federal electricity & water authority water directorate standard … pipe... · 2017. 2. 22. ·...

WAM

Client: FEDERAL ELECTRICITY AND WATER AUTHORITY (FEWA) Project: STANDARD SPECIFICATIONS FOR WATER WORKS

Engineer WATER DIRECTORATE - ASSET MANAGEMENT DEPARTMENT

Title: Technical Terms / Chapter 4/ Engineering Specifications / Pipeline Works Specifications.

PS02-DI PIPES MATERIALS & INSTALLATION

Office: DUBAI Order: Document: WMA_PRO_07/WAM-04-PS02 Rev: DEC/20142

SHEET:

1 of: 61

Federal Electricity & Water Authority

Water Directorate

Asset Management Department

STANDARD SPECIFICATIONS

FOR WATER WORKS

TECHNICAL TERMS

Chapter – 4

Engineering Specifications

E – Pipeline works Specifications

PS 02

DI PIPES MATERIALS & INSTALLATION

WAM


Engineer WATER DIRECTORATE / ASSET MANAGEMENT DEPARTMENT


PS 02-DI PIPES MATERIALS & INSTALLATION

Office: DUBAI Order: Document: MWA_PRO_07/WAM-04-PS02 Rev:

DEC/20142

Sheet: 2 Of: 61

A - SPECIFICATIONS FOR DUCTILE IRON PIPES, FITTINGS AND ACCESSORIES

TABLE OF CONTENT

1. SCOPE

2. APPLICABLE STANDARDS AND CODES

3. D.I. MATERIAL CHARACTERISTICS

4. D.I. PIPES

5. D.I. FITTINGS

6. JOINTS

6.1 Flexible Joints

6.2 Flanged Joints

6.3 Restrained Joints

7. INTERNAL LINING TO D.I. PIPES AND FITTINGS

7.1 General

7.2 Surface Preparation

7.3 Cement

7.4 Aggregates

7.5 Additives

7.6 Water

7.7 Mortar

7.8 Method of Lining

7.9 Curing

7.10 Repair of Defective or Damaged Areas of Lining

7.11 Thickness of the Lining

7.12 Mechanical Properties

7.13 Quality of the Lining, Tests and Records

8. EXTERNAL COATING TO D.I. PIPES AND FITTINGS

8.1 General

8.2 Metallic Zinc with Bituminous Coating to D.I. Pipes

8.3 Zinc Rich Paint with Bituminous Coating to D.I. Fittings

8.4 Polyurethane Coating

8.4.1 General

8.4.2 Materials

8.4.3 Surface Preparation

8.4.4 Application

8.4.5 Inspection

8.4.6 Repairs

8.4.7 Joint Protection

8.5 Fusion Bonded Epoxy Coating

WAM






DEC/20142

Sheet: 3 Of: 61

9. FLANGE ADAPTORS

10. STEPPED COUPLINGS

11. DISMANTLING JOINTS

12. SPLIT TEES FOR UNDER PRESSURE CONNECTIONS

13. DUCTILE CAST IRON COLLAR

14. PUDDLE FLANGES OR SEALING FLANGES

15. THRUST / ANCHOR FLANGES

16. POLYETHYLENE SLEEVES

17. VENDOR DOCUMENTATION

18. MARKING

19. TRANSPORTATION OF PIPES

20. HANDLING & STORAGE

21. WARRANTY

WAM






DEC/20142

Sheet: 4 Of: 61

B - SPECIFICATIONS FOR DI PIPELINE INSTALLATION WORKS

TABLE OF CONTENT

1. SCOPE OF SPECIFICATIONS


3. PIPELINE ROUTE SURVEY

4. EXCAVATION OF TRENCHES AND PITS

4.1 General

4.2 Setting Out

4.3 Grading of Pipeline Route

4.4 Trench Excavation

4.5 Trench Depth

4.6 Trench Width

4.7 Rock Excavation

4.8 Control of Groundwater

4.9 Methods of Excavation

4.10 Existing Services

4.11Support of Excavation and Adjacent Property

4.12 Surplus Excavated Material

5. D.I. PIPE HANDLING AND LAYING

5.1 Stretch Of Restrained Pipes Around Fitting

5.2 Handling and Storing

5.3 Repair of Detective or Damaged Areas of Lining

5.4 Stringing

5.5 Inspection and Rejection

5.6 Pipeline Bedding and Filling (Sand Surround)

5.7 Laying

5.8 Pipe Jointing

5.9 Pipe Cutting

6. BACKFILLING

6.1 General

6.2 Pipeline in Embankment

6.3 Backfilling of Trenches in Existing or Proposed Roads

6.4 Detectable Warning Tapes

6.5 Maintenance of Surfaces

7. PIPE PROTECTION

7.1 Protection in Buried Dry Conditions

7.2 Protection in Buried Wet Conditions

7.3 Protection to Buried Nuts, Bolts, Flanges and Couplings

7.4 Protection in Chambers

7.5 Cathodic Protection (CP)

8. ROAD CROSSINGS

8.1 Pipes Crossing Existing Roads

8.2 Major Road Crossings (Directional Drilling or NDRC)

8.2.1 General

WAM






DEC/20142

Sheet: 5 Of: 61

8.2.2 Design

8.2.3 Site Investigation

8.2.4 Health and Safety

8.2.5 Skilled Operators and Supervision

8.2.6 Casing Pipe Materials

8.2.7 Joint Packing

8.2.8 Lubricant

8.2.9 Tests on Bentonite

8.2.10 Joint Sealant

8.2.11 Grout

8.2.12 Thrust and Reception Pits

8.2.13 Pipe Installation within Sleeves

8.2.14 Micro-tunnelling

8.2.15 Line and Level

8.2.16 Thrust System

8.2.17 Lubrication Holes

8.2.18 Grouting

8.2.19 Records

8.2.20 Testing

8.2.21 Monitoring Ground Surface Movement

8.2.22 Undertaking

8.3 Relief Slabs

8.4 Temporary Traffic Ramps and Traffic Control

8.5 Pipes in Culverts

9. CROSSING OF SERVICES

9.1 General

9.2 Crossing of Oil/Gas Pipeline

10. CONNECTION TO EXISTING PIPELINES

10.1 General

10.2 Tapping Sleeves

11. HYDROSTATIC PRESSURE AND LEAKAGE TESTS

11.1 General

11.2 Test Procedure

11.3 Overall Leakage

12. DISINFECTION AND FLUSHING

13. CONNECTION TO EXISTING PIPELINES AND COMMISSIONING

14. DUCTILE IRON (DI) SPOOL PIECE, STOP COCK

15. WELDING OF D.I. PIPES ON SITE

16 RECONDITIONING OF D.I. PIPELINE MATERIALS

16.1 General

16.2 Reconditioning of Valves in Site

16.3 Reconditioning of D.I. Pipes and fittings Supplied by FEWA

16.4 Renewal of Bolts, Nuts, Gaskets Etc.

17. SAFETY REQUIREMENTS

WAM






DEC/20142

Sheet: 6 Of: 61

A- SPECIFICATIONS FOR DUCTILE IRON PIPES, FITTINGS AND ACCESSORIES

1. SCOPE

This specification covers the general requirements for Ductile Iron (D.I.) pipes, fittings and accessories including material specifications, internal lining, external coating, joints, polyethylene sleeves etc. This specification sets the minimum acceptable requirements. In case of difference between this specification and the specified international standards then the most stringent requirements shall prevail.


