Pipe Laying Procedures
November 30, 2010
Pipe laying between two adjacent manholes/chainages shall be started from the lower elevation to higher elevation for easy draining of ground water in the trench. However there can be case where need to lay pipes in opposite direction also.
• All pipes shall be laid to lines and grades shown on the drawings.
• Open ends of the installed pipes shall be plugged with a watertight plug/other approved way when there is no pipe laying in progress.
• When the pipes are to be ready for joining the plug shall be taken off.
• Material used for plugging shall be approved type that shall adequately protect the pipe from damage, prevent dirt, debris and water from entering the pipe.
• All pipes shall be checked for defects and cleaned before joining.
DUCTILE IRON PIPE LAYING
• All pipes shall be carefully inspected for defects before installation.
• Proper installation of pipe shall be carried following steps.
o Preparation of the bed for pipe
o Placing the pipe without damage
• The section of the pipe shall be fitted together correctly.
• Pipe shall be laid true to line and grade.
• As far as possible pipe shall be lowered by a crane.
• Whenever the work cease for any reason the unfinished end of the pipeline shall be securely closed.
• Where the water table is encountered, shall be kept below the sockets when joining by pumping or any other mean.
• Concrete Protection: Encased Concrete for pipes shall not be placed until the joints at each end of the pipe have been completed.
UPVC PIPE LAYING
• Pipes shall be stored out of direct sunlight but ventilation shall be provided.
• Cutting of the pipe shall be kept to a minimum.
• Cuts shall be perpendicular to the axis of the pipe and smooth.
PIPE LAYING IN RAILWAY CROSSINGS
Shop drawings shall be approved by the engineer before commencing work at every railway crossing.