Prefabricated buried pipe insulation is one of the main is buried pipe insulation, usually take the form of burial, the operation is more complicated, just perfect insulation installation continue to ensure full product performance play black and yellow insulation sandwiched kepi carried out insulation black leather jacket pipe insulation, protective substance delivered, and will not be conveyed material surface erosion and interference. At site must have some requirements in order to really focus on the thermal insulation properties of the product to fully play out. Polyurethane insulation tubes yellow security jacket warm skin, is to use rigid polyurethane foam pipe insulation made of insulating material, and its product mix from inside to outside as follows: work steel, polyurethane insulation layer and the high density polyethylene outer sheath tube. Categories its classification is complex, generally in accordance with people's habits at several ways: 1. laying methods can be divided in accordance with: Buried polyurethane insulation, polyurethane insulation overhead. 2. In accordance with its transmission medium temperature can be divided into: normal polyurethane insulation tubes, high temperature polyurethane insulation, cryogenic polyurethane insulation.