I'm relatively new to kegging and brand new to this site (if I am breaking any rules or need to post somewhere else, please let me know). I have a 20 LB C02 tank that I've been using for about a month now and I just noticed a slow leak in my regulator. I have the leak fixed, but my pressure reading is sitting right on 200 which is well below the fill line. The tank is being stored at 35 degrees so I know that it is actually higher than that, but I'm curious if there is any way to find out how much is actually left in there without setting the tank out and getting it back to room temperature. Is there any sort of conversion table for different C02 temperatures? Thanks to all!
You can weigh your tank to determine CO2 remaining. Somewhere on the upper portion of your tank is the stamped Tare Weight. It will look something like TW XX.X where the XX's are the empty weight. The difference in the actual weight and the TW is the amount of liquid CO2 remaining. Of course you have to take reg off to do this. Pretty sure 200psi @35F is zero liquid remaining. Here's the temp/press chart.
A pressure gauge measures pressure, not volume. You can't tell how much CO2 is in the tank by looking at a pressure gauge any more than you can tell the temperature of your car's coolant by looking at the speedometer. You buy CO2 by the pound. A full 5 lb tank will weigh 5 lbs more than the tare weight of the tank (marked TW on the tank). You can tell how much CO2 you have left by weighing the tank, then subtracting the tare weight.
To clarify, the high pressure gauge is, for all practical purposes, a binary indicator. You have liquid CO2 in the tank or you don't. The pressure will remain constant at a given temperature as long as there's liquid CO2 in the tank. It could be a full tank or it could be a single drop - the gauge doesn't know. Once the pressure begins to drop from that constant, it means you're literally running on fumes. You will not have enough gas for tonight's party. That's why most of us keep a spare tank on hand (pretty common practice with propane, too, for exactly the same reason - you get no warning when you're low)
i am a little perplexed by the question because it is irrelevant. may as well be asking "is your kegerator big enough to hold a bottle of CO2?" or maybe "is your kegerator white or stainless steel?" so long as people understand that CO2 cold or CO2 warm makes zero difference. Cheers.
That was my plan until I found a good price on a second 20 lb tank. Given that it only costs a few dollars more to fill 20 lb versus 5 lb, it was a no brainer. Check Craigslist frequently. You'be be amazed at what people are willing to practically give away in the name of cleaning out the garage. You'd also be amazed at how many people have old CO2 tanks collecting dust in their garage!
The only thing to watch out for with used tanks is the hydro test date. The test interval is 5 years, and it is not that expensive to get it done, so not a show stopper just something to consider when you are shopping. It can be a good negotiating point on the price.
My supplier will swap an out of date tank at no extra charge. ("That's my problem, not yours") Indeed!
