Methods for emplacing and maintaining transmission lines

Abstract

A transmission line is established between two distant points utilizing a pair of pipelines, one of which is insertable within the other. The outer or larger diameter pipeline is first installed or laid between the two distant points and the pipe is filled with a suitable high density lubricating liquid. The other pipeline which carries and houses the transmssion line is initially filled with an inert gas and in this condition the pipeline and transmission line are "floated" into and through the outer pipeline. After both the inner pipeline and transmission line are in place inside the outer pipeline, the high density lubricating liquid between the pipes may be removed and substituted with a high thermal-conducting non-polluting fluid. The inert gas within the inner pipeline is also replaced with a standard electrical grade insulating oil. The transmission line and inner pipeline may be retrieved from within the outer pipeline for maintenance or repair by reversing the floatation process and pulling the inner pipeline as required. During retrieval operation, the inner pipeline and transmission line are withdrawn into a storage pipeline or passageway.

Dependencies are inferred from the claim text.