Cold galvanized pipes are galvanized by electricity, with a small amount of galvanizing, only 10-50g/m2, and their corrosion resistance is much different from that of hot-dip galvanized pipes. Most legitimate galvanized pipe manufacturers do not use electric galvanizing (cold plating) to ensure quality. Only small enterprises with outdated equipment and small scale use electrogalvanizing, and of course, their prices are relatively cheaper. The Ministry of Construction has officially announced the elimination of outdated cold galvanized pipes and the prohibition of using cold galvanized pipes as water and gas pipes. The galvanized layer of cold galvanized steel pipes is an electroplating layer, which is independently layered with the steel pipe substrate. The zinc layer is relatively thin and simply adheres to the steel pipe substrate, making it easy to fall off. Therefore, its corrosion resistance is poor. In newly built residential buildings, it is prohibited to use cold galvanized steel pipes as water supply pipes.