Heat preservation pipes are steel pipelines that, after undergoing a thermal insulation process, ensure that the inner temperature of the working steel pipe meets or achieves the required temperature, regardless of different working environments and the influence of external media.

Insulation pipes are widely used in the transportation networks for liquids and gases, including in chemical pipeline insulation projects, oil and chemical industries, centralized heating networks, central air conditioning ventilation pipes, and municipal engineering projects.

High-temperature pre-insulated buried pipes are a type of buried pre-insulated pipe with excellent insulation properties, added safety and reliability, and low construction costs. They effectively address the issues of insulation, sliding lubrication, and waterproofing at the exposed pipe ends for high-temperature heat transfer in urban centralized heating systems ranging from 130℃ to 600℃. These high-temperature pre-insulated buried pipes not only possess advanced technology and practical performance that surpass traditional trench and overhead pipeline installations but also offer significant social and economic benefits, serving as a powerful measure for energy-saving heating. The adoption of the direct-burial heating pipeline technology in high-temperature pre-insulated buried pipes marks a new starting point for the development of China's heating pipeline technology.

Thermal insulation pipes are composed of steel pipes, glass fiber reinforced inner sheath, and glass fiber reinforced outer shell. They feature the inclusion of high-temperature-resistant insulation, lubricating layer, and elastic sealing components.

Composition of Insulated Steel Pipes:

External Steel Pipe: It protects the insulation layer from groundwater erosion, supports the working pipe, and can bear certain external loads, ensuring the normal operation of the working pipe.

2. Corrosion Protection Layer: Protects the outer steel pipe from corrosive substances, thereby extending the service life of the steel pipe.

3. Friction-reducing layer: Ensures free thermal expansion and contraction movement of the working steel pipe.

4. Polyurethane Foam Layer: Ensures the medium temperature is maintained, keeping the outer sheath surface at a constant temperature.

5. Barrier and Reflective Layer: Ensures organic foam materials do not enter the inorganic hard, high-temperature-resistant layer; reflects part of the high-temperature layer's heat.

6. Work钢管: Ensures normal flow of conveying medium.

7. Inorganic rigid thermal insulation: withstands high temperatures, maintains interface temperature between it and organic insulation, and ensures the foam does not carbonize.