Federal Electricity & Water Authority Water Directorate ... Piping...wam client: federal electricity and water authority (fewa) project: standard specifications for water works engineer

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.

PS09-AC PIPES- MATERIALS & INSTALLATION

office: DUBAI order: document: MWA_PRO_07/WAM-04-PS09 rev: DEC/2014 sheet: 1 of: 37

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 09

AC PIPES MATERIALS & INSTALLATION

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title: Technical Terms / Chapter 4/ Engineering Specifications / Pipeline Works Specifications



A- SPECIFICATIONS FOR ASBESTOS CEMENT PIPES, FITTINGS & ACCESSORIES

TABLE OF CONTENT

1. GENERAL

2. APPLICABLE STANDARDS AND REFERENCES

3. CLASS / DESIGN OF PIPES

3.1 Dimensions

3.2 Tolerance on External Diameter of the Calibrated End

3.3 Cement

3.4 Joints

3.5 Design Calculations

3.6 Coating

3.7 Elastomeric Joint Sealing Rings

3.8 Gaskets for Flanged Joints

3.9 Flanges

3.10 Nuts, Bolts, Screws And Washers

4. FITTINGS

4.1 GRP Fittings

4.2 Cast Iron & Ductile Iron Fittings

5. SAMPLING AND INSPECTION OF PIPES AND JOINTS

5.1 Acceptability of Inspection Lots

6. TESTING

6.1 Failure of Pipes and Joints at the time of Testing at Site

7. MARKING

8. SHIPPMENT OF PIPES

9. UNLOADING

10. VENDOR DOCUMENTATION

11. WARRANTY

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B - SPECIFICATIONS FOR AC PIPES INSTALLATION WORKS

TABLE OF CONTENT

1. SCOPE

2. APPLICABLE STANDARDS AND CODES

3. EXCAVATION AND PIPEWORK

3.1 Excavation

3.2 Pipe Handling, Laying, Jointing

4. BACKFILLING OF PIPELINES

5. ANCHOR AND THRUST BLOCKS

6. VALVE CHAMBERS

7. PROTECTION OF PIPELINE COMPONENTS

8. ROAD CROSSINGS

8.1 Tracks and Proposed Roads

8.2 Asphalt Roads

8.3 Encasing at Road Crossing by Open Cut

8.4 Backfilling of Trenches

8.5 Restoration of Surfaces

8.6 Wadi Crossing

8.6.1 General

8.6.2 Typical Cases

8.7 Road Crossing by Non – Disruptive Method (No-Dig Method)

8.7.1 General

8.7.2 Material

9. PIPES PROTRUDING FROM STRUCTURES, CONCRETE SURROUNDS & ANCHORS

10. TESTING OF THE PIPELINE

10.1 Field Pressure Test

11. DISINFECTION AND FLUSHING OF WATER PIPELINE

11.1 Method Statement

11.2 Sterilization

11.3 Flushing

12. CONNECTIONS TO EXISTING PIPES

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A- SPECIFICATIONS FOR ASBESTOS CEMENT PIPES, FITTINGS & ACCESSORIES

1. GENERAL

Pipes shall be made from a close and homogeneous mixture essentially consisting of Chrysotile Asbestos Fibres, Cement and Water excluding any materials liable to cause ultimate deterioration in the quality of the Pipes. Pipes shall be purchased from manufactures having previous successful experience in pipe supply and installation within the U.A.E. and approved by FEWA. All the pipes shall be supplied with joints.

The following are to be submitted along with the submittal for approval:

1) Quality assurance certified to conform ISO 9001 (or equivalent) series for the manufacturer.

2) Original detailed catalogues, product technical data, and any other required documents. 3) Details of past supply records for the last four years.

All the manufactured pipes shall be inspected and tested at the manufacturers works for general appearance, wall thickness bursting, transverse crushing, bending, pressure tightness, etc., as required by ASTM C500 and ISO 390 -1993. FEWA/Engineer may direct that some of the tests to be conducted at an independent laboratory designated by agreement.

2. APPLICABLE STANDARDS AND REFERENCES

The following standards are applicable where referenced in the following specification.

BS-EN 512 – 1995 Fibre-cement products. Pressure pipes and joints

BS EN 1092-1:2007 Flanges and their joints. Circular flanges for pipes, valves, fittings

and accessories, PN designated. Steel flanges. BS 6920-1:2000 Suitability of non-metallic products for use in contact with water

intended for human consumption with regard to their effect on the quality of the water. Specification.

BS 4027 - 1996 Specification for sulfate-resisting Portland cement ISO 2531 - 2009 DI Pipe, Fittings & Accessories for Pressure Pipelines ISO 390 -1993 Products in fibre reinforced cement – Sampling and Inspection ASTM C500 – 07 Standard Test Methods for Asbestos-Cement Pipe ASTM D1869-95(2010) Standard Specification for Rubber Rings for Asbestos-Cement Pipe ASTM C296/C296M-00(2009)e1 Standard Specification for Asbestos-Cement Pressure Pipe

3. CLASS / DESIGN OF PIPES

Pipe shall conform to the requirements of BS-EN 512:1995 Class 20, i.e. test pressure in the factory 20 bar as per BSEN 512, unless otherwise stated on the quantities schedules. The cement to be used in the manufacture of pipes shall be Sulphate Resistant Cement conforming to BS 4027. The finished product shall be entirely seamless and capable of being cut, drilled and tapped.

3.1 Dimensions

Asbestos cement pipe shall be manufactured and supplied in 5 or 3-meter lengths for all diameters. All joints and pipe ends shall have the following principal dimensions:

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CLASS - 20

Nominal Diameter

mm

Outside Diameter at the Pipe End

mm

Calibration Length At the End of Pipe

mm

Length of A.C. Joint Mm

100 126 125 120

150 178 125 120

200 234 155 150

225 255 155 150

250 288 155 150

300 344 155 150

400 456 210 200

450 508 210 200

500 560 210 200

550 616 210 200

600 668 250 240

700 780 250 240

800 888 280 270

900 1000 280 270

1200 1320 310 300

3.2 Tolerance on External Diameter of the Calibrated End

Nominal diameter mm

Maximum tolerance mm

Up to 300 ± 0.6

Over 300 up to 550 ± 0.8

Over 600 up to 1100 ± 1.0

Over 1100 up to 1600 ± 1.4

3.3 Cement

All cement used in the manufacture of asbestos cement pipe and joints shall be a high sulphate resisting cement conforming to BS 4027:1996. Copies of cement mill certificates shall be submitted with each consignment of pipe delivered upon request.

3.4 Joints

Asbestos cement pipe shall be provided with spigot ends to be joined with ‘Reka’ type couplings using two rubber rings. Each pipe shall be supplied with one joint and two rubber rings at no extra cost. Rubber rings shall conform to the requirements of ASTM D1869. The joints shall be capable of withstanding a test pressure of 20 bars without any leaks when deflected to the angle specified below:

Nominal Diameter mm

Joint Deflection Angle Degrees

Up to 225 5

250 - 350 4

400 - 550 3

600 - 1000 2

1100 - 1500 1

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Copies of test reports showing compliance to these requirements shall be submitted to FEWA/Engineer for approval if requested. REKA rubber rings for couplings shall be supplied in closed bags/containers shielded from sunlight. Each bag/container shall contain only one size of rubber rings and shall be marked with a clear print indicating the diameter and the number of rings in the bag.

3.5 Design Calculations

Pipe design calculation as per ASTM C296 shall be submitted to the FEWA for review, showing maximum safe burial depth for each diameter and class of pipe.

3.6 Coating

All the pipes, joints etc. shall be thoroughly cleaned and coated externally with a solution of bitumen refined from asphaltic crude oil.

3.7 Elastomeric Joint Sealing Rings

Elastomeric joint sealing rings shall be manufactured from ethylene propylene rubber (EPDM) and shall have a hardness measured in International Rubber Hardness Degrees (IRHD) compatible with the pipe material.

3.8 Gaskets for Flanged Joints

Gasket for flanged pipes shall be manufactured from ethylene propylene rubber (EPDM) 3.2mm thick and shall be dimensioned to full face of the pipe flange and to suit the flange drillings. The hardness of the rubber (IRHD) shall be in the range of 66 to 75.

3.9 Flanges

The flanges shall conform to BS EN 1092 and shall be of class PN 10 Raised face type.

3.10 Nuts, Bolts, Screws And Washers

All nuts, bolts, screws, washers, etc. used for fixing pipes and or accessories shall be of SS grade 316.

4. FITTINGS

The fittings for use with AC pipes shall be made of either of the following : i. Glass Fibre Reinforced Pressure Fittings (GRP) ii. Cast Iron iii. Ductile Iron

4.1 GRP Fittings

GRP fittings for use with AC pipes shall be made conforming to the requirements of document "Specification for GRP Pipes and Fittings." The fittings shall have ends to fit AC pipes supplied.

4.2 Cast Iron & Ductile Iron Fittings

The fittings shall have ends to fit AC class 20 coupling used for pipe jointing or a flange as appropriate.Ductile Iron and Cast Iron fittings shall be internally and externally coated with fusion bonded epoxy with a minimum dry film thickness of 300 microns.

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5. SAMPLING AND INSPECTION OF PIPES AND JOINTS

Any homogeneous consignment should be divided by the manufacturer into inspection lots. Each lot shall be maximum of 200 pipes. For each of these inspection lots authorised representative shall draw samples not exceeding 2% of each inspection lot subject to a minimum of 3 Nos. for testing. The pressure defining the class of pipes shall be maintained for 5 minutes. The FEWA shall also have the right to select up to 1% of the pipes and joints, delivered to the Store to be subjected to re-testing at the manufacturer’s works in the presence of the FEWA’s Engineer. In the case of imported pipes the re-testing must be arranged at local test facilities in the U.A.E. The Contractor shall provide such labour, material and transport as the FEWA representative may require to assist him in carrying out the sampling, inspection and testing of pipes and joints. No additional payment shall be made for the above number of tests conducted by the supplier/manufacturer.

In addition to the above, a sufficient number of quality control tests, based on the total production of pipes and joints, shall be made at regular intervals by the manufacturer to ensure that his products comply with the requirements of the FEWA and certified records of all such tests shall be kept for inspection by the Engineer.

