As there is no direct buried pipeline quota in Shanghai, the general practice is to dismantle and set quotas, such as steel pipe installation, painting, rust removal, plastic pipe installation, and filling at pipe joints, etc. This is also the case for steam buried pipes. How to fill and install polyurethane direct buried insulation pipes? Points to note during the installation of direct buried insulation pipes include: 1. Construction should avoid groundwater and rainwater immersion; if the ends are accidentally immersed, they should be dried before the connection coating. 2. Pipes should be stored on a flat ground, neatly stacked, with a height less than 1.5 meters. 3. Pipes should be handled gently, collisions and throwing are strictly prohibited, and direct hoisting with wire ropes is strictly forbidden. 4. Insulation and anticorrosion layers should be avoided from direct contact with flames. For the on-site installation of direct buried insulation pipes, please follow these steps: excavation of the trench, base treatment (drainage, sand pad), pipeline steel pipe welding inspection (water pressure), installation (test pressure), foam sealing of the foam holes. For maintenance and installation, our company can send personnel to the project site for joint insulation work, including the installation of joint coating pipes, the connection and sealing of joint coating pipes with the main pipe, foam work at the on-site joints, but not including steel pipe welding. (1) Method: sleeve joint. In this way, the polyethylene sleeve and the prefabricated insulating pipe have the same material and density. The polyethylene joint sleeve is connected and sealed to the main pipe to ensure water tightness of the joint. Then, foam holes on the joint sleeve are frothed. After the joint foam is completed, high-density polyethylene is filled or hot melt welding is used to seal the foam holes. (2) Heat Shrink Tape: In the joint mode of heat shrinkable tape, it is a crucial material for the life and sealing of the joint. The company only uses heat shrinkable tape products approved by the European Heating Association. The existing supplier of heat shrinkable products is from Canada or Canada. The bonding layer and hot melt temperature of the heat shrinkable tape for prefabricated insulation pipe joints are specially designed.