The difference between seamless steel pipe and welded steel pipe

Seamless steel pipe VS welded steel pipe:

1. Seamless steel pipe is a kind of strip steel with no joints around and a hollow section, which is widely used as a pipeline for conveying fluids. Compared with solid steel, it is lighter in weight with the same bending and torsional strength. It is an economical section steel and is widely used in the manufacture of structural and mechanical parts, such as automobile transmission shafts, oil drill pipes, bicycle frames and construction steel. Scaffolding etc.

2. Welded steel pipes are steel pipes made of steel plates or steel strips that are crimped and welded. The production process of welded steel pipe is simple, with many varieties and specifications, less equipment and high production efficiency, but its comprehensive strength is lower than that of seamless steel pipe. With the rapid development of continuous rolling production of high-quality strip steel and the advancement of welding inspection technology, the quality of welds has been continuously improved, the varieties and specifications of welded steel pipes have been increasing, and seamless steel pipes have been replaced in more and more fields. Welded steel pipes are divided into spiral welded pipes and straight welded pipes according to the form of welds.

The straight seam welded pipe has a simple production process, low cost, rapid development and high production efficiency. Generally, the strength of the spiral welded pipe is higher than that of the straight welded pipe. It is possible to use a narrower blank to produce a larger diameter welded pipe, or to use a blank of the same width to produce welded pipes of different diameters. However, the length of the weld is increased and the production speed is lower compared to the straight pipe of the same length. Therefore, straight seam welding is mostly used for small diameter welded pipes, and spiral welding is mostly used for large diameter welded pipes.