The manufacturer shall, on request furnish the FEWA with a certificate confirming that all the pipes supplied by him under this contract comply with the requirements of the FEWA.

5.1 Acceptability of Inspection Lots

a) When all the units in the sample are found conforming to the requirements of the tests, the inspection lots shall be considered acceptable.

b) When two or more units of the sample are found not confirming to the requirements of the tests, the inspection lots may be rejected.

c) When one unit of the sample is found not conforming to the requirements of the tests, a second sample should be submitted for test.

d) If all the units in the second sample are found conforming to the requirements of the tests, the inspection lot shall be considered acceptable.

e) If one or more units in the second sample are found not conforming to the requirements of the tests, the inspection lot shall be rejected.

The tenderer shall submit with his tender all catalogues giving the detailed specifications of the pipe he proposes to supply for the contract.

6. TESTING

Asbestos cement pipes shall be factory tested in accordance with section 4.6 of BS-EN 512-1995. Copies of test certificate shall be submitted for each consignment delivered. Inspection, sampling and lot size shall be in accordance with Annex A of BS-EN 512:1995.

The inspection lot size for sampling and testing to be carried out in presence of FEWA representative, will be at client discretion limited within minimum and maximum lot specified in BS 512, taking into consideration quality of past supplies. Lot size for diameters larger than 1000 mm shall be 200 pipe.

All test including destructive type tests shall be carried out by the manufacturer in presence of FEWA/Enginee before delivery. Testing and related activities shall be carried out at no

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additional cost. Pipes, which are destroyed in testing, shall be replaced at no additional cost as well. In addition to above, if requested by FEWA/Engineer, the contractor/supplier shall carryout tests on pipes/joints delivered to site at Contractor’s/supplier’s expense including transportation.

For outside U.A.E. manufacturer, all tests including destructive tests shall be carried out at manufacturer’s place in accordance with Annex A of BS EN 512-1995. The manufacturer contractor/supplier shall give 14 days advance notice.

In addition to that, 1% of total numbers of pipes of each size and class after delivery to FEWA stores/sites shall be tested at local laboratory for all tests including destructive tests. Any failure shall lead to for complete rejection of consignment and FEWA decision shall be final and binding to the tenderer. Pipes, which are destroyed in testing, shall be replaced at no extra cost by the Contractor. The cost of transport of pipes and joints for testing and delivery once again, shall be born by the contactor/supplier.

The pipes shall pass the result obtained from both formulae mentioned in BS 512 and ASTM C500. The following acceptance tests shall be carried out at the manufacturer’s works on pipes. a) Works hydraulic pressure test on all pipes. b) Hydraulic pressure test of pipes with joints at the maximum deflection

recommended by the manufacturer. c) Bursting (tensile tangential) strength test (number of tests as specified in ISO 390) on

specimen 0.5 to 1.0 m long, or on ring sections cut from the pipe barrel. d) Transverse crushing strength test (number of test as specified in ISO 390) on test

specimen cut from the pipe barrel. e) Longitudinal bending test for pipes up to and including diameter 150 mm (number of

tests as specified in ISO-390) on specimen at least 2.2 m long. 6.1 Failure of Pipes and Joints at the time of Testing at Site

During hydro-pressure testing at site after delivery to stores/site and, if pipes/ joints failed, shall be replaced at no extra cost including transport expenses. The reason of the failure shall be investigated by FEWA/Engineer and FEWA decision shall be final and binding to the tenderer.

7. MARKING

The pipes and joints shall be marked legibly and indelibly with the following: 1. Manufacturer’s name of trade mark. 2. Date of manufacture Month-Day-Year (for pipes only) 3. Class of pipe 4. Nominal diameter 5. BS-EN 512. 6. Home line positions at pipe ends. 7. The letters “FEWA” 8. Contract No.

8. SHIPPMENT OF PIPES

a) A.C. Pipe and Joints shall be properly and securely transported from the place of manufacture to the FEWA Store at Sharjah or other Work sites.

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No nesting of coated AC Pipe shall be allowed at anytime at the manufacturer’s yard, during transport or on site.

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.

b) Where any part of the transport is done by ocean freight or barge, or if AC Pipe is

imported from outside the U.A.E., then the following packing procedures shall be applicable and followed:

All AC Pipe and Joint shall be transported in full wooden crates. Crates shall be provided with transverse wooden spacers such that the unsupported span of AC pipe does not exceed 2 meters inside the crates. Crates shall be provided with skids to allow lifting by forklift. Pipes inside the crates shall be provided with rubber or polystyrene end protectors around the spigot surface of the pipe. Crates shall be marked with the manufacturer’s name, the contract number and details of contents. Pipes shall be individually crated.

9. UNLOADING

Unloading at stores/sites must be carried out carefully under the control and responsibility of the tenderer. Care should be taken to avoid severe impact with any solid object (i.e. other pipes, ground etc.). All packing and transportation expenses shall be deemed included in the supply rates, and no extra payment shall be made by FEWA.Unloading by rolling down planks or another form of inclined ramp will not be allowed

10. VENDOR DOCUMENTATION

The Contractor shall furnish following vendor data as a minimum, with the bid: - Pre-qualification documents of the proposed manufacturer. - Quality Management system Certificate - Type Tests Certificate for Pipes - Compliance Statement - Technical Data Sheet - Non Toxicity Certificate - 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.

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

11. WARRANTY

The manufacturer must give warranty for 5 years for all AC Pipes & Fittings from the date of the issue of the Provisional Taking-Over Certificate (PTOC).

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B - SPECIFICATIONS FOR ASBESTOS CEMENT PIPE INSTALLATION WORKS

WORKS

1. SCOPE

This specification covers the construction, installation, testing and commissioning of pipes and fittings for AC pipe system including route survey, excavation, backfilling, laying, protection, etc.The Contractor shall include for all labour, materials, tools and tackles, complete with all trenching and backfill.

The Contractor shall be responsible for the location of other services and the correct setting out of the installation.The work also involves the exposing of existing water pipelines for the purpose of transferring existing house connections if any to the new distribution system and for the connection of the new system thereto, and the recovery and disposal of all abandoned existing connection lines, all as indicated in the Drawings or otherwise directed by FEWA/Engineer.The Contractor shall allow in his programme for the non continuous nature of the work relating to the water services.

2. APPLICABLE STANDARDS AND CODES

Material items shall be to the latest ISO or equivalent comparable internationally recognised standard of construction and quality.The construction works shall conform to the following standards and other standards noted elsewhere in this specification unless otherwise specified.

Pipelines on land. BS 8010 : Part 1 Pipelines on land design, construction and installation. BS 8010 : Part 2 Disinfecting water mains. AWWA C651

3. EXCAVATION AND PIPEWORK

3.1 Excavation a) Surveying Alignments of Trenches, Cover of Pipes and General

The Contractor shall be responsible for all the necessary surveying and carryout full pegging out of the pipeline route survey and preparation of pipeline profile drawings , 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 FEWA/Engineer in writing. The final route and alignment shall however be approved by the concerned local Municipality 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/Engineer for approval before submitting the profiles.

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The Contractor shall prepare and submit to FEWA/ Engineer, all necessary survey drawings including longitudinal profiles for approval and record. 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.

The survey shall include information on all 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 centred on the pipeline route.

The survey work shall be deemed to be complete on receipt of the Engineer'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.

The lines of trenches for all pipelines are to be carefully set out to the alignment of the pipelines. 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.

The trenches shall be excavated to the required line and level as shown on the drawings or as approved by FEWA/Engineer, and shall, at all times, be drained and braced to ensure safe and efficient pipe laying. In locations where services, ruins, or other structures are near the pipeline route, only hand excavation will be permitted.

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.

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/Engineer's approval at intervals not exceeding about 2.0 m to 3.0 m. 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. Pipelines shall not be laid closer than 300mm to other pipelines, services or structures or as directed by FEWA/Engineer.

Excavation in rock shall be made to provide a minimum of 150mm clearance on each side of and below all pipes or fittings, any hard excavation must be carried out by hand.

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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 required depth including shoring, strutting, dewatering, leveling etc. The Contractor will also cut and fill the ground as required necessary, which includes making a service, duly compacted track, along the pipeline route, to make the ground formation even, to facilitate the laying 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 made as per BOQ.

The Contractor must estimate for himself the proper price for completing the whole job irrespective of difficulties met in excavations. No additional payment shall be made for the cost on account of this article.

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.

b) Grading of Pipeline Route:

The Contractor has to grade the pipeline route, as required, and is responsible for necessary cutting and filling in any type of soil. The cost for cutting, grading and filling shall be borne by the contractor, even if not included in the BOQ

Estimation for cutting and filling shall be done, according to AUTOCAD programme, submitted by the Contractor and verified by FEWA.

c) Timbering of Pipe Trenches

Where necessary, the Contractor shall support the sides of the pipeline trench and other excavation by suitable timbering so as to ensure the safety of workmen and freedom from damage of any structures or services that may be affected and to secure the excavations from falling in and to prevent any movement, and shall securely prop and stay any bridges, buildings, walls, sewers, culverts, drains, water mains, electric cables etc. The trench sides shall be close timbered, wherever FEWA/Engineer may so desire. Ordinarily timber shall be removed as the work proceeds and the trenches filled up after due test, but it may be necessary in certain cases to leave a certain portion of the timbering in the ground. No extra payment shall be made for any of such works.

The kind, quality and dimension of the timber used shall at all times be subjected to the approval of FEWA/Engineer. The Contractor shall furnish and maintain such planking, poling boards and wooden braces or struts as may be required to support the sides of excavation and to prevent any movement of the ground. FEWA/Engineer may order additional supports to be put in at the expense of the Contractor and the compliance with such orders will not relieve the Contractor of his responsibility for the sufficiency or otherwise of such supports.

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Great care shall be taken to prevent voids occurring outside the poling boards but if voids are formed they shall be immediately filled and rammed to the satisfaction of the Engineer. 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.

d) Removal of Timber

The operation connected with the removal of timbering shall not endanger the pipelines already laid and surrounding structures, buildings or property whether public or private.

