Since the closed porosity of polyurethane foam can reach more than 92%, therefore, using polyurethane foam as the insulation layer of direct buried pipe can not only play the role of heat insulation, but also effectively prevent the penetration of water, moisture and other kinds of corrosive liquid and gas, and prevent the breeding and development of microorganisms. Strong adaptability: polyurethane foam and various materials are not firmly bonded, therefore, as the insulation layer of direct buried pipe, there is almost no need to consider the problem of anti-corrosion layer bonding with it.

The raw materials and ratio of anti-corrosion steel pipe hard foam should be suitable for pouring construction, and the bulging force of polyurethane foam on the template after pouring construction should be as small as possible; in order to resist the possible larger bulging force of polyurethane foam on the template during pouring construction, reinforcement bars can be installed outside the template to ensure the outer layer specification after demoulding. The mold can be removed only after 30-40 minutes after pouring. After pouring the polyurethane rigid foam insulation layer should be fully rested for 24 hours before the next process of construction, external scaffolding should be checked before use whether there are gaps in the scaffolding board, probe plate, body guards, blocking plate, confirm qualified before use, the operation process encountered between the scaffolding and the building pulling joint, without the consent of the leader, is strictly prohibited to remove.
 
    If necessary, the scaffolder is responsible for taking reinforcement measures before dismantling, the tools and materials on the scaffold should be scattered and placed steadily, not to exceed the allowable load, it is strictly prohibited to step on the scaffold body rails and balcony railings for operation, the use of hand-held power tools, must be equipped with a leakage protector, before the operation should be tested and checked, the operation should wear insulated gloves, quality control. Polyurethane storage place and construction work area should focus on fire prevention measures, the site is equipped with fire extinguishers, there should be no open fire within 20 meters around, in case of strong winds above level 6 and heavy rain, outdoor high work should be stopped.