SETT OCH APPARAT FOR MONTERING AV ETT RINGELEMENT PA INNERVEGGEN AV ETT CYLINDRISKT TERMOPLASTROR

摘要

A method and an apparatus for fixing a ring element to the inner wall of a thermoplastic pipe are disclosed. The invention involves the clamping of the ring element on a cylindrical support member and the combined straightening and radial expansion of the ring element into contact with the inner wall. Previously, or simultaneously, the pipe is radially expanded stepwise to its final diameter, the apparatus including suitable mold portions which can impart the desired shape to the pipe end. One part of the mold portion can include radially expandable blockade means which can impart a portion of the desired shape to the pipe end and which can also be instrumental in the clamping and expansion of the ring element. Use of the invention results in a strengthened pipe end which is sized to mate with the end of a next length of pipe and which has a built-in means for mounting packing or other sealing elements.