D.I. pipes, fittings and accessories including coating and polyethylene sleeve shall comply with the latest issue of the following standards and other relevant standards noted elsewhere in this specification:

ISO 62 Plastic – Determination of water absorption ISO 527 Plastics-Determination of tensile properties. ISO 887 Plain washers for metric bolts screws and nuts. ISO 974 Plastics-Determination of the brittleness temperature by impact. ISO 2230 Vulcanized rubber-guide to storage. ISO 2531- 2009 / ISO 2531- 1998 and EN 545 – 2010/ EN545- 2006 Ductile iron pipes, fittings, accessories and their joints for water or gas

applications. ISO 3506 Corrosion - resistant stainless steel fasteners. ISO 4014 Hexagon head bolts – Product grades A and B. ISO 4032 Hexagon nuts, style 1 – Product grades A and B. ISO 4179 Ductile iron pipes for pressure and non-pressure pipeline – Centrifugal

cement mortar lining – General requirements. ISO 4587 Adhesives – Determination of tensile lap-shear strength of rigid-to-rigid

bonded assemblies. ISO 4633 Rubber seals – Joint rings for water supply, drainage and sewerage

pipeline – Specification for materials. ISO 6600 Ductile iron pipes, centrifugal cement mortar lining – composition controls

of freshly applied mortar. ISO 6506-1 Metallic materials – Hardness testing – Brinell test – Part 1: Test method. ISO 6708 Pipe works components – Definition and selection of DN ISO 7005-2 Metallic flanges – Part 2: Cast iron flanges. ISO 7268 Pipe components – Definition of nominal pressure. ISO 7483 Dimensions of gaskets for use with flanges to ISO 7005. ISO 8179-1 Ductile iron pipes – External coating – Part 1: Metallic zinc with finishing

layer. ISO 8179-2 Ductile iron pipes – External coating – Part 2: Zinc rich paint with finishing

layer. ISO 8180 Ductile iron pipes – Polyethylene sleeving. ISO 8501-1 Preparation of Steel Substrates. ISO 10804 Restrained joint systems for ductile iron pipelines – Part 1: Design rules

and type testing. ISO 9001:2008 Quality Management System EN 1092-2 Circular flanges for pipes, valves, fittings and accessories, PN designated

– Part 2: Cast iron flanges.

WAM






DEC/20142

Sheet: 7 Of: 61

EN 14901 Epoxy coating of ductile iron pipes, fitting and accessories BS 2782 Methods of testing. Plastic. introduction BS 3416 Specification for bitumen - based coatings. BS 7079 Specification for surface finish of blast-cleaned steel for painting. BSEN 681 Elastomeric Seals BSEN 1563 Founding Spheroidal graphite Cast iron BSEN 10025 Hot rolled products of non-alloy Structural Steels BS EN 15167-1:2006 Ground granulated blast furnace slag for use in concrete, mortar and

grout. Definitions, specifications and conformity criteria EN 197-1:2011 Composition, specifications & conformity criteria for common cements DIN 30671 Thermo set plastics coatings for buried steel pipes DIN 30672 Coatings of corrosion protection tapes and heat Shrinkable material. DIN 4226 Aggregates for concrete. ASTM E 28 Standard test methods for softening point of resins derived from naval

stores by ring-and-ball apparatus

3. D.I. MATERIAL CHARACTERISTICS

Ductile iron pipes, fittings and accessories shall meet the following requirements : Material Characteristics:

Material Pipes

Centrifugally

Cast

Pipes not Centrifugally

Cast, Fittings and

Accessories

Minimum tensile strength (MPa) 420 420

Minimum yield strength (MPa) 300 300

Minimum elongation after fracture (%)

DN 40 to DN 1000

DN 1100 to DN 2600

10

7

5

5

Maximum Brinell hardness, (HB) 230 250

4. D.I. PIPES

All D.I. pipes supplied shall be truly circular, of uniform thickness and supplied in the longest practicable length so as to minimize the number of joints.

Unless otherwise specified in the drawings or in the Particular Specification all pipes, joints and fittings shall be suitable for the maximum pressure under which they will operate (normal service pressure + surge pressure or the maximum site test pressure whichever is greater) and shall sustain without damage or substantial leakage the specified site hydrostatic test pressure. DI Pipes Clssification DI pipes shall be classificed either according to the nominal iron wall thickness of pipes and fittings “ K “ thickness classes in accordance with ISO 2531–1998 /EN 545 - 2006 and calculated as a function of the nominal size, DN, by the following formula, with a minimum of 6 mm for pipes and 7 mm for fittings

e = K (0.5 + 0.001 DN)

Where :

e : is the nominal wall thickness, in millimeters;

WAM






DEC/20142

Sheet: 8 Of: 61

DN : is the nominal size in millimeters;

K : is a coefficient used for thickness class designation. It is selected form a series of whole numbers :…….8, 9, 10, 11, 12……

Unless otherwise specified in the Particular Specification all pipes used shall be Class K9 (K = 9). Or DI pipes shall be clssified according to the internal pressure “C” pressure classes in accordance with ISO 2531 – 2009 /EN 545 – 2010 .

Dimensions and nominal iron wall thickness of fittings shall be in accordance with the ISO 2531/EN 545.

All Pipes shall be subject to Third Party Inspection during manufacturing.

ENGINEERING\WATER\STANDARDS ENHANCEMENT All pipes shall be marked as in item 18 of this specification.

Pipes shall be hydrostatically pressure tested for leak tightness and certified at the manufacturer's plant prior to coating or lining for at least 10 seconds at the following minimum internal test pressures:

1 50 bar for pipes DN 300 and smaller 2 40 bar for pipes DN 350 through DN 600 3 32 bar for pipes DN 700 through DN 1000 4 25 bar for pipes DN 1100 through DN 2000 5 18 bar for pipes DN 2200 through DN 2600

Unless otherwise stated in the Particular Specification all D.I. pipes supplied shall be of socket and spigot end. It shall be the Contracto's sole responsibility to order a percentage (minimum 2%) of the total length per diameter of pipes as calibrated pipes, for the purpose of cutting etc. These pipes shall be clearly marked and shall not be used for normal pipe laying unless it becomes clear that they are not required for the purpose of cutting any more. The percentage to be ordered shall give due regard to any changes in route which may occur during the course of the work for whatever reason.

5. D.I. FITTINGS

All D.I. fittings supplied shall be truly circular of uniform thickness according to ISO 2531 and EN 545.

All fittings shall be subject to Third Party Inspection during manufacturing.

For fittings the thickness e is the nominal thickness corresponding to the main part of the body. The actual thickness at any particular point shall be increased where necessary to meet localized high stresses depending on the shape of the casting (e.g. at internal radius of bends, at the branch body junction of tees, etc).

All fittings shall be marked as in item 18 of this specification.Fittings shall be pressure tested for leak tightness and certified at the manufacturer's plant prior to coating or lining. The test pressure shall be carried out for at least 10 seconds either with air at a pressure of 1 bar or with water at the pressure indicated below:

WAM






DEC/20142

Sheet: 9 Of: 61

1 25 bar for fittings DN 300 and smaller (for fittings with PN 10 flanges test pressure shall

be 16 bar) 2 16 bar for fittings DN 350 through DN 600 3 10 bar for fittings DN 700 and larger

6. JOINTS 6.1 Flexible Joints

Flexible joints shall be of spigot and socket "push-on" type suitable for angular deflection in any direction and capable of axial movement to compensate for thermal expansion or contraction and ground movement. All flexible joints for D.I. pipes and fittings shall be designed in compliance with ISO 2531/ EN 545. Test certificate to be provided.

Joints may permit angular deflection to accommodate ground movements and to negotiate large radius bends. All joints shall be designed to be fully flexible. Consequently, the allowable angular deflection declared by the manufacturer shall not be less than (See BS 545):

1 3.5º for DN 40 to DN 300 2 2.5º for DN 350 to DN 600 3 1.5º for DN 700 to DN 2000

Allowable deflection with respect to Nominal Diameter DN shall be as per BS EN 545 latest edition.Rubber ring joints shall be of a type that will not deteriorate under local conditions either during storage or during operation. The rubber gasket shall be of EPDM elastomer or equivalent in accordance with ISO 4633 suitable for drinking water supply. Minimum fittings quantity supplied as spares shall be 2% of the B.O.Q.quantity.

Where mechanical type joints are specified, proposed and approved they shall be supplied complete with approved gaskets, glands, DI / stainless steel grade 316, nuts and all other necessary accessories. Where retainer glands are specified they shall be supplied with bolts and/or other necessary accessories.

6.2 Flanged Joints

Flange ended pipes and fittings shall only be used when connecting to valves or other special fittings as approved by FEWA/Engineer.

The flanges shall be raised faced and integrally cast or welded on. Screwed on flanges or glued on flanges are not acceptable. Rotatable flanges may be used for pipes and fittings up to DN 600.The dimensions and drilling of the flanges shall be to ISO 7005-2 / EN 1092-2. The pressure rating of the flanges shall be as given in the Data Sheet or Particular Specification. Flanged joints shall be supplied complete with gaskets, stainless steel grade 316 bolts, nuts and washers. Rubber gaskets shall be EPDM elastomer or equivalent approved in accordance with ISO 4633 suitable for drinking water supply. The gasket shall be minimum 3 mm thick and shall be metal reinforced for pressure rating of 16 bar and higher. The dimensions of the flange gaskets shall be to ISO 7483.

