High temperature direct buried steam insulation (steel sleeve steel): production and processing range φDN20—ΦDN1800

Executive standard

CJ/T200—2004 "Technical Conditions for Prefabricated Directly Buried Steam Insulation Pipes for Urban Heating" One type is composed of elbows for conveying medium, anti-corrosion jacket elbows, and ultra-fine glass wool filled between elbows and outer jacket elbows. , It can also be composited with graphite, silicon-calcium tile shell and filled polyurethane foam. Steel casing (steel casing steel) embedding technology is a new waterproof, leak-proof, impermeable, pressure-resistant and fully enclosed embedding technology. It is a major breakthrough in the use of direct burial technology in areas with high groundwater levels. The primary problem of the protection tube of the directly buried pipeline is the reliability of tight waterproofing. In addition, it must have good mechanical strength. Due to the high strength of the steel casing, the welding connection is used, and the waterproof and sealing performance is very reliable. In addition, its high temperature resistance is also Unmatched by other external protection management institutions. In areas with high groundwater levels, in order to ensure that the groundwater does not affect the normal operation of the steam buried pipelines, the outer protective layer is best to use a solid and closed elbow shell.

Insulation structure

According to different sliding methods, the insulation structure of steel sleeve steel insulation pipe is divided into internal sliding type and external sliding type.

1. Internal sliding type: the heat preservation structure consists of working elbow, aluminum silicate, drag reduction layer, microporous calcium silicate, heat insulation layer, stainless steel fastening strip, aluminum foil reflection layer, polyurethane heat preservation layer, outer jacket elbow, and outer Anti-corrosion layer composition.

2. External sliding type: the heat preservation structure is composed of working elbow, glass wool heat preservation and heat insulation layer, aluminum foil reflection layer, stainless steel fastening tape, sliding guide bracket, air heat preservation layer, outer protection elbow, and outer anti-corrosion layer.

Structural mechanism

1. Anti-corrosion layer: protect the outer elbow from corrosion by corrosive substances and extend the service life of the elbow

2. Outer bend pipe: Protect the insulation layer from groundwater erosion, support the work pipe and can withstand a certain external load, and ensure the normal work of the work pipe.

3. Polyurethane foam layer: to ensure the temperature of the medium, to ensure that the surface of the outer protective tube maintains a normal temperature.

4. Barrier and reflective layer: to ensure that the organic foam material does not enter the inorganic hard high temperature resistant layer; it reflects part of the heat of the high temperature resistant layer.

5. Inorganic hard insulation layer: high temperature resistance, to ensure the interface temperature with the organic insulation layer, to ensure that the foam is not carbonized.

6. Drag reduction layer: to ensure the free movement of the working elbow during thermal expansion and contraction.

7. Working elbow: to ensure the normal flow of conveying medium.