Keg beer backing up into CO2 Line

I'm getting a bit of beer shooting up into my CO2 line from the keg. It's not a lot, but I am concerned that it might compromise the sanitation of the system.

Any thoughts?

Thanks

The beer shouldn't be going into the CO2 for any reason. You must not have something setup right or your doing something wrong. You could risk infecting your beer from that.

What's happening when it backs up into the line? You must have the lines connected backwards or your keg is filled right up to the top. Otherwise you wouldn't suck up beer in the CO2 line.

We need more info.

Are you shaking your keg and trying to carb it to fast? Also like the above post...If its filled all the way up to the gas tube it will give you blow back.

You've filled the beer very close to or above the gas in dip-tube and the pressure in the line from the CO2 is dropping below that of the keg and hence the beer is being pushed back up the line. Ensure that the gas is turned on and is set to at least that of the keg or more before you connect it.

Thanks - I had filled the keg up pretty high. I've cleaned the line and let out some beer, hopefully that should do the trick.

Are your turning off your co2 tank? If the line is pressurized, the keg pressure should not exceed that of the co2 lines.

Check valves might be handy; They will prevent beer from going into your regulator.

Set your PSI and turn on your gas; purge your keg, and then hook it up. I imagine this is only happening when you first hook up your keg? Are you naturally carbing?

Definitely install check valves in your CO2 lines. Many cheaper regulators leave them out.

kirscp said:

Are your turning off your co2 tank? If the line is pressurized, the keg pressure should not exceed that of the co2 lines.

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Definitely turn your gas on before hooking up...

Alright! I'm back in business and the hefe is flowing fine!

Ultimately, I think the problem was that I had overfilled the keg. I don't have a check valve, though one is on my 'to-get' list. Thanks for all the help.

I have check valves on all my gas lines.

Especially with mulptile kegs on a gas manifold. It's too easy for a higher pressured keg that is over filled to push beer up into the lines and to another keg that has lower pressure. It also is too easy for beer to find its way to the regulator.

For about 70 cents each...it's a no brainer.

US Plastics carries them.

BierMuncher said:

I have check valves on all my gas lines.

Especially with mulptile kegs on a gas manifold. It's too easy for a higher pressured keg that is over filled to push beer up into the lines and to another keg that has lower pressure. It also is too easy for beer to find its way to the regulator.

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If you are using a manifold aren't all the kegs at the same pressure? How could that cause beer to be pushed up into the lines? I just got this kit not too long ago and know it has a check valve on the regulator and ball check valves on the manifold. Just not sure if that is enough? I figured since they would all be at the same pressure and I use the set it and forget it method there wouldn't be any issues.

avaserfi said:

If you are using a manifold aren't all the kegs at the same pressure? How could that cause beer to be pushed up into the lines? I just got this kit not too long ago and know it has a check valve on the regulator and ball check valves on the manifold. Just not sure if that is enough? I figured since they would all be at the same pressure and I use the set it and forget it method there wouldn't be any issues.

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If your kegs are at a higher pressure then the regulator you could get backflow. One example of a way this could happen is if you're force carbonating at 30 psi and then turn down the regulator to serving pressure without bleeding pressure off the kegs. In this situation, if your gas connect is submerged in an overfilled keg, you can get backflow into into the gas lines and into your regulator if you don't have check valves on the gas lines.

With the set it and forget it method (i.e. carbing at serving pressure) you will probably be fine, however, when your gas runs out its possible that you'll get back flow if your kegs are overfilled. It's less likely to happen at serving pressure but check valves are cheap security.

If you have a keg that gets infect it will build up pressure and can back up into your manifold then spill infected beer into the other kegs...expensive lesson.

avaserfi said:

If you are using a manifold aren't all the kegs at the same pressure? How could that cause beer to be pushed up into the lines? ...

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That's what Edwort thought until his CO2 tank began to run low.
As he drew a pint from one of his older kegs, a newer keg fill up to the dip tube pushed beer through all his lines. Got into the regulator and turned his haus pale ale into a black and tan.

So I guess a check valve is the cheap solution. Once it is in do I need to pay any attention to it or will it just prevent any backflow? Looks like I should put it between the manifold and the keg, right?

As of now it looks like the only check valve on my system is one of these between the manifold and the regulator. The kit says the mainfold has 1 Brew Logic 3-way Gas Manifold that is fitted with three 5/16” barbed ball check shutoff valves does that mean I am good? I don't see the check valves, but don't really know what to look for. This kit and the manifold looks like this.

Is it generally accepted that the shutoff valve-style integral check valves are insufficient or do many people not use them?

GearBeer said:

Is it generally accepted that the shutoff valve-style integral check valves are insufficient or do many people not use them?

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Like I said, for 70 cents each (plus the cost of a couple hose clamps), it's not worth finding out.

They take about 90 seconds to install.

Do you use the 1/4" units with 5/16" ID line without issue? Guess I should get some to be on the safe side. Item 64048 at US Plastics.

Once it is in do I need to pay any attention to it or will it just prevent any back flow? Looks like I should put it between the manifold and the keg, right?

avaserfi said:

Do you use the 1/4" units with 5/16" ID line without issue? Guess I should get some to be on the safe side. Item 64048 at US Plastics.

Once it is in do I need to pay any attention to it or will it just prevent any back flow? Looks like I should put it between the manifold and the keg, right?

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Yeah, I used the 1/4" but it was item #64174. Not sure the difference.

Right...anywhere between the keg and the manifold or other splitter you may be using.

NOTE - Make sure to install them the right direction. I just blew into mine to determine the flow direction. I believe there is an arrow imprinted, but it's very hard to see.

I called and asked the difference. 64048 ($0.70) is made from polypropylene and 64174 ($1.46) is made from kynar. The kynar unit will have better chemical resistance and higher temperature ratings. So it seems the cheaper unit would be fine for kegging.

BierMuncher said:

I have check valves on all my gas lines.

Especially with mulptile kegs on a gas manifold. It's too easy for a higher pressured keg that is over filled to push beer up into the lines and to another keg that has lower pressure. It also is too easy for beer to find its way to the regulator.

For about 70 cents each...it's a no brainer.

US Plastics carries them.

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Thanks, BM. I had beer back up last week, read this thread, and installed the check valves. Great, cheap insurance.

This just happened to me. Made a bourbon vanilla porter. Didn't want to waste my beer so filled too full. I'm drinking some off the top now. BUT, I cut off the co2 line from the barbs and soaked in star sand. My question is should I let dry out before I push them back onto the barbs and clamp down or does it not much matter if there's some wetness inside co2 line? My guess is to let air dry. I just want to get back to carbonating my new beer so I can drink it!

I think its already been answered but either one of the following things is occuring:

A.) you got the gas tube on the liquid post.

B.) Beer is super high in the keg or you've tried force carbing with shaking at high pressure

C.) you turned up the pressure for a few days (force carbing) and then lowered the pressure on the regulator creating a vacuum on the higher pressurized keg.

All three of these thing happen with improper force carbing. I usually turn up the pressure to 30psi or so. Wait till I cant hear it pushing the gas in. Disconnect the gas line. Shake for 5 minutes (rolling on the ground is good). then reconnect gas line. Repeat 5-6 times. When you think youve done it enough, set the regulator to desired pressure and reconnect gas line. 1-2 days you will be at you desired pressure or close to it. If you didnt exceed that pressure, it should sounds like gas going into the keg. in fact, everytime you reconnect the keg to the gas line, you should hear the gas going into the keg. if not, youve over done it and need to vent.