What is mechanical assembly?
Mechanical assembly requires the use of fittings, generally working on the compression principle, to join different materials together. It is most commonly used with PE for joining the PE to a pipe or fitting of a different material, or in circumstances where fusion is not feasible.
Mechanical fittings generally include a stiffener which is placed inside the pipe or fitting to ensure stability when the fitting is compressed. These stiffeners are also designed to withstand end loading where necessary. The fittings also include gaskets which are compressed to effect the seal at the rated pressure of the fitting.
The fittings for use in gas and water can differ and it is essential to use the correct fitting for the application. If there is any doubt the manufacturer of the fitting should be contacted. Similarly the manufacturer's recommendations on installing the fitting, including any limitations on torque to be applied in tightening the fitting, should be followed at all times.
ISO 14236:2000 Plastics pipes and fittings - Mechanical-joint compression fittings for use with polyethylene pressure pipes in water supply systems.