304 and 316 resistance to aluminium sulphate and calcium chhloride

[ashtree]

I have been looking at some ISO container tankers for the possibility of storage of 47% aluminium sulfate (alum) and 30% calcium chloride.
I am getting some really mixed information with regards to the compatibility of the tanks with these chemicals. The tank supplier gave me a chemical compatibility chart which suggested the alum was okay but not good in the 316 model but Calcium chloride was excellent in the 304 tank. I have seen other charts which are the opposite, and others which suggest neither chemical is compatible with either tank.
I am sure the ISO tank material is specified somewhere but i have been able to get little detail on what the actual material is , they are typically just listed as 304 or 316.
This issue and a few other associated with ISO tanks is tending to change my mind on the overall suitability for the project, but i would be interested in some expert opinion on the compatibility problem.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[EdStainless]

So it doesn't matter if your first on is Al Sulfate or ALUM (Al K sulfate), I would expect pitting at the 'waterline' in either stainless grade.
316 will stand up fairly well, but don't expect it be completely undamaged.
The CaCl, no way in my book. The 304 will be very poor and the 316 only slightly better, but both pitting and CSCC are real risks.

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P.E. Metallurgy, Plymouth Tube

 

[ashtree]

Thanks Ed.

This was what i expected. 316 and alum probably acceptable and CaCl2 not. The chemical compatibility chart that was supplied was the problem.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"