METHOD STATEMENT FOR INSTALLATION OF GRP PIPES FOR STORM WATER
TOOLS / EQUIPMENT
- Portable Hand tools
- Portable Drilling machines
- Measuring rule
- An open ended cylinder 250 mm long and approx.150 mm internal dia. A piece of standard 150 mm dia pipe is suitable.
- A metal rammer 0f 36 to 40 mm dia. and weighing approx.one Kg.
Material Handling & Storage
On receipt of GRP pipes & fittings , the materials shall be handled & stored in line with the following procedure:
- Pipes will be stacked on a flat surface free from sharp projections, stones or other objects likely to cause point loading or pipe deformation.
- The storage area shall be kept in proper level, so that the stacked pipes may be uniformly supported throughout their length.
- Pipes will not be dropped on hard surfaces and will not be dragged along the ground. Wherever possible the loading and unloading of pipes will be carried out manually by hand.
- If mechanical lifting equipment is used, ensure no metallic slings, hooks or chains will be used in direct contact with the pipe. Rope or nylon belt sling will be preferred which will not damage or cut the pipe surface.
- When socket pipes are stacked, the sockets will be placed at alternative ends of the stack with the socket protruding so that pipes are evenly supported along their entire length.
- Pipe of different sizes or wall thickness will be stored separately or where this is not possible, those with larger diameters and / or thicker walls will be placed at the bottom of the stack.
- The stacks will be protected from direct sunlight by covering with tarpaulin sheets.
- All the pipe fittings will stored in the boxes as supplied by the fittings manufacturer.
- When storing the pipe on ground near the trench .it is necessary that the soil must be levelled and not to contain any hard bodies exceeding 40 mm that could damage thepipe. For long storage,pipe should be placed on supports of 10 Cm.wide at every 2.5 Mts. distance with side blocks to prevent the pipe from rolling.
- RUBBER RING STORAGE
Rubber rings must be stored in cool and dark place. Never let the rubber ring outside in the sun. Avoid contact of rings with grease or oil.
BELOW GROUND DRAINAGE & STORM WATER PIPE WORKS (GRP)
The Installation of GRP pipes for storm water shall be in accordance with manufacture ‘s recommendations, as per the approved drawings, and local muncipality requirements.
To carry out installation activities for GRP pipes for Storm water pipework, below mentioned procedure shall be followed step by step in sequential manner. Prior to commencement of installation it shall be ensured that all the previous activities have been completed & the area is released to proceed with MEP installations. Also it shall be ensured that all materials available at stores are inspected & approved by Consultant.
- Pipes shall be laid as per approved shop drawings over the blinded surface & anchored using rebars.
- All below ground Manhole to Manhole pipes and fittings shall be as per approved material submittal.
- The excavation and trench preparation shall be done as per approved shop drawings. Surveyor shall certify that the excavated level is correct.
- IMPORTANT POINTS WHILE LAYING GRP PIPES
- DO NOT store the pipes in direct sun for a long period.
DO NOT store the rubber rings under direct sun.
DO NOT handle pipes & fittings carelessly.
DO NOT allow any stones or any heavy items to fall on pipe.
DO NOT use single point lifts for lifting the pipes with crane.
DO NOT use any handling and backfill material without proper analysis of the same and also of the native soil.
DO NOT lay the pipes on a badly prepared bedding. Bedding material should be one suitable for the conditions and it should be compacted.
DO NOT forget to over – excavate at the locations of the joint.piipe should be levelled and aligned.
DO NOT join pipes or fittings with plain ends to th e integral Bell of of the pipe or double coupling.
- Plain ended pipes or fittings should be assembled with Mechanical coupling.
- Pipes will be transported to trench side by truck and installed on the leveled bed in the trench either by forklift / crane or manually .
- Pipes should be leveled and aligned. At the location of the joint.
RIGID PIPE CONNECTIONS
- When a pipe passes through a wall or is encased in concrete,the following Installation method must be used.
- For a distance along the pipe of a minimum of 2 pipe diameters,the trench must be a minimum of 3 pipe diameters in width and with a depth of one pipe diameter. The transition back to normal normal trench dimension shall be made during the next two pipe diameter length.
- A flexible joint must be installed within two pipe diameters of the rigid connection. Where the pipe is encased in concrete .as in a wall ,a band of neoprene ruber of 40 to 60 shore hardness 13 mm thick and 150 mm wide shall be wrapped around the pipe prior to placement of the concrete.The band shall be wrapped around the pipe inside the concrete area with the edge of the rubber at the embedment/ concrete interface.
- Whenever GRP pipe passes beneath road beneath road with less than 1.25 Mts. cover or passas beneath rail tracks with less than 3 Mts. Of pipe cover concrete encasement or suitably designed concrete slab is required. The depth of cover above the pipe crown upto the invert level of the road or rail track should be 1.25 Mts.and 3.0 Mts.respectively.
- The above depths of cover should be ensured before the work on road or rail track starts and heavy road rollers or any other highway equipment are used over the pipe.
- In all pressure piping system,unbalanced thrust forces will be present at locations where there Elbows, Reducers, Tees, WYES or Bulkheads.These unbalanced forces must be restrained through properly designed concrete thrust blocks.
- All tests shall be conducted in the presence have parties having jurisdiction.
- All works shall be in compliance with the Authorities Regulations.
- Inspection request shall be raised for installation of storm water pipes (below ground) with gravity/air test
- Inspection request shall be raised for installation of Storm Water pipes(below ground) with gravity test