Method of replacing underground pipes without excavating

摘要

The method involves pulling, longitudinal separating, and expanding devices, in order to replace underground lead or plastics piping. The old pipe (1) is cut by a knife-like cutter (6) mounted on a support (5) which is pulled along inside the pipe by a cable (4). The support is connected to an external head (7) which can travel over the pipe, and which may be conical. The head is coupled to a sleeve or production pipe (2), through which the split sections of the old pipe can be removed. The sleeve allows a new production pipe to be introduced simultaneously.