Thermoplastic pressure pipe sockets lining with prefabricated insert - to maintain the pipe system stress rating and locate an internal seal

摘要

The end of a thermoplastic pipe is converted into a socket by softening and dilating the end of the pipe to accept a prefabricated insert which is grooe to locate an internal annular seal. The insert is bonded to the inside of the pipe mount, at least at zones at or near both ends of the socket by adhesive or fusion welding. Used esp. for mfg. socket ends on pressure pipe without shortening the original pipe length. The insert compensates for loss of strength of the original pipe wall by thinning during dilation. Method has partic. reference to forming coupling sockets on PVC pipes.