Prefabricated thermal insulating tubes offer the first layer: Working pipe layer based on design and customer requirements are generally used seamless steel pipe, spiral pipe and straight pipe joints. Advanced steel surface after shot blasting process, steel rust rating up to GB8923-1988 standard Sa2 grade, surface roughness up GB6060.5-88 standard R = 12.5 m. Second layer: polyurethane insulation layer: high pressure foaming machine with a cavity between the pipe and the outer protective layer is formed in a one-time injection of liquid is made of rigid polyurethane foam, commonly known as "pipe-in-pipe foam." The third layer: high-density polyethylene protective layer: a certain thickness preformed black or yellow polyethylene plastic pipe. First, its role polyurethane insulation protection against mechanical hard object damage, and second, anti-corrosion, waterproof. Polyurethane prefabricated buried pipe insulation buried pipe insulation steel jacket steel jacket buried insulating pipe insulation Depending on the slide can be divided into two categories: 1, sliding: the work of pipe insulation, aluminum silicate, minus resistance layer, porous calcium silicate, insulation, stainless steel fastening strip, aluminum foil reflective layer of polyurethane insulation, jacket pipe, the outer coating composition. Sliding-type pipe insulation is made of steel transmission medium or porous calcium silicate composite rigid polyurethane foam coat glass pipe steel corrosion protection layer structure composed. Various pieces node thermal insulation technology is mature, reliable quality. Polyurethane prefabricated buried pipe insulation, also called two types of prefabricated pipe insulation: the plastic sleeve steel pipe insulation and steel jacket pipe insulation, it can be buried (so people used to call it-buried in permafrost in the 0.6 to 1.2 meters prefabricated pipe insulation or insulation), prefabricated buried pipe insulation with high efficiency insulation, waterproof, corrosion, insulation, sound insulation, fire-retardant, cold, corrosion, light capacity, high strength, simple and quick construction, heat loss than ordinary pipe can lower than 40%, the working life than other insulation corrosion materials increased by 3-5 times, life can reach 30 - 50 years. For details, see: http: //www.rbffbw88.com/