Spiral steel pipe is a spiral seam steel pipe made of strip steel coil as raw material, often warmly extruded, and welded by automatic double-wire double-sided submerged arc welding process. The spiral steel pipe feeds the strip into the welded pipe unit. After rolling by multiple rollers, the strip is gradually rolled up to form a circular tube blank with an opening gap. 3mm, and make both ends of the welding joint flush.

Spiral steel pipe is a product formed by welding technology, so the welding process requirements are very strict in the production process.

(1) The raw materials are strip coil, welding wire and flux. They must undergo strict physical and chemical inspections before being put into use.

(2) The head and tail of the strip are butted by single-wire or double-wire submerged arc welding, and automatic submerged arc welding is used for repair welding after rolling into a steel pipe.

(3) The electric contact pressure gauge is used to control the pressure of the cylinders on both sides of the conveyor to ensure the smooth conveying of the strip.

(4) Before forming, the strip is leveled, trimmed, planed, surface cleaned and conveyed and pre-bending.

(5) Adopt external control or internal control roll forming.

(6) The weld gap control device is used to ensure that the weld gap meets the welding requirements, and the pipe diameter, the amount of misalignment and the weld gap are strictly controlled.

(7) Both internal welding and external welding are used for single-wire or double-wire submerged arc welding by the American Lincoln welding machine, so as to obtain stable welding specifications.