High-Pressure Pipe-Type Cable Systems - The Pipe as a Structure [includes discussion]

In recent years the use of high-pressure pipe-type cable circuits for high-voltage underground power transmission has increased so rapidly that this has now become the most important means of bulk power transmission in locations where over-head lines are not permitted. Other papers have explored the electrical characteristics, current-carrying capabilities, installation methods, and similar considerations. Little has been published with regard to the pipe which is at once a structure, a pressure vessel, and the cable sheath. This paper is concerned only with the pipe. It deals with the selection of suitable pipe for high-pressure feeders, the preparation of pipe ends for welding, methods of welding, and weld testing. The need for anchoring pipes at terminal ends is discussed, as well as the question of protecting the pipes against corrosion.