Spluttering faucet

[Bru]

Ive got one faucet that splutters foam before the beer starts to flow. The spluttering goes away quite quickly but if there is more than 30 mins or so before pours the splutter is back. Only one out of 6 faucets does it.
Does anyone have any ideas as to what could be causing it ?

 

[Cybershadow]

sounds like an leak somewhere.

 

[Bru]

Yes, but from where ? If a fitting was leaking I'd be losing CO2.

 

[wilceaser]

What type of faucet? it sounds like something is sticking/dirty inside your faucet, also check to make sure the beverage hose for that faucet isn't kinked some where.

 

[Bru]

Perlick - from Keggconn.
To clarify - i open the faucet to pour, I get air, then a splutter, more air and then it pours as normal with no foam. And it doesn't drip when closed. No kink in the line either.

 

[ChadS99SVT]

I sort of get something similar.... how new is your setup?

I currently have a 4 tap setup and a commercial keg on one faucet and home brew on some of the others....the commercial has seen quite a bit of use and the first 5 gallon keg was giving us lots of pouring issues...including this sputtering you are speaking of. however the second keg is behaving nearly perfect. occasionally has some sputtering but it's very minor and never gives excessive head like the first.

so I guess what I am trying to say is maybe it's the beer/keg currently on that faucet.

the homebrew after settling for a few weeks is pouring perfect as well. running about 11psi on both regs. oh and using perlick creamers btw.

 

[Bru]

This specific tap / keg is a couple of months old.
Im going to try and swop the taps around to see if its the keg or tap. That will narrow it down before I start trying to fix it.
Im wondering if it may be something stuck in the output valve or a damaged o-ring (?).
I just havn't had the time to fix it.

 

[TheBroonery]

replace the o-rings in the faucet

 

[Homercidal]

I have this going on right now. I swapped the lines/faucets and it continued on the same keg, and the other keg still doesn't do it, so I assume it's the keg, not the line/faucet.

I think the only thing I can do now is to swap the poppets and see what happens. I have no spares, but I do have a spare keg ATM. I can't figure out what's wrong, but I've had it happen before a while back and think it may have been the same keg.

I gotta bottle some of that beer, so I can hopefully do it tonight. I'll try and post my results.

 

[tjpfeister]

If you think about it. The "sputtering air/no beer" cannot be caused by an obstruction inside the line or the faucet. The part about it going away then coming back 30 minutes later only confirms what I suspect. Please let the beer sit for 30 minutes, then inspect your lines. I'm willing to bet that you will find large pockets of CO2 in the one line that rise up to the level of your faucet and cause this sputter.

The cause? It can be several things, but ultimately it's caused by an imbalance in the system. Is the beer line longer on the one faucet? Is the keg you are serving on that faucet being held at a lower pressure? Is the one faucet somehow being warmed by a hot air vent or something that is not affecting the others? Have you confirmed the pressure on that keg with another gauge to make certain your regulator's gauge isn't off?

I know this sounds a little crazy, but I spent A LOT of time balancing my kegerator to prevent foaming issues. I'm still wrapping my head around the physics as I was lead to believe that the pressure inside a vessel is equal throughout the vessel (statically), yet somehow I have proven time and again that longer beer hose requires higher pressures (or lower temperatures) to prevent this "pocketing" effect.

 

[P-J]

My opinion? Bottom line, the keg was force carbed and is now over carbed for your selected serving pressure. As it sits, CO² is coming out of solution in the serving line as tjpfeister relates in his post. You will see "large pockets of CO2 in the one line that rise up to the level of your faucet".

If this ends up being the case, you need to release (vent) keg pressure several times over the next few days. This will decarb the brew to the level of your dispensing pressurel. They must be the same for a reasonable pour.

IMHO

 

[Bru]

All my kegs have the same length beer lines, they're all carbed by the same regulator and they're all force carbed. I already tried venting the keg just in case - it made no difference.

 

[Homercidal]

All my kegs have the same length beer lines, they're all carbed by the same regulator and they're all force carbed. I already tried venting the keg just in case - it made no difference.

Ditto. I have a single gas line, and have to swap between kegs. Both kegs are set to the same pressure.

I cannot fathom why one would be fine on either faucet, and the other would be rotten on both faucets unless the rotten one had something wrong NOT related to the faucets.

And the QDs should allow the pressure between the line and keg to remain balanced, so I am not sure why the CO2 in the line keeps wanting to come out of solution on the one keg.

It's possible that the keg is overcarbed, but I had it sit for 2 days, warm, at 20 lbs, then dropped to 10 lbs and placed in the fridge. I could give a small shake and vent the excess carb (it's not flat by any means) and see if that helps...

 

[Bru]

TheBroonery suggested replacing the o-rings on the out post. I suspect he may be right. Or there is something stuck under the valve. I'll get time to try things this weekend.
But you're right - if you swop the lines and it still foams then its clearly an issue related to the keg.
Ive swopped the lines around, I'll know more later when I pour the first pint.
Its a strange problem - if the tap wasn't sealing properly it would leak beer (its under pressure after all) and if it was leaking CO2 the CO2 would run out.

