Pipe connection for safety valve - has pair of sealing lips to receive ring projection of joint muff with watertight connection

摘要

The pipe connection for use as a closure cap or a safety valve in pipes, has a watertight ring shaped seal (164) connected to a primary muff, (168) the seal having a ring-shaped recess (178) to take the ring projection (180) of a secondary muff (166). The recess narrows inwards, and forms two thin, flexible ring shaped lips (182) which encompass the inner and outer periphery of the ring projection (180). These lips (182) according to high or low inner pressure, either locate inwards or outwards on the projection (180) of the secondary muff (166). A coupling is provided to join the primary (168) and secondary muffs (166), the first muff's watertight seal (164) serving also to seal the secondary muff (166). According to the sealing requirement, the depth of insertion of the second muff (166) in the seal recess (178) is adjustable by the coupling.