08-section 2-section 02210 hdpe pipeline-version 2.0

ADSSC/GSCW Division 02 Section 02210

HDPE Pipelines. Materials, Installation and Testing Rev: 02 April 2010 of 20

ABU DHABI SEWERAGE SERVICES COMPANY (ADSSC)

GENERAL SPECIFICATION FOR CIVIL WORKS

DIVISION 2 SITEWORK

SECTION 02210 HDPE PIPELINES. MATERIALS, INSTALLATION AND TESTING

General Specification for Civil Works Abu Dhabi Sewerage Services Company

(ADSSC)



DOCUMENT CONTROL SHEET

Revision No. Date Revision Description / Purpose of Issue

01 April 2008 First Issue.

02 April 2010 Modification Section # 2.1 – HDPE Pipe & Fittings Tables # 2.1.1, 2.1.2 & 2.1.3

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TABLE OF CONTENTS

1 GENERAL ....................................................................................................... 4 1.1 SCOPE ................................................................................................ 4 1.2 RELATED DOCUMENTS ..................................................................... 4 1.3 STANDARDS ....................................................................................... 4 1.4 SUBMITTALS ....................................................................................... 5 1.4.1 PRODUCTS AND MATERIALS APPROVAL. ....................................... 5 1.4.2 METHOD STATEMENTS ..................................................................... 6 1.4.3 DRAWINGS. ........................................................................................ 7 1.5 QUALITY CONTROL............................................................................ 7 1.6 DELIVERY, STORAGE, AND HANDLING ............................................ 7

2 PRODUCTS ..................................................................................................... 8 2.1 HDPE PIPES AND FITTINGS .............................................................. 8 2.2 QUALITY CONTROL TESTS ............................................................. 12

3 EXECUTION .................................................................................................. 14 3.1 PIPE INSTALLATION ......................................................................... 14 3.2 BUTT FUSION JOINTING .................................................................. 15 3.3 SADDLE/SIDEWALL JOINTING ........................................................ 16 3.4 ELECTROFUSION JOINTING ........................................................... 16 3.5 MECHANICAL JOINTS AND FITTINGS ............................................. 17 3.6 HYDROSTATIC TESTING ................................................................. 17 3.7 DEFLECTION MEASUREMENT OF PIPELINES ............................... 19


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1 GENERAL

1.1 SCOPE

This section of the standard specification gives the requirements for High Density Polyethylene (HDPE) pipeline materials and the installation and testing thereof for use in sewerage systems.

1.2 RELATED DOCUMENTS

The following sections of the specification shall be read in conjunction with this section.

Section 01000-07 Submittals. Section 01000-08 Quality control. Section 01000-09 Materials and equipment. Section 02130 Utility trench excavation and backfill. Section 02230 Sewage systems.

1.3 STANDARDS

All activities relating to this section of the specification shall comply with the following or approved equal standards.

ASTM D638 Standard test method for tensile properties of plastics. ASTM D790 Standard test methods for flexural properties of

unreinforced and reinforced plastics and electrical insulating materials.

ASTM D1238 Standard test method for melt flow rates of thermoplastics by extrusion plastometer.

ASTM D1505 Standard test method for density of plastics by the density-gradient technique.

ASTM D1693 Standard test method for environmental stress-cracking of ethylene plastics.

ASTM D2240 Standard test method for rubber property-Durometer hardness.

ASTM F1055 Standard specification for electrofusion type polyethylene fittings for outside diameter controlled polyethylene pipe and tubing.

BS EN 727 Plastics piping and ducting systems. Thermoplastics pipes and fittings. Determination of Vicat softening temperature.

BS EN 728 Plastics piping and ducting systems. Polyolefin pipes and fittings. Determination of oxidation induction time.

BS EN 744 Plastics piping and ducting systems. Thermoplastic pipes. Test method for resistance to external blows by the round-the-clock method.

BS EN 1053 Plastics piping systems. Thermoplastics piping systems for non-pressure applications. Test methods for watertightness.

