Polyurethane insulation pipe insulation, is to use rigid polyurethane foam insulation pipe insulation made of electric insulation pipe, its product mix from inside to outside as follows: work steel, polyurethane insulation layer and the high density polyethylene outer sheath tube. It can be divided according to different outer sheath: FRP outer sheath polyurethane insulation, high-density polyethylene outer sheath of polyurethane insulation, steel outer sheath of polyurethane insulation and other outer sheath insulation. Prefabricated buried pipe insulation is one of the main is buried pipe insulation pipe insulation tube, generally take the form of buried, the operation is more complex plumbing pipe insulation, as long as continue to ensure perfect installation of insulation full play to the performance of products carried out insulation, protective substance delivered, and will not be conveyed material surface erosion and disturbance. At site must have some requirements in order to really focus on the thermal insulation properties of the product to fully play out.