Pipe coupling

A pipe coupling is a fitting that joins two lengths of pipe together with a watertight seal. In UK drainage, common types include push-fit couplings with integral rubber seals, solvent weld sockets for PVC-U, and flexible elastomeric couplings used to join pipes of different materials or sizes. Standards include BS EN 295 for vitrified clay and BS EN 1401 for PVC-U sewer pipe. Flexible couplings, sometimes called repair or universal couplings, are widely used during drain repairs to connect new sections of PVC-U or HDPE to existing clay or pitch fibre pipes in Victorian London streets. Stainless steel banded couplings are favoured underground because of their corrosion resistance. Correct alignment and tightening to the manufacturer's torque are critical to a long-lasting joint.