Spiral steel pipes are produced by forming strip steel or coiled plate 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 water, electricity, chemicals, and other industries: By simply adjusting the forming angle, various diameters of steel pipes can be produced from the same width of strip steel, facilitating easy adjustment.
As they are continuously formed in a spiral shape, the fixed length of spiral pipes is not constrained, allowing for customization. The spiral welds are evenly distributed along the entire circumference of the pipe, resulting in high dimensional accuracy and strength. Additionally, the ease of altering dimensions makes them suitable for small-batch, multi-type production of spiral pipes.
The welds of spiral steel pipes are longer than those of straight-seam pipes of the same standard. Under the same wall thickness, spiral steel pipes can withstand the greatest pressure. However, a disadvantage of spiral steel pipes' welds is the "oblique defect." During use, the equivalent defect length in the principal stress direction (i.e., the axial direction of the pipe) is smaller than that of straight-seam pipes. Furthermore, since pipeline steel is typically rolled steel plate, it exhibits significant anisotropy in impact toughness, with the CVN value along the rolling direction being up to three times higher than that perpendicular to it.
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 practicality. Typical steel structure workshops comprise steel columns, beams, foundations, roof trusses, and roof coverings. In recent years, steel columns have gradually transitioned from channel steel, which has identified drawbacks in construction, to spiral steel pipes.
Spiral steel pipes exhibit several strengths in steel structure workshops. They have strong adaptability to standards, meaning that pipes of any standard can be produced. Their length can also be customized, with the longest reaching 30 meters. Moreover, spiral steel pipes can be fabricated into combined pillars, offering superior performance and more cost-effective solutions compared to channel steel.
