Longitudinal submerged arc welded pipe (LSAW) is generally made of steel plate as raw material. After different forming processes, double-sided submerged arc welding and post-weld diameter expansion are adopted to form welded pipe.
The main equipment includes milling machine, pre-bending machine, forming machine, pre-welding machine, expanding machine, etc. At the same time, there are many types of forming methods for LSAW steel pipes: UO (UOE), RB (RBE), JCO (JCOE), etc. The steel plate is first pressed into a U shape in the forming die, and then pressed into an O shape, and then internally and externally submerged arc welding is performed. After welding, it is usually called UOE welded pipe at the end or the full length range (Expanding). It is UO welded pipe. Roll Bending the steel plate, and then carry out internal and external submerged arc welding. After welding, the diameter is expanded to RBE welded pipe or not to RB welded pipe. The steel plate is formed in the order of J type-C type-O type, and the diameter is expanded to JCOE welded pipe after welding, or it is not expanded to JCO welded pipe.
UOE LSAW pipe forming process:
The three main forming processes of UOE LSAW steel pipe forming process include: steel plate pre-bending, U forming and O forming. Each process adopts a dedicated forming press to complete the three processes of pre-bending the edge of the steel plate, U forming and O forming in sequence to deform the steel plate into a circular tube.
JCOE LSAW pipe forming process:
Forming: After several steps of stamping on the JC0 forming machine, first half of the steel plate is pressed into a "J" shape, then the other half of the steel plate is pressed into a "J" to form a "C" shape, and finally pressurized from the middle to form An open "0"-shaped tube blank is formed.