Method and apparatus for making compound pipes.

摘要

The method involves an inner tube being inserted into an outer tube of different materials are involved. After insertion of the inner tube in the outer the inner tube is plastically deformed by the application of controlled pressure over its entire length the two tubes are connected to one another in a gap-free manner. By the controlled application of pressure (P), pref. of a fluid, on the inner surface of the inner tube (1), firstly the inner tube over its plastic area is plastically widened until it fits against the outer tube (2). Then, by increasing the pressure causing further plastic deformation of the inner tube the outer tube is widened in the elastic range. After pressure unloading, an adhesion pressure between the inner and outer tubes remains.