Advantages and characteristics of polyurethane insulated steel pipe
Advantages of prefabricated directly buried insulated steel pipe
Compared with the traditional steel pipe insulation method, the prefabricated directly buried insulation steel pipe has very prominent advantages: 1. The prefabricated directly buried insulated steel pipe does not need to build a huge trench, but only needs to bury the insulated pipe underground, which greatly reduces the land occupation of the project, is conducive to environmental protection, reduces the amount of earthwork excavation by more than 50%, and reduces the amount of civil masonry and concrete by 90%. At the same time, the insulation pipe construction is carried out in parallel with the on-site trenching, and only the on-site joint is required, which can shorten the construction period by more than 50%. 2. The heat preservation performance is good, and the heat loss is only 25% of that of traditional pipes. Long term operation can save a lot of energy and significantly reduce the energy cost. 3. It has strong waterproof and corrosion resistance. It does not need to attach a pipe trench. It can be directly buried in the ground or water. The construction is simple and rapid, and the comprehensive cost is low. 4. It also has good corrosion resistance and impact resistance under low temperature conditions, and can be directly buried in underground frozen soil. 5. The service life can reach 30-50 years. Correct installation and use can make the maintenance cost of pipe network very low. 6. The alarm system can be set to automatically detect the leakage fault of pipe network, accurately indicate the fault location and alarm automatically.2. Low heat loss and energy saving The thermal conductivity of polyurethane is: λ= 0.013-0.03kcal/m · h · OC, which 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 0.2kg/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 thermal insulation layer and high-density polyethylene or FRP protective shell with good waterproof performance outside, have changed the situation of "wearing wet cotton padded jacket" of traditional trench laying heat supply pipeline, and greatly reduced the overall heat loss of heat supply pipeline. The heat loss of heat network is 2%, which is far less than the international standard requirement of 10%. 3. Anti corrosion, good insulation and long service life Because the polyurethane rigid foam insulation layer is tightly bonded to the outer skin of the steel pipe, the infiltration of air and water can be isolated, and good anticorrosion effect can be achieved. At the same time, its foaming pores 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, the outer skin of working steel pipe is hard to be eroded by external air and water. As long as the internal water quality of the pipeline is treated well, according to foreign data, the service life can reach more than 50 years, which is 3 ~ 4 times longer than that of traditional trench laying and overhead laying.