The right of FEWA/Engineer to order poling boards and struts, etc., to be left in place shall not be constructed as creating any obligation on his part to issue such orders but the non-exercise of his right to do so shall not relieve the contractor, from any liability in respect of damage to persons or property occurring from or upon the work of laying the pipelines, occasioned by negligence or otherwise arising out of a failure on the part of the Contractor to leave in place in the trench sufficient timbering to prevent any caving in or moving of the ground adjacent to the trench.

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.

e) Shoring up of Building

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. 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.

f) Opening out Trenches

While excavating the trenches, the road metal, bricks, soling material, tiles, kerbstones, turf etc. shall be placed on the side and shall be preserved for reinstatement when the trench is filled up. Extra care shall be taken when trench is to be excavated through private property.Cutting of any fence or trees etc. in line of trench remains the responsibility of the contractor and shall be done only with the approval of FEWA/Engineer and concerned authorities. The cost on account of this article shall be included by the tenderer in the price for 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.

g) Removal of Water from Pipe Trenches The Contractor shall provide and carry out as part of the Contract all pumping, bailing out

or removing of water accumulated in the trench during the execution of work in such a manner as will neither cause hindrance or nuisance to the public nor to private property and no extra amount shall be payable for such works.

If the pipeline or other works have to be executed below underground water level, the trenches and excavation shall be kept dry during excavation, compaction, laying and jointing the pipeline and during testing of the pipeline employing well point dewatering system. Pipe laying, testing etc. shall not be allowed unless the trench is dry.

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The cost of dewatering and timbering required for such works shall be borne by the Contractor, even if not included in the BOQ. No additional payment therefore shall be made for the cost on account of this article, even if not included in the BOQ..

h) Width of Trenches

The width of trenches is shown in the drawings. Any excavation not done according to the above drawings may be rejected.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.Nominal trench widths for single pipelines shall be defined as 1.50 times the diameter plus 300 mm subject to a minimum trench width as given below. Nominal trench widths for two or more pipes in the same trench (laid in parallel with similar invert levels shall be defined as the sum of the internal diameters plus 450 mm between the pipes, plus 450 mm.

Any excavation from the bottom of the trench to 300 mm above the level of the crown of the pipe which exceeds the nominal widths shall be filled with concrete, or the specified bedding material as directed at site. In all cases the trench shall be excavated sufficiently wide to ensure efficient laying and jointing of the pipes.

i) Depth of Trenches

The trenches shall be dug to a depth so that 25 cm sand bedding can be provided under the pipeline and the normal cover shall be 90cms. for pipe of up to 300 mm. dia. and 110 cm for pipes above 300 mm. and up to 600 mm. dia. And 150cm for pipes above dia. 600 mm according to site conditions and FEWA /Engineer’s instructions or more above the top of the pipe. In sandy areas 25 cm depth for sand bedding shall not be required.

The bottom of the trench shall be properly trimmed off to present a perfectly plane surface and irregularities shall be leveled.The Contractor shall lay pipe in straight lines in horizontal and vertical planes.

In the hills and hard formations also the depth shall normally be 90 cm and in no case shall be less than 85 cm unless for any special reason, the FEWA/Engineer may approve otherwise.

The cost on account of extra depth (if any) involved for keeping the pipes straight in horizontal and vertical plane or for making connection with existing works or for avoiding interference with the existing services, structures or to get the proposed grading ground land profile…etc. shall be considered to have been included in the rate for excavation of the trenches.No angle, more than as specified in B.S.S., ISO, or manufacturer's catalogue shall be allowed between two pipes.

Where gate valves, butterfly valves, hydrants, air valves, etc. are to be fixed the depth shall be such as to leave the top of spindle caps not less than 150 mm. nor more than 500 mm. below the surface of the road, or underside of M.H. top slab. In case, the Contractor excavates any trench in good ground to a greater depth, the extra depth will have to be filled up at the contractor's expense, with such material as the Engineer may direct.

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j) Methods of Excavation

Wherever practicable, mechanical excavation methods are to be used, except where such methods may cause damage to existing structures, services, ruins or relics.In these locations the Contractor may only use manual methods. 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 so placed as to avoid any danger or hindrance to others.

k) Common Trench

Where pipes follow similar routes and levels the Contractor may require to lay more than one pipe in the common trench. The method of laying will only be adopted as instructed by FEWA/ Engineer and as shown in the standard drawing.

3.2 Pipe Handling, Laying, Jointing

a) Handling and Storing In case AC pipes are supplied by FEWA, the Contractor should note that all pipes, fittings, valves, etc. available at various FEWA stores, are in good condition. Hence the Contractor has to check the same for any defects, damages, corrosion, etc. prior to taking over from the respective store. The contractor shall transport all pipes, fittings, valves, etc, from FEWA stores to the different sites and restore the same at the site.Any defects, damages, corrosion, etc noticed after the taking over, the Contractor is responsible for the same, including repair, replacement, etc.

Special care shall be taken to avoid any damage during transporting, loading and off – loading, storage, etc.Pipes may be stored in the open, however they shall be stacked off the ground on 150 x 100 mm timber skids to be provided by the Contractor, and then the stacking shall be done according to the Manufacturer's recommendations.

The storage surface should be as level and as firm as possible and clear of rocks or solid objects that might damage the pipes. The stockpiles should not exceed a certain height.Asbestos cement coupling rings shall be stored lying flat and particular care shall be taken to prevent damage to the internal face of the ring or the turned ends of the pipes which may affect the sealing of the coupling.

Storing of pipe along side trenches shall be done only for the shortest time possible before placing into the trench.Pipes delivered to the site shall be stacked along the route at suitable spacing to suit construction requirements. Pipe stringing shall not be allowed.

Rubber sealer rings and gaskets fixing materials, instruments, valves, fittings, and such other material shall be stored in dry dark place properly ventilated indoor storage covered shed or yard, away from grease, oil and sunlight until required. It shall be withdrawn from storage and delivered to the site to suit the daily construction requirements.

Pliable straps, slings or ropes shall be used to lift pipes.All handling shall be done with slings fitted with padded hooks.Pipe hooks, chains or steel wires shall not be used. No pipe shall be moved by rolling.

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The provision and correct usage of broad band slings is particularly important for the lowering of pipes into the trench. Non metallic sling must be used for the handling of pipes and fittings.

The Contractor shall take the utmost care to prevent any damage to the pipes and fittings during lowering-in, alignment, jointing and final removal of the lifting sling.Pipes shall be finally inspected after laying and any damaged spots found shall be repaired to the entire satisfaction of FEWA/Engineer.

Loading onto rail cars, trucks, or other conveyances shall be done in accordance with API Recommended Practice 5L1 & 5L5 as applicable and as approved by FEWA.Suitable timber shall be used to protect the pipes against damage in transit. Rail cars, trucks, or other conveyances shall, prior to loading, be cleaned of debris or any other substance that might damage to pipes. The Contractor’s attention is drawn to the requirement of traffic regulations regarding the gross weight of loaded trailers, which is allowed on different roads, and the requirements of special permits, which may be required by the local authorities.

The number and location of storage areas at the site shall be selected and made available by Contractor to ensure proper flow of construction activities and shall be subject to approval of FEWA/Engineer and respective authorities.

Temporary packing, coverings or crates provided by suppliers for the protection of pipes material shall not be removed (except for purpose of inspection and installation).

Any pipe or fitting which is rejected by shall be FEWA/Engineer 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 FEWA/Engineer.

b) Laying

Pipes shall be laid and jointed in accordance with all relevant recommendations of the Manufacturer.Pipes shall be checked for soundness and be thoroughly cleaned out immediately prior to laying.

The pipes are to be lowered in dry trenches. Wherever poor soils which are liable for uneven settlements are encountered pipes may be lowered and installed on intermediate supports made of concrete saddles, granular beds or other proprietary arrangements in the approved method statements which shall follow the recommendations of the Manufacturer.Manual and mechanical tools and hoist for lifting and lowering of pipes are to be used for allowing smooth and continuous moving.

Before the pipe is lowered in the trench, the suitability of the material in the trench bottom shall be approved by FEWA/ Engineer.Additional excavations shall be carried out to provide extra space around couplings/joints. The trench bottom shall be free from stones and other sharp objects, which might damage the pipes. Before laying the pipe, the trench bottom shall be sufficiently compacted.

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During connection of pipe sections, the contact surfaces carrying sealing compounds shall be kept clean; all open ends for later connections shall be closed to avoid soil or other contamination entering into the bores.

All pipes shall be laid and maintained to the agreed alignments and grades ensuring that the pipe is properly bedded along its whole length.

Fittings and valves shall be provided at the required & FEWA approved locations. No deviation shall be made from the agreed alignment or grade except with the written consent of the Engineer. The permission to lay pipe will not be given in case the trench is not dewatered by employing dewatering equipment as described earlier.The trench shall be kept dry till the pipe is tested and backfilled. Before stopping the dewatering pumps the completed pipe should be plugged water tight so that the sub soil water do not seep into it.

All the pipes, fittings, valves etc. shall be carefully lowered into the trench using (winch) cranes and suitable nylon slings and equipments generally in accordance with manufacturers instructions in a manner that will prevent damage.

The pipe shall be continuously supported evenly on its full length. Care shall be taken to ensure that the pipes do not bear on the couplings and position of coupling shall be excavated/prepared such that bedding material is at least 50mm lower locally below the coupling. The pipes and couplings shall be carefully inspected before joints are made. The grooves of the coupling shall be carefully cleaned and rubber ring inserted.The rubber ring shall be fitted correctly.The pipes and couplings shall be carefully inspected before joints are made.The grooves of the coupling shall be carefully cleaned and rubber ring inserted.The coupling shall be lubricated using non-acid soft soap or other similar products and mounted on the pipes using friction and lever type pullers or crowbar and strap for small diameter pipes as recommended by the manufacturer.

Steel strap shall be fixed near the free end of the pipe prior to insertion in the coupling.The ends of the pipes and rubber rings shall be thoroughly cleaned and lubricated immediately prior to assembly. The lubricant for AC Pipes & GRP Fittings shall be of an approved type recommended by the manufacturer and approved by FEWA/Engineer for this purpose.

