So I got a brand new aluminum 20# CO2 tank (Catalina brand) at the gas supplier and I cannot get any co2 to come out of the tank. Even without the regulator installed when I crack the tank valve open nothing happens. At first when I cracked it open it hissed a VERY small amount, than nothing. I know for a fact that the tank is full as I weighed it and also I can feel the liquid sloshing around in it. I'm taking the tank back next week, but I figured I would throw this out there in case there is something I am missing. Bad tank valve??? Any ideas???