Methods and devices for the production of a pipe from biaxialy oriented thermoplastic material having an integrated socket

A method for forming an integral socket to a pipe made from biaxially oriented thermoplastic material, which pipe has a pipe body and is provided, at one or both ends, with an integral socket, comprising the steps of subjecting a pre-fabricated pipe from biaxially oriented thermoplastic material to a socket-forming operation using a socket-forming device, by means of which an end part, which has been heated to a suitably elevated temperature, of the pipe which has previously been produced is formed into a socket, after which the end part which has been deformed into a socket is cooled, and wherein the heated end part of the pipe, or an annular region of the said end part, is held in a substantially stationary position at one of its axial ends, and in that the other axial end of the end part is displaced in the axial direction with respect to the stationary axial end by displacement means associated with the socket-forming device, in such a manner that the end part, or the relevant annular region thereof, is lengthened in the axial direction.

A method for producing a pipe from biaxially oriented thermoplastic material, which pipe has a pipe body and, at one or both of its ends, an integral socket, a pre-fabricated pipe from biaxially oriented thermoplastic material being subjected to a socket-forming operation using a socket-forming device, which socket-forming device comprises a socket-forming mandrel which is slid into the interior of an end part of the pipe which has previously been produced, which end part, at a suitably elevated temperature, is formed into a socket, after which the end part is cooled and the socket-forming mandrel is removed from the end part, the socket-forming device being provided with force means for generating a force in order to push the pipe onto the socket-forming mandrel, wherein said force means is designed to engage on an annular region of the end part of the pipe which adjoins the free edge of the end part, and to push said annular region over the mandrel in such a manner that a tensile stress is generated in the end part when the end part is pushed onto the mandrel.