Polyurethane prefabricated buried insulation pipes are mainly used for hot water transportation in heating insulation pipelines, which can meet the transportation of hot water at 130 degrees Celsius, with a peak value of up to 140 degrees Celsius. Polyurethane insulation pipe is a process that uses a complete set of polyurethane foaming equipment to perform shot blasting and rust removal on the outer surface of the steel pipe, as well as corona treatment on the inner surface of the outer protective pipe.