Steel sleeve steel composite
Steel-in-steel composite insulation pipe insulation structures can be divided into two categories based on different sliding methods:
1. Internal sliding type: The insulation structure consists of working steel pipe, aluminum silicate, drag reduction layer, microporous calcium silicate, heat insulation layer, stainless steel fastening steel strip, aluminum foil reflective layer, polyurethane insulation layer, outer steel pipe, and outer anti-corrosion layer composition. The internal sliding insulated steel pipe is composed of a steel pipe for transporting media + composite silicate or microporous calcium silicate + rigid polyurethane foam + outer steel pipe + glass fiber reinforced plastic shell anti-corrosion protective layer structure. The insulation treatment technology for various pipe fitting nodes is mature and the quality is reliable.
2. External sliding type: The insulation structure is composed of working steel pipe, glass wool insulation layer, aluminum foil reflective layer, stainless steel fastening steel belt, sliding guide bracket, air insulation layer, outer protective steel pipe, and outer anti-corrosion layer.
Polyurethane
Polyurethane insulation pipe has a three-layer structure from the inside to the outside:
The first layer: working steel pipe layer
According to the design and customer requirements, seamless steel pipes, spiral steel pipes and straight seam steel pipes are generally used. After the surface of the steel pipe is treated with advanced shot blasting and rust removal technology, the rust removal grade of the steel pipe can reach the Sa2 level 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:
A high-pressure foaming machine is used to inject the raw liquid of rigid polyurethane foam into the cavity formed between the steel pipe and the outer sheath at one time, which is commonly known as "tube-in-tube foaming".
Third layer: high-density polyethylene protective layer:
Prefabricated black or yellow polyethylene plastic pipes with a certain wall thickness. Its function is to protect the polyurethane insulation layer from damage by mechanical hard objects, and to be anti-corrosion and waterproof.
