Polyethylene insulated spiral steel pipe refers to a steel pipeline that is processed through insulation technology to ensure that the temperature inside and on the surface of the working steel pipe meet or meet the requirements of use under different working environments and external media.

Insulated pipelines are widely used in the transportation network of liquids and gases, chemical pipeline insulation engineering, petroleum, chemical, centralized heating networks, central air conditioning ventilation pipelines, municipal engineering, etc. High temperature prefabricated direct buried insulation pipe is a type of direct buried prefabricated insulation pipe with good insulation performance, safety and reliability, and low engineering cost. Effectively solved the insulation, sliding lubrication, and waterproofing problems of prefabricated buried insulation pipes for high temperature heat transfer from 130 ℃ to 600 ℃ in urban centralized heating.

High density polyethylene plastic protected polyurethane foam prefabricated directly buried insulation pipe is very popular because of its excellent performance, convenient construction and long service life (30-50 years). Its structure is composed of three parts: external protection layer, insulation layer and anti leakage layer. The external protection layer is made of polyethylene jacket pipe or glass fiber reinforced plastic or other materials. There are three types of laying methods: direct burial, overhead, and trench laying.

Structural mechanism of polyethylene insulated spiral steel pipe

1. Outer protective steel pipe: protects the insulation layer from groundwater erosion, supports the working pipe and can withstand certain external loads, ensuring the normal operation of the working pipe.

2. Anti corrosion coating: protects the outer steel pipe from corrosive substances, prolongs the service life of the steel pipe.

3. Drag reduction layer: Ensure the free movement of the working steel pipe during thermal expansion and contraction.

4. Polyurethane foam layer: ensure the medium temperature, and ensure that the surface of the outer protective tube is kept at normal temperature.

5. Barrier and reflective layer: ensure that the organic foam material does not enter the inorganic hard high temperature resistant layer; Reflect some heat from the high-temperature resistant layer.

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

7. Inorganic hard insulation layer: resistant to high temperature, ensure the interface temperature between organic insulation layer and foam, and prevent carbonization.