Polyethylene pipes and pipe components can be joined with one another either thermally or mechanically. The most important thermal methods are butt welding and electrofusion welding. Welded piping systems are absolutely tight and do not require any additional sealing elements.

The most important procedure for joining of HDPE pipes is butt welding. Here, the surfaces to be joined are heated, after corresponding preparation (cleaning and flattening of the pipe ends) to welding temperature on a heating element and the pipe ends thus plasticized are, after removal of the heating element, forced together under pressure. Welding takes place in accordance with specified process operations, which are documented in DVS 2207.

Bell and socket and clamped joints are mechanical joining methods which are used primarily for building service connections.