Introduction to insulation spiral steel pipe

Insulated Spiral Steel Pipe refers to spiral steel pipes (SSAW pipes) that are specially treated for thermal insulation. The most common method of heat preservation is polyurethane insulation, where the steel pipe is coated with a layer of polyethylene or steel, with the thickness tailored to customer needs. Foam is injected between the pipe and its outer jacket, and the foam thickness can also be adjusted based on customer specifications. Insulated spiral steel pipes can be installed either overhead or underground. These pipes are widely used in the transportation of liquids and gases, as well as in chemical, petroleum, and municipal engineering projects, including central heating networks, central air-conditioning systems, and chemical pipe insulation.

Quality Standards for Insulated Spiral Steel Pipe:

Hydraulic Test:

The hydraulic test results for concealed pipelines and the entire steam system must conform to design specifications and construction standards.

Pipe Fixing Brackets:

The placement and structure of pipe fixing brackets must comply with design and construction specifications.

Installation of System Components:

The locations for expanders, pressure reducers, steam traps, and valves must adhere to design requirements. Additionally, the pressure after pre-stretching and adjustment must meet construction specifications.

Welding Restrictions:

Welding of branch pipes at butt welds and bend areas of the thermal insulation spiral steel pipe is strictly prohibited. The distance between joint welds, bending points, and the edges of supports or hangers must be no less than 50mm.

Filter Screen Requirements:

The material, specifications, and wrapping method of the filter screen for decontamination devices must meet the design and construction specifications.

Purging Quality:

After completing the steam supply system, the quality of purging must be checked thoroughly.

Slope Requirements:

The slope of the insulated spiral steel pipe should comply with design specifications.

Threaded Connections:

The threaded connections of carbon steel pipes must meet specific standards: threads should be clean, regular, and free from defects such as broken or missing threads. The connection should be firm, with 2-3 threads exposed at the root of the pipe.

Welding Quality:

The welding of carbon steel pipes should meet the following criteria: the straightness and surface of the welding joint must comply with design specifications. The weld should be free of defects such as burn-through, cracks, nodules, slag inclusions, or porosity, and the weld bead should be uniform.

Installation of Components:

The installation of reducers, steam traps, and valves must meet design specifications, including the correct model, specification, compressive strength, and tightness. The installation must ensure the components are positioned correctly, with firm and tight connections, flexible operation, easy accessibility, and a clean surface.

Pipe Brackets and Supports:

The installation of pipe brackets and supports must meet these criteria: proper structure, firm burial, neat arrangement, and close contact between the brackets and the pipes.

Painting Requirements:

The painting of insulated spiral steel pipes, boxes, and metal supports must meet design specifications, including the type of paint used and the number of coats. The paint should adhere well, without peeling, blistering, or missing spots. The paint film should have uniform thickness, consistent color, and be free from flow or contamination.