Tension proof connection device for plastic pipes used to transport gas or liquid, contains blocking bushing with non circular cross section

摘要

A blocking bushing (20) with a non-circular cross-section can be introduced into one or both pipe ends (B). The dimensions of the bushing are defined by the maximum and minimum allowable pipe diameter and pipe wall thickness. A device for forming a tension proof connection between the ends of two pipes for transporting a gas or liquid comprises a threaded muff (1) which can be slid tightly over one pipe, and a ring nut (6) with an inner periphery converging in the outwards direction for receiving a split clamping ring (8). A blocking bushing which can be introduced into one or both pipe ends has a non-circular cross-section when not in use, so that its outer parts lie on a diameter equal to the maximum allowable outer diameter of the pipe, which is made from a plastic material such as HDPE, minus the minimum allowable pipe wall thickness. The inner parts of the bushing lie on a diameter equal to the minimum allowable outer diameter of the pipe minus the maximum allowable pipe wall thickness. An Independent claim is also included for the bushing.