API 5L steel pipe according to the production process is divided into the submerged arc welding steel pipe, etc. 8. But the main use of Seamless steel tube (Seamless), high frequency straight seam Resistance Welding steel pipe (Electric - to hold the Arc Welding, shorthand for ERW), straight seam Submerged Arc Welding pipe (Longigudinally Submerged Arc Welding, shorthand for LSAW), spiral seam Submerged Arc Welding pipe, Spirally Submerged Arc Welding, shorthand for SSAW), etc.
Straight seam submerged arc welding pipe press forming method is divided into UO (UOE), RB (RBE), JCO (JCOE), etc. The steel plate in forming mould pressing U first, then pressed into an o-ring, and then evaluated for submerged arc welding, after welding are usually at the end or span range (Expanding) called the UOE welded pipe, hole diameter is not called UO of hole diameter welded pipe. The steel plate roller bend forming (Roll Bending), and then evaluated for submerged arc welding, after welding for RBE hole diameter welded pipe or not for hole enlargement RB welded pipe. Will the steel plate according to the order of type J - C - O forming, hole enlargement of JCOE welded pipe after welding or not for hole enlargement JCO welded pipe. Of the LSAW welded pipe is a widespread use of UOE. High frequency electric resistance welded pipe ERW mainly by high frequency current skin effect and proximity effect melted the tube embryo edge, then under the action of squeezing roller pressure welding, its characteristic is no foreign filler metal, heat affected zone is small, high production efficiency. Spiral welded pipe used in long distance line SSAW pipe has a long history, is our country at present mainly adopts the line pipe.
