Polyethylene pipe Installation
Relevant Standard AS/NZS 2033:2008
Specialized tools and equipment used in the Polyethylene pipe & installation, repair, testing and commissioning of fittings is essential.
Temperature considerations must also be taken into account and pipe may need to be de rated due to thermal effects of environment and service temperature.
Only trained and certified operators shall carry out fusion jointing and acceptable methods being electro-fusion, butt-fusion and socket-fusion.
Polyethylene pipe Installation Sliding supports shall provide a guide, without restraint, for the axial movement of pipes subject to thermal expansion.
Polyethylene pipe Installation Fixed supports shall restrain movement of the pipe or fitting by being clamped to the structure.
Polyethylene pipe Installation Provision for expansion must be made for thermal movement by fitting expansion joints, unless the movement can be controlled by other means.
Polyethylene pipes may require special processes since they may continue to expand significantly throughout the test period.
When a PE pipe is sealed under a test pressure there may be creep even in a leak free system, due to the response and stress relaxation of the PE material.
It may be considered good practice to initially fill the pipe with water twenty four hours prior to pressure testing to allow pipe temperature equilibrium with the water.