Spiral steel pipe is a kind of product formed by welding technology, so in the production process for the welding process is very strict. (1) Raw materials are strip coil, welding wire and flux. Strict physical and chemical tests must be carried out before being put into operation. (2) The joint

Spiral steel pipe is a spiral welded steel pipe made of strip steel or coiled plate as raw material, often extruded and formed by automatic double-wire double-sided submerged arc welding. Spiral steel pipe and its standard classification: spiral seam submerged arc welded steel pipe for pressure flui