Envelope element for a pipeline, mold for manufacture thereof, and method for covering a pipeline

摘要

A plastic envelope element (1) used with others to create a tube around an underwater pipeline (2) is disclosed. The tube when constructed around the pipeline has integral springs (8) in compression with the outer insulator coating (32) of the pipeline and are held in place by a strap (17). When the pipeline is submerged hydrostatic pressure causes the coating to compress and reduce in diameter as in the drawing. Because the springs where in compression even though the piped diameter is smaller the tube formed by the envelope elements still conforms to the pipeline and remains located properly. The springs are formed during injection moulding of the element.