The nuts, bolts hexagonal headed, washers shall be of stainless steel grade 316. Nuts and bolts shall be suitable for the pressure rating specified in the Particular Specification. Nuts and bolts shall be to ISO 4014 and 4032 and washers to ISO 887.

WAM






DEC/20142

Sheet: 10 Of: 61

6.3 Restrained Joints

D.I. pipes and fittings with restrained coupling shall be utilized where pipelines have to cross roads through existing ducts or in areas with restricted accessibility where the use of concrete anchor blocks is prohibited, or as directed by FEWA/Engineer.The Contractor shall submit with his bid full details of the type of restrained coupling he proposes to use. Whenever in the course of work the Contractor intends to utilize restrained couplings he shall obtain prior approval from FEWA/Engineer.Calculation of the number of pipe lengths with restrained coupling required, shall follow the manufacturer's recommendation and shall be subject to FEWA/Engineer approval.

Restrained joints shall be designed to resist the axial thrust forces but maintaining flexibility and angular deflection. Restrained joints shall be designed in accordance with ISO 10804-1. The joint shall be capable of withstanding the greater of the test pressure or the service pressure + the surge pressure. The type of restrained joint shall be subject to FEWA/Engineer approval.The thrust resisting mechanism shall be separated from the sealing action of the gasket and shall not be in contact with potable water in the pipeline.

7. INTERNAL LINING TO D.I. PIPES AND FITTINGS 7.1 General

Unless otherwise specified in the Data Sheet or Particular Specification all D.I. pipes and fittings shall be internally lined with Sulphate resisting blast furnace slag cement mortar in accordance with the following specification and shall be certified as suitable for use with potable water by an internationally accepted organization such as UK's WRC (Water Research Centre). The cement mortar lining for D.I. pipes and fittings shall be in accordance with ISO 4179.The internal surface of the socket bell of all zinc/bitumen coated D.I. pipes and fittings shall be painted with a non-toxic solvent-free two part fusion bonded epoxy coating applied as referred in item 8.5 of this specification and to a minimum dry film thickness (DFT) of 300 microns or equivalent corrosion protection system to be approved by FEWA/Engineer. The thickness of the coating may be reduced only at the gasket locating ring to conform to manufacturer's recommended tolerances. All flange fittings shall be painted with a non-toxic solvent-free two part fusion bonded epoxy coating applied as referred in item 8.5 of this specification and to a minimum dry film thickness (DFT) of 300

7.2 Surface Preparation

Prior to cement lining application the inner surfaces of pipes and fittings shall be cleaned of dirt, loose rust particles, grease, oil or any other material which could be detrimental to good contact between the metal and the lining.

7.3 Cement

Cement to be used shall be of any cement type (OPC or SRC) complying with the requirements of EN 197-1:2011. The type of cement chosen by the CONTRACTOR shall be as per manufacturer's fabrication standards process.In our contract SRC type shall be used.

WAM






DEC/20142

Sheet: 11 Of: 61

7.4 Aggregates Only clean, rounded or crushed natural mineral materials aggregates shall be used in accordance with the requirement of the latest issue of the German DIN 4226 standards.

The distribution of grain sizes shall be:

a) the amount of particles passing through a standard sieve with an aperture size of 0.125

mm shall not be more than 10% by mass. b) the amount of particles with a diameter up to 1/3 of the normal lining thickness shall not

be less than 50% by mass. c) the maximum particle diameter shall not be greater than 1/2 of the normal lining

thickness. The amount of shall not exceed 5% by mass. 7.5 Additives

The use of cement additives is allowed, subject to FEWA/Engineer approval, provided that they do not adversely affect the quality of the lining, and that of the transported water.Additives shall not contain any elements which impart potable change in colour, taste or odor or present a health hazard. Certificates of non toxicity prepared and signed by recognized, independent laboratories, shall be made available to FEWA/Engineer.

7.6 Water

Water used for the mortar shall be of potable quality and shall not contain elements which influence the hardening of the lining or the quality of the water flowing through the finished pipes.

7.7 Mortar

Mortar for the lining shall be composed of cement, sand and water. The mortar shall be well mixed and of proper consistency to produce a dense homogenous lining that will adhere firmly to the DI pipe or fitting surface.

Weight of cement and sand shall be accurate to + 3%. The water/cement ratio shall not be more than 0.40.

The cement mortar shall not contain less than one part of cement to 3.5 parts of aggregates by weight as per ISO 4179.

7.8 Method of Lining

Lining application and quality for finished surface shall be in accordance with ISO 4179.

All pipes shall be lined by a centrifugal process. The consistency of the mortar and the time and speed of spinning the pipe shall be so adjusted to minimize the segregation of aggregates from the cement.

Fittings shall be lined by a spray method.In all cases a smooth finish of the lining shall be obtained, entirely free from cavities or visible air bubbles.The lining shall be uniform and extend from the spigot end up to the beginning of the socket cavity on the other side. The socket shall be left free of mortar.No seal coat shall be applied to the cement lining unless otherwise instructed and approved by FEWA/Engineer.

WAM






DEC/20142

Sheet: 12 Of: 61

7.9 Curing After application to pipes and fittings, the cement mortar shall be cured under controlled conditions (minimum 48 hours at more than 15ºC and 75% relative humidity).Alternative methods of curing are subject to approval of FEWA/Engineer.

7.10 Repair of Defective or Damaged Areas of Lining

Defective or damaged areas of lining may, at FEWA/Engineer's discretion, be patched by cutting out the defective or damaged lining to the metal so that the edges of the lining not removed are perpendicular or slightly undercut. The cut out area shall then be trawled with fresh mortar in the following composition :

1 One part cement (by weight). 2 One part sand. 3 Water of potable quality, with non toxic additive dispense of synthetic materials subject to

FEWA/Engineer's approval. 7.11 Thickness of the Lining

Thickness of the cement mortar lining shall be as follows:

Lining Thickness (mm)

Normal Minimum Mean Value

Minimum Value at One Point

80 – 600 5.0 4.5 3.5

700 – 1200 6.0 5.5 4.5

1400 – 2000 9.0 8.0 7.0

2200 – 2600 12.0 10.0 7.0

N.B.: The above figures differ from ISO 4179.

7.12 Mechanical Properties

The cement mortar lining shall have adequate resistance against compression and bending action. Representative test pieces shall have the following minimum properties after 28 days.

Water Cement Ratio of Test Piece

Compression Strength N/mm²

Bending Strength N/mm²

0.45 40 5.0

0.40 45 5.5

0.35 50 6.0

7.13 Quality of the Lining, Tests and Records

The lining shall be free from voids, ridges or corrugations that reduce the thickness of the lining to less than the specified minimum thickness. Lining shall have a smooth surface. There shall be no cavities or entrapped air, similarly there shall be no evidence of differences between portions of lining.

Linings shall be placed so that there is no gap between the pipe barrel and the lining.In some

circumstances thicker linings may be required and these shall be stated in the appropriate specification.

WAM






DEC/20142

Sheet: 13 Of: 61

If a lining is damaged it may be repaired on site using a one to one cement/sand mortar mix. (proportions by weight). Repairs shall cure for at least 72 hours. Mortar lining may show evidence of cracking, crazing or debonding after delivery to site. The following conditions may be accepted.

a) Cracking - provided that the longitudinal length of a crack is not more than 600 mm, width of

crack not more than 0.8 mm, circumferential cracks are not more than 50% of the circumference.

b) Crazing - provided that individual cracks are less than the limits given in (a), crazing over an area not exceeding 25% of the lining area may be acceptable.

c) Debonding - area of disbondment and radial displacement shall not exceed the values given in BSEN 545.

The following tests and measurements shall be conducted, recorded and filed with frequencies according to ISO 4179 and ISO 6600.

1 Determination of lining thickness. 2 Cross sectional sample. 3 Water cement ratio. 4 Aggregates. 5 Bonding and compression strength.