BS EN 1437 Plastics piping systems. Piping systems for


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underground drainage and sewerage. Test method for resistance to combined temperature cycling and external loading.

BS EN 12061 Plastic piping systems. Thermoplastics fittings. Test method for impact resistance.

BS EN 12256 Plastic piping systems. Thermoplastic fittings. Test method for mechanical strength or flexibility of fabricated fittings.

BS EN ISO 9967 Thermoplastics pipes. Determination of creep ratio BS EN ISO 20088-3 Plastics. Determination of resistance to environmental

stress cracking (ESC). Bent strip method. DIN 8074 Polyethylene (PE) – Pipes PE63, PE80, PE100, PE-HD.

Dimensions ISO 161 Thermoplastics pipes for the conveyance of fluids.

Nominal outside diameters and nominal pressures. ISO 527 Plastics. Determination of tensile properties. ISO 1133 Plastics. Determination of the melt mass-flow rate

(MFR) and the melt volume-flow rate (MVR) of thermoplastics

ISO 1167 Thermoplastics pipes, fittings and assemblies for the conveyance of fluids. Determination of resistance to internal pressure

ISO 1183-3 Plastics. Methods for determining the density of non-cellular plastics. Gas pykonometer method.

ISO 2505 Thermoplastics pipes. Longitudinal reversion ISO 4427 Polyethylene (PE) pipes for water supply.

Specifications. ISO 6964 Polyolefin pipes and fittings. Determination of

carbon black content by clacination or pyrolisis Test method and basic specification

ISO 9000 Quality management systems ISO 11922 Thermoplastic pipes for the conveyance of fluids.

Dimensions and tolerances. ISO 13479 Polyolefin pipes for conveyance of fluids –

Determination of resistance to crack propagation Test method for slow crack growth on notched pipes

ISO 13967 Thermoplastics fittings. Determination of ring stiffness. ISO 18553 Method for assessment of the degree of pigment or

carbon black dispersion in polyolefin pipes, fittings and compounds

WIS 4-24-01 Specification for mechanical fittings and joints for polyethylene pipes for nominal sizes 90 to 1000.

1.4 SUBMITTALS

1.4.1 PRODUCTS AND MATERIALS APPROVAL.

a) In order to verify compliance with the specification the Contractor shall submit information for all products and materials used in the Works to the Engineer for approval sufficiently in advance of their use in accordance with the Contract programme allowing for ordering and


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approval times. Reference shall also be made to Section 01000-09 of the specification on products and materials approval. Information to be submitted shall comprise but not necessarily be limited to:

i. The manufacturers design calculations, complete and detailed

specification and test results of the proposed HDPE pipes and fittings required for the Works including manufacturer’s certificates of compliance with this section of the standard specification. Information on all items listed in Table 1.4.1 below shall be given for every diameter in each class of pipe.

ii. Should any details of the pipes and fittings be altered in any way during manufacture from those proposed and approved by the Engineer, submit for the Engineer's approval the revised details and test results.

iii. Submit to the Engineer the results of all quality control tests carried out on the manufactured pipes and fittings as soon as practicable after testing and in any case not later than the time of delivery of the relevant pipes and fittings to the site.

Table 1.4.1 – Product Information For HDPE Pipe And Fittings

Product Information Units Manufacturing Details Name of manufacturer - Manufacturing process for pipes - Manufacturing process for bends and fittings - Joint type - Details of all additives used in the manufacture - Polymer classification and certificate of origin - Summary of Design Criteria Rated working pressure MPa Design test pressure (165hrs or 100 hrs) MPa Internal vacuum pressure MPa Minimum required strength (MRS) MPa Pipe Details Nominal external diameter mm Wall thickness mm Standard dimension ratio (SDR) - Standard pipe length m 1.4.2 METHOD STATEMENTS

a) The Contractor shall submit method statements to the Engineer for approval 4 weeks in advance of commencing the site activity in accordance with Section 01000-07 of the specification. These shall


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comprise but not necessarily be limited to:

i. Procedures for handling, storage and installation of pipes. ii. Procedures for building pipes into concrete structures. iii. Hydrostatic testing procedures for HDPE pressure pipelines.

