Originally Posted by dlymn
From Article: Selection of stainless steels for handling chlorine (Cl2) and chlorine dioxide (ClO2)
Chlorine as a sterlizing or sanitising agent
When using chlorine as a sterilizer or sanitiser in contact with 316 type stainless steel
items, a maximum of 15-20 ppm (mg/lt) 'free' chlorine is suggested, for maximum times of 24 hours, followed by a thorough chlorine free water flush.
As with any additions, thorough dilution around the injection point is important to avoid localised 'over-concentration' problems.
Residual chlorine levels in waters of 2ppm maximum for 304 and 5ppm for 316 types should not normally be considered a crevice corrosion
1) Due consideration needs to be given, to the reality that reports and recommendations originating with vested interests groups (e.g. the British Stainless Steel Association), need to be accompanied by very large doses of both salt
2) Qualities of stainless steel (and there are very many substandard qualities of stainless steel on the market today, along with even deliberate mislabeling e.g. with rigging
wire, and this for uses that can very much get people killed, if inadequate products are supplied) in different environments at different temperatures, can potentially affect performance.
3) Uniform Attack is a far more serious issue, than crevice corrosion (though it can kick that off or contribute to it too), and it might be considered rather disingenuous, and motives questioned, for pretending that 'all is ok' as regards Uniform Attack, when things 'might' (or might not - and 'suggestions' and 'not normally' are not guarantees to customers) be ok with certain concentrations with regards to 'crevice corrosion'.
The 'crevice corrosion' Apples are bad enough, but we are talking the big stinky rotten Watermelon (not Oranges), with Uniform Attack.