8. EXTERNAL COATING TO D.I. PIPES AND FITTINGS 8.1 General

Depending on the existing local conditions the external coating of D.I pipes and fittings shall be one of the following as given in the Data Sheets or Particular Specifications.

1. Metallic zinc with bituminous coating layer. (Standard coating for pipes)

2. Zinc rich paint with bituminous coating layer. (Standard coating for fittings)

3. Polyurethane coatings. (Pipes in Subkha areas)

4. Fusion bonded epoxy coating. (Flanged fittings)

All coatings are subject to the prior approval of FEWA/Engineer. Where non-toxic coating is specified, certification shall be required from an internationally recognized independent laboratory certifying that the material is safe for potable water service. At the discretion of FEWA/Engineer all special coatings on pipes and fittings shall be subjected to thickness checks and for holiday testing on Site in order to satisfy FEWA/Engineer that the coatings are within the specified limits and that no pin holes are present.The thickness of the coatings may be reduced only at the gasket locating ring to conform to manufacturer's recommended fitting tolerance.

8.2 Metallic Zinc with Bituminous Coating to D.I. Pipes

The system consists of a factory applied metallic zinc layer to ISO 8179-1 and a finishing layer of black bituminous coating of tropical standard to BS 3416 with a minimum dry film thickness (DFT) of 100 micron.The zinc content shall be minimum 99.99% and the mean mass of the zinc coating shall not be less than 200 g/m2 applied on the bare metal of the external surface of the pipe.

The external surface of the D.I. pipe spigot end at a minimum length of 250mm shall have non-toxic bituminous paint applied to a minimum DFT of 100 microns.

WAM






DEC/20142

Sheet: 14 Of: 61

The internal surface of the socket end shall be painted with a layer of zinc rich paint 150 g/m2 (zinc content not less than 85%) plus a layer of non-toxic bituminous paint to a minimum DFT of 100 microns and a total average DFT of 120 microns.

8.3 Zinc Rich Paint with Bituminous Coating to D.I. Fittings

The system consists of factory applied zinc rich paint layer to ISO 8179-2 and a finishing layer of black bituminous coating of tropical standard to BS 3416 with a minimum DFT of 100 micron.The thickness of the zinc rich coating shall be minimum 150 g/m2 and shall contain minimum 85% zinc in the dry film.

The external surface of the D.I. fitting spigot end at a minimum length of 250mm and the internal surface of the socket end, which may have direct contact with potable water, shall have a non-toxic bituminous paint applied to a minimum dry film thickness of 100 microns, and a total average DFT of 120 micron.

8.4 Polyurethane Coating 8.4.1 General

This section covers the factory application of solvent free polyurethane coating to D.I. pipes and fittings by airless, hot -spray techniques. The coating application shall conform with DIN 30671 or equivalent standard. For polyurethane coated D.I. pipes and fittings the external surface of the spigot end at a minimum length of 250mm and the internal surface of the socket end which may have direct contact with potable water shall have non-toxic solvent free two part epoxy coating applied to a minimum dry film thickness of 300 microns.

8.4.2 Materials

The coating shall be a high build, 100% solids urethane consisting of two components, one component based on polyurethane resin, which may or may not be modified with coal tar, and a second component based on an isocyanate resin.

The coating shall be capable of being airless sprayed to provide an average of 2.0 mm dry film thickness in a continuous application if an unmodified polyurethane is used or 2.5 mm dry film thickness if coal tar modified polyurethane is used. Whichever coating is used it shall meet all the requirements for mechanical properties as specified in DIN 30671.

The Contractor shall provide FEWA/Engineer with test certificates for the coating system to be employed. No materials shall be used unless FEWA/Engineer has accepted the results of the test specified.Notwithstanding the requirements of DIN 30671 the coating shall be guaranteed to preserve its integrity and maintain storage, handling, installation, testing and operation in the ambient conditions prevailing in the country of manufacture and in UAE. The test certificate shall state the properties of the coating and shall specify the test method used. The polyurethane coating system shall comply with the data included in Table 1 below:

WAM






DEC/20142

Sheet: 15 Of: 61

Table - 1

Materials

Polyurethane nominal thickness Polyurethane min. thickness

nominal thickness 2000 microns

minimum thickness 1500 microns

Coal tar modified polyurethane, nominal thickness Coal tar modified polyurethane, min. thickness

nominal thickness 2500 microns

minimum thickness 1800 microns

Holidays test (voltage) 10Kv

Impact Test 10 J (1 pipe per day)

Adhesion test Incision knife edge

(1 pipe per day)

8.4.3 Surface Preparation

All slag shall be removed and all sharp edges shall be ground down. Prior to blasting, all oil, grease, etc. shall be removed. All surfaces to be coated shall be blast cleaned to BS 7079 2nd quality or to ISO 8501-1. The photographic standard of surface preparation shall be to SIS 05 5900 Grade SA 2.5. The amplitude of surface roughness shall be 75+ 15 microns as measured using a surface profile gauge. In cases of dispute a sample plate shall be prepared and the profile shall be measured using a traveling microscope.

The Contractoer shall ensure that the type of abrasive used, its particle size and the blasting pressure used are suitable for achieving the required profile. The compressed air used in blasting shall be clean, dry and oil free.After blast cleaning all dust shall be removed by vacuum or a clean, oil free, dry air blast.

The application of the coating shall follow with the least possible delay.Any pipe not coated within 4 hours after blast cleaning shall be completely reblasted before coating. The surface to be coated shall be maintained at a temperature of at least 5º C above the dew point of the surrounding atmosphere at all times during the coating procedure.

8.4.4 Application

The polyurethane coating shall be applied using airless spray painting equipment strictly in accordance with the paint manufacturer's recommendations.

The paint shall be applied in a continuous process to achieve a covering film free from misses, tears, runs, sags, etc. and the minimum dry film thickness at any point as stated in Table 1 above.

All painted area shall be thoroughly dried before being overcoated and be free of all loose particles, dust, debris and atmospheric contamination.

The external surface of the D.I. pipe spigot end at a minimum length of 250mm and the internal surface of the socket end which may have direct contact with potable wall shall have non-toxic solvent free two part epoxy coating applied to a minimum dry film thickness of 300 microns.

WAM






DEC/20142

Sheet: 16 Of: 61

8.4.5 Inspection

The pipe coating shall be completely continuous and free from all holidays, voids, pinholes or other defects. The thickness of the coating, the degree of adhesion to the pipe and the standard of workmanship generally shall be regularly checked in accordance with DIN 30671 and FEWA/Engineer's requirements.

Impact and adhesion tests shall be carried out on each day of production and the damage so caused shall be made good by the Contractor at his own cost.

The Contractor shall provide and operate an approved holiday detector with a loud alarm operating at the voltage specified. Holiday detection shall be carried out over 100% of surface area.The maximum number of holiday repairs allowed shall be six per nine meter length. The allowable number shall be reduced pro-rata for shorter pipe lengths. If, in the opinion of FEWA/Engineer holidays and other imperfections such as lifting edges, lack of adhesion, etc. are so frequent as to indicate poor application, the coating shall be stripped, the pipe cleaned and recoated at the Contractor's expense.

The pipe shall be repaired to pass the holiday detection test so that no holiday are present on the finally released coated pipe.

8.4.6 Repairs

In the event that problems are detected or repairs are needed, the Contractor shall take immediate steps to correct the situation.All repairs to the coated pipe shall be at the Contractor own expense. Scars, dents, damaged areas and holidays shall be cleaned by removing all rust, scale, dirt or foreign materials or loose coating using a small file. Repairs either in the factory or subsequently on site are to be made by means of a repair procedure approved by FEWA/Engineer prior to commencement of work.Any pipe subject to a coating repair procedure shall be fully re-examined in accordance with above inspection requirements.If cathodic protection is provided for the coated pipeline, coating at electrical connections shall be repaired according to the approved repair procedure.

