Straight seam submerged arc welded pipe is a longitudinally welded steel pipe manufactured using the submerged arc welding process. This process creates dense, uniform welds with high tensile strength. Its primary characteristic is its suitability for high-pressure applications. Compared to other welded pipes, Straight seam submerged arc welded pipe have stricter diameter and thickness requirements. Different specifications and models are suitable for different piping systems. Matching models improves efficiency during use, and simpler forming processes reduce production costs. Therefore, we are constantly innovating during production to expand its application.
So, how is Straight seam submerged arc welded pipe produced? What are the various forming processes involved?
JCOE forming: The steel plate undergoes four steps: pre-bending, gradual stamping, O-forming, and mechanical expansion.
UOE forming: The steel plate is first pressed into a U-shape, then into an O-shape, and finally expanded to a desired roundness. This is suitable for very large diameter pipes.
Pre-welding and finishing welding: After forming, pre-welding is performed using gas shielded arc welding, followed by double-sided submerged arc welding to form the main weld.
The entire Straight seam submerged arc welded pipe production process involves several critical steps, requiring careful attention:
Steel plate pretreatment: leveling, trimming, planing, and surface cleaning;
Weld quality control: X-ray inspection, hydrostatic testing, and weld mechanical property testing, with a pass rate of up to 99.92%;
Post-weld expansion: Eliminate residual stress and improve dimensional accuracy.
Perfect production processes are essential for long-term product performance, and therefore require continuous improvement and upgrading.
The production standards for Straight seam submerged arc welded pipe are also dependent on the production process. Commonly used standards in the market are as follows:
Outer Diameter: The most commonly used range is Φ355.6–1820mm, with a maximum of Φ3600mm. Custom sizes are available for larger sizes.
Wall Thickness: 5.0–50mm;
Pipe Length: 3–14m, depending on the application.
Material Grade: Q195–Q345, X42–X80, L555 high-strength steel, but production must adhere to applicable standards. To enhance the performance characteristics of Straight seam submerged arc welded pipe, a 3PE anti-corrosion layer can be added after production, allowing them to be used in corrosive environments, providing greater convenience for high-pressure transmission pipelines.