After assembly, the position of the sealing rings shall be checked, and where found unsatisfactory, the pipe shall be uncoupled and reinstalled using new rubber seal correctly placed. Under no circumstances shall a rubber ring be used twice and the contractor shall supply the second rubber ring on his own cost.

The pipe shall be pulled in the coupling using method as adopted for mounting coupling. The work of installing pipe joints shall be carefully supervised to ensure that joints are made with proper gaps between the pipe ends for expansion and movements of pipes.Direct contact between steel tools and pipe edges at any stage of pipe laying works shall not be permitted.

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After laying a length of pipeline but before preliminary testing is carried out, the pipeline shall be checked for level and gradient on top of the pipes. If a pipe is not at the correct level it shall be unjointed and removed, the bed shall be adjusted and the pipe shall be relaid and rechecked for line and level.

After the joint has been made and the preliminary testing completed the annular gap at the coupling outside the rubber ring shall be closed with cotton waste or other flexible material to prevent the entry of granular material/sands.

Unless otherwise instructed by FEWA/ Engineer, all valves, washouts, air release valves, fire hydrants, water meters, non-return valves shall be enclosed in a manhole in accordance with the relevant Tender Drawings.

The Contractor shall take every precaution to ensure that stones, earth or any other foreign matter do not enter the pipes during construction and interfere with the operation of the valves.

The Contractor shall not backfill any portion of the trench until and unless FEWA/ Engineer certifies in writing that the pipes are successfully tested as per specifications.

No pipeline or part thereof shall be covered up until, it has been inspected by the FEWA/Engineer or his representative but such inspection shall not relieve the contractor from his obligation.

Where it is necessary to shorten any pipe it shall be cut off squarely by an approved method without damage to pipe or lining. Cut ends shall be prepared for reuse as recommended by the pipe manufacturer including touching up or remaking of internal lining or external coating to provide equivalent degrees of protection.

Where directed the Contractor shall lay two or more pipelines in the same trench excavation as per the tender drawings. Unless otherwise directed the pipes shall be laid such that the projected horizontal distance between the outsides of the pipe barrels is not less than 250mm. Where two or more pipes are laid beneath carriageways and concrete surround is used each pipe shall have separate surround, subject to FEWA approval. With permission of the Engineer, the Contractor may use vertical diaphragms to separate the runs of concrete surround.

All pipes shall be laid to required straight lines or to regular curves Where flexibly jointed pipes are laid to curves the horizontal displacement at any joint as laid shall not exceed three quarters of the maximum allowed by the manufacturer. Shorter length of pipes may be used for form curves, if required. Where pipes are pulled to produce a regular curve, care shall be taken to ensure that the following tolerances for deflections are not exceeded.

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All bends and stop ends shall be securely anchored by concrete support placed between the bend or stop end and the solid undisturbed vertical face of the trench.

The concrete support shall be as detailed under ‘’Std. thrust blocks’’ in the tender drawings for dia upto DN 600 mm. For higher diameter pipe, the contractor shall design the thrust block and submit to FEWA for approval according to site conditions. Concrete thrust blocks of at least the dimensions shown on the drawings shall be placed at all bends, tees and tapers on the mains. Should poor ground conditions be encountered or for any reason the block cannot be constructed then the Contractor shall immediately inform the Engineer who shall determine the procedure to be adopted. Cut pipes shall have ends turned chamfered.

c) Sand Bedding

Where pipes are to be bedded directly on the trench bottom in rocky and hard soils , pipes and fittings must be laid on a layer of fine sand bed, 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 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 sand must be such that 100% passes through BS sieve No. 16 (1.00 mm) and not more than 50% pass through BS sieve No. 100 (0.152 mm). The depth of trench therefore shall be such that 25 cm of sand bed is provided below the pipe and the normal cover above the pipe is also not less than 90 cm for up to 300 mm dia. and 110 cm for pipes above 300 mm and up to including 600 mm dia. and 1500 mm for pipes above dia. 600 mm according to site conditions and FEWA Engineer’s instructions. Joint holes at each pipe joint shall be scooped away in the trench bottom to enable the joint to be made.Pipeline in sandy areas, where in the opinion of the Engineer, the excavated material is suitable for bedding and filling on sides and top, the extra excavation for sand bedding shall not be carried out. In such cases the pipes shall be laid after levelling and compacting the trench bottom and removing stones and other sharp objects. The excavated material shall be used for filling on sides and top.The contractor in this instance shall neither be paid for sand bedding nor for sand filling on sides and top. He shall only be paid for the item of backfilling.

Type of pipe & joint Nominal Diameter (mm)

Max. Joint Deflection Angle (Degree)

AC. Pipes “ Reka -Coupling Up to 200 5º

250 -300 4º

400 -500 3º

600-1000 1º

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d) Pipelines in Concrete Cradles and Surrounds Where pipes are to be laid with a concrete cradle or surround they shall be supported initially above the trench bottom on concrete setting blocks.The blocks shall either be laid accurately to level and covered with damp-proof sheeting beneath the pipe barrel or shall be provided with two hardwood wedges each to an approved pattern to enable the pipe level to be adjusted. The blocks and wedges shall be of sufficient size and strength to prevent settlement of the pipes during laying and at least two concrete blocks shall be provided for each pipe.The concrete shall be poured on one side of the pipe until it can be worked under the pipe along its full length to ensure that no voids develop. The concrete shall then be brought up equally on both sides of the pipe until the required level is reached.Approved measures appropriate to the pipe material shall be taken to prevent flotation or other movement during placement or curing of the concrete. Concrete cradles to pipes of all diameters and surrounds to pipes of one metre diameter or less shall be poured in a single operation. Concrete surrounds to pipes over one metre diameter shall normally be poured in two lifts, with a horizontal joint not more than 100 mm below the crown of the pipe. Concrete shall be prevented from entering pipe joints. Concrete cradles and surrounds shall be interrupted over their full cross sectional area at each pipe joint, by shaped expansion joint filler. The thickness of filler shall be 18 mm for pipe diameters less than 450, 36 mm for pipe diameters 450 to 1200 and 54 mm for pipe diameters greater than 1200.

Wherever practicable the placing and compaction of the surround material shall be carried out in sequence with the removal of the trench supports.In particular trench sheets or boards shall be raised clear of each layer prior to its compaction.

e) Pipelines on Granular Beds

Where granular bedding to pipelines are required the minimum thickness of bedding material beneath the pipe shall be: 150 mm (minimum 100 mm under sockets/couplings) for pipes not exceeding 300 mminternal diameter except when bedded on rock. 200 mm (minimum 100 mm under sockets) for pipes exceeding 300 mm internal diameter or for pipes of 300 mm internal diameter or less when bedded on rock. Pipe bedding material shall not contain more than 0.3 percent sulphate, expressed as sulphur trioxide.The bedding material to be sand or granular material free of stones any ashes, cinders, organic matter or other corrosive materials.Granular material for pipe laying shall be free draining, hard, clean, chemically stable and of maximum size of 3mm. The time interval between placing bedding material on the trench formation and commencing pipe laying shall be as short as is practicableThe bedding material shall be moisture conditioned to +2% of optimum and shall be compacted in layers not exceeding 150 mm to a density of not less than 95% of the maximum dry density.

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Hand tamping or punning will only be permitted where insufficient space is available to allow the use of mechanical plant.Recesses shall be formed in the bedding to accommodate pipe joints while ensuring continuous even support along the pipe length. Bedding material shall be prevented from entering pipe joints. After the joint has been made bedding material shall be carefully placed and hand compacted beneath the joint barrel to close any void left by the recess.

f) Pipe Laying above ground

There may be unavoidable situations when the pipeline may have to lay above the ground. There can be two different cases in this section. One is pipe laying on level ground and the other is pipe laying on steep incline. In both cases, concrete pedestals have to be designed for fixing the pipes at each joint of pipe as per standards. The pedestals must be placed behind a socket with a saddle and a fixing clamp with rubber lining. Also, the expansion factor of the pipe should also be considered. The clamps are of galvanized steel (painted) and all bolts and fixings must be stainless steel. Also, nominal reinforcement and concrete protection shall also be considered for pedestals.

4. BACKFILLING OF PIPELINES

After completing of placement and compaction of the surrounds to the pipelines backfilling shall proceed using selected excavated materials in accordance with the relevant specifications.The use of power rammers will not be permitted over any pipe until the depth of fill above the crown of the pipe is at least 300 mm.

The Contractor shall backfill the pipes as follows :

The backfilling material shall be brought upto both sides of the pipe first to the level of thecentre of the pipeline and then to height of 300 mm above the top of the pipe barrel.This backfill material shall be placed in layers each not more than 150 mm thickness and shall be carefully compacted for the full width of the trench to the satisfaction of FEWA/Engineer.

Under the Road, Parking Areas and Footpaths Backfill shall be in layers of thickness not exceeding 150 mm.Backfill shall have a minimum soaked CBR of 15% (BS 1377) and compacted to not less than 95% of the maximum dry density as determined by BS 1377. Backfill within 300 mm of road subgrade level shall meet the requirements of improved subgrade as per approval of FEWA/Engineer.

Outside the Road Backfill shall be in layers of thickness not exceeding 250 mm compacted carefully to aminimum of 90% maximum Dry Density to the finished ground level.In order to prevent stones and soil from entering the pipe, a suitable cap and or plug shall be provided with which the last pipe laid shall be closed when pipelaying is not actually inprogress. The plug shall be of the screw up expanding type or of tapered wood.Where the cover to pipes is less than 1.0 m or where ordered by FEWA/Engineer, protection in the form of concrete slabs above the pipe shall be provided according to anapproved drawing by FEWA/Engineer.

5. ANCHOR AND THRUST BLOCKS

Anchor/Thrust blocks shall be provided for all tees, bends, reducers and end caps on pipelines of all diameters. Anchor and thrust blocks shall be designed to withstand the forces resulting from internal pressure when the pipeline is under test pressure to satisfy the criteria of:

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a) Stability against sliding. b) Stability against overturning. c) Bearing pressures within allowable limits as to avoid overstressing of founding soil. d) Structural capacity of reinforced concrete sufficient to resist the applied forces at the ultimate limit state conditions.

