Patent ID: 6135159
Filing Date: 2000-10-24
Classification: B29C,B29K,F16L,Y10S

Abstract:
A composite conduit for underground conveyance of fuel oil, gasoline, or petrochemicals, the conduit consisting essentially of:an inner substantially rigid yet deformable tube consisting essentially of copper or an alloy thereof having an outer diameter of 1/16 inch to 4 inches; anda single outer thermoplastic layer extruded around the inner substantially rigid tube, the outer layer of flame retardant flexible thermoplastic material having a thickness of up to about one-third inch and directly contacting the circumference of the inner substantially rigid tube for protecting the inner tube from corrosive effects of a subterranean environment, wherein the inner tube and the outer layer each have a substantially uniform radial wall thickness, and the outer layer is affixed to the tube without adhesives, and wherein the single outer layer is thin so that it can bend without cracking.