Beer coming out gas line when qd disconnected

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JawnnyO

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I am having a lot of trouble with my second keg. My first went fine. I bought four used kegs and they are all different. They are pin lock. One doesn’t hold water upside down because the top has a wobble bigger than the lid and new o-ring can seal. The other three seem to hold gas.
The one I am having trouble with is on my single tap, with a double line manifold. Before I had the double manifold I gave it a burst of co2 to clear oxygen. When I took the qd off to vent, beer spewed out the gas line. Tried it twice. Big mess. I tried to check the popit and saw the gas tube inside the keg was quite long. About 2 inches.
I bought the double manifold so I could set and forget. My first keg emptied and I tried the second keg the beer was flat. When I put on the third keg to replace the first for set and forget, beer from the second keg flowed out the gas line and into through the gas line of the third keg. I hadn’t turned off the gas to the second keg. Which I did, and then the third keg seemed to start to carbonate. There is gas in the canister because the beer comes out the tap, but flat.
Tried it again this morning. The beer is flat and now tastes bad too. Maybe because I didn’t get the oxygen vented?
I have the co2 set at 12 psi and the temperature is 48* (basement temperature). If I turn the fridge on it drops too low, so I keep the kegs in the kegerator, plugged in but turned off.
What can I do?
Thanks.
 

VikeMan

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The one I am having trouble with is on my single tap, with a double line manifold. Before I had the double manifold I gave it a burst of co2 to clear oxygen. When I took the qd off to vent, beer spewed out the gas line. Tried it twice. Big mess. I tried to check the popit and saw the gas tube inside the keg was quite long. About 2 inches.
It sounds like your gas tube is submered in beer. I use a dremel to cut off most of the length. It really only needs to be long enough to mount the O-ring, but I leave them a tad longer than that, for easier installation.

ETA: And you poppet probably needs to be replaced, unless the "spew" was very short and stopped quickly when sealed by the poppet.
 

okiedog

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I agree with VikeMan. I've had the same problem, and now pay careful attention to how high I fill my kegs. I make sure the bottom of the gas tube is at least 1/2 above the beer. Also, I eventually plan on shortening the gas tube for all my kegs. Does your manifold have check valves?
 
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JawnnyO

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I thought that might be it. The batch I made yesterday I used my shortest gas tube. There are individual taps for each line, but no check valves. I have a big note on the inside of the fridge to turn off taps before changing kegs.

Is it too late to cut the gas tube now?
 

VikeMan

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Is it too late to cut the gas tube now?
You'd be exposing the beer to O2 while it's open, but personally, I'd do something about it. Either cut the gas tube or dispense enough beer that the surface goes below the end of the gas tube.
 

okiedog

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Until I installed a manifold with check valves, I had way to much experience with this issue.

1) Tap a pint of beer to drop the level in the keg below the gas dip tube.
2) Close the shutoff valve and disconnect from the keg.
3) Cut and replace the line.
4. Open the valve and vent the pressure in the line with your pinky or some small flat ended device that won't damage the pin (the eraser end of a pencil works).
5) Sanitize the connector and connect to your keg.

How is oxygen going to get into your keg?

Hopefully beer hasn't made it all the way to your manifold. If it has, you need to pull the manifold and clean and sanitize that too.

Otherwise, if you don't want to, you don't have to cut or replace the line.

1) Tap a pint of beer to drop the level in the keg below the gas dip tube.
2) Shut off the valve and disconnect from the keg.
3) Then open up the connector and let the line drain.
4) Next, spray sanitizer into the line while holding the line up until sanitizer completely coats the inside of the line, and runs all the way to the shutoff valve.
5) Then drain the line, reassemble the connector, making sure the connector and its parts are clean and sanitized.
6) Open the valve and vent the line as before, then hit the connector with sanitizer and connect to your keg.
 
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JawnnyO

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This is a great help. I will do this this evening. Thanks
 

okiedog

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So JawnnyO, how did it work out? I hope your manifold was clear, otherwise it's a PITA.

I should mention that, even with check valves, you can get beer pushed up the gas line from the keg. That is rare, but it can happen if your keg is pressurized more than the gas line, and the shutoff valve is closed. I've had this happen when I forgot to vent excess pressure from keg conditioning.

Shorten the gas in dip tube, don't over fill your kegs. Also, connectors are available with check valves, in both pin lock and ball lock. Or, if you have MFLs, you could just add this check valve between connector and line: Disconnect Check Valve (williamsbrewing.com)
 

DuncB

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I've got check valves ( built into the ball locks ) on all my kegs but if the pressure is set to 12 psi in the gas line does that equate truly to keg pressure or is there a few psi or more difference, especially to trigger the inflow of gas. I have a feeling that it's a few psi less in the keg but not totally sure. I'd have thought that each time I pull a pint I ought to hear the gas flowing in thru the check valves?
 

VikeMan

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I've got check valves ( built into the ball locks ) on all my kegs but if the pressure is set to 12 psi in the gas line does that equate truly to keg pressure or is there a few psi or more difference, especially to trigger the inflow of gas. I have a feeling that it's a few psi less in the keg but not totally sure.
At equilibrium, the pressure in the gas line is the same as the pressure in your keg's head space.

I'd have thought that each time I pull a pint I ought to hear the gas flowing in thru the check valves?
When you pull a pint, your headspace pressure will momentarily drop slightly and the check valve will allow gas to flow until the pressure is the same again on both sides of the valve. I wouldn't expect to hear anything unless there is a large amount of gas flow, like when purging a keg, but your mileage (and hearing) may vary.

Check valves are nice insurance, but cutting gas tubes down to size and not overfilling kegs is cheaper.
 
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JawnnyO

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It went well. The beer is carbonating and has not yet gone bad due to oxygen exposure. I only have a single tap so will keep drinking from this keg to not the oxygen age. I will be getting check valves next visit to the LHBS. Which is farther for me than a the hops farm or malterie in the area.
 

DuncB

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Vikeman all gas tubes are flush with the bulkhead fitting of the ball lock post, except in the sparkling water keg which is at higher pressure before the inline regulator to the beer.
I do tend to really only hear the gas going thru the NRV on the cylinder and into the water, when I draw water, perhaps because this is at 30psi and the rest of the setup is at 11psi?
Beer seems well carbonated so probably ok.
Thank you
 

okiedog

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At equilibrium, the pressure in the gas line is the same as the pressure in your keg's head space.



When you pull a pint, your headspace pressure will momentarily drop slightly and the check valve will allow gas to flow until the pressure is the same again on both sides of the valve. I wouldn't expect to hear anything unless there is a large amount of gas flow, like when purging a keg, but your mileage (and hearing) may vary.

Check valves are nice insurance, but cutting gas tubes down to size and not overfilling kegs is cheaper.
My point was to lower the level of the beer in the keg, so it is below the bottom of the gas in dip tube.
 
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JawnnyO

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It turns out one of my manifold check valves was bad. LHBS replaced it. No other issues since.
 

okiedog

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What? You have check valves? I must have missed that. Had I known, my response would have been different. The specific purpose of check valves is to prevent beer from flowing up the gas lines. If gas flows up a gas line toward the manifold, either there is no check valve, or the valve isn't seating or is stuck open. I am glad you got it fixed, though.
 
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