CO2 Pressure Drop

Hi Everyone,

Another Newbie question,

I kegged my first batch on Tuesday. I have a 5# CO2 tank which I was using the "set it and forget it" method. Checked for leaks-no problems. The tank pressure stayed pretty much constant until Friday night, where the tank pressure began dropping considerably. This morning, the pressure is down to zero.

I read a few posts on pressure problems and there was some conflicting responses but I think I got it. Just to verify, a tank will maintain pressure and then begin to rapidly lose pressure when it becomes low on CO2 volume. Is that true?

A second question - is a 5# tank too small for force carbing?

Thanks,
Craig

The CO² is in a liquid state in the tank (5 lbs of it) and the tank pressure will remain constant until all of the liquid vaporizes. Once all of the liquid CO² is gone, the tank pressure will drop very rapidly as has happend to you. A 5 pound tank is more than enough to carbonate and serve several kegs of beer.

In my humble opinion, you have a major leak in your system.

5 lbs is pretty small but like PJ say enough for 2 maybe 3 kegs. Here's the problem with 5 lb tanks as I see it.

1. expensive to fill (because of the labor, it cost almost the same to fill a 5 lb as a 20lb tank)

2. As you just found out unless you weigh the tank you will run out with little or no warning.

3. Murphy's law is extremely applicable to CO2 tank you will run out at the worst possible time.

So for those reasons a 5 lb tank makes a great backup supply for a 20 lb main tank and they make great traveling companions if you want to take your keg to a party or get together.

Sounds like you have a leak. A 5# tank is more than enough for force carbing, especially when starting out.

I suggest you go to Lowes, HD et.al. and get Gas Leak Detector



You can easily find the smallest leak using this product. Soapy water will not get it done unless it is a really bad leak.

Thanks everyone,

I was afraid it was a leak. I did try soapy water both when setting up the keg and again when I saw the pressure dropping, but I guess it didn't work. I'll try the commercial leak detector. I replaced all of the gaskets before kegging - so I'm hoping it's something like a loose hose fitting. The only problem, is now that the pressure down to zero, I'll have to wait until I can refill the tank, which is next Sat.

Also, keg lube will be a great friend, especially with new orings.

Another thing to be sure you do is to "seat" all of your seals by setting your initial psi to 30+ to get a proper seal (I went through several tanks before i figured that one out!) I will also have issues with my older pressure relief valves, I have to wiggle them a bit to get them to seat, but I've been replacing them, so thats no longer a problem.

BigJerk said:

Another thing to be sure you do is to "seat" all of your seals by setting your initial psi to 30+ to get a proper seal (I went through several tanks before i figured that one out!) I will also have issues with my older pressure relief valves, I have to wiggle them a bit to get them to seat, but I've been replacing them, so thats no longer a problem.

Click to expand...

Lets hope this was the problem because I was able to get some CO2 today and test all of the connections with the commercial leak test fluid. I didn't find any leaks.