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

15.17.14.7 Clear out space shall be left for jointing and lowering pipe in place and bringingto grade by tamping under pipe or removing excess concrete under pipe. Afterthe joint is made, the remainder of the concrete embedment may then bepoured and thoroughly tamped to make bond with original concrete.15.17.14.8 Care must be exercised in tamping to prevent lifting of the pipe out ofalignment or grade. Back filling shall be done in a careful manner and suchtime after the concrete cushion, embedment or encasement is placed, as not todamage the concrete in any way.15.17.14.9 All pipes shall be so laid that the contact in the joint between the two lengths ofpipe shall be uniform throughout the circumference of the joint. Where curvesin the alignment are indicated on the drawing and the curves are flat, standardpipe will be used with the outside adage of the joint pulled away from the seatto make a smooth joint.15.17.14.10 Where curves are sharp, standard or specially made bends will be used.capped and sealed.15.17.15. Laying of pipes and specials15.17.15.1 All precautions shall be taken during excavation and laying operations to guardagainst possible damage to any existing structure / pipe line of water, gas,sewage, etc. After excavation of trenches, pipes shall not be lowered unlessthe dimensions of trenches and bedding work for pipes at the bottom of thetrenches are approved and measured by Engineer. Pipes and fittings / specialsshall be carefully lowered in the trenches.15.17.15.1.1 The pipes and special shall be stacked along the alignment in advance withutmost care during the transit so that they are not damaged. Any damage due15.17.15.1.2 The pipe shall be lowered and laid only after the trenches are finally ready andlevels duly checked by the Engineer. It shall be seen that no damaged pipe islowered in the trench. Every precaution shall be taken to prevent foreignmaterials from entering the pipes when they are being placed in the line.15.17.15.2 Normally the socket ends shall face the upstream. When any portion of theexcavation shall have been carried down to the necessary depth, the contractorshall obtain permission from the Engineer before commencing the laying ofpipes or concrete or the construction of masonry.15.17.15.3 Special arrangements such as cranes, tripods with chain pulley block forlowering the pipes and fittings / special shall be made by contractor. In no casefittings / special shall be dropped. Slings of canvas or equally non abrasivematerial of suitable width or special attachment to fit the ends of pipes andfittings / special shall be used to lift and lower the coated pipes and fittings /special.15.17.15.3.1 The pipes and fittings / specials shall be inspected for defects and be rung witha light hammer preferably while suspended to detect crack, whereverapplicable. If doubt persist, further confirmation shall be done by pouring a littleparaffin / kerosene on the inside of the pipe at the suspected spot. No sign ofparaffin / kerosene should appear on the outside surface.Urban Administration & Development Department Page 192