The composition of thermal insulation steel pipe:

1. External protective steel pipe: protect the insulation layer from groundwater erosion, support the working pipe and withstand a certain external load, and ensure that the working pipe works normally.

2. Anti-corrosion layer: protect the outer steel pipe from corrosive materials and prolong the service life of the steel pipe.

3. Drag reduction layer: to ensure the free movement of the working steel tube during thermal expansion and contraction.

4. Polyurethane foam layer: ensure the temperature of the medium and the surface of the outer protective tube to maintain normal temperature.

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

6. Working steel pipe: ensure the normal flow of the conveying medium.

7. 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.