PE insulation pipe is also called PE outer protection pipe, jacket pipe, sleeve pipe. The direct buried polyurethane insulation pipe is made of HDPE insulation pipe as the outer protective layer, the middle filled polyurethane rigid foam is used as the insulation material layer, and the inner layer is steel pipe. Polyure-thane direct buried insulation pipe has good mechanical properties and thermal insulation performance. Under normal circumstances, it can withstand high temperature of 120-180 °C, and is suitable for various cold and hot water high and low temperature pipeline insulation projects.