Polyurethane Insulation Pipe, full name: High-Density Polyethylene Plastic Outer Sheath Pre-fabricated Direct Burial Insulation Pipe with Polyurethane Foam Insulation Layer, which is sequentially combined outwardly by the working steel pipe for conveying medium, the polyurethane insulation layer, and the polyethylene plastic outer sheath.

National standard polyurethane insulated steel pipes are structured in three layers from the inside out.

Layer 1: Working Steel Pipe Layer - Generally, seamless pipes (GB8163-87), spiral-welded pipes (GB9711-88; SY/T5038-92), and straight seam welded pipes (GB3092-93) are selected according to design and customer requirements. After being treated with advanced shot blasting rust removal technology, the surface rust removal level of the steel pipes can reach Sa2 grade as per GB8923-1988 standard, and the surface roughness can reach R=12.5 micrometers as per GB6060.5-88 standard.

Second Layer: Insulating polyurethane layer - formed by injecting the liquid raw material of rigid polyurethane foam plastic into the cavity between the steel pipe and the outer sheath with a high-pressure foaming machine in one go. Also known as the "pipe-in-pipe foaming process". Its functions include: 1) waterproofing, 2) thermal insulation, and 3) supporting the weight of the thermal network. When the temperature of the medium being transported ranges from -50℃ to 120℃, rigid polyurethane foam plastic is used as the insulation layer.

Layer 3: High-density polyethylene protective layer - Pre-fabricated black (yellow) plastic pipes with predetermined wall thickness, serving the purpose of: 1) Protecting the polyurethane insulation layer from mechanical damage by hard objects, and 2) Anti-corrosion and waterproof.

Product Structure: The pre-fabricated buried steam保温 pipe consists of a core tube (working steel pipe), insulation layer, reflective layer, securing steel strip, sliding bracket, air layer, outer steel pipe, sprayed polyurethane, and wrapped glass fiber reinforced plastic.

Features:

Made with steel pipes for the external protective layer, it boasts high strength and is resistant to damage, capable of withstanding substantial overhead loads. To ensure longevity, anti-corrosion treatment is necessary for the steel jacket pipe.

The rolling support structure design is rational, featuring minimal rolling friction and reduced load on the fixed supports. The mechanical analysis principle is simple, significantly enhancing the pipeline stability and safety.

The vacuum layer completely eliminates heat conduction and convection through the air layer, reducing heat loss. Compared to an air layer structure, it can lower the outer wall temperature by 8-13°C under the same insulation thickness.

The vacuum pump device completely solves the problem of corrosion on the inner wall of the outer steel casing tube by hot and humid air, significantly extending the service life of the buried steam pipeline. The product lifespan is increased to 30 years.