Expert ForumsCorrosion

Topic: Re: What's the best MOC for a clean-in-place tank?

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In my experience, this is a more difficult question than it might seem. At these concentrations, if there are issues they will be caused by the bleach and not the sodium hydroxide. In general, metallic materials such as 304 and 316 stainless steel are not recommended for use with bleach. However, it is generally believed that there is a point where the sodium hypochlorite is dilute enough such that it is no longer corrosive to stainless steels. Having said this, there is anecdotal information "on the street" that residues left on stainless steels from dilute bleach cleaners may cause staining and corrosion. Assuming the manufacturer of Chlor-Mate is marketing this product as a stainless steel cleaner, I would ask them to provide compatibility data for MOCs, including 304 and 316 stainless steels, at the recommended use concentrations. To minimize risk, you could design your system so that only the amount of CIP solution needed is made up and once used is discarded. This would allow the CIP tank to be rinsed and flushed with water afterwards thereby minimizing the contact time of the tank with the bleach and also minimizing the possible formation of bleach residues.