The thrust blocks shall be designed by the Contractor in accordance with BS 8110.The contractor has to submit the detailed calculation for the design of the thrust block for FEWA/Engineer’s approval.Also, the Contractor has to design the thrust block, considering the site conditions and provision of space for existing and future services.

For dia. of pipes above DN 600 mm, the cost for thrust block for all tees, bends, reducers and end caps shall include design, soil investigation, extra excavation, extra backfilling, concrete, bitumen painting, polyethylene sheet, etc.

Thrust blocks shall be constructed such that the joints, including bolts will be accessible. They shall be placed along the line of the resultant of the forces acting on the pipe.

The concrete used for thrust blocks shall be grade 20 (Roughly corresponding to 1:1-1/2: 3) and cement shall be sulphate-resisting cement. The thrust blocks shall be painted with two coats of approved bituminous paint.

Thrust/anchor blocks for various pipe diameters and fittings shall be constructed in accordance with the tender drawings and the timber shuttering shall be used.Straps and bolts if used in anchor / thrust blocks shall be of Stainless Steel Grade 316.Before any internal pressure is applied to a pipeline, all the permanent concrete thrust blocks shall have been cast in contact with the undisturbed ground and cured for a minimum of 7 days.For drag anchors the joints may be embedded in the block. Furthermore, the thrust blocks are to be placed against undisturbed soil. Whenever possible, recesses to form shear keys for thrust blocks shall be excavated vertically or near vertically. In such cases concrete shall be poured directly against the side walls of the excavation. Where conditions are deemed to make this impossible, wood shuttering may be used. Wood shuttering, however, shall be removed after the concrete has sufficiently hardened. Any space between the block and the excavation shall be filled with approved fill material and thoroughly compacted.

Filling shall be done in layers not exceeding 300 mm after which the soil shall be compacted by using explosion or other approved compactors.The thrust blocks shall be constructed on a 100 mm blinding layer of unreinforced concrete.

Before pouring of concrete for the line anchors, the wrapping tape protecting the pipes shall be removed in the vicinity of the block and be properly reinstalled at the anchor block pipe inlet before backfilling. Necessary recesses, sleeves, or other provisions shall be applied for leading cables, small pipelines or other services through, which are located adjacent to the pipeline and which are not be relocated.

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6. VALVE CHAMBERS Gate valve, butterfly valve, washout, air valve, fire hydrant, water meter, electromagnetic flow meter, non-return valve etc., shall be installed in RCC valve chambers constructed in accordance with the drawings supplied with the Tender documents.

The fire hydrant fitting and the air release valves shall be mounted on completed pipe work with flanged connections. Stainless steel bolts and CAF gaskets to BS 1560 shall be used. The bolts shall be tightened with torque wrenches. The connection of sluice valves shall be with flexible 'Reka' Couplings. All precautions and instruction stipulated by the manufacturer shall be followed. The installations shall follow the requirements of BS 6683.

The ductile cast iron access manhole cover and frame for valve chamber to be supplied by the contractor shall be 600 mm. circular or square, heavy duty. In case the cover is square, it shall be in two triangular parts. The access cover shall be located in a corner of chamber/above steps, to facilitate the lineman to go down in to the chamber and operate the valve. The access manhole cover and frame shall comply with BSEN 124: 1994 class-D 400. Covers to air valve chambers shall be ventilated unless vent pipes are detailed. Surface Box shall be 150mm circular complying to BSEN 124 – 1994 class D400.

Casting shall be smooth, true to pattern and free from projections, sand holes, blowholes or other distortions. Covers and frames shall be grit blasted and coated with suitable heavy-duty abrasion resistant epoxy paint to minimum dry film thickness (DFT) of 400 microns in black colour. iron steps shall be set into the wall of the chamber for access into the chamber. iron steps shall be either galvanized steel or stainless steel complying to BS 1247-1-1990 or plastic encapsulated iron steps comply to BS 1247-2-1990 or corrosion protected ductile cast iron. Steps should be minimum 125 mm long away from the wall with minimum 150mm overall width.

The covers are to clearly have the BS No. / class / manufacturer’s name and FEWA Name cast thereon.Waterproofing for all chambers shall be torque applied membrane with production, with prior approval from FEWA/Engineer.

Waterproofing for all thrust blocks and other concrete membranes, shall be two coats of approved bituminous paint.In AC pipelines, the gap between the sleeve and pipe is to be filled with polyurethane foam and sealed on both sides of wall with polysulphide sealant, whereas in DI. Pipelines the wall concrete can be casted directly to the pipe barrel.The joint between two panels of cover slab is also to be sealed with an approved sealant.

Normally a separate chamber shall be provided for each valve, meter etc. But as per site conditions, in some cases, it could be feasible/economical or necessary to provide combined chamber for two or more valves, meters etc. In such cases combined chamber may be provided, in consultation with FEWA/Engineer. In such cases, size, location and number of chamber access cover(s) etc. shall be finalized in consultation with the FEWA/Engineer.

7. PROTECTION OF PIPELINE COMPONENTS

All buried valves, couplings, flange adaptors, and other metal components shall be encased to guard against corrosion. Other pipe joints, valves and similar items on both buried and exposed pipelines shall be encased where specified or shown on the drawings. The encasing shall be by one of the following methods, as detailed.

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1) Surrounding with Grade 20 concrete. 2) Enclosed by an approved hot-poured bitumen compound. 3) Wrapped with tape.

The item to be encased shall first be dry, cleaned and its original surface treatment made good.The surface encasing shall be carried out before the pipeline has been tested.The bitumen compound shall be cast in purpose-built moulds in accordance with instructions issued by the supplier.

Before wrapping with tape the item to be encased shall be enclosed with an approved mastic or inert putty-like filler which shall be moulded by hand so as to provided a smooth surface for the tape. The tape shall be tightly spirally wrapped with 25 mm overlaps so as to enclose the whole of the item and a minimum of 150 mm of pipe length on each side. The enclosure shall be firmly pressed out to prevent air being trapped under the wrapping.

8. ROAD CROSSINGS

Wherever the route of the pipeline crosses an existing or proposed road, road crossings are to be made.

8.1 Tracks and Proposed Roads

Crossings of known tracks and proposed roads to be built in future shall be made by open cut method and pipeline installed at a minimum depth of 2 metre below road level. The excavation, trench works and pipe laying shall be executed in accordance with this specification except that the trench shall be filled and compacted as follows :

• Soft sand as per specification 4. • Sabka with min CBR of 30% compacted to 98% mpd in accordance with test 13 of BS1377

in layers not exceeding 20 cm. • Pavement restoration similar to original works

The Contractor shall liase with the concerned authorities and obtain their written approval before the road crossing is made. Arrangements shall be made by diversions and road signs as appropriate to prevent stopping of vehicular movement.The works shall be executed as per method statements approved by FEWA/Engineer.

8.2 Asphalt Roads

Cutting of asphalt roads generally will not be permitted. The Contractor shall liaise with FEWA/Engineer and the concerned authority to obtain approvals for the crossing. When approved, road cuttings shall be made following the conditions imposed by FEWA/Engineer/Local Authorities. The road shall be restored to the same specification as the original work. All locations where open cut of asphalt road is not permitted crossings shall be made following the non-destructive thrust/augur boring techniques.

8.3 Encasing at Road Crossing by Open Cut

The Contractor will encase Asbestos Cement pipes, Ductile Iron pipes and GRP pipes in concrete at all places where the proposed pipeline crosses the roads. Asphalt, blocks, tiles,

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grass bed or other surface through which road crossing is passing shall be restored to its original specifications. Encasing shall be as per FEWA's Tender Drawings.

For road crossing, in lieu of encasing, reinforced concrete relief slab could be acceptable for DI. Pipelines according to the site condition and to FEWA/Engineer approval. The relief slab shall be centrally placed not more than half the diameter above the pipe. Slab shall have a 5-10 cm. recess equal to diameter of the pipe, which shall be filled with synthetic foam or such other compressible material. Width of slab as a minimum shall be pipe diameter plus 50 cm. on either side and minimum thickness shall be 20cm.

8.4 Backfilling of Trenches

After the pipes have been laid, jointed and tested and proved to be water tight, the trenches shall be refilled in the manner described below after taking written permission of FEWA/Engineer.The first 25 cm of filling material immediately above the top of pipeline and on the sides of pipe shall consist of fine sand. No lumps of material shall be put around the pipe or thrown into the trench until the same has been protected in the manner described above. If the excavated material is found suitable for this 25 cm filling, FEWA/ Engineer may ask to use the same and the contractor shall not be paid separately for this item of work. He shall only be paid for backfilling work described in succeeding paragraph.This filling on sides of pipeline and above, the pipes shall be properly compacted. After the first 25 cm of material has been placed in position, the remainder of the depth shall be backfilled with the excavated material and rammed in layers not exceeding 15-25 cm at a time.Sufficient water shall be used to aid the consolidation of the trenches so as to achieve a maximum dry density of 90%. The top 30 cms under the sub grade level of the road shall be compacted to achieve a maximum dry density of 95%.The cost of restoration of unpaved surfaces, grass area and other such surfaces to it's original condition and level before the start of work, shall be included in the rate of backfilling. The Contractor shall make compaction test, as required and instructed by FEWA/ Engineer and payment for the same shall be included in the item.

8.5 Restoration of Surfaces

All tiled, interlock block, paved or asphalted surfaces through which the pipe is laid shall be restored in as good condition as before disturbance or the execution of the work.Any deficiency in the filling materials, tiles, blocks etc. resulting from theft, damage, wastage or any other cause whatsoever shall be made good by the Contractor at his own cost and shall be considered included in his rates.In case of roads the operation may be divided in 2 phases to facilitate the immediate resumption of traffic. In the first instance the trenches shall be compacted with hand rollers and the soling laid so that it shall conform to the finished formation level of the road.After further compaction has occurred with movement of traffic, the requisite thickness of road metal shall be provided, compacted and finished with such surface dressing as prescribed.

The soling may be removed and re-laid to accommodate the road metal, etc., if found necessary.

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The thickness and type of asphalting/tiling/paving/base/sub-base material etc. shall be restored to the original specification of the surface before it was disturbed. 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.