1.4.3 DRAWINGS.

a) The Contractor shall submit drawings to the Engineer for approval in advance of commencing the site activity in accordance with Section 01000-07 of the specification. These shall comprise but not necessarily be limited to:

b) Drawings of the pipes, fittings, joints, pipe specials and the assembly

thereof.

c) Pipe laying diagram and schedule showing location, length, design designation and designation by number of each pipe section and pipe special to be furnished and installed.

d) All data on curve and bends for both horizontal and vertical alignment.

1.5 QUALITY CONTROL

a) Prior to dispatch of any product and/or material from source the Contractor shall notify the Engineer in writing in sufficient time to allow the Engineer the opportunity to inspect and test the product and/or material prior to delivery in accordance with Section 01000-08 of the specification.

b) Products and materials shall be from a manufacturer/supplier who

operates a quality system which is registered to ISO 9000 series or approved equal.

c) To allow the Engineer to inspect the Works the Contractor shall give the

Engineer a minimum of 24 hours notice of carrying out the following activities on site:

i. Installation of pipeline. ii. Hydrostatic testing of pipeline.

1.6 DELIVERY, STORAGE, AND HANDLING

a) Delivery, storage and handling of products and materials shall be in accordance with the manufacturers recommendations, Section 01000-09 of the specification and the following provisions.

i. Delivery storage and handling shall at all times be performed in a

manner to avoid product damage and be in accordance with the manufacturer’s recommendations.


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ii. Pipes and fittings shall not come in contact with any sharp projections that may cause damage to the pipes and fittings during transportation loading and unloading. Ensure that pipes and fittings are well secured during transit and adequately supported along their length. Do not allow pipe to overhang the end of a vehicle during transportation.

iii. Ensure that pipes and fittings are lifted using nylon or large diameter rope slings positioned at a quarter of the pipe length from each end. Do not allow the use of wire rope chains or unpadded forks or clamps on forklifts to lift pipes.

iv. Store pipes and fittings on a flat level area as recommended by the pipe manufacturer. Ensure that pipes and fittings supplied either on pallets or crated, remain on the pallets or in their crates until required.

v. Stack non-crated pipes to the approval of the Engineer.

Stack pipes of different sizes and thickness separately. Do not allow stacked pipes to exceed 2m in height or as

recommended by the supplier whichever is the lesser.

vi. The Contractor shall visually inspect all products upon delivery to site and report any damage to the Engineer.

Any products damaged during delivery, storage and handling

shall be marked by the Contractor and set aside. Proposals for repair of any damaged products shall be

submitted in writing to the Engineer for approval. Any damaged products deemed unsuitable for repair by the

Engineer shall be removed from site and replaced. Scratching or scoring of pipe surface to a depth greater or equal

to 10% of wall thickness shall constitute an automatic rejection of that pipe section.

2 PRODUCTS

2.1 HDPE PIPES AND FITTINGS

a) Pipes and fittings shall be manufactured from polyethylene containing only those antioxidants, UV stabilisers and pigments necessary for the manufacture of pipes conforming to specification ISO 4427 and for its end use, including weldability when it is possible. Minimum content of carbon black shall be 2,4%

b) All HDPE pipes and fittings shall be manufactured from material

conforming to polymer classification PE100 having a minimum required strength value (MRS) of 10MPa at 50 years and 20o

C in accordance with ISO 4427. Design stress shall be 8MPa. Pipes shall have a standard dimension ratio (SDR, outside diameter/wall thickness) of either 11 or 17 unless indicated otherwise by Engineer. Material shall be procured from the manufacturer accepted to PE100+ Association.


