Double sided submerged arc welded spiral steel pipe is a professional term, abbreviated as spiral welded pipe or spiral steel pipe. It is named because its production process is double-sided submerged arc welding (commonly known as internal welding and external welding), and the weld seam is spiral shaped around the steel pipe. The raw materials used for producing double-sided submerged arc welded spiral steel pipes are steel strips or hot-rolled coils, and the materials generally include carbon structural steel (Q235 series and 20 # steel) and low alloy steel (Q345 series)