Straight seam steel pipes are manufactured by rolling steel plates or coils into a cylindrical shape with the seam running parallel to the pipe axis. They are produced via High-Frequency Electric Resistance Welding (ERW/LSAW) or Submerged Arc Welding (LSAW). Compared to spiral pipes, straight seam pipes offer higher dimensional accuracy, superior roundness, and excellent performance for medium-to-large diameters and high-pressure applications.