Galvanized steel pipe is a welded steel pipe with a hot-dip or electro-galvanized layer on the surface.  Galvanizing can increase the corrosion resistance of steel pipes and prolong their service life.  Galvanized pipes are widely used.  In addition to being used as pipeline pipes for general low-pressure fluids such as water, gas, and oil, they are also used as oil well pipes and oil pipelines in the petroleum industry, especially offshore oil fields, and oil heaters and condensation pipes for chemical coking equipment.  Pipes for coolers, coal distillation washing oil exchangers, trestle piles, and support pipes for mine tunnels, etc.