Prefabricated directly buried thermal insulation pipe fittings mainly include thermal insulation elbow, thermal insulation elbow, thermal insulation tee, thermal insulation reducer, etc. Thermal insulation parallel tee also belongs to one of them, which uses polyurethane foam thermal insulation technology. Polyurethane foam has good mechanical properties and thermal insulation properties. Generally, it can withstand 120 ℃, and can withstand 180 ℃ through modification or combination with other thermal insulation materials. The structure of prefabricated directly buried thermal insulation pipe fittings is mainly divided into three layers. The steel pipe fittings with good sales volume are themselves, and the layer is polyurethane foam, which plays a role in thermal insulation performance and supports the weight of the heating network. The third layer is made of polyethylene, which serves as waterproofing (based on actual reports) and anti-corrosion (based on actual reports). Widely used in centralized heating, cooling, and transportation of hot oil, as well as insulation and cooling engineering in warm rooms, cold storage, coal mines, petroleum, chemical and other industries. Main equipment: steel pipe buffer platform, pipe pulling unit, traction machine, pipe threading machinery, high-pressure blasting machine, repair platform, transmission line, steel pipe preheating furnace, shot blasting machine main inspection platform and unqualified steel pipe return transmission line, fast in roller group, fast out roller, inspection platform, etc