Polyurethane prefabricated directly buried thermal insulation pipe can play a good anti-corrosion role because the polyurethane rigid foam thermal insulation layer is closely bonded with the steel pipe skin, which isolates the penetration of air and water. At the same time, its foaming holes are closed and its water absorption is very small. High-density polyethylene shell and glass fiber reinforced plastic shell have good corrosion resistance, insulation and mechanical properties. Therefore, the outer skin of the working steel pipe is not easy to be eroded by external air and water. The reason of low water absorption is that the closed cell rate of polyurethane foam is as high as 92%. The low thermal conductivity and water absorption, coupled with the insulation layer and the high-density polyethylene or glass fiber reinforced plastic protective shell with good waterproof performance outside, have changed the situation of "wearing wet cotton-padded jacket" in the traditional trench laying of heating pipelines, greatly reduced the overall heat loss of heating pipelines, and the heat loss of heating pipelines is 2%, which is less than 10% required by international standards. The practice results of more than ten years have fully proved that the laying method of polyurethane thermal insulation direct buried pipe has many advantages compared with the traditional trench laying and overhead laying.
Advantages of steel steam insulation pipe with steel casing-advantages and characteristics?
1, reducing the project cost. ?
According to the calculation of relevant departments, the double-pipe heating pipeline can generally reduce the project cost by about 25% (using FRP as protective layer), 10% (using high-density polyethylene as protective layer). ?
2. Low heat loss and energy saving. ?
Its thermal conductivity λ = 0.0 13—0.03kcal/m? h？ OC is much lower than other commonly used pipeline insulation materials in the past, and the insulation effect is improved by 4~9 times. Moreover, its water absorption is very low, about 0.2 kg/m2. The reason of low water absorption is that the closed cell rate of polyurethane foam is as high as 92%. The low thermal conductivity and water absorption, coupled with the insulation layer and the high-density polyethylene or glass fiber reinforced plastic protective shell with good waterproof performance outside, have changed the situation of "wearing wet cotton-padded jacket" in the traditional trench laying of heating pipelines, greatly reduced the overall heat loss of heating pipelines, and the heat loss of heating pipelines is 2%, which is less than 10% required by international standards. ?
3, corrosion resistance, good insulation performance and long service life. ?
Due to the close combination of polyurethane rigid foam insulation layer and steel pipe skin, high-temperature prefabricated directly buried insulation pipe can isolate the penetration of air and water and play a good role in corrosion protection. At the same time, its foaming holes are closed and its water absorption is very small. The service life of high-density polyethylene shell and glass can reach more than 50 years, which is 3~4 times longer than that of traditional trench burial and overhead laying. ?
4. Less land occupation and fast construction. The advantage of steel steam insulation pipe with steel casing is that it is beneficial to environmental protection.