How to Handle and Install GFRP Pipes

Transport GFRP pipes:

While transporting GFRP pipes, attention must be given on securing pipe sections properly. All pipe sections should be supported on flat timbers, spaced at maximum 4 metres with a maximum overhang of 2 metres. Also all the pipes should be chocked to maintain stability and separation and to avoid abrasion.

Stack height should not cross 2.5 metres. Strap the pipe to the vehicle over the support points using pliable straps or rope. Never use steel cables or chains without adequate padding to protect the pipe from abrasion. Bulges, flat areas or other abrupt changes of curvature should not be allowed. Further, transport of pipes outside of these limitations may result in damage to the pipes.

Unloading GFRP pipes:

Once the pipes reach the site, maintaining control of the pipe during unloading should be ensured. Guide ropes attached to pipes or packages will enable easy manual control when lifting and handling. One may use spreader bars when multiple support locations are necessary. Avoid dropping, impacting or bumping the pipe, particularly at pipe ends.

Handling GFRP pipes:

When handling single pipes, use pliable straps, slings or rope to lift. Avoid using steel cables or chains to lift or transport the pipe. Pipe sections can be lifted with only one support point, while two support points is the preferred method for safety reasons, as it makes the pipe easier to control. Do not lift pipes using hooks at pipe ends or by passing a rope, chain or cable through the section end to end.

How to store GFRP pipes:

It is advisable to store pipes on flat timber to facilitate placement and removal of lifting slings around the pipe. When storing pipes directly on the ground, be sure that the area is relatively flat and free of rocks and other potentially damaging debris. Placing a pipe on mounds of backfill material is an effective way of site pipe storage. Further, all pipes should be chocked to prevent rolling in high winds.

Installation of GFRP pipes

Few of the "how to do" aspects are given hereunder for you while installing GFRP pipes

Standard trench profile: The width of the trench at the spring line of the pipe need not be greater than necessary to provide adequate room for jointing the pipe in the trench and compacting the pipe zone backfill at the haunches.

Bedding: The bedding should be placed over a firm, stable trench bottom so as to provide proper support. The finished bed must provide a firm, stable and uniform support for the pipe barrel and any protruding feature of its joint. Provide 100 - 150 mm of bedding below the barrel and 75 mm below the coupling. For a soft or unstable trench bottom, an additional foundation may be needed to achieve firm support for the bedding.

Backfilling: Immediate backfilling after joining is recommended as it will prevent two hazards, i.e. floating the pipe due to heavy rain and thermal movements due to large temperature fluctuations. Floating of the pipe can cause damage and create unnecessary reinstallation costs, whilst the cumulative effect thermal expansion and contraction over several lengths can compromise seal integrity at one joint.

Jointing: GFRP pipe sections are typically joined using couplings. Pipe and couplings are supplied either separately or the pipe may be supplied with a coupling installed on one end. If the couplings are not delivered pre-mounted, it is advisable that they be mounted at the storage yard or at the trench side before the pipe is lowered to the trench bed.

Site testing: Once pipes are installed, testing should be conducted frequently to assure compaction and pipe deflection criteria are being achieved.

Maintenance and Repair :

Normally, pipes with minor damages can be repaired temporarily at the job site by covering outside of the defect with a laminate. For this purpose the pipeline must be made pressure-less and dried to prevent the laminate from getting wet. If it is not possible to dry the pipe, then the pipe is recommended to be emptied.

References:

1. CPHEEO manual

2. Other IS and AWWA Standards – 12709