8.6 Wadi Crossing 8.6.1 General

Where the proposed pipeline crosses different kinds of wadi. Although the wadis are dry during most of the seasons, during seasonal rains, these wadis could be flooded and hence the contractor has to include in their proposal proper wadi crossing designs. The contractor has to ascertain and include the details of wadi crossings and the price incurred in all respects in the tender.In any case, the wadi crossing must offer full safety and stability for the pipeline that passes across.

8.6.2 Typical Cases a) Type I – Wide Wadi (Buried Crossing Through Wadi Bed)

Where the wadi is very wide (Width of wadi bed more than 6M) the proposed routing of the pipe line can be diverted below the wadi bed, so that the pipeline will be buried below the wadi bed to a required depth. In this case, pipeline coming from a higher elevation will be dropped to a lower elevation by connecting with proper bends and associated fittings. The buried pipes should be protected in all respects from the possible erosion at top. Proper encasing or other protection methods, pitching, etc. have to be proposed by the contractor subject to FEWA/Engineer approval depending upon the type of terrain, surface slope, natural surroundings.FEWA prefers this type of crossing wherever maximum possible.

b) Type II – Narrow wadi with depth between 3M up to 6M (Option for c) (crossing over

viaduct) Where depth of wadi with respect to the overhead pipeline centre is between 3M to 6M and the width of wadi bed is < 6M, proper viaduct type crossing has to be designed.This consists of concrete pillar on individual footings at proper spacing and associated works. The columns shall be in turn connected by pre-cast or cast in situ beams to form viaduct to carry the water pipelines at designed elevation. The exact design and construction method etc. should be furnished by the Contractor during its design. The Contractor must include the cost of every component required for this considering the most economical and stable design. Also, the Contractor must take into consideration the connection details, settlement factors, pipe fixing methods, soil investigation details etc. The whole structure should be of RCC construction with all protection methods. Selection of crossing purely depends on FEWA Engineer’s decision. All precast reinforced concrete of viaduct units shall be made of concrete grade 30 at least and shall comply with the section -1.7 requirements. The surface of reinforced concrete viaduct units shall be obtained directly by concreting without mortar coating, and the resulting surfaces of the concrete shall be perfectly smooth,

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hardened dense concrete without abrupt or gradual irregularities, as offsets, pitting, waviness. The piers shall have variable heights so as to fit in with the pipeline levels required at every spot. The piers shall be inserted into recesses left in the footings and fixed in position and filled in grade 30 concrete. Every pier shall be loaded 7 days after placing the concrete fill.Lifting eyes shall be provided in every reinforced precast concrete unit during pre -casting to enable the units to be conveniently lifted and accurately located in the work. The rates for pipeline crossing wadi over viaduct shall be deemed to cover the cost of all labour and materials in cast in situ / pre casting of RCC members, foundation, waterproofing as required delivery, erecting, supply and laying / fixing the pipes on the viaduct including the required GI. Clamps, fastener bolts, isolating rubber, etc. The measurement for this item shall be for the exposed length of pipe from wadi edge to opposite edge.

c) Type III – Narrow Wadi with Depth Greater than 6M (Option for b): (Crossing Over Pipe Culvert)

Where the depth of wadi with respect to the overhead pipeline is greater than 6M, and also the width of wadi bed is around 6M, pipe culvert of standard design could be adapted. For pipe culverts, proper concrete bedding should be designed, considering possible settlement and other parameters. The selection of No. of pipes should be in such a way that the width of wadi and the catchments area are the deciding factors. In this regard there will be two cases:

Pipe culvert with one pipe

Pipe culvert with two pipes. Usually, pre-cast concrete pipes of 500 mm dia. With minimum wall thickness of 85 mm, well reinforced in both directions to take the bending moment as well as longitudinal stresses have to be selected. The head wall and wing wall must be designed in such a way that the embankment with its natural side slopes is accommodated without sliding or erosion. Proper slope protection, upstream and down stream protection, pitching, etc. are to be considered. Selection of crossing type is at FEWA Engineer’s disposal. Pre-cast concrete pipe which is to be used in culvert construction shall comply with B.S. 5911:Part 3 – Specification for Pipes and Fittings with ogee joint. Pipes with spigot and socket joints to BS. 5911 Part 1 – Specification for Pipes and Fittings with Flexible joints may be used with the approval of FEWA/ Engineer. In this case Class M pipes to be used. The effective lengths of pipes for culverts shall be between 0.5 m to 5.00m inclusive. The Contractor shall inform FEWA/ Engineer of the effective lengths of the pipes that the manufacturer is able to supply in a given nominal size.The cement used in the manufacturer of such pipes shall be sulphate-resisting cement.No admixture shall be included in the concrete without the written approval of FEWA/ Engineer.The fully compacted concrete shall contain not less than 400 kg cement per cu. M. and shall have maximum water – cement ratio of 0.45.

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Steel bars for reinforcement shall be manufactured in accordance with BS 4461 or BS 4449. and the bending dimensions shall comply with BS-4466.Joints for concrete pipes shall be of ordinary ogee type as specified in Clause 15 of BS.5911 Part 3. The joint shall be filled with rubberized bituminous compound and then covered with cement – sand 1 : 1 Mortar reinforced with mesh fabric. All such pipes shall be carefully transported and handled so as to eliminate the risk of damage.Excavation for pipes shall comply generally with the requirements of item 3 of this specification. The formation of the excavation shall be finally trimmed by hand or such other method as the case may be, and well compacted immediately prior to the concrete blinding . A blinding layer of concrete grade 20 shall be laid evenly over the full width of the formation to a minimum thickness of 10 cm and accurately to the required gradient of the finished pipeline. The layer of blinding concrete shall be allowed to set for at least 24 hours before pipe laying commences. Each such pipe shall be laid accurately providing no reverse gradient.The pipe to be laid shall be firmly supported to true line and gradient on precast concrete spacer blocks. The plain concrete bed shall be placed and compacted evenly between the rigid shutters to the required minimum width and thickness of bedding as shown in the tender drawings. After the concrete bed has been cured for not less than 24 hours the remainder of the excavation shall be filled out and well compacted.

8.7 Road Crossing by Non – Disruptive Method (No-Dig Method) 8.7.1 General

Apart from laying the pipeline across the road, by conventional open cut trench method, there is a provision for laying the pipeline across the roads by Directional Drilling/Thrust boring or such other NO-DIG Method.

The factors influencing the actual location could be alignment and route of pipeline, density of traffic, existing services, congestion and other such site conditions.

The Engineer may instruct the contractor to lay the pipeline by open cut trench method instead of boring or vice versa, depending on site conditions and local body's requirements. The Contractor shall employ a specialist Sub-Contractor approved by FEWA/Engineer.The Contractor shall decide which technique shall be used, based on the length of the crossing, the soil conditions, the location, etc. and include the same in a method statement for each NDRC to be submitted for approval by FEWA/Engineer.

The method statement shall consider the following matters :

The material and the thickness of the casing pipe shall be sufficient to provide the axial strength required to withstand the forces encountered during the jacking operation.

Wherever possible NDRC shall be at right angles to the road.

The Contractor shall determine the location and depth of all services to be included in the detailed design of the crossing.

The excavation of the pits shall be kept to a minimum, but shall be of sufficient dimensions for satisfactory completion of the work. If so required, bracing and shoring shall be provided to adequately protect the workmen to protect the roadway.

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Excavated material shall be removed immediately and continuously from the conductor pipe as excavation progresses. Method of removal will be at Contractor's selection. No accumulation of excavated material within the conductor pipe shall be permitted.

The Contractor shall design, supply and construct the water pipeline inside the casing pipe. The material of water pipeline and method of construction and joining at both ends with AC pipes shall be as per approval of FEWA/Engineer.

After installation of the water pipeline through the casing, the pipeline shall be tested separately from the rest of the line with a test pressure of 9 bar.

The space between the pipeline and the inside of the casing pipe shall be grouted with sand/cement mixture after separate testing of the firemain.

The grout mixture proposed by the Contractor shall ensure complete filling of the space between jacking and transmission pipes at the whole length between shafts. The mixture is subject to FEWA/Engineer approval.

The Contractor shall enable access to works for inspection purposes as requested by FEWA/Engineer.

The Contractor shall undertake and maintain all necessary security measures during time of operation.

The payment shall be made for actual method by which pipeline is laid and actual length. Further in estimating the quantities it is assumed that for dual carriage way roads, starting point shall be on one side of the road and target point on the other side with boring continuing through central reservation/island.

The drilling /Boring shall be done to it’s approved alignment and level.

While laying the pipeline by Thrust boring method, first casing pipe shall be installed along with boring. The duty pipe shall be laid through the casing pipe. Casing pipeline shall be of welded construction.

The Drilling/boring shall be done to it's approved alignment and levels and the casing shall be free from kink(s), bend(s) etc. In horizontal boring method the duty pipe must pass through the casing pipe, freely without applying any undue pressure. If any Drilling/Boring is found to have kink(s), bend(s) etc. or is out of alignment or level beyond reasonable allowance, such boring shall be rejected.

Such Drilling / Boring shall be rejected and filled with lean concrete and abandoned. It will not be allowed to retract casing pipe from such borings. The Contractor shall not be paid for any of the material, labour or works carried out for such abandoned boring.

A new alignment shall be finalized in consultation with the Municipality and FEWA/Engineer in lieu of the abandoned boring, and the contractor shall drill a new boring as per specifications. In this case, the payments shall be made for lesser length of duty pipe of the two Drillings/Borings i.e. the length if abandoned boring had been successful and the length of the actual successful boring at new location.

The rates quoted for this item in Directional Drilling method shall include all expenses involved for completing the work in a professional manner. The cost of mobilization, demobilization, thrust blocks (if needed), start/target pits or trenches, actual boring, supply & installation of HDPE pipe & Stub Flange with steel backing ring, flange x spigot adaptor, cleaning, backfilling,

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reinstating the area to it’s original condition, warning/danger signs, all labour, material and works shall be considered included in the unit rates quoted for this work. The rates quoted for this item in Horizontal Boring method shall include all expenses involved for completing the work in professional manner. The cost of mobilization, demobilization, thrust blocks (if needed), start/target pits or trenches, actual boring, casing and duty pipes, centering the duty pipeline, filling the gap between duty and casing pipe, sealing, cleaning, back filling, reinstating the area to it's original condition, warning/danger signs, all labour, material and works shall be considered included in the unit rates quoted for this work.

