First, the product introduction
The steel sleeve steel composite steam prefabricated direct buried insulation pipe produced by our company is used for conveying steam pipes with pressure of 2.5Mpa and temperature below 350 °C. In view of the characteristics of high pressure and high temperature of the conveying medium, the composite thermal insulation structure (inorganic thermal insulation layer and organic thermal insulation layer) is used for heat preservation; the outer protective tube of the product is steel pipe.
Second, the product structure:
Product structure of steel sleeve steel composite steam prefabricated direct buried insulation pipe: working steel pipe, aluminum silicate cotton felt, microporous calcium silicate tile, aluminum foil reflective layer, polyurethane foam (Berlin, Germany), outer protective tube, The outer anti-corrosion layer is tightly combined. The structure is as follows:
Third, product features:
1. Long-term safe operation with the highest reliability (good strength, stiffness, temperature resistance, advanced technology);
2, the sealing waterproof performance is optimal (new technology, new structure design is easy to implement);
3, pipeline anti-corrosion to ensure long life (three PE);
4, the potential hidden danger is small (the fatigue strength of the outer steel tube is large, long-term operation in the environment of thermal expansion and contraction, the interface is not easy to disengage like the outer protective tube of glass fiber reinforced plastic);
5, significant energy saving (good sealing performance, no leakage, better insulation effect);
6, convenient construction, node sealing;
7. Construction welding technology The steel pipe is more mature and the means of leak detection is advanced.
Fourth, product material performance:
◆Working steel pipe (core pipe): Pipe for conveying steam. Material properties, outside diameter dimensions, dimensional tolerances, and minimum wall thickness are in compliance with relevant national or industry standards. When the working pipe DN≤150mm, the seamless steel pipe is generally used. When the DN is larger than 150mm, the spiral welded steel pipe is generally used.
◆Protective cushion: Prevents the interlayer of the inorganic thermal insulation layer from being damaged by the displacement of the working steel pipe between the working steel pipe and the thermal insulation layer. When the working tube is made of a spiral welded steel pipe and the inorganic insulating layer is a hard material, a protective cushion layer is provided. The protective cushion layer is made of aluminum silicate felt, the density is ≤192kg/m3, the thermal conductivity at room temperature is ≤0.056w (m.k), and the shrinkage rate of heating wire is ≤4%.
◆Inorganic insulation layer: Insulation layer made of high temperature resistant inorganic insulation material. Microporous calcium silicate is selected, the thermal conductivity at room temperature is ≤0.055w(m.k), (density ≤220kg/m3), and the moisture content, temperature resistance and compressive strength of the material can meet the relevant requirements.
◆Organic insulation layer: insulation layer made of organic insulation material. Polyurethane rigid foam, density 60-80kg/m3, compressive strength ≥0.2Mpa, normal temperature thermal conductivity ≤0.027w/(m.k)v, water absorption=≤3%, applicable temperature ≤140°C.
◆External protective tube: The outer protective layer that protects the thermal insulation layer from groundwater erosion, supports the core tube and can withstand certain pressure, and the material is steel outer protective tube. This product uses steel pipe as the outer protective pipe, especially in areas with high water level or abundant surface water, steel outer protective pipe must be used. Steel outer protective tube material properties and tolerance dimensions, in line with relevant national or industry standards. The outer surface of the steel pipe is treated by shot blasting.
◆ Anti-corrosion layer: A protective layer that prevents soil corrosion. This product three PE is used as the anti-corrosion layer of the outer steel pipe. If necessary, it can be supplemented with "cathode protection" measures.
Five, prefabricated pipe fittings and node processing
The company's direct buried steam insulation pipe fittings: such as elbows, tees, fixed joints, reducers, water delivery sections, etc., are factory prefabricated. Not only can the construction time on site be reduced, the construction is convenient and fast, and the quality of corrosion protection, waterproofing, heat preservation and mechanical strength of all pipe fittings can be ensured. The outer protective pipes of all pipe fittings adopt the same anti-corrosion and heat preservation methods as the straight pipe sections, and the manufacturing process of pipe fittings is strictly carried out according to relevant enterprise standards. The elbow is prefabricated by the factory and is treated with anti-corrosion treatment. On-site construction requires filling a certain thickness of soft material around the outer protective pipe, and then sanding and compacting to eliminate stress concentration at the elbow. For the right-angle elbow, in the operation process, in order to compensate the axial and lateral displacement occurring at the elbow and the working steel pipe expands and contracts in the limited space of the outer protective pipe, according to the calculated thermal displacement amount, the outer protective pipe is locally enlarged. For the elbows less than 90 °C, the outer casing does not need to be thickened.
6. Drainage treatment
A permanent drainage hole is provided on the heat preservation pipeline to smoothly discharge the steam generated in the insulation layer, so that the insulation layer and the outer protection tube are not damaged. A drain pipe is arranged on the inner (outer) fixed support, one end of the drain pipe penetrates into the insulation layer of the fixed support, and the other end is led out of the ground through the drain pipe, and is protected from rain, water and protection at the end.
Straight pipe section product specifications
Unit: MM
Nominal diameter
Inner steel pipe
Outer diameter × wall thickness
Coat steel pipe
Outer diameter × wall thickness
Insulation thickness
Product size
The diameter of the steel pipe is Φ40-Φ920mm, the medium temperature is 150°C-350°C, and the underground depth is 1-2m.
The scope of products
The internal sliding type steam direct buried composite insulation pipe is suitable for high temperature steam pipes for urban district heating. It is also suitable for high temperature heat pipes in petroleum, chemical, electric power and other industrial sectors.
Shandong Yitong Energy Saving Co., Ltd. is a professional manufacturer of polyurethane prefabricated direct buried and empty rack pipes integrating scientific research, development, manufacture and sales. The company has passed ISO9001 quality system certification, IS014001 environmental system certification, OHSAS18001 occupational and health safety management system certification, production license, quality supervision and inspection certificate. The company's products have repeatedly passed the quality inspection and testing of the department through the national authority and the corresponding test report. The factory covers an area of 55,000 square meters, with 3 high-density polyethylene outer tube production lines, 2 sets of automatic plastic sleeve insulation production lines, 5 sets of high and low foaming machines and on-site foaming machines, and a specialized steel pipe anti-corrosion production line. One production line, one set of steel pipe shot blasting equipment. Shandong Yitong Energy Saving Co., Ltd. always adheres to scientific and technological innovation and develops polyurethane prefabricated direct buried insulation pipes that meet industry standards or exceed industry standards. The product has good waterproof, shockproof, anti-pressure, heat insulation, corrosion resistance, convenient construction and long service life. It is widely used in heating, fire, chemical, electric power, oil transportation, water delivery, and has a service life of up to 30 years.
