Application description

Widely used in long-distance oil and gas transmission, water supply pipelines, sewage systems, piling for foundations (bridge piers, port structures), industrial slurry transport, and power plant cooling lines. Also suitable for structural columns and large-diameter ductwork. The spiral weld provides excellent strength for high-pressure and large-diameter applications.

Production description

Steel coil is unwound, leveled, and fed into a forming machine at a helical angle to create a spiral tube shape. The edges are welded by submerged arc welding (SAW) from both inside and outside simultaneously. The continuous pipe is then cut to length, and the weld seam is inspected by X-ray or ultrasonic. The pipe undergoes hydrostatic testing, end beveling, and optional coating before final inspection.

Shipping Packaging

For export, spiral welded pipes are packed with plastic end caps, wrapped in VCI paper and moisture-proof polyethylene (or coated with rust preventive oil), secured with steel straps, and loaded in bundles or individually. Large diameter pipes are shipped with edge protectors and blocking inside containers or on flat racks. Labels include grade, size, length, and heat number for safe sea freight.

Why Choose Us?

1.Factory Strength:Direct manufacturer with advanced spiral submerged arc welding (SSAW) lines, capable of producing pipes from 219mm to 3048mm OD, with double-sided weld for high strength and consistent helix angle.

2.Quality Assurance:Strict control of chemical composition, mechanical properties, and dimensional tolerances (OD ±0.5%, wall ±0.2mm); 100% X-ray or ultrasonic weld inspection, hydrostatic testing; compliant with ASTM A53/A252, API 5L, EN 10217-1, SY/T 5037.

3.Certifications & Reports:Mill test certificates (MTC) with each shipment; third-party inspections (SGS, BV, DNV) and NDT reports (RT, UT) available upon request.

4.Customization & Service:Wide range of carbon steel (GR.B, X42–X80, S235–S355) and alloy steel, OD 219–3048mm, wall 4.0–25.4mm, custom lengths, end finishes (plain, beveled, grooved), and coatings (3PE, FBE, galvanized, black paint) with fast lead times.

5.Export Packaging:Plastic end caps + VCI paper/moisture-proof wrapping (or rust preventive oil) + steel strapping + edge protectors + container or flat rack loading for safe sea freight, especially for large-diameter pipes.

FAQ

1. What is the advantage of spiral welded pipe over straight seam welded pipe for large diameters?

Spiral welded pipe can be produced in a wider range of diameters (up to 3048mm) using narrower steel coils, making it more cost-effective for large-diameter applications. The spiral weld also provides uniform mechanical properties along the pipe and better resistance to circumferential stresses.

2. Can spiral welded pipes be used for high-pressure oil and gas transmission?

Yes, when manufactured according to API 5L standards (PSL1 or PSL2), spiral welded pipes are widely used for oil, gas, and water transmission lines. 100% X-ray and hydrostatic testing ensure weld integrity and pressure resistance.

3. How do you prevent weld seam defects during spiral welding?

We use automatic submerged arc welding (SAW) with real-time monitoring of welding parameters. The weld seam is inspected online by ultrasonic or X-ray, and any defects are marked and repaired. Third-party NDT inspection is also available upon request.