CO2 Keg Pressure when Valve Closed? - Home Brew Forums
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Old 01-28-2013, 06:24 PM   #1
cdenneen
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Jan 2013
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I'm looking to find out if my Pressure Relief Valve on the Keg Coupler is working properly and decided to try this test but I'm not sure how accurate it is.

1. Pressurize Keg to 10psi
2. Close Main CO2 valve (keg pressure stays at 10psi)
3. See if pressure stays after few hours (nope dropped to 0lbs within a few hours).

Does this mean I'm leaking CO2 or does it dissipate like this normally?

Reason for this test is because I had an issue where the secondary valve on the regulator was screwed in and pushed 60 psi into keg. I quickly fixed that and pressure stayed at 10-14 psi. The built-in pressure relief valve on the coupler popped out and depressurized the keg. The style I have isn't a ring type to pull but a circle you grab and pull out. Granted I lost a lot of CO2 because of this but even after fixing it within 2 days the CO2 tank was empty without any beer being poured.

So I figured if I don't pour any beer out of the keg.. the pressure should stay even if I close the CO2 tank (whatever was in there should remain).

I'd rather not have to continuously close my tank to save CO2 but don't know of an easier way to find out if it's now working properly or not.

Thanks



 
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Old 01-28-2013, 06:28 PM   #2
grathan
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IS this carbonated beer? Is it possible the beer is absorbing this pressure over the course of the hour?



 
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Old 01-28-2013, 06:34 PM   #3
jeffersonjames
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Jan 2013
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You could have a leak in the keg. Keg lube would be a really cheap easy fix. I had similiar issues and keg lube on the gaskets and o rings fixed it.

 
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Old 01-28-2013, 06:53 PM   #4
cdenneen
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Jan 2013
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I guess it is possible the beer is absorbing it but I had it set to pressurize the keg for a few hours before i turned off the CO2 tank. So I would think the absorption should have been done. Maybe not.

I could have a leak in the keg but considering this is a brand new kegerator and O-rings I think the seal on the coupler is fine.

I've tried to find some information about this type of PRV but it seems every distributor uses the type with the ring pull and mine just looks like a round circle with flat face that you grab and pull so I'm not sure if there is a way to adjust it.

Actually I've tried to tighten the PRV valve by turning to right and when I do this the keg will not pour at all (like no CO2 gets in). If I back out the PRV valve by turning to left it allows tower to pour and I can pull the PRV and it hisses so it seems the gas is staying in there but more concerned about when i pressurize the keg, turn off CO2 and don't pour anything the pressure isn't staying... is it supposed to with CO2 off or is it normal that with CO2 off and not pouring beer it will dissipate?

 
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Old 01-28-2013, 07:04 PM   #5
NivekD
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Pressurize the keg to 10 psi, turn off the tank valve, disconnect the gas in connector...wait a few hours and then reconnect the gas in and see if you still have close to 10 psi in the keg. If no, the keg is leaking, if yes, then you have a leak between the keg and the main valve.

 
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Old 01-28-2013, 07:10 PM   #6
cdenneen
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Jan 2013
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Quote:
Originally Posted by NivekD View Post
Pressurize the keg to 10 psi, turn off the tank valve, disconnect the gas in connector...wait a few hours and then reconnect the gas in and see if you still have close to 10 psi in the keg. If no, the keg is leaking, if yes, then you have a leak between the keg and the main valve.
Ok so the assumption is that if I don't pour anything out of the keg the pressure should remain with CO2 tank off, else there is a leak.

So steps here if I understand are:

1. Open CO2 tank and pressurize keg to 10PSI
2. Close CO2 tank
3. Untap Keg - take coupler off
4. Leave for a few hours and retap Keg
5. If reading on regulator is still 10 then keg is holding if not then keg is leaking and Keg Lube is next option?

 
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Old 01-28-2013, 07:28 PM   #7
Bobby_M
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Quote:
Originally Posted by cdenneen View Post
I guess it is possible the beer is absorbing it but I had it set to pressurize the keg for a few hours before i turned off the CO2 tank. So I would think the absorption should have been done. Maybe not.
Absolutely not. It takes somewhere between 2-3 weeks to reach equilibrium based on the chart pressures. It's best to test this sort of thing with an empty keg where you don't have any lag in CO2 solution or any discrepancy between dissolved and gaseous CO2.

It's a lot easy also to just spray everything down with soapy water while under pressure.
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Old 01-28-2013, 07:30 PM   #8
JeepDiver
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IF you only had the gas on the beer for a few hours, then the beer is not carbed (uless this is a commercial keg, and then it may be less pressure than your regulator is set at). It can take over a week at normal pressure, so you might not have a leak. take the Line off the keg, charge it and close the valve. it should hold the psi for days, if not then you have a leak in the line. If it holds, then you either have a leak between the keg and the coupler, or your beer isn't fully carbed and the gas is going into the beer.

 
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Old 01-28-2013, 07:33 PM   #9
cdenneen
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Quote:
Originally Posted by Bobby_M View Post
Absolutely not. It takes somewhere between 2-3 weeks to reach equilibrium based on the chart pressures. It's best to test this sort of thing with an empty keg where you don't have any lag in CO2 solution or any discrepancy between dissolved and gaseous CO2.

It's a lot easy also to just spray everything down with soapy water while under pressure.
2-3 weeks... who has a tapped keg sitting around 2-3 weeks

and with that logic the amount of CO2 tanks I'd go through would be incredible trying to determine if this is leaking.

 
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Old 01-28-2013, 07:34 PM   #10
cdenneen
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Jan 2013
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Quote:
Originally Posted by JeepDiver View Post
IF you only had the gas on the beer for a few hours, then the beer is not carbed (uless this is a commercial keg, and then it may be less pressure than your regulator is set at). It can take over a week at normal pressure, so you might not have a leak. take the Line off the keg, charge it and close the valve. it should hold the psi for days, if not then you have a leak in the line. If it holds, then you either have a leak between the keg and the coupler, or your beer isn't fully carbed and the gas is going into the beer.
Yes commercial keg from distributor.



 
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