Patent ID: 8794500

Claim:
Method of mounting a connecting element at an end of a helically corrugated pipe of metal where said helically corrugated pipe of metal has an end face extending along a helical turn of a helical thread formed from its corrugation and where said connecting element to be fastened to the pipe includes a pipe piece of metal which has a helically extending inner surface corresponding to the helical thread of the corrugation of the pipe, and a smooth cylindrical outer surface, said method comprising the steps of: initially severing the pipe at an end along a screw thread with a cut in axial direction of the pipe connecting a beginning and an end of the helical thread after one revolution; a pipe piece of metal, which is provided with a helically extending inner surface and has a non-corrugated cylindrical outer surface, is subsequently screwed onto the pipe; subsequently a metal ring, which has two sections with different inner diameters, is pushed onto the pipe piece with a section of said metal ring having the greater diameter, which rests with its section having the smaller diameter on the pipe, and has on this section an end face corresponding to said helical turn of the thread of the pipe and extending along a helical line; the ring is then welded at its helically extending end face to the end face of the pipe; and that the ring is finally welded to the pipe piece.