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08-02-2011, 11:30 AM   #1
veedub
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Jul 2011
Upton, MA
Posts: 14

I just finished building my keezer and put the first beer in it last night. A couple questions on Co2. I have my 10lb bottle inside the keezer right now which is at about 38 degrees. When I picked up the gas it was on a loading dock at the welding shop and it was 90 degrees out. When I put the regulator on it was 1100psi. After cooling the gas down in the keezer the gauge reads 700psi. I can't hear a gas leak anywhere and soaped the connections is this kind of pressure drop normal with a drastic temp drop?

I have forgotten my second question so that's it for now

08-02-2011, 11:34 AM   #2
stratslinger

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Dec 2010
Terryville, CT
Posts: 2,541
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Completely normal. Gas pressure (of any gas) tends to drop significantly with temp drops, and rise with temp increases. It's why we buy gas by the pound, instead of by PSI.

08-02-2011, 11:46 AM   #3
veedub
Recipes

Jul 2011
Upton, MA
Posts: 14

Thanks that's what I thought, the fact that I am not bordering on the red zone of the regulator (700) just made me wonder.

08-02-2011, 01:32 PM   #4
Mpavlik22

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Apr 2011
Pittsburgh, PA
Posts: 316
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Gas pressure is directly affected by temperature.

If you look at the following chart (http://www.kegerators.com/carbonation-table.php) you'll notice 2.5 volumes at 40F is 12.5PSI.

To compare 2.5 volumes at 65F is 29PSI.
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08-03-2011, 12:23 AM   #5
veedub
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Jul 2011
Upton, MA
Posts: 14

I have seen this chart in various forms all over the web what I can't find is how it converts to time and if this is effected by pressure as well. Right now I have the keezer at 36* ( the warmest I can get it with the free thermostat mod) and have the gas at 10 psi how long can I except for a slow carbing method at these temps/pressure?

08-03-2011, 12:32 AM   #6
Mpavlik22

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Apr 2011
Pittsburgh, PA
Posts: 316
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Quote:
 Originally Posted by veedub I have seen this chart in various forms all over the web what I can't find is how it converts to time and if this is effected by pressure as well. Right now I have the keezer at 36* ( the warmest I can get it with the free thermostat mod) and have the gas at 10 psi how long can I except for a slow carbing method at these temps/pressure?
I can't give you a length of time, but I can tell you that co2 absorbs much better at colder temps.

I can typically carb a 5 gallon corney at 38F in ~6 days to 2.5 volumes. Likewise it takes me about two weeks to equally carb at room temp ~68F.
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08-03-2011, 12:48 AM   #7
Golddiggie

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Dec 2010
Posts: 11,995
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If you THINK you have a gas leak, then there's a simple way to find out. Charge the system with gas, remove the gas lines from the kegs (pull the disconnects off the kegs, leave the disconnects on the lines) and then turn off the tank. Mark where the high pressure gauge reads and then walk away. Check on it in 30-60 minutes. If the needle hasn't moved, let it go overnight. If it still hasn't moved, let it go to the same time tomorrow. If it still hasn't moved, you're leak free. If it has moved, then you need to hunt down the leak and fix it.

I just went through this exercise myself. It took charging my system to over 20psi before I discovered I had a leak. I've spent the past few hours checking, tightening, and changing connections. I'm 99.5% sure the system is leak free now. I'm simply letting it go a bit longer before I certify it as leak free. If you charge your system (off the kegs) to 20-30 psi, any leak should become very evident. Even more so if you turn off the tank once charged.

I also experienced the high pressure gauge display difference at different ambient temperatures. When I first put my CO2 tank in the fridge, I thought I had a major leak since it dropped a few hundred PSI. Come to find out, I didn't... I've since placed the tank outside the fridge, running through a bulkhead fitting. It's a bit more work to setup, initially, but at least I can easily see where the tank pressure is.

BTW, BobbyM has a thread about carbonating kegs on gas... I would suggest reading it. Very useful information as to the different techniques to carbonating in kegs (with gas)...
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08-03-2011, 02:47 AM   #8
TwoGunz
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Jan 2011
Syracuse, New york
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08-03-2011, 03:06 AM   #9
Golddiggie

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Dec 2010
Posts: 11,995
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It's one of the stickies in this very section... http://www.homebrewtalk.com/f35/keg-...strated-73328/
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Hopping Tango Brewery

On Tap: Caramel Ale, Mocha Porter II, MO SMaSH IPA
Waiting/Carbonating: 12.5% Wee Honey II, 8.9% Old Ale, English Brown Ale, Lickah ESB, Mocha Porter II
Fermenting
K1: