Simple process flow for making polyurethane thermal insulation steel pipe

The simple process of making polyurethane heat preservation steel pipe: The first step is to inspect the anti-corrosion steel pipe to make it meet the conditions for making heat preservation steel pipe, and comprehensively inspect the steel pipe; the second step is to remove the embroidery on the steel pipe and use some The special raw materials are clear of the rust on the surface of the steel pipe, so that the steel pipe is not corroded; the third step is to pass through the tube, the rust-proof and anti-corrosion steel pipe is sheathed in the polyethylene sleeve; the fourth step is to repair the head, and the middle is injected with polyurethane Foam to fully fill the gap between the steel pipe and the polyethylene sleeve to make it one; the final step is the finished product inspection, the finished insulated steel pipe is tested for the finished product, and the products that meet the specifications are sold. The product undergoes refurbishment and improvement

Polyurethane insulation pipe structure

Polyurethane insulation pipe is divided into three layers from inside to outside:

The first layer: working steel pipe layer According to the design and customer requirements, generally choose seamless steel pipe, spiral steel pipe and straight seam steel pipe. After the surface of the steel pipe is processed by the advanced shot blasting derusting process, the derusting grade of the steel pipe can reach Sa2 grade in the GB8923-1988 standard, and the surface roughness can reach R = 12.5 microns in the GB6060.5-88 standard.

Second layer: Polyurethane insulation layer: The high-pressure foaming machine is used to inject the rigid polyurethane foam plastic liquid into the cavity formed between the steel pipe and the outer sheath at once, which is commonly known as "tube-in-tube foaming".

Third layer: high-density polyethylene protective layer: pre-made black or yellow polyethylene plastic pipe with certain wall thickness. Its function is to protect the polyurethane insulation layer from mechanical hard objects, and to prevent corrosion and waterproof.