316 or 304 SS

Getting ready to convert a large adult beverage container into a ekeggle. Should I use 316 or 304 fittings?

I'm going weld (Tig) it.

304 should be just fine, the only difference is 316 has a higher Nickel content than 304.

Yes, 316 is used for eg. salt water.

316 has slightly better corrosion resistance. I know at work we specify 316 for all process piping. Anything else (hot water sets for the media side of a heat exchanger, equipment framework, etc) can be 304.

Yes, the corrosion environment of the typical brewery setting does not require 316. But it can be used. diS may be a little off regarding 316 and its use around salt water. When I was working with the South Florida Water Management District, they required 317 stainless when metal structures like hydraulic gates were at the sea coast.

If the OP is welding, then the preferred grade would be 304L stainless. The L indicates its formulated for welding.

If 316 was required for a particular application that also required the use of a beer keg, you would be screwed because the keg is 304!