Spiral steel pipes are produced by bending strip steel or coils into a spiral shape and welding the inner and outer seams using double-sided submerged arc welding. Due to the following reasons, they are widely used in industries such as water, electricity, and chemicals: By simply adjusting the forming angle, various diameters of steel pipes can be produced from the same width of strip steel, facilitating easy adjustment.
Since the formation is continuous and curved, the length of spiral pipes is not constrained and can be customized as desired. The spiral weld seam is evenly distributed around the entire circumference of the pipe, resulting in high dimensional accuracy and strength. Additionally, it is easy to adjust the dimensions, making it suitable for small-batch, multi-type production of spiral pipes.
The weld seam of spiral steel pipes is longer than that of straight seam pipes of the same standard. Under the same wall thickness, spiral steel pipes can withstand the maximum pressure. However, a disadvantage of spiral steel pipes lies in their "oblique defects" in the weld seam. During use, the equivalent defect length in the direction of the principal stress, i.e., the axis of the pipe, is smaller than that of straight seam pipes. Furthermore, since pipeline steel is typically rolled sheet steel, there is significant anisotropy in impact toughness. The CVN value in the rolling direction can be three times higher than that perpendicular to the rolling direction.
To meet the demands of modern production, steel structure workshops have emerged. Compared to early component workshops, steel structure workshops offer several advantages, including shorter production time, lower costs, and increased efficiency. Generally, steel structure workshops encompass steel columns, steel beams, steel foundations, steel roof trusses, steel roofs, etc. In recent years, steel columns have gradually transitioned from using channel steel, which has been found to have limitations in construction, to spiral steel pipes.
In steel structure workshops, spiral steel pipes offer several advantages. They are highly adaptable in terms of standards, allowing for the production of pipes of any standard. The length of spiral steel pipes can also be customized, with the longest reaching 30 meters. Additionally, spiral steel pipes can be fabricated into combined pillars, offering superior performance compared to channel steel and at a more economical price.
