摘要 |
For welding composite pipes (1, 1%), a welding ring (13) is used which lies against the side wall sections (7, 8) of elevations (4). The welding ring comprises thermoplastic material and is provided with an electrical resistance heater (19). Before welding, there exists between the front walls (10, 10%) of the pipes (1, 1%) an annular gap (23) to which a volume-compensating groove (24) in the welding ring (13) is allocated. By at least partial melting of the welding ring (13), a connection of the pipes (1, 1%) in their region outside their inner pipe (2) takes place, the end walls (10, 10%) lying unwelded against one another. <IMAGE> |