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c) The pipes and fittings shall be homogeneous throughout and free of visible cracks, holes, foreign inclusions, voids and other injurious defects.

d) Butt fusion fittings shall be in accordance with ASTM D3261 and shall be

manufactured by injection moulding, a combination of extrusion and machining, or fabricated from PE pipe conforming to this specification. Fabricated fittings shall be manufactured using a Datalogger to record fusion pressure and temperature. Butt fusion fittings shall have a pressure rating no less than that of the pipe. The fittings shall be homogeneous throughout and free of visible cracks, holes, foreign inclusions, voids and other injurious defects.

e) Electrofusion fittings shall be manufactured from the same base resin as

the pipe to ASTM F1055 and shall have a pressure rating no less than that of the pipe.

f) Flanged and mechanical joint adaptors shall be manufactured to WIS 4-

24-01 and have a pressure rating no less than that of the pipe.

g) Pipes and fittings shall be fabricated to be capable of withstanding the working pressures, test pressures and loadings specified.

h) Pipes and fittings must be designed to achieve a minimum working life of

50 years under all applicable loadings, environmental and installation conditions.

i) Pipes and fittings shall be suitable for carrying raw sewage, treated

sewage effluent, surface water and potable water at temperatures up to 40o

C as appropriate for the particular application.

j) Nominal outside diameters of pipes and fittings shall conform to ISO 161 and the tolerances on these diameters shall be in accordance with ISO 11922.

k) Only fittings supplied or recommended by the pipe manufacturer and

approved by the Engineer shall be used. Fittings shall be installed in accordance with the approved method statement.

l) The pipe shall contain no recycled compounds.

m) The properties of the polymer, extruded pipe and fittings shall be as

shown in Tables 2.1.1, 2.1.2, and 2.1.3 below.


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Table 2.1.1 – HDPE Resin Properties

Property Required Value Test Method European

Test Method ASTM

Density >940kg/m3 ISO 1183-3 D1505

Melt mass flow index or rate (2.16) 0.2 to 1.4g/10min* ISO 1133

condition 4 D1238 4

Melt mass flow index or rate (5.00)

0.2 to 1.4g/10min* ISO 1133 condition T D1238 5

Melt mass flow index or rate (21.6)

>8g/10min ISO 1133 condition G D1238 6

Environmental stress crack resistance (10% stabiliser)

>250hrs BS EN ISO 20088 D1693

Resistance to internal pressure

>165hrs ISO 4427 DIN 8047 -

Oxidation induction time (2000 >20mins C)

BS EN 728 -

Flexural creep modulus >900MPa - D790

Shore D hardness (400>50 C)

- D2240

Tensile strength at yield (50mm/min) >20MPa ISO 527 D638

Elongation at break >600% ISO 527 -

Modulus of elasticity >1000MPa - -

Charpy impact No break - -

Vicat softening point >1250 BS EN 727 C -

Thermal expansion (20-900<0.20mm/m/C)

0 - C -

Thermal conductivity (200<0.6W/mK C)

- -

Carbon black content >2.4 ISO 6964

Carbon black dispersion ≤60µm (grade 3)

ISO 18533

*- Maximum deviation of +/- 20% of the nominated value


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Table 2.1.2 – HDPE Pipe Properties


Test Method ASTM

Density >940 kg/m3 ISO 1183-3 D1505

Melt mass flow index or rate (5.00kg, 1900 0.2 to 1.4/10min* C)

ISO 1133 condition 1T D1238 5

Oven test Defects shall not develop ISO 12091 -

Resistance to internal pressure (200C, water in water, hoop stress 12.4MPa, 100hrs)1

No failure or defects

ISO 1167

ISO 4427 -


No failure or defects

ISO 1167

ISO 4427 -

Resistance to internal pressure (800C, water in water, hoop stress 5.0MPa, 1000hrs)

No failure or defects 1

ISO 1167

ISO 4427 -

Creep ratio >900MPa BS EN ISO 9967 -

Longitudinal reversion (1000 <3% C) ISO 2505 -

Shore D hardness >50 - D2240

Tensile strength at yield 50mm/min) >20MPa ISO 527 D638

Elongation at break >350% ISO 527 -

Ring flexibility Refer standard BS EN 1446 -

Impact strength TIR 10% BS EN 744 -

Ring stiffness To SN or SD required

BS EN ISO 9969 -

Quality Grade N ISO 11922

Thermal stability (2000 20mins C) BS EN 728 -

Notch test (at 500 hours) Refer Standard ISO 13479 Legend to Table 2.1.2 1) Either on pipe or from sample pipe using same resin and process. *- Change of MFR by processing +/- 20% of the compound value


