In order to improve the corrosion resistance of the steel pipe, galvanized steel pipe is carried out. Galvanized steel pipe is divided into hot dip galvanized steel and two kinds of electric galvanized, hot dip galvanized layer thickness, low cost, the surface is not very smooth. Oxygen blowing pipe: used for steel smelting blowing tube, usually with a small diameter of the welded steel pipe, specifications from 3/8-2 inch eight. With 08, 10, 15, 20 or 195-Q235 of the steel production, in order to prevent corrosion, have to carry out the treatment of aluminum.

Hot dip galvanized pipe is made of molten metal and iron substrate reaction to produce alloy layer, so that the substrate and the coating two. Hot dip galvanizing is first to pickling steel pipe, in order to remove iron oxide in the surface of steel, pickling, by ammonium chloride or zinc chloride aqueous solution or ammonium chloride and chloride zinc mixed aqueous solution groove cleaning is then fed into hot dip tank. Hot dip galvanized coating with uniform, strong adhesion, long service life, etc.. The complex physical and chemical reactions of the steel tube matrix and the molten bath have formed the structure of corrosion resistant. Alloy layer is integrated with the pure zinc layer and the steel tube. Therefore, its corrosion resistance.1, the uniformity of galvanized layer: steel specimen in copper sulfate solution impregnation 5 times shall be red (copper plating)2. The surface quality: galvanized steel surface should be a complete galvanized layer shall not not plated with spots and bubble exists, allowing a small rough surface and local zinc tumor.3, weight of zinc coating: according to the requirements of the buyer, galvanized steel pipe can be as zinc coating weights determined. The average value shall not be less than 500g / square meters, including any specimen shall not be less than 480g/ square meters.

Cold galvanizing is electric galvanized, galvanized amount is very few, only 10 - 50g/m2, the corrosion resistance of its own specific heat galvanized pipe is a lot of difference. Regular galvanized pipe manufacturers, in order to ensure the quality, most do not use electric galvanized (Leng Du). Only those small, old equipment used in small enterprises, of course, their prices are relatively cheaper. At present, the Ministry of construction has officially below, the elimination of backward technology of cold galvanized pipe, the future is not allowed to use cold galvanized pipe for water, gas pipe. The zinc layer is the plating layer, the zinc layer and the steel tube substrate independent layer. The zinc layer is thin, and the zinc layer is attached to the steel tube, which is easy to fall off. Therefore, its corrosion resistance. In the new housing, the use of cold galvanized steel pipe as a water pipe.