Apparatus for welding plastic pipes

摘要

The invention relates to an apparatus for welding the faces of two thermoplastic pipe ends to each other. First of all, the regions at the face and end of the pipes are heated and the faces are then welded to each other under an axial pressure and, during pressing together of the faces, the end regions of the pipes are subjected to a radially acting, calibrating internal pressure by means of a radially expandable element, the outer circumference of which is provided with a heating source. At the same time, heat is applied to the end regions from the interior of the pipe. The invention is characterised by an expanding element which is part of a cylinder-piston unit which can be inserted into the interior of the pipe. <IMAGE>