Cold galvanized pipe is electro-galvanized, and the amount of galvanized is very small, only 10-50g/m2. The corrosion resistance of the cold galvanized pipe is much worse than that of hot galvanized pipe. Regular galvanized pipe manufacturers, in order to ensure quality, mostly do not use electroplating zinc (cold plating). Only those small businesses with small scale and outdated equipment use electro-galvanizing, and of course their prices are relatively cheap. At present, the Ministry of Construction has officially formally eliminated the cold galvanized pipes with obsolete technology and will not use cold galvanized pipes as water and gas pipes in the future. Cold galvanized steel pipe galvanized layer is a plating layer, and the zinc layer and the steel pipe substrate are layered independently. The zinc layer is thin, and the zinc layer is simply attached to the steel pipe substrate and it is easy to fall off. Therefore, its poor corrosion resistance. In new residential buildings, the use of cold galvanized steel pipes as water supply pipes is prohibited. Source of information: http://