Chemical Moisture Barrier Cable for Underground Systems

A "universal" moisture/chemical barrier sheath for power, instrument and control cable is described. The combination of copolymer coated aluminum wrapped longitudinally about a cable core, sealed at the overlapped seam, and jacketed with chlorinated polyethylene forms a sheath which is suitable for direct burial, use in cable trays, conduit or aerially. The sealed seam forms an effective chemical/moisture barrier, the aluminum serves as an effective screen against electrical transients, and the bonded chlorinated polyethylene provides improved mechanical properties as well as ignition resistance. Economics are favorable compared to lead or continuously welded sheaths and UT requirements for Type TC, PLTC and MV-90 cables are met.