Originally Posted by barrooze
25*12*(3/16)^2*pi/4 cubic inches worth.
So if the formula is right (which I have no reason to believe its not), that should be 8.28 cubic inches or roughly 4.59 fl ounces.
However, in the tube or in the keg should not matter. Its all the same pressure throughout the system and the tube should be refrigerated anyway. Right?