Is it code to check PLUMBING DRAINAGE AND VENT SYSTEMS with air only? and what is the minimum of reventing? 36in. ff 42, 60 or 72 in ff. thx for your help!
As far as "reventing", that's an "industry term" we use in my neck of the woods to describe connecting one fixture vent to another. Code only gives us max horizontal and vertical distances, as long as you size correctly and don't exceed the max distances you should be fine. That is unless the code in your area is different than the UPC.