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Table 2.1.3 – HDPE Injection Moulded Fittings Properties


Test Method ASTM

Density >940kg/m3 ISO 1183-3 D1505

Melt mass flow index or rate (5.00kg, 1900 0.2 to 1.4g/10min* C)

ISO 1133 condition 1T D1238

Stiffness As required ISO 13967 -

Impact Refer standard BS EN 12061 -

Mechanical strength or flexibility Refer standard BS EN 12256

Thermal stability (2000 >20 mins C) BS EN 728 -

Resistance to internal pressure (800C, water in water, hoop stress 5.5MPa, 165hrs)

No failure 1

ISO 1167

ISO 4427 -


No failure

ISO 1167

ISO 4427 -

Water tightness No leakage EN 1053 -

Legend to Table 2.1.3 1) For moulded materials use either an injection moulded or extruded pipe from same

materials. *- Change of MFR by processing +/- 20% of the compound value

2.2 QUALITY CONTROL TESTS

a) The routine factory quality control tests listed below shall be carried out at the required frequencies and records of all tests and inspections shall be maintained by the manufacturer. The Engineer shall be provided with two copies of all test certificates and reports.

i. Quality testing of all raw materials to ensure that they comply with

the relevant specification. ii. Control of processing parameters in terms of temperature, pressure,

flow rates, haul-off speed and energy input. iii. Visual inspection of the pipes to check general appearance,

dimensional compliance and any indication of inclusions or processing flows in pipe barrels and joining ends.

iv. Production short-term tests to identify any variations in the plant functioning.

v. The following tests shall be performed in accordance with the


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vi. relevant standards in order to ensure the quality of the extruded pipes:

Melt mass-flow rate of raw material. Density of raw material. Carbon black content. Carbon black dispersion. Long-term stress crack resistance at 80°C. Long-term MRS at 20°C on the raw material (data not older that

24 months) Appearance. Long term hydrostatic test at 20°C. (100hrs test) Welding. Slow tear test Oxidation induction time value. Visual inspection of pipes. Dimensional check of pipes. Heat reversion of pipes. Hydrostatic creep strength tests of pipes. Bend test / reverse bend test

b) When conditioning is required for laboratory tests, condition the

specimens in accordance with the appropriate standard.

c) Tensile testing for pipe resin, pipes and welds shall be performed on an approved tensilometer capable of delivering safely and accurately 120 % of the stress required by the sample. The tensilometer shall be connected to a computerised system capable of delivering information in data and graphical form. The information required from tensile measurements are tensile strength at yield and peak and elongation at yield and peak.

i. Test specimens shall be milled to exact size using approved

designated milling machines. Each specimen shall be measured to an accuracy of 10 microns

ii. The Contractor shall submit statistical analysis based on minimum sample populations of 32. Cumulative analysis based on overall and on individual pipe resin batch based data shall also be provided.

iii. Welded samples shall be visually examined after tensile testing for signs of adequate bonding and ductile and brittle failure. Weld samples with greater than 25 % brittle failure shall be rejected.

iv. Tensile graphs indicating brittle failure shall be considered as failures.

d) The selection of samples of pipe, resin and welds for testing shall be as

directed by the Engineer.

e) If the results of any test fail to meet the requirements of this specification, the test shall be repeated once again. If, upon retest, failure occurs, the batch quantity of product represented by the test shall be rejected.


