Polyurethane thermal insulation directly buried pipe has become a comparatively mature advanced technology in some prosperous countries abroad. Over the past decade, through digestion and absorption of this advanced technology, China's heating engineers and technicians are pushing the domestic pipeline network laying technology to a higher level. Over the past decade, the theoretical results have proved that the laying method of polyurethane tyre thermal insulation buried pipe has many advantages compared with traditional trench and overhead laying. This is also the inherent driving force for the rapid development of polyurethane thermal insulation buried pipe in China's heating projects.
Advantages of polyurethane thermal insulation directly buried pipe:
1. Reduce the cost of construction. According to the calculation of relevant departments, double-pipe heating pipeline can reduce the cost of construction by 25% (using FRP as maintenance layer) and 10% (using high density polyethylene as maintenance layer) under normal conditions.
2. Low heat loss and energy saving. Because polyurethane rigid foam plastic is used to stop the heat preservation of directly buried pipes, its thermal conductivity is as follows: lambda = 0.013-0.03kcal/m.h.oC, which is much lower than other commonly used heat preservation data of pipes in the past, and the heat preservation effect is improved by 4-9 times. And its water absorption is very low, about 0.2 kg/m2. The reason for low water absorption is that the polyurethane foam has a closed porosity of about 92%. Low thermal conductivity and low water absorption, together with high density polyethylene (HDPE) or fiberglass reinforced plastics (FRP) maintenance shell with good insulation layer and external waterproofing performance, have changed the situation of traditional trench laying heating pipeline "wearing wet cotton jacket", greatly reducing the overall heat loss of heating pipeline, heat loss of heating network is 2%, less than the international standard requirements of 10%.
3. Anti-corrosion, good insulation performance and long service life. The directly buried insulation pipe is tightly adhered to the outer skin of the steel pipe because of the rigid polyurethane foam insulation layer, which can isolate the infiltration of air and water, and can play a good anti-corrosive effect. At the same time, its foaming holes are closed and its water absorption is very small. High density polyethylene shell and FRP shell have good anti-corrosion, insulation and mechanical properties. Therefore, it is very difficult for the outer skin of the working steel pipe to be corroded by the outside air and water. According to foreign materials, the service life of polyurethane tyre insulation pipeline can reach more than 50 years, which is 3-4 times longer than that of traditional trench laying and overhead laying.
With a brief summary of the straight seam steel pipe on the black jacket, I hope it will be helpful to our customers. If you don't understand or ask for help, please click on our official website: https://www.sdhpgy.com or call for consultation. We will try our best to solve it for you.
