What Are The Types Of Galvanized Pipes

1. Hot dip galvanized steel pipe
Hot dip galvanized steel pipes have the advantages of uniform coating, strong adhesion, and long service life. Most of the processes in the north use galvanized tape to directly roll the pipe and supplement the zinc. Hot dip galvanized pipes produce an alloy layer by reacting molten metal with an iron substrate, thereby bonding the substrate and coating together. Hot dip galvanizing is the process of first pickling steel pipes. In order to remove iron oxide from the surface of the steel pipes, after pickling, they are cleaned in an ammonium chloride or zinc chloride aqueous solution or a mixed ammonium chloride and zinc chloride aqueous solution tank, and then sent to a hot-dip galvanizing tank. The steel pipe substrate will undergo complex physical and chemical reactions with the molten plating solution, forming a corrosion-resistant and tightly structured zinc iron alloy layer. The alloy layer is integrated with the pure zinc layer and the steel pipe substrate, so its corrosion resistance is strong.
2. Cold galvanized steel pipe
The zinc 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 easily adheres to the steel pipe substrate, making it prone to detachment, resulting in poor corrosion resistance. Therefore, the use of cold galvanized steel pipes as water supply pipes should be prohibited in residential areas.
Cold galvanizing is also known as electroplating galvanizing, with a very small amount of galvanizing, only 10-50g/m2. Its corrosion resistance is much different from that of hot-dip galvanized pipes. Legitimate galvanized pipe manufacturers, in order to ensure quality, mostly do not use electroplating (cold plating). Only small enterprises with small scale and outdated equipment adopt electroplating, and of course, their prices are relatively cheaper.