According to the data of HDPE pipe manufacturers, high-density heat-resistant polyethylene pipe has the following characteristics compared with ordinary steel pipes: (1) excellent thermal insulation performance, inner thermal conductivity is only 0.42W/m. K, heat loss is much lower than the steel pipe, long-term operation can save a lot of energy, significantly reduce energy costs. (2) with strong waterproof and corrosion resistance, reliable sealing, no leakage; no corrosion, no water pollution, no scale blockage, in the daily management and maintenance of the thermal pipe network has a great advantage. (3) It also has excellent corrosion resistance and impact resistance under low temperature conditions. The embrittlement temperature of the material reaches -70℃, which can be easily used in cold areas. (4) Pressure and temperature resistance, reliable performance, the service life can reach 50 years at 70℃.
(5) Hot melt butt and electric fusion welding is convenient, firm and reliable. (6) The construction process is simple and quick, the construction and installation is convenient, there is no need to install pipe ditch, which can be directly buried in the ground. This feature considerably saves the construction cost of PE-RT II pipeline and shortens the construction period. Considering the cost of labor, materials and mechanical equipment, the construction cost of PE-RT II pipeline can save 30% compared with that of steel pipe.
(7) This kind of pipe has excellent resistance to rapid cracking and moderate crack growth, and can be recovered after flattening; once the pipeline is broken, damaged, etc., the pipe pressure can be used to achieve local water blocking operation, convenient emergency maintenance, cost and time saving. (8) Economic feasibility: with diameter below 90mm, the material cost of high-density heat-resistant polyethylene pipe is comparable to that of steel pipe; above 110mm, 10~20% higher than the steel pipe. If combined with construction and operation, the economy of high-density heat-resistant polyethylene pipe is higher than that of steel pipe under dn355.
Precautions for the use of high-density heat resistant polyethylene insulation pipe in heating (1) Raw materials should be closely checked, and attention should be paid to distinguish PE-RT II products and PE-RT I products. (2) During welding, when the nominal outer diameter of the working pipe is less than 90mm, it is appropriate to use electric melting pipe fittings for connection; when the nominal outer diameter of the working pipe is greater than or equal to 90mm, hot melt butt should be used. (3) If elevated-density heat-resistant polyethylene insulation pipe is used in the transformation of some pipe sections of the thermal pipe network, it is necessary to pay attention to the connection between the steel pipe and plastic pipe cannot use steel-plastic conversion. Instead, flange and heat-resistant sealing rings should be used for connection. (4) PE material by ultraviolet radiation will accelerate its aging, should not be used on the ground, should be buried. Avoid sunlight during storage and construction.