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

Steel pipes can be used to transport fluids and powdered solids, exchange thermal energy, and make mechanical parts and containers, it is also an economical steel. For example, the use of steel pipes to make grids, pillars and mechanical supports for building structures can reduce the weight and