Spiral Welded Steel Pipe (SSAW)

• ​Introduction

Spiral Welded Steel Pipe is a type of welded steel pipe manufactured by helically forming and welding steel strips or coils. It is widely used in oil and gas transportation, water supply, piling, and structural applications due to its high strength, cost-effectiveness, and ability to produce large diameters.

• ​Main Functions

Fluid Transportation: It is mainly used to transport oil, natural gas, water, sewage, and other fluids. Its spiral weld structure enables it to withstand certain internal pressure, ensuring the safe and stable transportation of fluids.

Structural Support: In construction, bridges, and marine engineering, it serves as structural components such as columns and piles, providing strong load-bearing capacity.

Pipeline Networks: It is an important part of urban pipeline networks (e.g., water supply, drainage, and gas pipelines), playing a role in connecting and transmitting resources.

• ​Tubing Standards

ASTM A53，ASTM A500，API 5L，ASTM A252； EN 10217-1，EN 10219-1； GB/T 13793，GB/T 3091，GB/T 9711.

• ​Material & Performance

ASTM A53: Grade A、B，ASTM A500: Grade B、C、D，API 5L: L245(B),L290(X42),L320(X46),L360(X52),L390(X56),L415(X60)；

EN 10217-1: P235GH、P355GH、P355NH，EN 10219-1: S235JRH、S355NH、S355J2H；

GB/T 13793: Q195、Q215A/B、Q235A/B、Q355B、Q390B, GB/T 3091: Q215A/B、Q235A/B、Q355B, GB/T 9711: L245(B),L290(X42),L320(X46),L360(X52),L390(X56),L415(X60)；

Mechanical properties: High tensile strength (generally 300-600 MPa), good elongation, and impact toughness to resist external forces and pressure.

Corrosion resistance: Can be enhanced by anti-corrosion treatments such as galvanizing, epoxy coating, or 3PE coating, extending service life in humid or corrosive environments.

Sealing: The spiral weld is subject to strict non-destructive testing (such as ultrasonic testing, X-ray inspection), ensuring tightness and preventing leakage.

• ​Manufacturing Process

Uncoiling and leveling: The steel strip is uncoiled from the coil and leveled to eliminate internal stress and ensure flatness.

Edge Milling: The edges of the steel strip are trimmed and beveled to meet the welding requirements.

Forming: The steel strip is continuously rolled into a spiral pipe blank through a forming machine, with the forming angle controlled to ensure the pipe diameter accuracy.

Welding: The spiral seam is welded using submerged arc welding (SAW), which can be single-sided or double-sided welding to ensure weld strength.

Sizing and cutting: The welded pipe is sized to correct the diameter and then cut into fixed lengths according to requirements.

Inspection: Non-destructive testing (Ultrasonic Testing (UT), X-ray), Hydrostatic Testing, and dimensional inspection are carried out to ensure product quality.

Anti-corrosion treatment (optional): Coating or other anti-corrosion processes are applied according to customer needs.

• Specifications