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f) The Contractor shall conduct quality checks at the manufacturer's premises to ensure that the in-process manufacturing quality checks are being conducted correctly and at the stated frequency. Test certificates relating to the batch shall be furnished to the Engineer before acceptance of the delivery. The test certificates shall contain all the details in the agreed format of reporting.

g) Marking shall be applied to the pipe in such a manner that it is legible

after installation and durable throughout the construction period. Each standard and random length of pipe and every fitting shall be marked before despatch from the pipe manufacturer’s works as required in ISO 4427 and as follows:

i. The manufacturer’s name, initials, or trade mark. ii. The dimensions nominal outside diameter X nominal wall thickness. iii. The outside diameter tolerance. iv. The designation of the pipe material. v. The nominal pressure. vi. The pipe series. vii. The date of manufacture and batch number. viii. Stencil in legible letters the pipe identification number on the inside

and outside at each end. Ensure that the same number appears on all record sheets and documents relating to the manufacture, delivery and testing of that pipe.

ix. The manufacturing standard. 3 EXECUTION

3.1 PIPE INSTALLATION

a) Trench excavation shall be carried out in accordance with Section 02130 of the specification.

b) Install pipe, fittings, and accessories in accordance with manufacturer's

instructions.

i. Provide qualification details of the manufacturer's technical expert to be assigned to the Contract. The technical expert shall have expertise, experience and skills necessary for advising and monitoring all aspects of transport, storage, handling, installation and testing of pipes as appropriate.

ii. The technical expert shall provide comprehensive technical assistance to the Contractor throughout the Contract and regularly monitor the Contractor's activities and report on shortcomings.

iii. The Contractor shall provide the Engineer and ADSSC copies of all instructions advice or reports given by the manufacturer's technical expert to him. The technical expert shall immediately inform the Engineer and ADSSC of any omission, variations and detractions from the specification.

c) The pipeline shall be within 20mm of the specified line and the invert


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level shall be within 6mm of the specified value and shall be such that there is no backfall at any point on a gravity pipeline.

d) Install bedding, surround and backfill in accordance with the pipe

manufacturer’s requirements or if not given as specified in Section 02120 of the specification and shown on the drawings.

e) Install appurtenant facilities on the pipeline such as manholes, valve

chambers as specified in Section 02300 of the specification.

f) Lay pipes from downstream to upstream unless agreed otherwise with the Engineer.

g) HDPE pipelines can accommodate gradual changes of direction in the

vertical and horizontal plane. However the pipe should not normally be bent to a radius less than 25 times the outside diameter of the pipe.

h) When cut pipe is required, ensure that the cutting is done by a machine,

leaving a smooth cut at right angles to the axis of the pipe.

i) Ensure that all pipes and fittings are sound and clean before laying. When pipe laying is not in progress, ensure that the pipe ends are at all times fitted with watertight plugs or caps. The plugs or caps shall only be removed for the purposes of making a connection of the pipe end or testing the pipeline. The plugs or cap shall be replaced immediately on completion of the test.

3.2 BUTT FUSION JOINTING

a) Butt fusion jointing shall only be used to join pipes of the same PE material with compatible MFR and with the same nominal wall thickness and outside diameter. The following procedures shall serve as a general guide only. The Contractor shall obtain detailed jointing instructions from the manufacturer who shall have a technical representative available at the Engineer’s request during the jointing process.

i. The butt fusion machine should be sited within a shelter and the

ends of the pipe being joined should be covered or plugged to prevent through drafts.

ii. Each component that is to be fused should be held in position in the purpose built clamping jig. The lengths of pipe hanging outside the jig should be supported by means of roller cradles.

iii. The pipe ends should be faced so that the finished surfaces are perfectly smooth free of visible ridges, valleys or other surface imperfections.

iv. The outside diameters of the pipe ends should match closely without the offset exceeding 10%

v. The pipe ends should be heated to the pipe manufacturer’s recommended temperature and interfacial pressure. The Contractor should use a pyrometer or other surface temperature measuring


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device to confirm and record the actual surface temperature for each weld. Temperature indicating crayons should not come into contact with the surface to be welded.

vi. After the pipe ends have been properly melted, the heater tool should be removed within the specified time. The molten pipe ends should be brought together and allowed to cool without disturbance to form the permanent weld. The proper bead size and geometry specified for the pipe being welded should be formed.

