Insulated steel pipes are steel pipes that, after undergoing heat preservation processing, ensure that the internal temperature of the working pipe meets or reaches the required temperature in various working environments and the influence of external media. They are extensively used in liquid and gas transmission networks, insulation projects for chemical pipelines, oil and chemical industries, centralized heating networks, central air conditioning ventilation pipes, and municipal engineering projects. Steel-clad steel composite insulated pipes are also processed with heat preservation techniques to ensure the internal temperature of the working pipe meets or reaches the required temperature under various working conditions and the influence of external media. These pipes are widely applied in liquid and gas transmission networks, chemical pipeline insulation projects, oil and chemical industries, centralized heating networks, central air conditioning ventilation pipes, and municipal engineering.
Steel-clad steel composite insulated pipelines can be divided into two major categories based on the different sliding methods of the insulation structure:
1. Inside Sliding Type: The thermal insulation structure consists of working steel pipe, aluminum silicate, drag-reduction layer, micro-porous calcium silicate, insulation layer, stainless steel fastening steel strip, aluminum foil reflective layer, polyurethane insulation layer, outer steel pipe, and external anti-corrosion layer. The inside sliding type insulated steel pipe is composed of a steel pipe for conveying medium + composite silicate or micro-porous calcium silicate + rigid polyurethane foam plastic + outer steel pipe + glass fiber reinforced plastic shell anti-corrosion protective layer. Various pipe fitting joints have matured insulation treatment technology and reliable quality.
2. External Sliding Type: The thermal insulation structure consists of working steel pipe, glass wool thermal insulation layer, aluminum foil reflective layer, stainless steel fastening steel strips, sliding guide brackets, air insulation layer, outer protective steel pipe, and outer anti-corrosion layer.
External sliding thermal insulation steel pipe structure: 1. Inner steel pipe 2. Zinc-rich primer 3. Sliding guide bracket 4. High-temperature-resistant glass wool 5. Aluminum foil reflective layer 6. Air insulation layer 7. Outer steel pipe 8. Anti-corrosion layer for outer steel pipe
Insulation pipes are steel pipes that have undergone heat preservation processing, ensuring that the internal temperature of the working pipe meets or reaches the required temperature in different working environments and under the influence of external media. Insulation pipes are widely used in pipeline networks for the transportation of liquids and gases, as well as in chemical pipeline insulation projects, oil and chemical industry, centralized heating networks, central air conditioning ventilation pipes, and municipal engineering. Steel-clad steel composite insulation pipes
Steel-clad steel composite thermal insulation pipes can be divided into two main categories based on different sliding methods: 1. Internal sliding type: The thermal insulation structure consists of working pipe, aluminum silicate, drag reduction layer, micro-porous calcium silicate, insulating layer, stainless steel fastening steel strip, aluminum foil reflective layer, polyurethane insulation layer, outer steel pipe, and external anti-corrosion layer. The internal sliding type thermal insulation steel pipe is composed of a steel pipe for conveying medium + composite silicate or micro-porous calcium silicate + rigid polyurethane foam plastic + outer steel pipe + glass fiber reinforced plastic shell anti-corrosion protective layer structure. Various pipe fittings and joints have mature thermal insulation treatment technology and reliable quality. 2. External sliding type: The thermal insulation structure consists of working pipe, glass wool insulation and heat preservation layer, aluminum foil reflective layer, stainless steel fastening steel strip, sliding guide bracket, air insulation layer, outer protective steel pipe, and external anti-corrosion layer. The structure of the external sliding type thermal insulation steel pipe includes: 1. Inner steel pipe 2. Zinc-rich primer 3. Sliding guide bracket 4. High-temperature-resistant glass wool 5. Aluminum foil reflective layer 6. Air insulation layer 7. Outer steel pipe 8. Outer steel pipe anti-corrosion layer. Steel-clad steel composite thermal insulation pipes are a type of buried pipeline used underground, which can be buried underground without a concrete structure. The thermal expansion of the working pipe is conducted within the outer pipe, thereby reducing material costs, shortening construction time, and ensuring the safety of heating pipelines. They can be widely applied in different temperature environments, especially suitable for high-temperature steam pipeline projects. The operating temperature can reach 150℃-450℃. The pipeline ends are generally sealed with polyethylene film or three-layer PE cold wrap tape to prevent moisture or water from entering before installation or during construction. The multi-layer staggered wrapping of the thermal insulation material effectively reduces heat loss, while control measures are taken on the outer surface of the casing to prevent the formation of cold bridges, thereby ensuring the temperature control of the anti-corrosion layer. Wrapping multiple layers of aluminum foil reflective material with thermal insulation material effectively reduces heat loss, making steam pipelines more economical and reasonable. The drainage system adopts a fully enclosed form, with flexible layout, reasonable structure, and high safety reliability.
The moisture drainage pipe on the steel casing pipe can promptly exhaust moist gases and also serve as an alarm signal pipe for daily operation. The thermal compensation of the pipeline is achieved using a bellows compensator, installed inside the casing in a direct-burial configuration, eliminating the need for observation wells, making construction operations convenient and shortening the construction period. Suitable for transporting steam or other media at pressures up to 2.5MPa and temperatures below 350°C, this product features a steel pipe outer protective layer with high strength, resistance to damage, easy construction and maintenance, and a long service life. Polyurethane-insulated steel pipes are used on medium and small diameter pipelines for the transport of crude oil or heating systems to reduce heat loss to the soil. The commonly used insulation material is rigid polyurethane foam plastic, with an applicable temperature range of -185 to 120°C. This material is soft in texture, and to enhance its strength, a layer of high-density polyethylene is applied externally to the insulation layer, creating a composite material structure to prevent groundwater from渗入 the insulation layer. The outer surface of the steel pipe is treated with shot blasting to remove rust and the outer surface of the protective pipe is subjected to corona treatment using a high-pressure polyurethane foam equipment set, enhancing the bonding properties of the insulation pipe. The insulation material is a rigid polyurethane foam with a density of 60 to 80 kg/m3, filling the gap between the steel pipe and the casing completely, and possessing a certain degree of bonding strength, forming a solid and integrated structure among the steel pipe, outer casing, and insulation layer. Polyurethane foam exhibits excellent mechanical and thermal insulation properties, generally with a temperature resistance of 120°C, which can be increased to 180°C through modification or combination with other insulation materials.
