Pressure rises from 12psi to 18psi overnight

[Kazi the Younger]

I did a little internet search and called my local homebrew shop and I haven't been able to find a good answer to this question.

I rack my 40 degree home brew into a keg in my 40 degree fridge. I clear the head space and then set the regulator to 12 psi. Clear headspace a few more times to just "seat the beer" or whatever. Then I leave it. Overnight it climbs to 18.

Why would it climb to 18? Do I have a bad regulator? I first tried to remedy this problem by turning down the regulator to 12 psi. When I did this, the next morning it was 8 psi--Blast!

Should I have just pulled up on the pressure release valve until the pressure drops from 18 to 12 rather then turn down the regulator?

How do you guys deal with this, or do you ever have the problem?

[stumblemonk]

Have you used this regulator before? How old is it and where did it come from? I would be concerned about PSI rising that much overnight.

[Kazi the Younger]

Yes I've had this regulator for a while and it always seemed to do this from the beginning. Eventually it would hold a pressure with much dialing the screw up and down and bleeding off pressure with the relief valve. But what a pain!

I was trying to do it right the first time with this beer, but I'm obviously not there yet

[Kazi the Younger]

by the way--changes in temperature should have nothing to do with this right? Temperature effects dissolved co2 but it should not effect the amount of pressure leaving regulator, correct? So this can't be temperature related, right?

[bcmaui]

by the way--changes in temperature should have nothing to do with this right? Temperature effects dissolved co2 but it should not effect the amount of pressure leaving regulator, correct? So this can't be temperature related, right?

Changes in temperature will change the gas pressure, but sounds more like a regulator issue, as I don't think a 30F swing (40 to 70F?) would change the pressure that much on a full keg, but I could be wrong. I've never taken a full keg out and let it warm up to find out.

[Kazi the Younger]

How can i test if it's a regulator issue? Could it be "sticky"? How can I test it?

[Quin]

I think the issue is whether you are turning the regulator up to 12 psi or down to 12 psi. When the pressure is higher in the keg than you are setting the regulator at, you can't get a good reading on the pressure gauge without bleeding some pressure off to get below your target pressure. You basically turned the regulator down too far and it ended at 8 psi.

If you are increasing the pressure from 8 to 12 psi, you should be OK.

[Kazi the Younger]

Another important detail:

the Co2 tank and regulator are inside my fridge, so it's opperating @ 40 degrees. I read on MoreBeer that regulators work best at room temperature--I am not opperating mine at room temp. Here is the full quote form MoreBeer:

"Regulators work best at room temperature. If you must use your regulator in the cold it will take up to 4 hours for the adjustment to register. For example: If you are at 10 PSI and you change the pressure to 12 PSI the regulator will move to 14 or 15 PSI over the next 4 hours. Once you have found the correct pressure the regulator will work perfectly fine but it will take some trial and error to get it adjusted. "