Manufacturing Techniques of LSAW Steel Pipe

The biggest advantage of the lsaw steel pipe is that it can produce specifications that high-frequency longitudinal-seam steel pipes, spiral welded steel pipes and seamless steel pipes can't manufacture. At present, the manufacture techniques of the lsaw steel pipe mainly have UOE, CFE, RBE, JCOE and PFP etc. Among them, there are only UOE and JCOE belonging to the country's main forming methods. UOE is one of the most advanced molding method in the world, and it is famous for its high production efficiency and quality, but it also needs expensive equipments well as large amount of investment. JCOE, its product quality is the same as those made with UOE, but its unit price is much lower than that of the UOE unit, has low production efficiency.

And a more newly introduced manufacturing technique is to use steel coils to form longitudinal submerged arc welding pipes continuously. A domestic welded pipe manufacturer developed two production lines using this kind of technique, and it has applied for national invention patent. The main process is as follows: after uncoiling the steel coils, it needs to carry out 3 groups of flattening, edge milling with plain-barrelled roll. And make it bend gradually through 16 groups of edge bending rolls and 12 groups of rack of plain-barrelled roll to reach C molding and D molding. At the same time, to finish the welding of automatic submerged arc of the inside welding line in the way of flat welding. And then mill the outer welding line of the steel pipe to be a V, cutting into the required length. Finally, put the welding line upwards and weld up the automatic submerged arc of the outside welding line adopting flat welding method.