Well this is great.

After letting my new keg system sit over night i went and checked it this morning and the pressure of the Co2 tank (5 lb tank) went from 800 psi last night, to 600 this morning. is that normal when cooling it down in the fridge or do i have a leak and am losing Co2?

reverend

Doubtful you have a leak.......Gas pressure is a measurement of the number
of collisions of molecules with the walls of the container. The velocity and the number of collisions of these molecules changes when the temperature of the gas increases or decreases. Greater temperature = increased collisons and therefore an increase in pressure. Lower temperature like in your refrigerator = fewer collisions and lower pressure. If you took the tank out and allowed it to equilibrate to room temperature then you'd be back up at your 800 psi on that regulator. No worries, you're system is most likely fine.

CO2 pressure varies a lot with temperature, what you've seen is normal.

It's PROBABLY ok. Yes, the drop in pressure is expected with a drop in temperature but you still need to monitor it after the tank has cooled to see if pressure continues to drop... you still could have a leak.

Also know the the high side gauge on CO2 regulators dont measure the pressure of the CO2 inside directly. This is because this CO2 is in liquid form inside the tank not gas like nitogen or beer gas. The high side only becomes accurate when you are almost out of gas.

i just read about this liquid/vapor phase of Co2 on a website for paintball of all things. they had a nifty chart that described it. It did not say what size the tank was but that at 70 degrees the pressure was something like 851 and at 40 degrees it was like 621. so perhaps my drop in PSI is the norm. the only reason i was worried was because intially it took my O ring about 20 seconds or so to seat itselfs properly and stop making the hissing sound.

still a good idea to go over the whole thing with soapy water just to make sure.

just like what others have said, your drop in pressure is fine, BUT make sure you don't also have a leak. especially if you just set everything up, you can either use soapy water, star san, dunk it in water, or disconnecdt it from the keg, pressurize it, turn off the tank, and then see if it loses any pressure. do this early on, it will save you trips to the welding supply shop, or wherever you fill your tanks.

Well i just had SWMBO check out my pressure and she said it was right under 600. So i guess it was just from cooling my tank that lowered the pressure. all is good. brew on!

reverend

Ideal Gas Law
P * V = n * R * T

P = pressure
V = volume
n = # of moles of gas
R = universal gas constant
T = temperature

If T goes down and V remains the same, P also goes down.

I moved my kegerator last night. When I took the tank out of the fridge, it was 600 psi. Once it warmed up to room temp the gauge was back up into the green. 1000psi I think.

Got home about 45 min ago and the pressure is steady at just below 600, so i am good to go. Now all i have to do is somehow will my beer to condition faster so that i can take a few ten pulls off the keg before i go tailgate for the husker game tomorrow!!!!!!!!!!

Thanks guys

Reverend

Reverend JC said:

Now all i have to do is somehow will my beer to condition faster so that i can take a few ten pulls off the keg before i go tailgate for the husker game tomorrow!!!!!!!!!!

Thanks guys

Reverend

Click to expand...

Crank it up to 30 psi and every time you walk by tonight and tomorrow morning, shake the keg every once in a while. It will help absorb the C02 quicker.

again, thank you for the sage advice (going to go shake it now)