1. Raw materials include strip coil, welding wire and flux.Strict physical and chemical inspection should be carried out before input.

2. Single wire or double wire submerged arc welding is used for butt butt of strip steel, and active submerged arc welding is used for repair welding after rolling steel pipe.

3. The electric contact pressure gauge is used to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth delivery of strip steel.

4. Before forming, strip steel after leveling, cutting, planing, surface cleaning, transportation and bending processing.

5 selection of external control or internal control roller molding.

6. Weld gap control equipment is selected to ensure that the weld gap is satisfied with the welding requirements. Pipe diameter, staggered edge and weld gap are strictly controlled.

7. American Lincoln welding machine is used for single wire or double wire submerged arc welding for internal and external welding, so as to obtain stable welding specifications.