Large diameter seamless steel tube forming methods are: UOE method, conventional forming method, RBE roll forming method, JCOE molding method, C formation method, the people first party continuous bending method, etc.. A brief introduction is as follows: 1 . UOE first pre bending plate edge in U stamping die pressure into a U shape, and then forming in O stamping die pressure into O shape welded pipe hole.

2.CFE method and forming machine is composed of a pre molding frame, flat roller frame, edge bending roll and short ribs and frame composition, because many of the same line and forming of the plate during the process of trajectory on the edge of the arrangement is almost straight, to avoid the heavy caliber seamless steel pipe edge tension phenomenon. It is mainly applicable to large volume production of steel pipe, but it is difficult to produce high strength thick walled steel pipe and large diameter steel pipe.

3.RBE molding method in three or four of the repeated rolling forming roll plate, in the use of performance and reliability of the pipe production is close to UOE welded pipe.

4.JCOE forming method, first in the hydraulic press J shape, the pressure on both sides, many after stamping, finally through the O shape into O shape. JCOE product quality is close to UOE welded pipe, while the operating line is much lower than the UOE unit, but its production efficiency is low.

5.C form two C to replace the UOE unit news O molding method, molding process: the pre bending plate of the first half of the press forming board, and then in another news form the other half of the circle tube sheet. Large diameter seamless steel pipe production technology production scale, production quantity is moderate, the production line price is low.