huskerbrew wrote: The guy wants to sell me a HUGE tank...like 70 cubic feet! Is it me or is that a tad extravagant? Seems to me that a bottle like that would be more at home in a pub, not at home. Am I wrong? The tank is $200, $45 to fill, fees for testing, plus I still need a regulator to fit this monster, then a faucet, shank, etc. I know this is gonna be a moderate expense, but isn't a tank from NB or B3 or whatever sufficient? I'm only gonna run one faucet, so I'm thinking a smaller tank would be OK. Anyone out there with experience that can help a brother out??
A "70 cubic foot bottle" has a capacity of about 0.65 cubic feet. When it is filled with gas to about 1600 psig and that gas is allowed to expand back to 1 atmosphere (at 0 °C) the expanded gas will have a volume of about 70 cubic feet i.e. the 70 number refers to the gas once it has been let out of the bottle. A 70 cubic foot bottle is (other than lab demo bottles) the smallest size made (I believe). The cylindrical part is about 30" high (valve assembly on top of that) and about 7" in diameter.
There are about 7.5 gal in 1 cu ft so that 70 cu ft will displace 70/15 = 9.3 half barrel kegs of beer
if you draw them at 0 psig (1 atm) with 100% nitrogen. As a nitrogen system is likely to have a partial pressure of nitrogen of at least 2 (14.7 psig) or 3 (29.4 psig) atmospheres (to push that beer through the sparkle plate at hefty velocity) you would expect a 70 cu ft bottle to push 3 - 4.5 kegs. So no, 70 isn't that huge.
Now all this assumes that you are buying pure N2 and blending it (i.e. you have a blender which is a fairly expensive piece of equipment). Absent that you would have to arrange to have the tank filled with either "beer mix" (about 65% CO2) or "stout mix" (about 25% CO2).
You ought to be able to find a place that will give you the gas in one of their bottles, charge less than $45 for a refill and not charge you for the hydro tests.
