Polyurethane insulation in accordance with different transmission media can be divided into: water supply prefabricated polyurethane insulation, high temperature polyurethane insulation polyethylene pipe insulation, vapor transport using polyurethane composite prefabricated buried steam pipe insulation, the use of oil buried hard polyurethane foam insulation pipe corrosion and so on. There are many terminologies, such as polyurethane pipe, polyurethane prefabricated pipe, buried prefabricated polyurethane tube, polyurethane jacket pipe jacket pipe insulation, polyurethane foam insulation tubes and so on. Prefabricated buried pipe insulation are generally buried in the proper installation of underground hot water pipe insulation for the transmission medium, primarily to be able to insulation, waterproof, it does not appear so-called corrosion, rusting, cracking, etc. Instead of this product, durable, long life, has good resistance to high temperature and low cold performance, environmental adaptability, and waterproof, not easily broken and so on. It is a certain weight, so the storage and transportation have some difficulty.