Spiral steel pipe is a spiral steel pipe made of strip steel coil as raw material, extruded at regular temperature and welded by automatic double-wire double-sided submerged arc welding process.

(1) raw materials, namely, strip coil, welding wire, welding flux. In the input before are subject to strict physical and chemical inspection.

(2) The head and tail of the strip is butt-joined, using single or double wire submerged arc welding, and automatic submerged arc welding is used to fill in the rolled steel pipe.

(3) Before forming, the strip is leveled, edge cutting, edge planing, surface cleaning and conveying and bending edge treatment.

(4) Adopt electric contact pressure gauge to control the pressure of the press down cylinder on both sides of the conveyor, which ensures the smooth transportation of the strip steel.

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

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

(7) Both internal and external welding are performed by single or double wire submerged arc welding with American Lincoln welding machine, so as to obtain stable welding specification.

(8) The finished welds are inspected by online continuous ultrasonic automatic flaw meter, which ensures the nondestructive testing coverage of 100's spiral welds. If there are defects, automatic alarm and spray mark, production workers according to this at any time to adjust the process parameters to eliminate defects in a timely manner.