8.7.2 Material A) Directional Drilling Method

Duty Pipe The duty pipe shall be of “HDPE” pipes PE 100, SDR 11, PN 16 as specified in Chapter-4 of this specifications. HDPE pipe ends shall be Butt fused with the stub flange.

Length for Payment For the purpose of payment in Directional Drilling Method, the maximum length of the Duty pipe shall be considered as the asphalt road(s) width including central reservation/island plus three meters on either side of edge of asphalt. In other words, the asphalt road(s) width plus central reservation/island plus six meters shall be paid for Drilling & HDPE duty pipe at each crossing. Any additional length done at site or necessitated by the site conditions shall not be considered for the payment. This will be considered included in the rates quoted by the Contractor.

B) Horizontal Boring or Micro-Tunelling Method

Casing Pipe Casing pipe shall be mild steel conforming to ASTM - A 53, Grade A or API - 5L, Grade A or BS 4360, Grade 43 A. The casing pipe shall be of welded construction and welding shall be carried out in accordance with API - 1104-1983 or similar specifications. Each length of pipe shall be legibly marked by rolling, stamping or stenciling to show, the name or brand of manufacturer, the kind of pipe and the specification number to which it conforms. The contractor shall submit the bill of lading and mill certificate showing chemical composition and strength test results, if requested by FEWA/Engineer. Further, if required by FEWA/Engineer the Contractor shall get the quality of steel confirmed by carrying out necessary tests at the local laboratories. The cost of such tests shall be considered included in the tenderer's quoted price for the work

The casing pipe's internal diameter shall be at least 300 mm. more than the outside diameter of duty pipe and it's joints, which is passing through the casing.The boring diameter shall be determined considering the outside diameter of casing pipe. The casing pipe shall be designed to withstand the external pressure under the heavy road traffic conditions.Assuming that the minimum ground cover above the casing pipe under the road shall be maintained to 135 cms., the minimum wall thickness for casing pipe shall be the following :

For pipes up to and including 450 mm. diameter (18 inch), the wall thickness shall be 6.35 mm. (0.25 inch) and for pipes from 450 mm dia. to and including 750 mm. dia. (30 inch), the thickness shall be 7.92 mm. (0.312 inch).

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The inside and outside of casing pipe shall be sandblasted to Sa 2-1/2 and coated with anti-corrosive bituminous paint. The coating shall be applied in two or three coats and total thickness shall be about 2 x 150 microns. The coating shall be applied as recommended by the manufacturer. If the primer is recommended by the manufacturer, then the blast cleaned surface shall be first applied with the recommended primer and then the coating as specified above shall be applied.

Duty Pipe The duty pipe shall be designed to withstand the internal hydrostatic test pressure specified elsewhere for pipes.The duty pipe shall be of GRP as specified in, chapter-4 of this specifications and laid central to the casing pipe i.e. the space all around duty pipe shall be uniform. To achieve this, suitable spacer blocks or pads shall be fixed on all sides of the pipe.

The duty pipe shall be in one piece or reinforced overlay joint type as per site requirement and joint shall be suitably wrapped in accordance with the manufacturer's recommendations before placing in the casing pipe. The duty pipe (at each crossing) shall have spigot at both ends to make connection by couplings with AC pipe/GRP fitting as the case may be. Cost of coupling at each end shall be considered included in duty pie.

After laying the duty pipeline, the annular space between the casing and duty pipe shall be grouted with approved mix design through it's length having water cement ratio about 0.90. Care shall be taken to ensure that grout fills the gap all through the length. At both ends the mortar shall be neatly finished and sealed suitably. Cost of grouting shall be considered to be included in the rates quoted by the Contractor.

Ductile iron pipes, the method for crossing shall be horizontal boring only and the duty pipe shall be carbon steel schedule 40, with internal cement lining inside and external wrapping by “SERWIWRAP” or equivalent, with an overlap of 55%.Both the ends of the pipe shall be flanged and the rating shall be according to BOQ.

Length for Payment For the purpose of payment in case of horizontal boring method, the maximum length of the Duty pipe including boring & casing pipe shall be considered as the asphalt road(s) width including central reservation/island plus three meters on either side of edge of asphalt. In other words, the asphalt road(s) width plus central reservation/island plus six meters shall be paid for horizontal boring, casing pipe & GRP duty pipe at each crossing. Any additional length done at site or necessitated by the site conditions shall not be considered for the payment. This will be considered included in the rates quoted by the Contractor.

9. PIPES PROTRUDING FROM STRUCTURES, CONCRETE SURROUNDS AND ANCHOR

BLOCKS Unless otherwise detailed a pipeline at or below ground level protruding from a structure shall have two flexible joints adjacent to the structure.Method statements may propose that the first joint be formed by building an appropriate sleeve, collar or coupling into the wall of the structure. Where such a detail is proposed the sleeve, collar or coupling must be capable of maintaining an effective seal under the specified deflection and loading conditions specified for flexible joints in the specifications.

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Between the structure and the first joint any disturbed ground below the pipe will be removed and replaced with concrete in the form of a cradle, all to the direction of FEWA/Engineer.The cradle shall not extent beyond the first joint. Beyond the first flexible joint within the excavated working space of the structure the concrete fill shall be brought up 300 mm below the pipe invert only. Specified bedding materials will then be used.

10. TESTING OF THE PIPELINE 10.1 Field Pressure Test

The arrangements for field pressure testing of pipeline shall be made in accordance with ISO 4483 subject to the provisions of this specification. The Contractor shall submit a detailed statement for hydrotest for FEWA/Engineer's approval at least 4 weeks ahead of programme for testing.The Contractor shall provide written notice to FEWA/Engineer of any tests two days before the test is to be carried out. All tests must be witnessed by FEWA/Engineer.

The Contractor shall maintain written records of the tests and provide copies of the recordsto FEWA/Engineer prior to the completion of the project.The Contractor shall provide all, water, fittings, pipe stoppers, test pump, pressure gauges and the necessary equipment and tools for pipework testing.Hydraulic pumps, gauges and apparatus shall be equipped with locking devices to prevent tampering during the test period.

Prior to hydraulically testing the pipelines the Contractor shall provide adequate temporary thrust blocks at the ends of uncompleted sections.Pipes shall be partially backfilled to about 500 mm above the crown of the pipe, in order to anchor the pipes during testing. The backfill shall be placed so that the internal pressure will not give rise to any transverse or vertical displacement of the pipe. Joints and fittings, however, shall remain uncovered for inspection until the pipeline has been tested satisfactorily. All permanent anchors shall be installed before the test, where concrete anchors are used concrete shall attain an age of minimum 7 days before commencement of test.The pressure testing shall be carried out in a single operation on individual test sections.Valves shall not be used to isolate sections forming the pipeline whilst testing operation are in progress.The water shall be introduced at the lowest point of the test section and air vents kept open until all air has escaped. At every high point an automatic air release valve must be installed. After expelling all the entrapped air out of the test portion, all air release valves should be closed. If it is not possible to fill the line from the lowest point an additional outlet should be added at the inlet point to release air at that point and this line/section should be kept filled for 24 hours before the pressure test.Expected losses due to absorption shall be as specified by the pipe manufacturer.The pipework, joints and connections shall be examined.

AC. Pipeline

After laying the pipeline in the trench as specified above, it must be tested with the fittings, valves etc. in sections of about 500 meters or as directed by FEWA/ Engineer or as dictated by site conditions, at a time, with a pressure testing pump.

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The section of the pipeline to be tested shall be filled with water at a rate sufficiently slow to ensure that all air is expelled.After having been filled with water, the test section shall stand for an initial period of at least 24 hour under a static pressure of about 3 bar.

Should a failure occur, the procedure of filling and of raising pressure shall be repeated after remedial work has been carried out.After the period of 24 hours the exposed parts of the test section shall be visually inspected. If neither appreciable movement of the pipeline nor any leakage has been found during the aforementioned visual inspection, the section shall be subjected to the actual pressure test.

The pressure shall be gradually raised to 15 bar and be maintained for at least 4 hours.During this test period, additional quantity of water shall be pumped at half-hourly intervals, to make up for water lost in absorption by the pipes. The quantity of make up water pumped each time shall be such as to restore the original test pressure. The quantity of make up water added each time shall be recorded and sum up at the end of the test period. The total quantity of make up water added to maintain the pressure during the whole of this test period shall approximately be as permissible under ISO-4483, 1979.As per this standard the permissible quantity of make up water for 100 mm dia A.C. pipeline, for 100 meter length is 3.67 liters. For other diameters (d mm) the permissible make up water (n) is as follows.

n" in liters = d in mm x 3.67 100 If the water added to maintain the test pressure does not vary considerably from the quantities referred above (and as given in ISO-4483), and on visual inspection if no leakages are noticed, then the test shall be considered successful.

The successive measurements of make-up water shall always show a decreasing trend. In case the leakages are noticed in the pipeline or the quantity of make up water far exceeds the permissible limits signifying leakage in pipeline, then the pressure test shall be repeated after rectifying the fault, till it is successful.The tests are to be carried out by the Contractor under the supervision of FEWA/ Engineer.

No backfilling shall be done until and unless a clear certificate in writing is given by FEWA/ Engineer that the pipeline section has been successfully tested.The Contractor shall inform FEWA/Engineer well in advance when testing is to be carried out. The trenches shall be kept dry, by employing dewatering pumps-if required, during the test. The testing shall be done as soon as a stretch of pipeline is completed.

The Contractor shall not be allowed to keep laying the pipeline, without carrying out testing simultaneously. The length of any section shall generally not be greater than 1000m and the section shall be selected by FEWA/ Engineer to suit the site conditions and taking into account local factors such as contour of pipeline, time available before filling of trench, location of permanent concrete anchors and thrust block, etc.

Procedure in Case of Test Failure

If the test fails for any reason, the contractor has to repair the failing parts and the damage caused to the sand bed or trenches if any and then to repeat the test on the whole length on which the test was carried out earlier, as many times till this length passes the test specified above.

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Water for Testing

The Contractor should fill the pipes for testing with water arranged from his own source.

