In addition to Chinese and foreign production of buried pipe insulation pipe insulation manufacturer, has leakage alarm line, it can at once dedicated instrumentation on polyurethane buried pipe leakage occurs somewhere pipe insulation, conduction through the police line pipe insulation, shows seepage pipe insulation, the exact location and extent of the size of the leak leaking to notify the subject of infiltration staff quickly handle leaking pipe, ensure the safe operation of heating pipe network. At the end of the domestic production of pipe insulation provided leakage alarm line, to be fill this gap. High Temperature prefabricated buried pipe insulation pipe insulation is mainly composed of four parts. Steel (1) work: according to the medium technical requirements were adopted seam steel pipe, seamless, double-sided spiral submerged arc welded steel pipe. (2) Insulation layer: the rigid polyurethane foam plastic. (3) protective shell: the use of high-density polyethylene or fiberglass.