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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)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 2 of 15
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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General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 3 of 15
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
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 4 of 15
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.
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 5 of 15
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
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 6 of 15
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
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 7 of 15
Property DI GRP HDPE uPVC VC
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
Resistant to soil corrosion,
Chemically inert
Resistant to soil corrosion,
Chemically inert
Resistant to soil corrosion,
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
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 8 of 15
Property DI GRP HDPE uPVC VC
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
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 9 of 15
Property DI GRP HDPE uPVC VC
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
pressure or 1.25 times max surge pressure,
whichever is greater
1.5 times operating
pressure or 1.25 times max surge pressure,
whichever is greater
1.5 times operating
pressure or 1.25 times max
surge pressure,
whichever is greater
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.
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 10 of 15
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.
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 11 of 15
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.
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 12 of 15
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:
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 13 of 15
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
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 14 of 15
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.
General Specification for Mechanical Works Abu Dhabi Sewerage Services Company
(ADSSC)
ADSSC/GSMW Division 15 Section 15010
Pipework Rev: 02 Jan. 2011 Page 15 of 15
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