8.4.7 Joint Protection

All joints of polyurethane ductile iron coating coated pipes shall be protected by heat shrinkable pipe sleeves or collars. The heat-shrinkable sleeves or collars shall have a high shrink ratio as well as high penetration resistant thick walled structure which together with an internally coated adhesive mastic sealant shall ensure a reliable vacuum-tight anti corrosion coating over the bare pipe joint and the polyurethane coated pipe ends. The heat-shrinkable sleeve shall be manufactured from a radiation cross linked, thermally stabilized, UV-resistant modified polyolefin sheet material with an inner surface of a controlled thickness visco-elastic sealant which shall be in accordance with the following minimal requirements :

WAM






DEC/20142

Sheet: 17 Of: 61

Heat -Shrinkable Sleeve Material

PROPERTY TEST METHOD

CONDITION REQUIREMENT TYPICAL VALUE

Tensile strength ISO 527 23ºC, CHS* 50 mm/min

17 MPa (min.) 24 Mpa

Ultimate elongation ISO 527 23ºC, CHS* 50 mm/min

500% (min.) 750%

Impact brittleness ISO 974 Below –40ºC Pass

Thermal ageing DIN 30672 100ºC,100 days

Followed by test for

Ultimate elongation ISO 527 23º, CHS* 50 mm/min

-25% loss of elongation

4%

Water absorption ISO 62 23ºC, 24 hrs 0.1 % (max.) 0.05%

* CHS = cross head speed

Sealant Material

PROPERTY TEST METHOD

CONDITION REQUIREMENT

TYPICAL VALUE

Softening Point ASTM E28 85ºC (min.) 92ºC

Peel strength to steel, PE and epoxy

DIN 30672 23ºC, CHS* 100 mm/min

15N/cm (min.) 25 N/cm

Peel strength to steel After conditioning for 100 days at 50ºC

DIN 30672 23ºC, CHS* 100 mm/min

12N/cm (min.) 25 N/cm

Shear strength

ISO 4587 23ºC, 1 mm thickness

CHS*50 mm/min

10N/cm²(min) 15N/cm²

*CHS = cross head speed Dimensions

Backing thickness as supplied : 0.9 mm nominal Sealant thickness as supplied : 1.5 mm nominal Sleeve width as supplied : 300, 450 or 600 mm nominal. 8.5 Fusion Bonded Epoxy Coating

The system consist of factory applied fusion bonded powder epoxy coating externally and internally. The minimum dry film thickness of the coating shall be 300 microns.The powder epoxy resin shall be applied by electrostatic spray and shall be non toxic suitable for use in contact with drinking water. The powder material and method of application shall be subject to FEWA/Engineer approval.

The D.I. pipe or fitting shall be blast cleaned to SIS 05 5900 Grade SA 2.5 Rust, grease and other foreign maters shall be removed prior to coating application as per ISO 8501-1.

The temperature of the metal shall be adjusted to ensure complete polymerisation of the powder material.After coating application the coating shall be allowed to cure before being cooled with water to permit handling and inspection.

WAM






DEC/20142

Sheet: 18 Of: 61

The coating shall be free from blisters, pinholes, runs, sags or any other irregularities and shall have uniform color, gloss and thickness. The coating shall be free from holidays. Every D.I. pipe or fitting shall be inspected for holidays over 100% of its coated surface. The holiday detector shall be set at 2.2 kV with a rate of travel of the probe over the surface shall not exceed 300 mm/s.The minimum impact resistance of the coating when tested in accordance with ASTM G14 shall be 18J without causing holidays.

The coating shall not show any tendency for disbondment or blistering. Cathodic disbondment test shall be carried out in accordance with ASTM G42. The maximum coating disbondment shall be 5mm radius from the edge of the artificial holiday.

9. FLANGE ADAPTORS

Flange adapters shall be installed as shown on the drawings to facilitate removal of valves and other items for servicing/replacement. The material of the body end ring and sleeve shall be ductile iron grade 420/12 to BSEN 1563 or steel grade S275 to BSEN 10025 as approved by FEWA/Engineer. The studs, nuts, bolts shall be stainless steel grade 316 for flange connection between adaptor to piping or equipment. The gasket shall be EPDM to ISO 4633 or BSEN 681-1 suitable for drinking water.

The flange pressure rating shall be as given in the Data Sheet or Particular Specification. The coating shall be factory applied non toxic fusion bonded epoxy powder with min dry film thickness of 300 microns.

10. STEPPED COUPLINGS

Stepped couplings shall be used to connect the spigot ends of two pipes of different nominal diameters.The material of the body ring and sleeve shall be ductile iron grade 420/12 to BSEN 1563 or steel grade S275 to BSEN 10025. The nuts, bolts and washers shall be stainless steel 316 for flange connection between coupling to piping or equipment . The gaskets shall be EPDM to ISO 4633 or BSEN 681-1 suitable for drinking water. The coating shall be factory applied non toxic fusion bonded epoxy powder with min dry film thickness of 300 microns.

11. DISMANTLING JOINTS

Dismantling joints shall be installed as shown on the drawings to facilitate removal of valves and other equipment for servicing/replacement. The dismantling joints shall be of the tied/restrained type.

The material of the body, ring and sleeve shall be ductile iron grade 420/12 to BSEN 1563 or steel grade S275 to BSEN 10025 as approved by FEWA/Engineer. The nuts, bolts, studs, tie rods, washer shall be stainless steel 316 for flange connection between dismantling joint to piping or equipment. The gaskets shall be EPDM to ISO 4633 or BSEN 681-1 suitable for drinking water.

WAM






DEC/20142

Sheet: 19 Of: 61

The pressure rating of the flanges shall be as given in the Particular Specification. The coating shall be factory applied non toxic fusion boded epoxy powder or Rilsan Nylon II with normal dry film thickness of 300 microns and minimum DFT of 250 microns.

12. SPLIT TEES FOR UNDER PRESSURE CONNECTIONS

Split tees shall be ductile iron grade 420/12 to BSEN 1563. The sealing mechanism shall be by rubber ring set in a locating groove around the branch opening and held firmly against the mainline pipe by the pressure of the opposite bolted half or alternatively by full length rubber gaskets along the mating halves and at the separate end flanges. The rubber gaskets shall be EPDM to ISO 4633 or BSEN 681-1 suitable for drinking water. The bolts, nuts, washers shall be stainless steel 316. The split tees shall be coated with non toxic fusion bonded epoxy powder with min dry film thickness of 300 microns.

13. DUCTILE CAST IRON COLLAR

DI. Collar shall be movable on the Pipe barrel (slide type) with mechanical joint on both sides. 14. PUDDLE FLANGES OR SEALING FLANGES

Puddle flanges or sealing flanges shall be used in all situation where a ductile iron pipe is cast into a chamber wall where restraint is not required. The sealing should be water tight between the pipe and the opening through which it will pass. If the seal is made of two parts jointed by nuts and bolts they should be galvanized.

15. THRUST / ANCHOR FLANGES

Thrust/anchor flanges shall be used where D.I. pipes or fittings are cast into the chamber wall and shall be designed to restrain the connecting valves or other equipment installed inside the chamber.Thrust/anchor flanges shall be integrally cast or factory welded on to the pipe piece as approved by FEWA/Engineer. Bolted or screwed on thrust flanges shall are not acceptable. The coating to the thrust/anchor flange shall be similar to that of the pipe/fitting. The position of the thrust/anchor flange shall be as shown on the drawings or determined on site.

16. POLYETHYLENE SLEEVES

Protective polyethylene sleeves shall be used with all D.I. pipes and fittings to be installed in buried condition and shall be in accordance with ISO 8180. The polyethylene sleeve manufacturer shall have the ISO 9001/2000 quality control certificate.

The polyethylene sleeve shall be black, resistant to the effect of ultra violet light, tubular film in accordance with the latest issue of ASTM D-1248 or approved equivalent standard. The minimum nominal thickness of the sleeve shall be 0.010 inch (250 microns) with a maximum minus tolerance of 10%.

The material shall be made from a polymer with a melt flow index as measured according to BS 2782, of 10 or less and a density in the range of 0.915 to 0.925 g/ml. The sleeve shall be free from pinholes, gels, undispersed raw materials and particles of foreign matter. The film may not contain more than 5% by weight of material other than polyethylene.

WAM






DEC/20142

Sheet: 20 Of: 61

Polyethylene sleeving shall be stored in cool dry store away form direct sunlight or excessive heat. Rolls shall be supplied individually packed in black polyethylene sacks and clearly labeled with the date of manufacture, the length of the roll, the pipe size for which it is intended, the name of the manufacturer and the country of manufacture. The stock of the polyethylene sleeve shall be rotated on the first in/first out basis.

