Galvanized Steel Pipe

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Galvanized Steel Pipe Galvanized Steel Pipe Galvanized Steel Pipe Galvanized Steel Pipe

Generally, galvanization treatment is applied on ordinary steel to improve the corrosion resistance and extend service life. Our company can provide a series of galvanized steel pipe with reliable performance. Advanced technique is used in this product and alloy layer can be formed by reaction of molten metal and iron matrix. So iron matrix and layer can combine together. The detailed process is as follows. Firstly, steel tube is pickled to remove iron oxide on the surface. After that, it is cleaned by aqueous solution of ammonium chloride or zinc chloride or a combination solution of them. Then it is immersed into hot-dip plating bath. With uniform layer, strong adhesion, coating won't fall off after long-time use to ensure reliable corrosion resistance of galvanized steel pipe.

Apart from transporting low pressure fluid such as water, gas and oil, galvanized steel pipe is also used in oil industry, particularly oil well tubes of offshore oilfield, pipeline, oil heaters of chemical coking equipment, condensing cooler, oil exchange tube of coal distillation of wash, trestle piles and mine tunnel support frame tubes, etc.

As typical amphoteric metal, zinc coating of galvanized steel pipe has bluish-white appearance and standard electrode potential is 0.76V. It is also soluble in acid and dissolved in alkali. Zinc is very stable in dry air and critical humidity is bigger than 70% for corrosion. So it can form a thin film, mainly composed of basic zinc carbonate, with carbon dioxide and oxygen in humid atmosphere. This thin film can slow the corrosion process. It can also react with hydrogen sulfide and form zinc sulfide. In addition, zinc is not stable in seawater because it is vulnerable to chloride ion.

Standard potential of Zinc is smaller than iron, so as an anode coating for iron and steel it can provide reliable electrochemical protection. Zinc layer can be chosen as protective measure in iron and steel products which are used in industrial atmosphere, rural atmosphere and oceanic atmosphere. And its service life is almost proportional to its thickness. When there is industrial exhaust pollution in atmosphere, zinc layer has better performance than cadmium coating. Whereas the opposite is true in seawater.

Application temperature of zinc layer of galvanized steel pipe should not exceed 2500℃because zinc crystal tissue becomes deformed and brittle, thus anti-corrosion ability decreases. It can form white loose corrosion product called white frost, when it is in contact with volatile compounds of non-metallic materials such as, low molecular weight carboxylic acids, aldehydes, phenols and ammonia in closed or ventilation poor space or humid air. In addition, zinc has the tendency of growing filamentous single crystal which is called long hair.

Detailed Specifications
Size (outer diameter X wall thickness): 13.7 - 168.3mmX 1.8-6mm
Standard: GB/T 3091 BS1387 ASTM A 53
Grade of steel: Q195/Q235B/Q345B
Length, lathe thread at both ends, pipe clamp and plastic cap can be customized according to the specific requirements of customers.

UNIGLORY is a professional galvanized steel pipe supplier in China. We provide a vast array of products, including API 5L line pipe, cold rolled steel coil, steel H-beam, carbon steel welding electrode, and more.

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