3.3 SADDLE/SIDEWALL JOINTING

a) Saddle /sidewall fusion jointing shall be accomplished by using a mechanical saddle fusion machine that has been designed for this purpose to ensure proper alignment, temperature and force control. The following procedures shall serve as a general guide only. The Contractor shall obtain detailed jointing instructions from the manufacturer who shall have a technical representative available at the Engineer’s request during the jointing process.

i. Any dirt or coating that might interfere with the proper operation of

the saddle fusion machine should be removed from the pipe and the surfaces of the pipe and saddle roughened to expose fresh material and any reside brushed away.

ii. Test fit the saddle fusion machine to ensure that alignment and contact are as they should be.

iii. Commence the fusion process and periodically verify the surface temperature using a pyrometer or other surface temperature measuring device. If temperature indicating crayons are used, they should not be used on a surface which comes into contact with the surfaces to be welded.

iv. After the heating period, remove the heater plate and check for the correct melt pattern on both the fitting and the pipe. Join the fitting to the pipe with the prescribed fusion force.

v. Cool the joint without disturbance until the melt has formed a permanent weld. The joint should not be subjected to any external stresses until the fusion joint has cooled.

3.4 ELECTROFUSION JOINTING

a) Electrofusion jointing involves heating the electrofusion joint internally, either by a wire coil at the interface of the joint or by a conductive polymer. Heat is created by an electric current passed to the conductive material in the fitting.

i. Ensure that the fitting is dimensionally appropriate for welding to the

pipe. Clean the pipe surface in the joint area. Cut the end of the pipe square. Mark on the pipe surface the proper position of the fitting to be installed. Scrape the surface of pipe area to be joined, removing all surface degradation and contamination. Avoid contamination of the scraped pipe surfaces.

ii. Place the pipe and fitting in the clamping fixture to prevent


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movement of the pipe or fitting. iii. Connect the electrofusion control box to the fitting and to the power

source. Apply electric current to the fitting as specified in the manufacturer’s instructions. Turn off the current when the proper time has elapsed to heat the joint properly.

iv. Allow the joint to cool for the recommended time and remove the clamping fixtures. Do not remove prematurely from the clamps as any strain on a joint that has not fully cooled can be detrimental to joint performance.

3.5 MECHANICAL JOINTS AND FITTINGS

a) Many types of mechanical connection styles and methods exist. The Contractor shall submit suitable mechanical joints. All such joints shall be recommended and acceptance tested by the manufacturer of the pipe. Where marked on the drawings end-load resistant fittings of an approved type shall be used.

b) When tightening polyethylene flanges care shall be taken to produce an

equal torque load to the limits given by the manufacturer. A torque wrench shall be used. Since polyethylene creeps under load it is essential that the bolts are re-tightened several times prior to commissioning to minimise the risk of leakage.

c) All joint materials and gaskets shall be suitable for use in the prevailing

climate, soil, ground water, potable water and irrigation water conditions. 3.6 HYDROSTATIC TESTING

a) Proposed methods and program for testing, including details of test equipment, shall be submitted to the Engineer for approval. All tests shall be witnessed by the Engineer or other person appointed by the Owner. All equipment necessary for carrying out testing and cleaning including water, pumps, gauges and calibration certificates, piped connections, stop ends and all other temporary works shall be provided prior to commencement of testing.

b) In addition to any tests of individual joints or other interim tests, which

may be specified elsewhere, submit all parts of the pipelines to a final test. Carry out at any stage of construction other tests that the Engineer considers desirable to check materials and workmanship on the pipeline. Ensure that the obligations to perform successful tests under the Contract are achieved.

c) Use potable water for hydrostatic testing and pipeline cleaning. The

Contractor must make his own arrangement for the supply and disposal of water used for testing which must be obtained from a source accepted by the Engineer.

d) The pipeline shall be tested in sections as the Engineer may direct or

permit. Each section shall be tested separately. Testing shall not be


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carried out against closed valves.

e) Use properly designed fittings for the purpose of temporarily closing the openings in pipelines to be tested. Use fittings adequately strutted to withstand the pressure specified.

f) Where multiple pipelines are laid in common trench, test only one line at

any one time.

g) The pipeline shall be thoroughly cleaned prior to testing.

