Our insulated steel pipes adopt an integrated composite structure. The inner steel pipe is responsible for media transportation, the middle polyurethane insulation layer has excellent thermal insulation performance and is waterproof and moisture-proof, and the outer high-density polyethylene or 3PE anti-corrosion steel pipe resists soil corrosion and external impact. The whole can be directly buried without the need to excavate and build pipe trenches, which is convenient for construction, occupies less land, and the pipe material is pressure resistant and settlement resistant. It is equipped with a complete set of prefabricated insulated pipe fittings, which are simple to install on site, with less heat loss, low energy consumption, long service life buried underground, and low maintenance costs. It can meet the needs of various transportation conditions such as municipal heating, industrial hot water and high-temperature steam.