Polyurethane insulation steel jacket composite steam pipe insulation is made with rigid polyurethane foam insulation pipe insulation material, 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 steel jacket buried insulating pipe manufacturers, 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. Polyurethane insulation construction technology is more of a preparation based on: People's Republic of China urban construction industry standards standard: CJ / T114-2000 promulgated by: People's Republic of China Ministry of Construction Effective Date: 2000-10-01 Second, according to atlases 4.4.1 It states: pipe ends should stay out of the first 150mm-250mm bare uninsulated area to prepare for welding. Third, the production process: the production process, Mr. outputs a high-density polyethylene outer sheath tube, then in polythene armor tube and the space between the pipe and then cast polyurethane rigid foam insulation production process is what we often say 'two-step'. Production process: steel rust - polyurethane foam - forming - product testing - storage