What kinds of galvanized steel pipes are there?

Galvanized steel pipe is mainly divided into cold plating pipe and hot plating pipe.

1. Hot dip galvanized pipe: The molten metal reacts with iron to produce an alloy layer so that the substrate and the coating are combined.

2. cold galvanized pipe: cold galvanized is electric galvanized, galvanized amount is very small, only 10-50 grams per square meter, its own corrosion resistance is much different than hot galvanized pipe.

Hot dip galvanizing is to first pickling the steel pipe, remove the iron oxide on the surface of the steel pipe, after pickling, through ammonium chloride or zinc chloride aqueous solution or ammonium chloride and zinc chloride mixed aqueous solution tank for cleaning, and then into the hot dip plating tank. Hot dip galvanizing has the advantages of uniform coating, strong adhesion and long service life. Most of the processes in the north adopt the zinc replenishment process of galvanized belt direct coil pipe.

Regular galvanized pipe production plants, in order to ensure quality, most do not use electric galvanizing (cold plating). Only those small enterprises with obsolete equipment use electric galvanizing, of course, the price is relatively cheap. Do not use cold galvanized pipes as water and gas pipes.

Hot-dip galvanized steel pipe:

Complex physical and chemical reactions occur between the steel tube substrate and the molten bath to form a tight zinc-iron alloy layer with corrosion resistance. The alloy layer is integrated with the pure zinc layer and the steel pipe matrix. Therefore, its corrosion resistance is strong.

Cold galvanized steel pipe:

The zinc layer is an electric coating, and the zinc layer is independently layered with the steel pipe matrix. The zinc layer is thin, and the zinc layer is simply attached to the steel tube matrix and easy to fall off. Therefore, its corrosion resistance is poor. In new residential buildings, it is prohibited to use cold galvanized steel pipes as water supply pipes.