Prefabricated polyurethane foam insulation pipes are commonly used in liquid and gas transportation pipeline networks, chemical pipeline insulation projects, petroleum, chemical, central heating networks, central air-conditioning ventilation pipes, municipal engineering, etc. The high-temperature prefabricated direct-buried thermal insulation pipe is a direct-buried prefabricated thermal insulation pipe with good thermal insulation performance, safety and reliability, and low engineering cost. Effectively solve the problems of heat preservation, smooth sliding and waterproofing of exposed pipe ends of prefabricated direct-buried thermal insulation pipes for high-temperature heat transmission at 130°C-600°C in urban central heating. High-temperature prefabricated direct-buried thermal insulation pipes not only have advanced technology and applicability that are difficult to compare with traditional trenches and overhead pipelines, but also have significant social and economic benefits, and are also a powerful measure for heating and energy saving. High-temperature prefabricated direct-buried thermal insulation pipes adopt direct-buried heating pipeline technology, marking that China's heating pipeline technology has entered a new starting point.

Prefabricated polyurethane foam insulation pipe: The insulation layer of this type of insulation pipe is composed of two kinds of insulation materials. The insulation layer, the maintenance shell of the insulation layer, and the working steel pipe passing through the heat medium cannot be firmly bonded together. The inner layer is made of new high-temperature insulation materials, such as centrifugal glass wool felt, composite silicate, glass foam, and the outer layer is made of polyurethane rigid foam.

Prefabricated polyurethane foam insulation pipe structure:

The tube core-the thermal insulation layer of the steel pipe that transports fluid-uses polyurethane rigid foam, which is a closed type, so it has good thermal insulation performance, low water absorption and low thermal conductivity. The separation strength from the steel pipe is higher than the tensile strength of the foam itself, so it also has an anti-corrosion effect on the steel pipe. Outer jacket—a plastic pipe drawn from low-pressure and high-density polyethylene with high tensile, flexural and impact resistance.

Prefabricated polyurethane foam insulation pipes are mainly used in the northern central heating industry, transporting various media within the range of -50°C to 150°C, and can be used in the central cooling industry in some areas in the south, as the power of cold water and hot water. kind. In short, only the medium requiring heat preservation at a temperature below 150 degrees can use this kind of heat preservation pipe. The working steel pipe can adopt different steel pipes according to the different conveying medium, and the thickness of the insulation layer can be changed according to different technical requirements.

Prefabricated polyurethane foam insulation pipe characteristics:

1. Rigid polyurethane with low thermal conductivity and good thermal insulation performance is used as the thermal insulation material, which has excellent thermal insulation.

2. After normal operation, when the 130℃ water is transported to 40 kilometers away, the temperature drop is only about 1℃.

3. It has strong waterproof and corrosion resistance ability. It does not need a pipe trench, and can be directly buried in the open or in the water. The construction is cumbersome and fast, and the overall cost is low.

4. It also has good corrosion resistance and impact resistance under low temperature conditions, and can be directly buried in frozen soil.

5. The prefabricated insulation pipe uses a corrosion-resistant (HDPE: high-density polyethylene) outer pipe, which is not affected by biological and chemical corrosion.

6. ​​According to user needs, various pipe diameters and insulation thicknesses between DN20 and DN1200 and matching pipe fittings (elbows, tees, reducers, fixed joints, etc.) can be provided

7. The product implements the CJ/T114-2000 and CJ/T115-2001 standards of the People’s Republic of China on the establishment of industry standards for cities and towns.

8. In order to ensure the trinity of prefabricated direct-buried thermal insulation pipes, the surface of the steel pipe before foaming is treated by shot blasting, and the inner and outer surfaces of the plastic pipe are treated with corona. The rust removal level reaches the rule of Sa2.5 in GB/T8923-1998, and the inner and outer surface tension of the outer casing pipe is reached. 50 dynes/cm.

Features and advantages of prefabricated polyurethane foam insulation pipe:

1. Reduce project cost.

According to calculations by relevant departments, dual-pipe heating pipes can reduce the project cost by about 25% (using FRP as the maintenance layer) and 10% (using high-density polyethylene as the maintenance layer) under normal conditions.

2. Low heat loss and energy saving.

The thermal conductivity of prefabricated polyurethane foam insulation pipe is: λ=0.013 — 0.03kcal/m·h·oC, which is much lower than other commonly used pipe insulation materials in the past, and the insulation effect is improved by 4 to 9 times. Moreover, its water absorption rate is very low, about 0.2kg/m2. The reason for the low water absorption rate is that the closed cell rate of polyurethane foam is as high as about 92%. Low thermal conductivity and low water absorption, coupled with the high-density polyethylene or glass fiber reinforced plastic maintenance shell with good insulation layer and external waterproof performance, has changed the traditional "worn jacket" situation of heating pipes laid in trenches, and greatly reduced the cost of heating pipes. The overall heat loss, the heat loss of the heating network is 2%, which is less than the international 10% standard request.

3, anti-corrosion, good insulation performance, long service life.

The prefabricated polyurethane foam insulation pipe is tightly bonded to the outer skin of the steel pipe due to the rigid polyurethane foam insulation layer, which insulates the infiltration of air and water, and can play a good anti-corrosion effect. At the same time, its foaming cells are closed, and the water absorption is very small. Both HDPE shell and FRP shell have good anti-corrosion, insulation and mechanical properties. Therefore, the outer skin of the working steel pipe is hard to be corroded by outside air and water. As long as the internal water quality of the pipeline is well disposed, according to the introduction of foreign materials, the service life of high-temperature prefabricated direct-buried insulation pipe can reach more than 50 years, which is 3 to 4 times longer than the service life of traditional trench laying and overhead laying.

4. Less land occupation, fast construction, favorable for environmental maintenance and reduce construction disturbance to the residents.

Prefabricated polyurethane foam insulation pipes do not need to build huge trenches, but only need to bury the insulation pipes publicly, thus greatly reducing the project area, reducing the amount of earthwork excavation by more than 50%, and reducing the amount of civil masonry and concrete by 90% . At the same time, the insulation pipe processing and on-site trenching are stopped in parallel, and only on-site joints are required, which can greatly shorten the construction period. As the transportation of bricks, cement, sand, gravel, residual soil, etc. is reduced, vehicle exhaust emissions, dust emissions, and noise emissions during the construction process are reduced, thereby maintaining the environment.

The prefabricated polyurethane foam insulation pipe is a combination of outer protective steel pipe plus steel pipe anticorrosion, polyurethane foam insulation layer and inner working steel pipe. The steel sleeve steel steam composite insulation pipe is suitable for conveying steam or other media under 2.5MPa and 350 degrees Celsius. The product uses steel pipe as the outer protective layer, which has the advantages of high strength, not easy to damage, cumbersome construction and maintenance, and long service life.