07-22-2012, 12:39 AM
(This post was last modified: 07-22-2012, 12:48 AM by Tony Wells.)
Food contact stainless grades are normally T316 or T304. Both are NSF approved for piping systems involving beverages and food products. I would recommend T316 for anything with PH that is very far off neutral. It is far more corrosion resistant. Of course, sanitizing the system prior to use is still required. I have done a fair amount of design and manufacturing work on water purification systems, and have investigated the very issues you are concerned with. If you must weld any part of the system rather than use sanitary fittings, specify T316L or T304L.