11. DISINFECTION AND FLUSHING OF WATER PIPELINE

Before the pipeline is placed in service, and before issue of the Provisional Acceptance Certificate by FEWA/Engineer, all pipelines shall be disinfected and flushed as per AWWA C651 or as directed by FEWA/Engineer. The pipelines shall normally be disinfected at the same time as the hydrostatic tests performed or as directed by FEWA/Engineer.

11.1 Method Statement

Contractor shall prepare a detailed Method Statement (MS) for disinfection. This MS shall describe in detail how the Contractor proposes to perform the various disinfection and flushing activities to ensure compliance with the requirements as set in this Specification and applicable Codes and Standards, as well as with all requirements as set forward by the relevant Authorities.

11.2 Sterilization

Pipeline should be sterilized by introducing water with a chlorine dose of 30 to 50 mg/I (30 to 50 ppm). The chlorine dose shall be obtained from a chloral solution or other suitable solution to be approved by FEWA/Engineer.

After standing for 12 hours to 24 hours the water should be tested for residual chlorine to ensure that satisfactory sterilization has been achieved.

Samples taken from the pipeline during disinfection at locations directed by FEWA/Engineer shall be checked to ensure that the sterilising liquid is present throughout the system and at sufficient concentration. At the end of the 24 hour period at operating pressure the chlorine concentration shall be checked. If there is less than 1 mg/l of free available chlorine in the water, more chloral solution shall be introduced and left for a further 24 hour period after which the free available chlorine concentration shall be checked again. This procedure shall be repeated as necessary until the free available chlorine taken after 24 hours exceeds 1 mg/l for all taken samples.

The hydrostatic test shall not be commenced until this requirement is satisfied. Should the hydrostatic test fail and repair work involve emptying the pipeline then the disinfection and subsequent testing procedures shall be repeated in full at the Contractor's own expense.

It shall be a condition that the water in the existing network at the point of extraction shall register a minimum of 0.4 mg/l of free available chlorine when tested with a site comparator prior to any approval being given to commence flushing.

The bacteriological tests shall be carried out only at the FEWA laboratory at Sharjah. Cost of tests / (and retests if required so) shall be borne by the Contractor. The cost of testing will be charged according to the prevailing FEWA rates and the contractor shall include these in the relevant items of the schedules.

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The pipeline shall not be considered acceptable until faecal coliforms are undetectable in a 100 ml sample, the bacterial count is within approved limits, the recorded total chlorine content is a minimum of 0.2 mg/l and the pH is within acceptable limits.The pH value of water contained in newly constructed cement mortar lined pipes can be significantly higher than acceptable limits. The Contractor should thus make allowance for additional flushing if required, in order to reduce the pH to a value which is acceptable.

If the tests show that a satisfactory drinking water standard has not been achieved, the Contractor shall repeat the disinfection procedure, tests and flushing, all at his own expense, until these requirements are met.

11.3 Flushing

The pipeline shall be washed with potable water and commissioned at working pressure.Potable water may then be used to displace the chlorinated water, but the pipeline shall not be put into the service until bacteriological tests of water delivered at the end of the pipeline show that a satisfactory potable standard has been achieved.Flushing entry and exit points shall be designed to allow a minimum of 1.0m/s water velocity in the main pipeline to remove any sand or other debris. The quantity of flushing water shall be calculated as the equivalent to 3 times the volume of the pipeline to be flushed unless directed otherwise.When FEWA has a water source, close to all the work sites, and allows using it for washing, then the Contractor needs to fix a temporary meter for using this water and the tariff will be charged as per FEWA rules and regulations.However, if there is no FEWA water source nearby, the contractor should arrange the water for flushing by himself. The payment for this item shall be made as mentioned in the Schedule of Quantities and Rates.All temporary connections used during the testing and commissioning procedures should be closed off and securely blanked before pipeline is brought up to full operating pressure.Flushing water shall be discharged via temporary discharge lines to the surrounding open desert area or into the existing storm water system or, if feasible, into road tankers.Discharging of flushing water into the existing storm water system shall be subject to approval of the relevant Authorities.

12. CONNECTIONS TO EXISTING PIPES Where shown on the Drawings or as instructed by FEWA/Engineer, the Contractorshall make connections to existing pipelines. These may be ductile iron, asbestos cement, glass fiber reinforced or some other pipelines to various dimensional standards. The Contractor shall ensure that the materials supplied for the works are wholly suitable and complete for the required connection works.Exact locations for connection to existing works shall be determined from available data and confirmed by trial excavations at the site carried out by the Contractor.

Disturbance of the water supply shall in all cases be kept to an absolute minimum by the adoption of efficient connection procedures.Fully detailed procedures shall be proposed two weeks in advance of any connection works and shall be modified if required by FEWA/Engineer. No connection shall be carried out without the written approval of a procedure for the specific works to be undertaken.

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The Contractor shall drain existing pipelines after any necessary isolation of such sections. Connections between the new or relocated pipelines shall allow for all transition pieces and adaptors necessary to tie into the existing D.I., A.C., GRP/E or any other pipelines whatever their dimensions.

For connection to existing flanges the Contractorshall ensure compatibility of bolt configurations and provide and fix new gaskets. Spigot ends taken out of service shall be capped or plugged in a manner approved by FEWA/Engineer. Concrete thrust blocks shall be provided wherever necessary as shown on the drawings or as instructed by FEWA/Engineer.

For all works relating to connections, tappings, disconnections and any associated works the Contractor shall include in the appropriate Bill of Quantities rates for all items such as,but not limited to additional excavation, dewatering, draining, disposing of water, labour and equipment working outside normal working hours as necessary to complete these works in accordance with the site conditions, FEWA's requirements, their method of operation and all factors related to the proper and efficient execution of such works.

Where it is necessary to cut the existing pipeline to make a connection, the cut shall be neatly and accurately performed by machine so as to leave the pipe end a true circle, normal to the pipe axis. After cutting the pipe, grinding or turning of the cut end shall be carried out. The cut end of the iron pipe shall be painted and any damage repaired in accordance with Manufacturer's recommendations. The cut end of an asbestos-cement pipe shall be turned evenly to suit the jointing system supplied and in accordance with the Manufacturer's recommendations.

13.Safe Installing, Handling & Disposal of Asbestos Cement Pipes.

Fine dust produced during installation of the pipes is a hazard to the workers and ommunity.When the pipes are dug up and removed, fibers are released as they are broken and crushed. If the pipe is left in place or removed in such a way that it is not crumbled, pulverized or reduced to powder, it would not be subject to the NESHAP (National Emission Standards for Hazardous Air Pollutants). avoid creating an active waste disposal site . Damaged Pipes (during installation works) shall be removed from the site and transported as an asbestos waste material to a landfill which accepts asbestos waste material (requires obtaining local Municipality Approval).The broken/ replaced asbestos cement pipe (buried) could remain in the ground close to the newly polyethylene pipe ( HDPE pipes when replaces AC pipes).

14.Waste Disposal and Transportation

All RACM (asbestos-containing material) shall be contained in transparent, leak-tight wrapping and shall remain adequately wet to prevent dust emissions during removal, transport, storage. and shall be transferred to proper landfill disposal qualified to receive asbestos waste following local national regulations. Landfills have special requirements for handling and securing the asbestos containing waste to prevent releases of asbestos into the air. Transportation vehicles that move the waste from the point of generation to the asbestos landfill have special labeling requirements and waste shipment record. Asbestos waste removed from storage (Depots) shall be in accordance with EPA’s Environment Protection (Prescribed Waste) Regulations to a licensed waste treatment facility site / approved landfill.

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Asbestos Supervisor” must be appointed for each asbestos removal job. This person must be trained to oversee AC removal work and provide additional guidance to work crews as required, with complete personal protection /safety tools and accessories. Carry out safe excavation works - Trenches and Shafts. Carefully uncover pipe to remove or repair section. Once exposed, manual excavation should be used to minimize further damage to the pipe. - Use of Non Powered Tools to cut asbestos pipe, wetting down of pipe. - Safe Removal of Asbestos Cement Water Pipes ; Personal Protective Clothing & Equipment: Employees involved and carrying out the cutting, repair, removal, tapping, bagging and wrapping or altering bursting asbestos cement pipes with polyethylene pipes must ensure compliance with legislative requirements of the Occupational Health and Safety Regulations 2007.This applies to the repair, connection, removal, handling or transportation of asbestos cement pipes and must wear the following PPCE : Disposable Mask, Disposable Cover , Disposable Gloves, Gum Boots; and Other Safety Equipment

Cutting and Disposal

Wear PPCE before commencing any works that may release asbestos fibers or create AC dust or AC pipe fragments.

Prepare plastic for the disposal of contaminated PPCE and asbestos waste.

Thoroughly wet area to be cut to further reduce the release of dust containing fibers when cutting (i.e before cutting starts and during cutting ensuring it is wet at all times).

Only use non-powered hand tools, such as Reed cutters, chain cutters or hand saws as these generate a smaller quantity of predominately coarser dust or waste chips. Power tools and abrasive cutting or sanding discs must not be used on asbestos cement products. Alternatively, break AC pipe collar with a hammer or similar implement.

Remove section of pipe from trench including all off-cuts, residue, soil and any collected dust before disposal as asbestos waste.

Double wrap asbestos cement pipe in plastic sheeting and collect small quantities. Ensure plastic sheeting is fully sealed with duct tape and labeled “Asbestos Waste” before transport back to the depot.

Dispose of disposable clothing, disposable respirators, all pre-filters and filter cartridges and disposable gloves by wetting down before placing with asbestos debris. All disposable PPCE shall be used once only and disposed of after use.

All tools and equipment shall be washed down prior to removing them from the excavation.

Wash hands immediately after handling AC pipe. Following work with AC pipe, employees should shower at the end of the working day.

All double wrapped asbestos waste shall be securely loaded on vehicle and transported directly from the work site to the depot.

Disposal of stored material shall occur by transferring to an EPA approved Waste Disposal Site by an approved and permitted waste disposal contractor.

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Federal Electricity & Water Authority Water Directorate ... Piping...wam client: federal electricity and water authority (fewa) project: standard specifications for water works engineer