What is the difference between LSAW steel pipe and high-frequency straight-seam steel pipe? LSAW steel pipe refers to welded steel pipe with only one longitudinal weld along the length of the pipe body. GB / 9711.1 specifies that LSAW steel pipes with a diameter greater than 914.4 may have two longitudinal welds with a weld angle of 180 degrees. For LSAW steel pipes with the same weld, welding quality requires consistent technical parameters.
Classified by production technology: ERW high-frequency LSAW pipe, JCOE LSAW pipe, rolled LSAW pipe.
LSAW pipe is a general term for products made by high-frequency LSAW, submerged-arc LSAW, electric-welded LSAW, pipeline LSAW, and other production technologies.
High-frequency ERW pipe uses the skin effect of high-frequency current so that both edges of the steel plate reach high temperature in a short time and are fused together under external pressure. This is a true base-metal butt joint without filler weld. ERW high-frequency straight-seam pipe is made from hot-rolled coil, and wall thickness can be uniformly controlled to about ±0.2mm. Both pipe ends comply with API or GB / T9711.1, offering advantages in delivery and related aspects. In recent years, various natural-gas network projects and gas companies have widely adopted ERW pipe as the main steel pipe for urban networks. At present, ERW high-frequency straight-seam pipe accounts for 60% of world steel-pipe consumption.
Straight-seam steel pipe usually refers to double-sided submerged-arc straight-seam pipe produced by JCOE. It uses the JCOE cold-forming process, and the weld uses welding wire with granular flux for submerged-arc welding, hence the name SAW straight-seam pipe. Production of SAW straight-seam pipe is mainly flexible and can produce any specification with outside diameters from 325mm to 1420mm. This greatly meets the dimensional requirements of steel pipe in countries around the world. High-frequency straight-seam pipe is commonly used in production as well.
High-frequency LSAW pipe among black-jacketed products. Direct-buried LSAW pipe is referred to as the original steel pipe. The industry uses names different from submerged-arc LSAW pipe or hot-expanded high-frequency LSAW pipe.
