Hot-dip galvanized steel pipe: the molten metal and iron matrix reaction to produce alloy layer, so that the 

matrix and the combination of the two. 

Hot-dip galvanizing is the first pickling of the steel pipe, in order to remove the iron oxide surface of the 

steel pipe, pickled, through ammonium chloride or zinc chloride aqueous solution or ammonium chloride 

and zinc chloride mixed water tank cleaning, and then into hot dip bath. 

Hot galvanized with uniform coating, strong adhesion, long life and other advantages. Hot-dip galvanized steel 

pipe matrix and molten bath complex physical, chemical galvanized steel pipe should be formed to corrosion-

resistant structure of a close zinc-iron alloy layer. 

Alloy layer and pure zinc layer, steel pipe body integration. 

So its strong corrosion resistance.

Hot-dip galvanized seamless steel pipe: very little galvanized, only 10-50g / m2, its own corrosion resistance than 

hot galvanized pipe a lot worse. 

Formal galvanized pipe manufacturers, quasi-cold galvanized pipe for water, gas pipe. 

Galvanized galvanized steel galvanized layer is the electroplating layer, zinc layer and the steel pipe matrix 

independent layer.

Zinc layer is thin, zinc layer simply attached to the steel pipe matrix, easy to fall off. 

So its poor corrosion resistance. 

In the new residential, the use of cold galvanized steel pipe as a water supply pipe.