Keg keeps on carbonating

[zlehmann]

Hey everyone,

I'm still relatively new to kegging and am having a small issue. My keg seems to keep rising in pressure even after locking the regulator. I usually cheat and put it on 15-20 psi for 3 days to carb fast, then slow it down to 10 or so. but even after purging the valve, it seems to start climbing back up to 20 or so afterwards. Any ideas?

 

[porterpounder]

If the system hasn't reached equilibrium and there is still 15-20 psi of pressure in the head-space from undissolved gas or gas the came out of solution when you vented to relief-valve, it's going to back-pressure the system and read high for a few days. Either that or you have a bad reg.

 

[Johow]

Are you venting the valve on the regulator or on the keg? I'm also new to kegging and noticed the same thing When I vented the poppet on the regulator instead of the keg. After releasing the keg poppet all was well.

 

[zlehmann]

I am venting from the keg.

 

[JONNYROTTEN]

Set to desired psi
Close tank,open relief valve to 0 psi-close relief valve
Open tank see if your at the same pressure
Repeat until your at desired psi,It will hold at set psi this way

 

[NickTheGreat]

Completely remove the gas line from the keg and see if this still persists.

If not, bad reg. If so, headspace/equilibrium.

 

[day_trippr]

I don't see any mention of a CO2 back-flow-preventer (aka "check valve") downstream of the regulator low pressure port. Without that, headspace pressure will prevail if it's above the regulator setting.

fwiw, if a regulator has a low pressure shut-off valve and a auto/manual PRV, the best way to set an accurate pressure is to close the shut-off, turn the regulator pressure way down, pop the PRV, then dial up the desired pressure.

Once that pressure is set, open the shut-off and note what happens to the low pressure gauge.
If it goes up, that's a keg talking...

Cheers!

 

[zlehmann]

I don't see any mention of a CO2 back-flow-preventer (aka "check valve") downstream of the regulator low pressure port. Without that, headspace pressure will prevail if it's above the regulator setting.

fwiw, if a regulator has a low pressure shut-off valve and a auto/manual PRV, the best way to set an accurate pressure is to close the shut-off, turn the regulator pressure way down, pop the PRV, then dial up the desired pressure.

Once that pressure is set, open the shut-off and note what happens to the low pressure gauge.
If it goes up, that's a keg talking...

Cheers!

I understood about half of what you said here. Any chance you got a link for some good references I can read up on?

 

[day_trippr]

Well, there's this
http://www.micromatic.com/beer-questions/co2-regulators-check-valves
and I'm sure there are tons of articles on the topic just a Google away.

Bottom line, what I believe you were experiencing was an over-carbed keg of beer that was outgassing as you lowered the regulator pressure, causing the low pressure gauge to register the keg pressure.
And until the keg of beer outgassed enough to calm down to a proper carbonation level, that paradigm would continue.

A check valve is simply a one-way valve. So, if you pressurize your keg to, say, 20psi, then dial down the regulator, the gauge won't creep up to match what is in the keg.

That said, a check valve will not cure overcarbed beer...

Cheers!