Large-diameter welded pipe production units

There are various production methods for large-diameter straight seam submerged arc welded pipe (20 - 64 inches) production units. The UOE method produces pipes with the best quality and highest reliability, but due to the huge construction investment, no new UOE units have been built since the 1980s. The roll bending forming process, originally mainly used for producing large-diameter structural pipes (with a maximum outer diameter of 4000mm), has been transformed into the RBE method. Thanks to its high production flexibility and low investment, the RBE method has been promoted in developing countries. Among the 13 large-diameter straight seam submerged arc welded pipe production units built abroad since the 1990s, some are RBE units. In addition, the PFP forming method developed by SMS-Demag in Germany is also applied to produce large-diameter straight seam submerged arc welded pipes. Moreover, large-diameter spiral submerged arc welded pipe production units are still being constructed in some countries, used for manufacturing both structural pipes and pipeline pipes for oil and gas transportation, with the highest steel grade reaching X80.