17. VENDOR DOCUMENTATION

The Contractor shall furnish the following vendor data as a minimum, with his bid:

- Pre-qualification documents of the proposed manufacturer. - Quality Management system Certificate - Type Tests Certificate for Pipes, Fittings & gaskets. - If fittings are supplied separately from pipes, full “Third Party Type Tests Certificate” and

their compatibility with the pipes shall be made available by supplier to FEWA. - Compliance Statement - Technical Data Sheet - Non Toxicity Certificate for pipes & fittings material, lining, gasket, epoxy coating - Dimensional details of pipes and fittings. - Detailed material specifications. - Local (UAE) agent name and address. - Any other Certificate required as per Standard - Reference list showing experience details of supply & installation for minimum three years

of performance history in Government utilities in UAE/GCC Countries for different diameters.

Bids not accompanied by any of above-mentioned information/data shall be considered incomplete, and liable to be rejected.

18. MARKING All items shall bear the following distinct marks :

- Number of standard - Manufacturer's identification mark - Indication that the item is made of ductile iron - Nominal diameter - Class of pipes and flanges - Year of manufacture - Home line positions at pipe ends - Client’s name, i.e. “FEWA” - Contract No. - Batch No.

19. TRANSPORTATION OF PIPES

DI pipes and fittings shall be properly and securely transported from the place of manufacture to the site/ stores. No nesting of DI pipe shall be allowed at any time during the transport.Where pipes are transported by truck, the pipes shall be transported on wooden cradles or skids and shall be properly protected from contact with metal surfaces by rubber or wooden spacers or wedges.

WAM






DEC/20142

Sheet: 21 Of: 61

20. HANDLING & STORAGE Pipes DN100 to DN400 should be supplied in bundles. Larger diameter pipes will be supplied as singles. Delivering pipes in bundles rather than single pipes provides a number of benefits viz during transportation, for pipe laying Contractors, stack ground personnel and site operatives. Care should be taken not to lift the bundles by their retaining straps.The composition of bundles for various diameters of pipes are as follows:

DN No. of Layers x No. of pipes

100 3X5

150 3X5

200 2X3

250 2X2

300 2X2

350 2X2

400 2X2

500 2X2

600 2X2

The fittings and glands should be delivered in non-returnable pallets, covered with plastic film.For lifting single pipes, use appropriately shaped hooks coated with a polyamide type protection. Use wide flat slings maintained sufficiently widely opened to prevent accidental slippage.For storing of gaskets, the temperature should not exceed 250C. They must be stored under clean and moderately humid conditions. Also the pipes and fittings stacked in the stores or on site must permit correct inventory control and facilitate any repair work.Each pipe bundle should be secured to two base timbers which can be laid directly onto a hard standing surface. The bundles may be stacked one on top of the other with the axes of the pipes parallel and thus the maximum stack height should not exceed three bundles. Where individual pipes are to be stacked, it is recommended that the parallel method is used using wooden battens between rows. The maximum recommended number of layers in a stack is given below:

DN Max. recommended No. of layers

in a stack

100 16

150 14

200 12

250 10

300 8

400 7

500 6

600 4

21. WARRANTY

The manufacturer must give warranty for 10 years for all DI Pipes & Fittings from the date of the issue of the Provisional Taking-Over Certificate (PTOC).

WAM






DEC/20142

Sheet: 22 Of: 61

B - SPECIFICATIONS FOR DI PIPELINE INSTALLATION WORKS 1. SCOPE OF SPECIFICATIONS

This specification covers the construction, installation and testing of Ductile Iron (D.I.) pipes and fittings including route survey, excavation, backfilling, pipe wrapping, laying, protection, etc.


Unless otherwise specified the works shall conform to the following standards and other standards noted elsewhere in this specification.

BS 8010 : Part 1 Pipelines on land : general

BS 8010 : Part 2.1 Pipelines on land : design, construction and installation

AWWA C651 Disinfecting water mains

3.PIPELINE ROUTE SURVEY

The Contractor shall be responsible for all the necessary surveying and pegging out of the pipeline route, tank site, storage area(s), camp area(s) etc. Deviations from the proposed route shown on the tender drawings due to the local site condition shall require the approval of the FEWA in writing. The final route and alignment shall, however, be approved by the concerned roads authority and other related authorities.

The Contractor shall prepare trial pits at each kilometer to know the soil conditions and for

requirement of sand bedding or filling and water table level for requirement of dewatering and submit report to FEWA for approval before submitting the profiles.

The Contractor shall prepare and submit to the FEWA, all necessary survey drawings including

longitudinal profiles for approval and record.

The survey work shall be deemed to be complete on receipt of the FEWA's written approval and upon acceptance of the work, the Contractor however shall be obliged to maintain the pegs in an acceptable condition and at their respective locations, for as long as may be considered necessary for the construction works.

Before commencement of excavation for pipe trench, the CONTRACTOR shall carryout full route

survey and preparation of pipeline profile drawings, all in accordance with the construction programme, subject to FEWA's approval. All survey work shall be referred to the National Grid, Universal Traverse Mercator (UTM).

The survey shall be carried out using calibrated survey equipment approved by FEWA. The survey

work shall be executed by qualified land surveyor approved by FEWA.

The Contractor shall set out the route of the pipeline in accordance with the drawings. The route shall be marked by 75x75x1000mm wooden poles set in to the ground in a concrete surround. The poles shall be set along centre line of the pipeline at intervals of 50m chainage, at every bend, air valve, washout or valve chamber and at all physical obstructions (existing chambers, excavations, etc.).The chainage of the pipeline shall be marked on every pole. All poles shall be painted as follows: -

WAM






DEC/20142

Sheet: 23 Of: 61

Red - Centreline of pipe or pair of pipes Red with White stripe - Horizontal bend, washout or valve chamber, etc. White marker - Outer limits of the working width Yellow marker - Other Service

From the results of this survey, the Contractor shall prepare the pipeline alignment and profile drawings. Pipeline profile drawings shall be presented at a horizontal scale of 1:000 and a vertical scale of 1:100 or as directed by FEWA/Engineer. All drawings shall be submitted to the FEWA for approval on ISO size A1 paper prints or any suitable size.

The Contractor shall plot on these drawings the detailed routes and profiles of the pipelines. The

profile shall comply with the requirements of pipeline minimum cover, minimum gradient and spacing of air valves, washout and valve chambers and the location of the marker posts. The distance between marker posts from any bend (Change of Direction on) of the pipeline to the next post of the straight runs, and all post/s thereafter shall be at 200 Meters interval. The distance between the last post of the straight run and the next bend shall be as per FEWA/Engineer’s approval. As required FEWA reserves the right to change the distances of marker post/s between bends to compensate for any distance less than 200 M. The route profile shall be plotted under the relevant section of the pipeline route plan. The route plan shall show a strip of land 20m wide, centered on the pipeline route, including the adjacent asphalt road if any.

The profiles shall also show the chainage of the pipeline at the points of ground level

measurements and at any change in profile. The Contractor shall determine the invert level of the pipeline at the points of level measurement and mark these levels on the drawings. The diameter and details of the pipeline shall also be shown.

FEWA shall approve or otherwise amend the route or profile of the pipelines and the Contractor

shall revise the drawings accordingly. The revised approved drawings shall be marked "APPROVED" and thereafter shall become the Contract Drawings for the pipeline construction. These drawings may also then be used by the Contractor for finalizing the pipeline materials order.

The survey shall include information on all the existing services and facilities such as roads, power

lines and cables, sewers, treated effluent pipelines, irrigation pipelines, water pipelines, oil/gas pipelines, drainage channels and culverts, and plantations, within a 20m wide strip centered on the pipeline route.

The existing underground utilities traversing the pipeline route shall be exposed by hand excavation

and their exact lines and levels shall be included in the results of the survey. The Contractor shall record by site investigation the exact lines and levels of the pipelines that are to be connected to the proposed pipeline. The results of the survey shall be presented in soft and hard copies to FEWA.

4. EXCAVATION OF TRENCHES AND PITS 4.1 General

The lines of trenches for all pipelines are to be carefully set out to the alignment of the pipelines.Excavation for trenches shall be carried out for a maximum of four pipe lengths in advance of the pipe laying or as determined by the FEWA. The trenches shall be excavated to the required line and level as shown on the drawings or as approved by FEWA, and shall, at all times, be drained & dried and braced to ensure safe and efficient pipe laying. In locations where services, or other structures are near the pipeline route, only hand excavation will be permitted.

