Abstract: A process for producing a pipe fitting of thermally weldable material for attachment to or repair of conduits of thermally weldable material. The first injection mold has channels formed as windings and having channel walls. A heating wire is formed to a wavy heating strand which is laid into the first injection mold between the channel walls. A first welding material is introduced into the channels so that a first broad side of the wavy shape of the heating strand is pressed against a first mold surface of the injection mold and an intermediate product with embedded wavy heating strand is formed. The outside surface is formed by the first mold surface against which the heating strand is pressed and provides the contact surface with the conduit in the end product. The first broad side of the wavy shape of the heating strand remains visible at the outer surface of the intermediate product.

Abstract: A device is disclosed for welding an accessory of thermoplastic material to a pipe or to two pipes of thermoplastic material to be connected to one another. The accessory has at least two segments embracing the circumference of the pipe or pipes. The segments have electrical heating elements at least over portions of their inner surfaces contacting the pipe or pipes. The segments are connected to a welding device via two electrical connecting lines. The two connecting lines form with two connector lines a line combination for a parallel electrical switching of all heating elements. The segments have at their outer surfaces two electrical coupling members for supplying and carrying away an electrical current through the line combination. Counter coupling members of the line combination are contacted with the coupling members of different segments, wherein the coupling members and the counter coupling members are different from each other and are not compatible with each other.