Specifications Part 1 - Water Supply, Sewerage and Tube Well Works

12.13.3 Care should be taken to leave adequate area around the joint free of backfill toallow for inspection during testing of the pipeline.12.13.4 Successive layers of backfill of 75 mm thickness may then be placed over andcompacted to a height above the crown of not less than 150 mm. Lightvibrating machinery may be used, but not directly above the pipe.12.13.5 On completion of the surround to the pipe, suitable excavated material may bethen replaced as backfill in 250 mm compacted layers up to the top of thetrench.12.13.6 No heavy compaction equipment to be employed until there is at least 300mmof fill above the crown of the pipe.12.14 Performance requirement of solvent cement joints-12.14.1 Internal Hydrostatic Pressure- when assembled according to thejoint shall withstand an internal pressure of upto and including 0.05 MPa (0.5 bar) for a minimum period of 15 min withoutleakage.12.14.2 Internal Negative Hydrostatic Pressure (Internal Vacuum)- when assembledons, the joint shall withstand aninternal negative pressure (internal vacuum) of up to and including 0.03 MPa(0.3 bar) for a minimum period of 15 min without leakage.12.14.3 Leak tightness of Elastomeric sealing Ring Type socket joints : The method oftesting of joints under positive internal pressure and with Angular deflection isgiven in detail in Annexure-A.12.15 Measurements:The lengths of pipe shall be measured in the running meters nearest to a cm aslaid, lowered and jointed from in side of one manhole to the inside of the othermanhole. The length shall be taken along the centre line of the pipes.12.15.1 All fittings such as bends, junction, etc., which shall not be measuredseparately. Excavation, refilling, shoring and timbering in trenches and cementconcreting where ever required shall be measured separately under relevantitem of work.12.15.2 Security money for testing should be kept at 10 % of the value of the work.After testing of the complete sewerage system to the satisfaction of theengineer in-charge the same shall be released.12.16 Rate12.16.1 The rate shall include the cost of material and labour involved in all theoperation described above including the cost of concrete which shall be paidseparately.Urban Administration & Development Department Page 142