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

15.17.15.3.2 Pipes and fittings / special damaged during or aligning shall be rejected byEngineer.15.17.15.4 All the pipes are to be laid perfectly true both in alignment and to gradientspecified. Pipes in a trench shall be laid and fitted previous to the jointing beingcommenced.15.17.15.4.1 In case of spigot and socket pipe the socket end of the pipe shall faceupstream, except when the pipe line runs uphill in which case the socket endsshould face the upgrade of a slope. After placing a pipe in the trench, the spigotend shall be centered in the socket and the pipe forced home and aligned torequired gradient.15.17.15.4.2 The pipes shall be secured in place with approved backfill material tampedunder it except at the socket. Pipes and fittings / special which do not allow asufficient and uniform space for joints shall be removed and replaced withpipes and fittings / special of proper dimensions to ensure such uniform space.Precaution shall be taken to prevent dirt from entering the jointing space.15.17.15.4.3 At times when pipe laying is not in progress, the open ends of pipe shall beclosed by a watertight plug or other means approved by engineer. During theperiod that plug is on, the contractor shall take proper precautions againstfloatation of the pipe owing to entry of water into the trench.15.17.15.4.4 Wherever it is necessary to deflect pipe from a straight line, either in thevertical or horizontal plane, to avoid obstructions or where long radius curvesare permitted, the deflection allowed at joints shall not exceed 2½ 0 in the caseof pipes, with joint to be made with loose collars, the collars shall be slipped onbefore the next pipe is laid. The pipe shall be laid such that the marking onpipes appears at the top of the pipes.15.17.15.5 Properly fitted temporary wooden stoppers shall be provided to close the endsof all incomplete pipe lines. The stoppers are only to be removed when pipesare being laid and jointed. Pipe laying and jointing shall be started andcompleted only section wise as per the instruction of the engineer.15.17.15.5.1 During the progress of pipe laying the open ends of pipe shall be closed andwater tight. Sight rails shall be provided at all change of direction or gradientsat distance of @ 30 m along straight lengths.15.17.15.5.2 All the invert levels shall be confirmed from the sight rails with the help ofproper boning rods as per the standard practice. The pipe shall be jointed withcement mortar 1:1 and proper caulking shall be done. After a particular sectionof the pipe is laid and jointed hydraulic testing shall be done section wise.15.17.15.6 Just prior to placing each pipe section in the line, damaged coating shall berepaired and the interior shall be cleaned off all foreign materials. Cleaningshall be accomplished by brushing, blowing with compressed air and washingwith water or as specified by the Engineer.15.17.15.7 The item for laying of pipe line also includes labour work for lowering, layingand jointing various pipes including jointing with specials, leveling, etc. Thecontractors shall transport pipes and specials from stores, for their varioussections in such quantities as may be required for laying.Urban Administration & Development Department Page 193