Straight seam steel pipe refers to a welded steel pipe with only one weld in the longitudinal direction of the pipe body. GB/9711.1 stipulates that when the diameter is greater than 914.4, straight seam steel pipes can have two straight welds, and the angle between the welds is 180 degrees. The quality requirements of the weld seam are consistent with the technical parameters of the straight seam steel pipe for the same weld seam.

According to the production process, it is divided into ERW high-frequency straight seam steel pipe, JCOE straight seam steel pipe, and rolled straight seam steel pipe.

Straight seam steel pipe is a general term for high-frequency straight seam, submerged arc straight seam, electric welding straight seam, pipeline straight seam, and other production process products.

The high-frequency straight seam steel pipe adopts the skin effect of high-frequency current to generate high temperature at both ends of the steel plate in a short period of time and then extruded and fused together by an external force, which is the real base metal butt joint without welding rod. ERW high-frequency straight seam steel pipe uses hot-rolled coil as raw material, and the uniform wall thickness can be controlled at about ±0.2mm. Delivery and other advantages. In recent years, various natural gas pipeline network projects and gas companies have widely used ERW steel pipes as the main steel pipes of urban pipeline networks. At present, ERW high-frequency straight seam steel pipe accounts for 60% of the world's steel pipe usage ratio.

Straight seam steel pipe often refers to the double-sided submerged arc straight seam steel pipe produced by JCOE. It adopts the JCOE cold forming process, uses welding wire for the weld seam, and uses particle flux to submerge the arc at the same time, so it is named submerged arc straight seam steel pipe. Submerged arc welded straight seam steel pipe is mainly flexible in the production process, and can produce any specification and wall thickness between 325 mm-1420 mm. It greatly satisfies the use of steel pipe size standards in various countries in the world, and high-frequency straight seam steel pipes are usually produced in commonly used specifications.

The high-frequency straight seam steel pipe is usually called the original pipe, and the industry distinguishes it from the name of the submerged arc welded straight seam steel pipe or the heat-expanded high-frequency straight seam steel pipe.