What is the main difference between straight seam welded pipe and spiral welded pipe?

The main difference between straight seam welded pipe and spiral welded pipe is the difference of welding method. Straight seam welded pipe is a high frequency current and proximity effect process. 

Before welding and forming, the forming machine is produced by the solder layer, and the edge of the tube blank is heated and melted, and melted and cooled under a certain pressure. 

High frequency straight seam welding tube uses high frequency current (erw), the edge of the melted tube blank is called straight seam buried arc welded pipe (lsaw). 

Spiral welded pipe is the low carbon structural steel or low alloy structural steel strip rolled into a pipe with a certain spiral Angle (also known as forming Angle), and then welded into pipe joints, 

can use narrow strip steel to produce large diameter steel pipe. The spiral welded pipe is mainly the spiral submerged arc welded pipe (ssaw), which is often used in the construction of various gas transmission 

pipelines in China. Its specifications are used."Outer diameter * wall thickness" is shown. 

The spiral welded pipe is single-sided welding and double-sided welding. The welded pipe shall ensure that the hydrostatic test, tensile strength and cold bending performance of the weld meet the requirements. 

The strength of spiral welded pipe is generally higher than that of straight welded pipe. The main production process is submerged arc welding. Spiral welded pipe can produce welded pipes with the same width 

of different diameter billet, but also can produce welded pipes with narrower billet with larger pipe diameter. The production process of straight seam welded pipe is relatively simple, mainly divided into high frequency 

welding straight seam welded pipe and buried arc welding straight seam welded pipe. Straight seam welded pipe has high production efficiency, low cost and rapid development. However, compared with the same length 

of the straight pipe welding pipe, the welding length is increased by 30-100, and the production speed is low. Therefore, small diameter welding is mostly straight seam welding, and large diameter welding is mostly spiral welding.