Composed of conveying medium, working steel pipe, foam insulation layer, and polyethylene plastic outer protective tube, which are sequentially combined outward by the equipment
First layer: working steel pipe layer
According to the design and customer requirements, seamless pipes (GB8163-87) spiral welded pipes (GB9711-88; SY / T5038-92) and straight seam welded pipes are generally selected.
(GB3092-93). After the surface of the steel pipe is processed by the advanced shot blasting and rust removing technology, the steel pipe can reach the level of Sa2 in the GB8923-1988 standard.
, Surface roughness can reach R = 12.5 microns in GB6060.5-88 standard.
The second layer: polyurethane insulation layer
A high-pressure foaming machine is used to inject a rigid polyurethane foam plastic stock solution into the cavity formed between the steel pipe and the outer protective layer at one time. Commonly known
"Tube-in-tube foaming process". Its role is to waterproof, the second is to maintain heat, and the third is to support the weight of the heating network. When the temperature of the conveying medium is: -50 ℃ —
At 120 ° C, rigid polyurethane foam is used as the insulation layer.
Third layer: High-density polyethylene protective layer
Pre-made into a black (yellow) plastic pipe with a certain wall thickness. Its role is to protect the polyurethane insulation layer from mechanical hard objects.
Anti-corrosion and waterproof.
Outer diameter mm 238 Wall thickness mm 3.5 Weight Kg 2.475 Allowable deviation mm ± 0.28 Corresponding steel pipe outer diameter mm 159
Corresponding insulation thickness mm 37 Corresponding sleeve mm 245
1. Reduce project cost. 2. Low heat loss, saving energy. 3. Anti-corrosion, good insulation performance and long service life.
4. It occupies less land, and construction is quicker, which is beneficial to environmental protection.