Galvanized steel pipes are焊接 pipes with a hot-dip or electro-galvanized zinc coating on the surface. The galvanizing increases the anti-corrosion ability of the pipes, extending their service life. Galvanized pipes are widely used, not only as pipeline pipes for conveying water, gas, oil, and other general low-pressure fluids, but also as oil well pipes and oil pipelines in the petroleum industry, particularly for offshore oil fields. They are also used in oil heaters, condensers, and cooling systems for petrochemical coking equipment, as well as for pile tubes in bridges and support pipes for mine tunnels.