First, acid pickling the steel pipe to clean oxide of iron on the surface.
After that, clean the pipe by ammonium chloride or zinc chloride or ammonium chloride and zinc chloride mixed aqueous solution in tank, and then sent to the hot dip plating tank.
Hot dip galvanized steel pipe has advantages such as with uniform coating, strong adhesion, long service life, etc.
Most manufactures in the northern adopt galvanized belt with direct volume tube zinc supplementation.
