im gonna use the 1.5" butterfly valves and have the whole setup 1.5" tri clamp. i wana make a 13.5 gallon fermenter also with a triclamp pro racking port, 4" oxygen stone, tri clamp thermometer, and be able to carbonate or pressure rack the thing. thats gonna be wayyyy later on though. this build is gonna set me back a little (alot). im having trouble finding stainless welders in my area. the guy i bought the kegs from said he knows someone so if could get a little deal that'd be awsome.