Basic Definition
Spiral steel pipe, also known as spiral double-sided submerged arc welded steel pipe, is a major category of large-diameter welded steel pipe. It is commonly referred to as spiral pipe or spiral welded pipe in the industry.
Made from hot-rolled steel coils/strips, the steel strips are continuously rolled into cylinders at a fixed spiral angle using a forming unit. Then, double-sided submerged arc welding is used to weld the pipe, resulting in a continuous spiral weld seam on the pipe wall, hence the name spiral welded steel pipe.
Spiral Steel Pipe Production Process Flow
Raw material inspection → Uncoiling and leveling → Edge trimming and planing (trimming the bevels on both sides of the steel strip) → Spiral coiling and forming → Internal and external double-wire submerged arc automatic welding → Online ultrasonic non-destructive testing (UT) → Sizing and straightening → Length cutting → Hydrostatic pressure resistance test → Anti-corrosion processing (3PE / epoxy powder / cement mortar lining) → Finished product inspection and warehousing.
Key Specifications
Diameter Range: Outer diameter DN219～DN3048mm (8 inches～120 inches), capable of producing ultra-large diameter pipes, covering a large size range that straight seam welded pipes and seamless pipes cannot easily cover;
Single Length: Standard 6/12 meters, ultra-long single pieces supported, reducing on-site welding joints;
Mainstream Materials: Q235B, Q355B/D/E low alloy steel; pipeline steel L245, L360, X42/X52/X60/X70 (API 5L oil and gas grade steel).
Advantages of Spiral Steel Pipe
High Cost-Effectiveness for Large Diameter Pipes
This results in high raw material utilization and production costs far lower than LSAW (submerged arc welded) pipes, making it suitable for long-distance, high-volume pipeline projects.
More Stable Weld Stress
Under the same pressure conditions, the stress of the spiral weld is only 75%~90% of that of the straight seam weld, providing stronger resistance to foundation settlement and external extrusion, making buried pipelines less prone to cracking and leakage.
Continuous and Efficient Production
Continuous feeding and forming of steel coils results in high production efficiency and short delivery cycles, suitable for large-scale municipal and oil and gas projects.
Strong Corrosion Resistance
One-stop processing is available at the factory for 3PE, FBE epoxy powder, cement mortar lining, and polyurethane insulation composite corrosion protection, directly meeting the needs of buried, high-temperature, and corrosive soil conditions.
Excellent structural bearing capacity
The spiral welds on the pipe wall form an integral reinforced structure, resistant to bending and compression, and widely used in bridge pile foundations, wind power foundations, and cofferdam structures.
Applications of Spiral Steel Pipes
Municipal Pipeline Networks
Urban large-diameter main water supply pipelines, sewage discharge pipelines, urban and rural centralized heating direct-buried insulated pipes, and urban gas branch lines, standard configuration with 3PE buried anti-corrosion;
Oil and Gas Energy Industry
Oilfield gathering and transmission pipelines, long-distance oil and gas branch pipelines;
Infrastructure Steel Structure Pile Foundations
Bridge steel pipe piles, wind power foundations, port cofferdams, wharf support, and river dredging slurry transport pipes;
Industrial Fluids and Water Conservancy
Power plant circulating water pipelines, hydropower station pressure water transmission pipelines, and chemical ne
Conclusion
We supply SSAW spiral steel pipes with complete anti-corrosion treatments including 3PE, FBE, cement mortar lining and PU thermal insulation. Our products comply with GB/T9711 and API 5L standards with full MTC test reports. Contact us for project quotation according to your diameter, wall thickness and underground service conditions.