Galvanized steel pipes are welded steel pipes with a hot-dip galvanized or electro-galvanized layer on the surface. Galvanizing can increase the corrosion resistance of the steel pipe and prolong the service life. Galvanized pipe has a wide range of uses. In addition to line pipes for conveying water, gas, oil and other general low-pressure fluids, it is also used as oil well pipes and oil pipes in the petroleum industry, especially offshore oilfields, as well as oil heaters and condensation for chemical coking equipment. Pipes for coolers, coal-distilled wash oil exchangers, pipe piles for trestle bridges, and pipes for support frames in mine tunnels, etc.