PROCESS AND APPARATUS FOR INSTALLING A NEW PIPE INSIDE AN EXISTING PIPE

摘要

A thermoplastic pipe in a flattened and folded shape and of selected characteristics is formed by manufacturing it in this reduced shape. It is inserted in the flattened and folded shape and in a pliable state into a pipeline to be lined. It is then expanded and when set serves as a rigid or semi-rigid pipe within a pipeline capable of withstanding external hydrostatic and earth pressures. The thermoplastic pipe is heated during its installation for installing it into an existing pipeline and for expanding it.