Production Details and Advantages of Spiral Welded Steel Pipes

Spiral-c steel pipes are manufactured by forming steel strips or coiled plates into a spiral shape and welding both inner and outer seams using double-sided submerged arc automatic welding. They find extensive application in water, power, chemical, and other industrial sectors due to the following reasons:

 

By simply adjusting the forming angle, pipes of various diameters can be produced from steel strips of the same width, facilitating easy profile modification.

 

The continuous bending process allows for unlimited fixed-length production, with lengths customizable as needed. The weld seam spirals uniformly around the entire circumference, ensuring high dimensional accuracy and superior strength. This flexibility in sizing makes it ideal for small-batch, diverse production runs.

 

Compared to straight-seam pipes of the same specification, Spiral-welded steel pipes feature longer weld seams. At identical wall thicknesses, spiral-welded pipes withstand the highest pressure ratings. The weld seam of spiral pipes exhibits a "diagonal defect." During service, the equivalent defect length along the primary stress direction (i.e., the pipe axis) is shorter than that of straight-seam pipes. Additionally, since pipeline steel is a rolled plate with significant anisotropy in impact toughness, the CVN value along the rolling direction can be up to three times higher than that perpendicular to the rolling direction.

 

The weld seam of spiral-welded steel pipes is longer than that of straight-seam pipes of the same standard. Under the same wall thickness standard, spiral-welded steel pipes can withstand the highest pressure. The weld defect in spiral-welded pipes is a "diagonal defect." During service, the equivalent defect length along the pipe's axial direction-the primary stress direction-is smaller than that of straight seam pipes. Additionally, since pipeline steel consists of rolled plates, its impact toughness exhibits significant anisotropy. The CVN value along the rolling direction can be up to three times higher than that perpendicular to the rolling direction.

 

Spiral-welded steel pipes offer several advantages in steel structure workshops: - Exceptional dimensional flexibility-any standard can be produced - Customizable lengths up to 30 meters - Capability to form integrated columns with superior performance and lower cost than channel steel.