IMPROVEMENTS IN OR RELATING TO PIPE JOINTS

A pipe joint comprising a socket end 2 of one pipe 1 adapted to receive a spigot end 14 of a second pipe 15, in which the socket end is provided with an annular extension member 8 welded to the end thereof and incorporating a peripheral groove 9 extending around the inner surface thereof; one or more protrusions 16 located in ring-like disposition around the outer periphery of the spigot; and a resilient locking ring 12 located within the groove in the extension member 8 of the socket; the arrangement being such that on insertion of the spigot 14 through the extension member 8 of the socket 2, the annular protrusion or protrusions 16 thereon force the resilient locking ring 12 radially outwardly into the groove 9 in the extension member 8 until the protrusion or protrusions have passed the ring, whereafter the locking ring springs into contact with the spigot behind the protrusion or protrusions thereby locking the spigot in the socket. In particular flexible pipelines with non-locking pipe joints can be readily modified to locking format by the welded addition of the extension member.