h) Ensure that gauges used for testing pipelines have a dial diameter of not less than 100mm and a full scale reading not greater than twice the specified test pressure. Before any gauge is used, arrange for independent laboratory to check the accuracy of the gauge. Provide a dated certificate of its accuracy to the Engineer.

i) Before pressure testing commences pipes and valves shall be

rechecked for cleanliness and the operation of all valves shall be rechecked. The open ends of the pipeline, or sections thereof, shall be blanked off and additionally secured where necessary by temporary struts and wedges. All anchor and thrust blocks shall be completed and all pipe straps and other devices intended to prevent the movement of pipes shall be in place.

j) Tables for pressure testing and for make-up water for testing at elevated

temperatures between 230C up to 400

C shall be provided by the resin manufacturer of the pipe.

k) When the temperature of the pipe wall, test water and air temperature are all less than 35oC the test pressure shall be 1.5 times the rated pressure of the lowest rated component in the section of pipeline under test.

l) Pipelines that have been pressurised and depressurised shall be kept

depressurised for a period of at least 12 hours to stress relax before applying pressure again

m) During summer months all pressure testing shall be carried out when

ambient temperatures are at their lowest in order to avoid excessive stresses on the pipe during testing. Exposed areas of pipe in trenches, such as at joint locations, shall be shaded during hydraulic testing at all times throughout the year.

n) The fill and test position shall be located at the lowest point of the

pipeline profile to encourage the expulsion of air as the pipe is being filled. Adequate air release mechanisms shall be sited at all high points. An air bleed shall be incorporated as close to the crown of the pipe at the highest point and at each end of the test section.


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o) The pipeline shall be filled taking all appropriate precautions to avoid air entrapment as the presence of air could invalidate the test. The pipeline shall then be left to stabilise for a minimum of 3 hours and air released as necessary by opening the bleed valves.

p) Visually inspect all exposed pipe, fittings, valves and joints during the

tests

q) Ensure that all valves in the pipeline are satisfactorily operating under working pressure.

3.7 DEFLECTION MEASUREMENT OF PIPELINES

a) Deflection measurement of pipelines shall be carried out at the discretion of the Engineer, but the Contractor shall be deemed to have included for deflection testing in his rates.

b) Excavation for or laying of HDPE pipelines shall not proceed until an

approved device for gauging pipe deflections is on site.

i. Use a suitable mechanised device to the approval of the Engineer for gauging pipe deflections. Maintain devices for gauging pipe deflections in good working order. Submit calibration certificates before every period of use. For pipes of 600mm diameter and greater. Measure deflection by physical entry into the pipes. Use a regularly calibrated telescopic spring loaded graduated rod to measure percentage deflections in each diameter. Provide a suitable trolley to facilitate access into the pipe. Record all measurements.

c) The pipeline shall be inspected for deflection and ovality immediately

after 600 mm of the soil envelope has been placed to obtain a reference status. The final deflection shall be taken 30 days after the backfill has been built up to final ground level. The Contractor is advised to check for deflection at all times so that he may make corrections during the backfill construction phase.

d) When fully installed and completely backfilled to ground level the

deflection inclusive of any initial ovality shall not be more than 5.0 % based on the base outside diameter and measured 30 days after installation.

e) If the visual inspection or the deflection test indicates excess deflection,

the Contractor shall determine the exact cause of the deflection before proposing a remedy.

i. Isolated areas of severe deflection may be the result of construction

loads being on the pipe before adequate cover has been placed. These areas may be able to be re-rounded with special equipment without any excavation. Long lengths of pipe with high deflection levels may be indicative of overall installation deficiencies. The


(ADSSC)



Contractor shall submit proposals for corrective action in the event of unacceptable deflection or upon indications of poor installation likely to cause future distress to the pipeline.

ii. Depending on the severity, the material around the pipe may have to be excavated and replaced with the recommended backfill and compacted. Provided the pipe has not deflected to the point of reverse curvature, it may be allowed to be returned to its original round shape before acceptance.

END OF SECTION

08-section 2-section 02210 hdpe pipeline-version 2.0

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