WAM






DEC/20142

Sheet: 24 Of: 61

All rubbish, filth and matter of an offensive nature taken out of any excavation shall be disposed of at once and not left on the surface.

The pipeline laid around and about Head works, well fields, Tanks, existing services, Pumping

stations and other similar works, shall be laid at such depths as are required to suit the works to which they are intended to be connected, or to avoid interference with the existing services and installations.

The rate for excavation given in "Schedule of Quantities and Rates" is for making the trenches in all

types of soils (soft, medium, hard solid rock, paved or asphalt etc.) and in all types of locations/circumstances including making the formation level even and service track and to the depth as mentioned in Article 4.5 including shoring, strutting, dewatering, leveling etc.

The Contractor shall also cut and fill the ground as required necessary, which includes making a

service track, duly compacted, along the pipeline route, to make the ground formation even, to facilitate the laying, inspection, as well as for FEWA’s maintenance. The service track shall be properly maintained by periodic watering, grading and leveling etc. as required, throughout the period of contract. The payment for cutting and filling shall be according to the relevant Item of the B.O.Q.

The Contractor must estimate for himself the proper price for completing the whole job irrespective

of difficulties met in excavations. The Tenderer in his price for relevant item/items shall include cost on account of this article as given in the `Schedule of Quantities & Rates'. No additional payment shall be made for the cost on account of this article.

4.2 Setting Out

The lines of trenches for all pipelines are to be carefully set out to the alignment of the pipelines. The Contractor shall be entirely responsible for accurately setting out the WORKS. The levels shall be relative to the ACD levels as mentioned in the contract administration requirements. Before commencing any work the Contractor shall give such notice to the FEWA to enable FEWA to check the setting out, and in any event not less than 48 hours notice. No approval either given or implied by the FEWA shall relieve the Contractor of his obligations in connection with the setting out.

The Contractor shall set out the Works in accordance with the drawings or as otherwise instructed by the FEWA. Should the Contractor wish to alter the line, level or any other part of the WORKS, the prior written approval of the FEWA must be obtained.

4.3 Grading of Pipeline Route

The Contractor shall cut and fill the ground, including supply of imported material and carting off surplus earthworks, as required necessary which includes making a service track along the pipeline route to make the ground formation level even, for his own convenience as well as for FEWA’s inspection and maintenance. It shall be made in such a way that FEWA representative can inspect the route in a normal car. No extra payment shall be made for all such types of works.

The Contractor also has to grade the pipeline route, as required, and he is responsible for necessary cutting and filling in any type of soil. The payment for such cutting and filling works shall be according to the relevant item of schedule of quantities and rates.

WAM






DEC/20142

Sheet: 25 Of: 61

4.4 Trench Excavation

The Contractor shall provide and maintain suitable temporary crossings over pipe trenches at those positions where the excavation of a pipe trench prevents the normal movements of traffic. To permit the passage of pedestrian, vehicular and other traffic the Contractor shall phase the excavation, pipe laying, jointing and reinstatement in such a way as to provide reasonable access to houses, roads, footpaths, etc. The Contractor shall remove the whole of the turf, topsoil, concrete, flagging, paving, kerbing, road metalling and other materials from the site of any excavation and preserve the same for re-use afterwards. The ground shall be excavated for the permanent and temporary works to the required depth, widths and levels so that the dimensions of the permanent work shall not be less than is shown on the drawings, or as may be directed.

4.5 Trench Depth

The depth of cover shall be kept 900 mm. for pipe of up to 300 mm. dia. and 1100 mm for pipes above 300 mm. and up to 600 mm diameter. and 1500 mm for pipes above 600 mm diameter or as shown on the drawing, measured from the surrounding or finished surface level except where the pipe may be lifted or lowered when crossing other services as instructed by the FEWA.

In special cases, for example where the sub-soil is heavily impregnated with corrosive substances, pipelines may occasionally have to be laid on the surface, if traffic and other conditions permit. In such cases the pipes shall be supported on dwarf blocks of cement concrete, as per the FEWA's approval at intervals not exceeding 3000 mm.

Where trenches are required to be deeper than the general depth mentioned above, the Contractor shall dig the trench to the required depth with a gradual slope necessary for the proper laying of the pipeline. Pipelines shall not be laid closer than 600mm to other pipelines, services or structures or as directed by the FEWA.

The trenches shall be carefully trimmed on sides and bottom so that pipelines, when laid shall rest on the sand bed (as described hereafter) of the trench through their full lengths and shallow joint holes being left for the joints where necessary.

4.6 Trench Width

The trench width is dependent on the nature of the ground, depth, and pipe size. The clear width of the trench at any level shall be minimum of one pipe outside diameter, plus 300mm clearance on either side. In all cases the trench shall be excavated sufficiently wide to ensure efficient laying and jointing of the pipes.

WAM






DEC/20142

Sheet: 26 Of: 61

The following table shall be used as a guideline for trench widths for various sizes of pipes:

Nominal Pipe Diameter (mm)

Trench Width (mm)

100 700

150 700

200 800

250 900

300 900

400 1000

500 1200

600 1400

700 1500

800 1600

900 1700

1000 1800

1200 2000

4.7 Rock Excavation

Excavation in rock shall be made to provide a minimum of 150mm clearance on each side of and below all pipes or fittings.

Blasting shall not be carried out in any part of the works without the permission in writing from FEWA. If allowed, it is the responsibility of the Contractor to obtain all the required permission from the concerned authorities for blasting which includes all liabilities.

4.8 Control of Groundwater The Contractor shall include in his excavation rates all necessary provisions for removing all water from excavations if encountered, and shall provide all plant, labour and all other items and machinery necessary to maintain all excavations and trenches dry during construction work. The cost of such works shall be included in the rate of the trench excavation.

4.9 Methods of Excavation

Wherever practical, mechanical excavation methods shall be used, except where such methods may cause damage to existing structures or services. In such locations, the Contractor shall make hand excavation only.

Where shoring is used to stabilize excavations, the shoring shall be removed progressively to ensure that adequate backfilling is carried out without leaving voids. All excavated material shall be placed so as to avoid any danger or hindrance to others.

4.10 Existing Services

The Contractor shall apply to various departments, for obtaining NOC's and advising that he intends to start the work on any site/route in order to obtain all available records of existing services.

Before the Contractor interferes with roads, pavements or services, he shall obtain prior written approval to proceed from the FEWA and the Department/Authority concerned.

4.11 Support of Excavation and Adjacent Property

The Contractor shall keep all excavations stable at all times during construction of the pipeline.

WAM






DEC/20142

Sheet: 27 Of: 61

The Tendered cost of the project shall be inclusive of all works required for shoring up of the buildings along or near the trench which are likely to be endangered by the execution of the work.

When excavating in unstable soils or where the excavations are necessarily deep, the Contractor shall submit to the FEWA his detailed proposals for supporting the excavations at the site at least seven days prior to commencement of any excavation work. His proposal shall take into account the nature of the ground to be excavated, the water table level at the site and the closeness of adjacent buildings and roads.

If, in the opinion of the FEWA the support proposed by the Contractor is insufficient, then the FEWA will order the provision of stronger or alternative support for the excavations than that proposed by the Contractor. In this event the Contractor shall adopt the same at no extra cost to the FEWA. The Contractor shall not remove any temporary works supporting the excavation until in the opinion of the FEWA, the permanent work is sufficiently advanced to permit such removal. This shall then be executed under the personal supervision of a competent foreman. The cost on account of this article shall be included by the Tenderer in his price for the relevant item/items as given in the "Schedule of Quantities and Rates". No additional payment therefore shall be made for the cost on account of this article.

4.12 Surplus Excavated Material

All surplus excavated material, or material unsuitable for D.I. pipeline backfilling, arising from any part of the trench excavation, shall be removed from the site and disposed off by the Contractor at location as allocated by the local concerned authority at his own cost.

5. D.I. PIPE HANDLING AND LAYING

In general D.I. pipes shall be handled and laid according to an approved standard. 5.1Stretch Of Restrained Pipes Around Fitting

A.) For restrained pipes, a weld bead on the pipe spigot is required, which can be done by electric welding unit, as per manufacturer's recommendation.

