Thermal insulation requirements of polyurethane insulation pipe
As the two mainstream choices in the field of pipeline insulation, polyurethane insulation pipes and rubber-plastic insulation pipes have significant differences in materials, performance, and applicable scenarios, and their specific insulation indicators also have different emphases. The polyurethane insulation pipe uses rigid polyurethane foam as the insulation layer and is covered with a high-density polyethylene protective layer. It has high structural strength and good pressure resistance (≥0.3MPa). It can withstand medium temperatures from -196°C to 120°C, and with a temperature as low as 0.
With a thermal conductivity below 033W/(m·K), it has leading thermal insulation and energy-saving effects. Factory prefabricated production ensures stable quality and a design life of up to 30 years. It is especially suitable for large-scale direct burial projects such as centralized heating, cooling, and crude oil transportation. In contrast, rubber-plastic insulation pipes are made of nitrile rubber foam. They are soft in texture, easy to construct, and have outstanding anti-condensation properties. However, they have low strength, are easy to age, and have a lifespan of only 5 to 10 years. They are more suitable for air-conditioning ducts and indoor plumbing systems in buildings and have lower initial costs. As far as the core insulation requirements of polyurethane insulation pipes are concerned, GB/T must be strictly followed 29047-2021 standard, the foam density must be no less than 60kg/m³, the closed cell rate must be more than 88%, and the water absorption rate must be controlled within 10% to ensure long-term stable operation in a humid buried environment; at the same time, the heat resistance must meet the 120°C working condition, and the axial shear strength must be no less than 0.12MPa at room temperature to ensure the firm bonding between the insulation layer and the pipe wall. All in all, the choice of material should be based on the actual project: if the focus is on long-term energy saving and structural reliability, polyurethane insulation pipes are the ideal choice; if the focus is on short-term economy and indoor condensation prevention, rubber and plastic insulation pipes have more cost-effective advantages.