Can sodium hypochlorite be used with metal equipment and pipes?
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Can sodium hypochlorite be used with metal equipment and pipes? Is it necessary to use non-metallic materials such as PP, FRP, and PVC? What is its corrosion mechanism on carbon steel and stainless steel?
Sodium hypochlorite... as the name suggests, it contains chlorine... It causes uniform corrosion in carbon steel, and it can lead to pinhole defects in stainless steel. From a product perspective, when carbon steel is corroded, iron ions dissolve in sodium hypochlorite, which may result in color changes. It is recommended to use plastic materials for storage and transportation, such as FRP or materials lined with Teflon...
UPVC pipes, gasket material FPM
Chemical corrosion + electrochemical corrosion: Hypochlorite can react directly with iron, and the corrosion of stainless steel can be explained by electrochemical corrosion. The materials are simple; under normal temperature and pressure, PVC is sufficient, with fluoroplastics being even better.
Both HClO and hypochlorous sodium have strong oxidizing properties; in fact, the ClO- ion also possesses strong oxidizing capabilities. When it comes into contact with metals, it oxidizes Fe to Fe+, thereby triggering corrosion reactions. Both are salts of strong bases and weak acids, and they are prone to hydrolysis, which is why hypochlorous sodium should not be stored in metal containers. Plastics such as PVC have good corrosion resistance.
Titanium or fluorinated lining; PP, FRP, and PVC are not very suitable
Metal pipes work fine! If you have money, go for titanium materials!
If metal is necessary, then line it with an anti-corrosion layer, usually rubber.