Also for restrained pipes the following is the schedule of the length (stretches) of restrained pipes, on either side of the fitting (bend/Tee/blank flange) under the following soil conditions:

Soil is gravel, silty sand or clay.

Internal angle of friction of soil = 30 degree

Resistance = 0.6da N/cm2

Density = 2 t/m3

No water table is present

Pipe coated with zinc & bituminous paint

Safety coefficient = 1.2

Test pressure = 10 bar

Note: The following table indicates that the lengths mentioned are minimum, and the Contractor has to design and follow manufacturer's recommendations.

WAM






DEC/20142

Sheet: 28 Of: 61

DN

90° bend

45° bend

22.5° bend

11.25° bend

Tee / Blank Flange

Depth of cover

1m

1.5m

1m

1.5m

1m

1.5m

1m

1.5m

1m

1.5m

011 4.5 7.3 7.5 3.7 1.9 1.3 0.1 1.3 9.6 5.3

041 3.3 5.3 5.4 7.7 3.3 0.4 0.5 0.1 6.4 9.3

311 6.6 9.4 9.0 5.3 7.5 3.5 0.4 0.7 03.9 4.3

341 03.1 4.7 3.4 4.3 5.3 3.6 3.3 0.4 04.7 01.9

711 05.0 6.4 4.3 9.0 5.6 7.5 3.9 0.4 03.6 03.4

511 03.6 03.9 00.0 3.4 9.3 5.5 7.7 3.7 33.4 09.1

411 30.4 04.7 07.5 6.4 3.4 4.7 5.1 3.4 33.5 06.4

911 34.1 03.6 04.4 00.0 4.3 9.3 5.9 7.7 70.4 33.4

311 34.3 31.5 03.4 03.3 6.4 3.0 4.3 7.4 74.4 34.6

411 70.3 33.4 06.5 05.0 01.6 3.6 4.4 5.3 76.4 36.1

611 75.0 34.1 30.3 04.9 00.6 4.3 9.7 5.9 57.5 70.6

0111 79.6 33.3 33.6 09.6 03.4 6.4 9.4 4.1 59.6 75.3

0011 76.5 36.5 35.4 04.3 07.3 01.3 3.7 4.5 41.3 73.5

0311 50.6 70.5 39.1 06.4 05.9 01.6 3.3 4.4 47.5 51.1

. For other special conditions the following points shall be taken care of:

In case of pressure (P) other than 10 bar the length shall be multiplied by the factor P/10.

In case where polyethylene sleeves are used, the length shall be multiplied by 2.0.

5.2 Handling and Storing All pipes, fittings and equipment shall be handled and stored in such a manner as to avoid any damage to them. In case it is mentioned that part of the materials are available in FEWA stores, the Contractor needs to take off the same from the FEWA stores to the respective sites. The materials, to be supplied by the Contractor, shall be taken directly from the port to the Contractor’s store yard(s) and shall be carefully unloaded. Upon receipt in the Contractor’s store yard the materials shall be checked by the FEWA for quality and damages, and any repairs shall be made by the Contractor in accordance with manufacturer’s requirements/ recommendations. All pipes and fittings shall be examined and no piece shall be accepted which is found to be defective. Pipes may be stored in the open, however they shall be stacked off the ground on 100 x 100 mm timber skids to be provided by the Contractor. The stacking shall be done according to the manufacturer's recommendations. Fixing materials, instruments, polyethylene sheeting etc. shall be stored under cover to be provided by the Contractor according to the manufacturer's recommendation. It shall be noted that rubber gaskets shall be stored in appropriate stores where the temperature is below 25ºC. Fittings, rubber gaskets, nuts, bolts etc. shall be withdrawn from storage and delivered to the site to suit the daily construction requirements.

The Contractor shall at all times have ample supervision, labour, construction plant, materials and stores in use in such operations to prevent in any way damaging the pipe or injuring its protective coating or sleeving. In particular the Contractor shall submit to the FEWA his proposals for the

WAM






DEC/20142

Sheet: 29 Of: 61

prevention of damage to wrapped or sleeved pipes during transportation from the tape-wrapping yard to the pipeline trench.

The provision and correct usage of broad band slings is particularly important for the lowering of pipes into the trench. The Contractor shall take the utmost care to prevent any damage to the coating or sleeving during lowering-in, alignment, jointing and final removal of the lifting sling. In all cases an approved non metallic sling must be used for the handling of pipes and fittings. Pipes shall be finally inspected after laying and any damaged spots found shall be repaired to the entire satisfaction of the FEWA.

In general, the distance between two isolation valves shall not exceed 1000 metres and the maximum distance between two air valves shall be 800 metres. However, the pipeline route drawings and the B.O.Q shall govern this principle, based on the approved drawing of FEWA , proposed by the Contractor.

5.3 Repair of Detective or Damaged Areas of Lining

Defective or damaged areas of lining may, at FEWA's discretion, be patched by cutting out the defective or damaged lining to the metal so that the edges of the lining not removed are perpendicular or slightly undercut. The cut out area shall then be trawled with fresh mortar in the following composition:

One part cement (special approved repairing cement to be supplied by the manufacturer) (by weight)

One part sand

Water of potable quality, with non toxic additive dispersion of synthetic materials subject to FEWA's approval.

5.4 Stringing

No stringing of pipes is allowed. Pipes shall be stacked along the route at distances of 50m to 100m. Pipes shall not be stacked more than that specified by the manufacturer. The lowest layer shall be supported off the ground by timber.

5.5 Inspection and Rejection

Pipe materials when brought to site and stacked as above, shall be inspected by the FEWA before being lowered into the trench.

Any pipe or fitting which is rejected by the FEWA shall be sprayed "REJECTED" and shall be removed from the site to be repaired in a predetermined area, set aside exclusively for repairs. Until the rejected material is removed, the whole stack shall be suspended from use.

Rejected materials which have been repaired, can only be used in the WORKS after approval of the FEWA.

5.6 Pipeline Bedding and Filling (Sand Surround)

When, in the opinion of the FEWA, the bottom of the excavated trench is not suitable to form a bearing surface for the pipes or where the pipeline is in rock or any other hard material, then the bottom of the trench shall be cushioned with well compacted soft bedding material to a minimum thickness of 150mm below the barrel of the pipes and extending for the full width of the trench for pipes of diameter up to DN 300mm, thickness of 200mm for pipes of diameter DN 400 to 600mm

WAM






DEC/20142

Sheet: 30 Of: 61

and thickness of 250mm for pipes of diameter DN 800 to DN 1200mm. Any soft spots shall be excavated and refilled with lean mix concrete or selected fill materials as directed by FEWA. The same above respective thickness shall be installed for filling too.The pipes shall be laid in such a manner that the whole length of the pipe barrel is supported on the bedding material. At collars, sockets, flanges etc. the bedding material shall be removed to avoid point loads occurring at these locations.Bedding and filling material is subject to FEWA's approval and shall be free from clay, large stones, rubbish, perishable matter or any other material which could damage the pipeline coating or assist in setting up corrosion.

All costs for the supply, transportation and placing of pipeline bedding material shall be deemed to be included in the relevant items of Schedule of Quantities and Rates.The trench shall be excavated, keeping a provision for the bedding.

In case FEWA feels that the sand surround is not required, the Contractor shall not be paid for the same and the payment shall b made only for the backfilling Item.

5.7 Laying

It shall be the Contractor’s responsibility to accurately survey the route of the pipeline before commencing construction. The Contractor shall establish and maintain centerline, chain age and level reference points to the satisfaction of the FEWA. The Contractor shall submit proposed profile and alignment for every pipeline to the FEWA for approval. The profile shall be agreed in accordance with the parameters and any other requirements instructed by the FEWA.

Before pipes are lowered into the trench, the suitability of the material in the bottom of the trench shall be subject to approval of the FEWA and if found unsuitable be replaced with approved material.

Additional excavations will have to be carried out to provide extra space around couplings. These shall be large enough to allow unhindered joining of the pipes. All pipes shall be laid and maintained to the agreed alignment and grade ensuring that the pipe is properly bedded along its whole length

federal electricity & water authority water directorate standard … pipe... · 2017. 2. 22. ·...

Documents