Spiral Submerged Arc Welded Pipe

Spiral submerged arc welded (SSAW) pipes has spiral welding joints and the pipes are welded and formed at the same time. The strip steel with the same specification can produce SSAW pipes with various diameters. The welding joints can avoid major stress and have better force resistance. Disadvantages are poor geometrical diameters; longer welding joints and joints are easily to have cracks, porosity and other welding defects. According to the design specification of oil and gas pipeline, SSAW pipes only can be used in the third and fourth class areas. Developed countries have improved the technology, apart forming and welding, and have pre-welding and precise welding processes which make the quality of welding close to UOE pipes. Currently, the domestic market doesn’t master this technology which needs to be improved. SSAW pipes produced by traditional technique are widely used in the project of natural gas transmission from West to East China. The US, Japan and Germany believe that it’s not suitable to use SSAW pipes as main trunk; Canada and Italy use it partially and Russia use it in a small scale with strict additional condition. China, due to historical reasons, still uses SSAW pipes as main trunks in majority areas.