Corrosion of the three-stage gasket in the reciprocating acetylene compressor
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The three-stage seal aluminum gaskets used in our company’s reciprocating acetylene compressors are exposed to circulating water for extended periods of time. It usually starts to corrode after about 20 days. What substances in water can cause corrosion of aluminum gaskets?
Aluminum generally corrodes in water containing chloride ions; corrosion also occurs when the pH of the water is below 6.
Let’s first take a look at the chemical properties of aluminum: Aluminum is a metal with extremely reactive chemical properties; immediately upon exposure to air, a dense oxide layer forms on its surface, protecting it from further oxidation. The alumina layer is resistant to water； Spraying aluminum powder and forming an aluminum powder-air mixture in the air makes it extremely prone to combustion or explosion ； Aluminum is amphoteric; it can react with strong bases as well as with dilute acids. Under alkaline conditions, aluminum can react continuously with water to produce aluminum hydroxide and hydrogen gas. Aluminum can react significantly with water vapor when heated, but from the very beginning of this reaction, oxygen present in water forms a dense oxide film that prevents further reaction. Based on these properties of aluminum, it is estimated that the aluminum gasket came into contact with alkaline water, resulting in a reaction; at the same time, its contact with other metal materials that have a significant potential difference from aluminum exacerbated the corrosion of the aluminum gasket.