Hot dip galvanized steel pipes are generally galvanized to improve their corrosion resistance. Galvanized steel pipes are divided into hot-dip galvanizing and electroplating galvanizing. The hot-dip galvanizing layer is thick, the galvanizing cost is low, and the surface is not very smooth.

Hot dip galvanized pipes react molten metal with an iron substrate to produce an alloy layer, which combines the substrate with the coating. Hot dip galvanizing should first acid wash the steel pipe. In order to remove the iron oxide on the surface of the steel pipe,

After acid washing, the passability will be poor. Cold galvanized steel pipes are prohibited from being used as water supply pipes in newly constructed residential buildings.