Spiral steel pipe

   Spiral steel pipe is a kind of spiral seam steel pipe, which is made of strip coil as raw material and is often extruded and welded by automatic double wire submerged arc welding process. The spiral steel pipe feeds the strip into the welded pipe unit. After rolling by multi-rollers, the strip is gradually rolled up to form a circular billet with opening clearance. The reduction of the extrusion roll is adjusted so that the weld clearance is controlled at 1-3 mm and the weld ends are even.