Are there any special requirements to qualify a 304L SS tank as food grade? Cleaning methods, welding practices, special inspections? Any insite is appreciated!
Yes. If you google sanitary stainless construction or something similar, you will find that there are many specifications regarding weld finish, corners, cleaning accessibility, dissassembly (pipeline, as in dairy), etc.
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.