Galvanized welded pipe is a welded steel tube with hot dip or electrogalvanizing layer on the surface.
In order to improve the corrosion resistance of steel tube, it will be galvanized. Galvanizing can increase the corrosion resistance of steel tube and prolong service life. Galvanized pipe use very wide, in addition to a general low pressure fluid such as water, gas, oil line pipe, also used as oil industry, especially the ocean oil field like oil well pipe, oil pipe, chemical coking equipment of oil heater, the condensing, exchange of coal distillation wash oil cooler for tube, and trestle pile, mining tunnel supporting frame tube, etc. Zinc-plated welded pipe is divided into hot galvanizing and cold galvanizing.
Hot dip galvanized pipe
The hot-dip galvanizing tube is used to make the molten metal react with the iron matrix to produce the alloy layer, thus combining the substrate and the plating layer. Is hot dip galvanized steel pipes to pickling, in order to remove iron oxide on the surface of the steel tube after acid cleaning, by ammonium chloride or zinc chloride or ammonium chloride and zinc chloride mixed aqueous solution tank cleaning, and then sent to the hot dip plating tank. Hot galvanizing has the advantages of uniform coating, strong adhesion and long service life.The complex physical and chemical reactions of the hot-dip galvanized steel tube matrix and molten plating have formed the corrosion resistant structure of a zinc - iron alloy layer. The alloy layer is integrated with pure zinc layer and steel tube matrix. Therefore, its corrosion resistance is strong.
Cold galvanized pipe
Cold galvanizing tube is electric galvanizing, galvanizing amount is very few, only 10-50g/m2, its own corrosion resistance is worse than hot galvanizing tube. Generally the tube manufacturer in order to ensure the quality, most do not adopt electrogalvanizing (cold plating). The galvanizing layer of cold galvanizing steel tube is the electroplating layer, the zinc layer and the steel tube matrix are independent stratified. The zinc layer is thin, the zinc layer is simple attached to the steel pipe matrix, easy to fall off. It has poor corrosion resistance. In the new residence, the use of cold - galvanized steel pipes is prohibited.
So hot dip galvanized steel pipes are widely used in construction, machinery, coal, chemical, electric power, railway vehicles, automotive industry, roads, Bridges, containers, sports facilities, agricultural machinery, petroleum machinery, and prospecting machinery manufacturing industry.
Edit by Ms. Julia Zhu of KRM/BSW (Sales Dept.)
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