-water absorbent closed cellular structure.

b) The insulation shall be not less than 40mm thick with a thermal

conductivity of 0.02 W/MºC. c) The exterior of the lagging shall be Polyisobutylene suitable for colour

coding. Other types of insulation may be approved by ADSSC. d) Valves and fitting shall be insulated using detachable moulded sections,

and terminated ends shall be finished with a plastic disc taped hat, and all seams shall be joined underneath the pipe.

1.10 PIPELINE IDENTIFICATION

All pipework shall be colour coded as stated in Section 15003: General M and E Specification.

1.11 STEEL PIPES

a) Where fabricated steel pipework is offered then the fabricators and coating applicators shall have been approved by ADSSC or his nominated Representative.

b) All pipework fabrications shall be protected against corrosion as

specified in Section 15004 : Corrosion Protection. c) All materials shall have manufactures and mill test certificates, not

letters of conformity. d) When specified, all procedure approval tests shall be witnessed by

ADSSC. or his nominated Representative. e) The cost of carrying out any pre-qualifying trial shall be borne by the

Contractor. f) The welding of steel pipework shall be in accordance with the appropriate

standards as follows:

i. BS 2633 Class I Arc Welding of Ferritic Steel Pipework for carrying Fluids.

ii. BS 2971 Class II Arc Welding of Carbon Steel Pipework for carrying Fluids.

iii. BS 4677 Arc Welding of Austenitic Stainless Steel Pipework for carrying Fluids.


(ADSSC)



1.12 GALVANISED STEEL

Where screwed joints are proposed then all joint threads shall be sealed with PTFE tape or hemp and paste and exposed threads shall be treated with galvafroid after assembly, and prior to the application of the final finish paintwork.

1.13 UPVC/ABS

a) For uPVC and ABS pipework and fittings, consideration shall be given to pipe supports and the elimination of vibration transmission in order to reduce fatigue. Pipe support shall therefore be spaced at intervals not exceeding 1.8 m.

b) Pipework shall be protected against degradation through exposure to

sunlight. 1.14 FLEXIBLE HOSEWORK

a) Flexible hosework shall be nylon reinforced PVC hose. b) Hoses used in the installation shall be of high strength, resilient and

compatible with the contact chemicals. There shall be no joints which are out of sight of plant operatives, particularly where hoses are ducted underground.

c) Hoses which are installed above ground and within the building shall be

securely attached to adjacent walls and also be transparent. Where hoses are exposed to daylight they must satisfy the opacity test, set out in BS EN 1452-5 or equivalent.

d) All dosing lines shall be non toxic and provided with a means of bleeding

air from the pipework system. The latter is considered essential to ensure that the correct metered amount of chemicals is to be transferred to the injection point.

END OF SECTION

Documents

04-Division 15-Section 15010 Pipework-Version 2.0