 

[Homercidal]

I have been putting off fixing it due to lots of stuff to do around here, but my theory is that if the O-rings on the posts need replacing, they should be leaking...

 

[tjpfeister]

LoL. I can't believe I have to come back and argue for arguments sake. But I have my coffee in me and I'm fiesty!

It's not a leak of any kind. A leak would either drip beer or bleed off CO2. However, neither of these things would cause the air bubbles in the beer line. A gas leak would merely be replaced by more gas as the regulator did it's job and a liquid leak ... well a liquid leak is no different then opening the faucet.

It's also not a disturbance in the flow of beer through the line. This would cause foam DYNAMICALLY. He stated that it sputtered and foamed initially, then as it flowed it became normal. This is the opposite of disturbance in the flow of beer as a restriction (or orifice) only creates a pressure differential while fluid is moving.

This leads back to the only possible explanation: imbalance. Now, if the lines are the exact same length and the inner diameters are all the same, and if the faucets and lines are all the same temperature then there is really only one possible explanation that remains. The beer in our suspect keg was over-carbonated and now the serving pressure is too low to maintain balance.

This of course still begs the question about the pressure inside a vessel being equal at all points through out the vessel. But as I stated earlier I have proven time and again in my own fridge that serving pressures lower than carbonation pressure will cause these air pockets.

Coffee just kicked in! Time to get some paperwork done ;-)

 

[shortyjacobs]

He said they were all carbed off the same reg, so overcarbing is probably out. My bet, tjpfeister, is what you already said - temp problem. There is a warm spot on that one line. I had the same problem with my fridge until I put a small fan in it to even everything out.

 

[tjpfeister]

He said they were all carbed off the same reg, so overcarbing is probably out. My bet, tjpfeister, is what you already said - temp problem. There is a warm spot on that one line. I had the same problem with my fridge until I put a small fan in it to even everything out.

I thought I read somewhere in there that the 30psi shake was performed, but I re-read and see that I was mistaken. I agree then if it was carbonated slowly inside the fridge that then the only remaining variable has to somehow be temperature.

 

[Bru]

I always force carb (chill to 2*C, 30sec shake at 30psi followed by 48hrs at 30psi). Bear in mind I use this method with every keg and never had a problem. But, just to make sure I vented the keg a few times and its made no difference. Also, this keg is carbed from a t-peice which goes to another keg - this keg has no problem. Any over-carbing would have gone away after two odd weeks in the keg at 8 psi (my standard serving/storing pressure).
It can't be temperature either - all 6 kegs are at the same temp and pressure.
I swopped the lines to a different tap - still foam (on new tap).
I cleaned the post/valve/dip tube and reassembled new 0-ring and food-grade grease.

The only thing remaining that I can think of is I noticed a small ding on the edge of the beer post - as if the keg was dropped at some point - could this be causing the problem ?
I appreciate all the suggestions - thanks all so far.
shortyjacobs - I have 6 kegs/lines - is it possible I can have a warm spot on one line but not on the others ? For clarity - I have 2 X 3-tap Towers.
Also, I replaced the large O-ring that sits at the top of the post - do I need to replace the poppet valve as well ?

 

[Homercidal]

I still can't figure out why a leak would cause this, since as was mentioned, a leak would indicate some beer leaking out, which it isn't. I guess it must be overcarbed. I tried changing the out post and it's still doing it. I was loathe to purge the gas and shake the keg, because I wanted to fill a few bottles, but just messing with the post stirred it up, so I might go ahead and do that. OR crank up the gas pressure a bit and see where it stops doing this.

The brown ale right next to it has had ZERO problems.

 

[wilceaser]

just for giggles before your pour your next glass from that tap, look at the beer line, there should be beer all the way up to the tap. If there is isn't you have leak somewhere that is allowing the beer to flow backwards into your keg.
The system should be at serving pressure through out the lines >Tank>GasLine>Keg>BeverageLine>Tap

becuase they way decribe the pour is; that there is gas coming out first then foam then beer...then more gas untill it starts to pour correctly.

 

[Bru]

I think you hit the nail on the head - I changed the O-ring and cleaned out the posts, poppets and dip tube and its stopped spluttering.
I now have another tap doing the same thing
I suspect sediment gets caught in the poppet valve.

 

[Homercidal]

I think I got it. Somehow the beer got carbed too much, and after I dropped the keg pressure down, it's no longer enough to hold the gas in solution in the lines.

Once the lines are filled with beer, the CO2 comes out of solution and creates gas voids in the lines. The solution may be to increase the pressure in the keg to keep the pressure in the lines equal to the beer, or to degas the beer enough to match the gas pressure.

At any rate, I filled a couple of bottles and it seems a little bit better. The keg is getting kind of low now, so I'll just leave it. It's almost time to move the Wit into a keg and start carbing that up. I'll try to do a better job this time...

 

[wilceaser]

I think you hit the nail on the head - I changed the O-ring and cleaned out the posts, poppets and dip tube and its stopped spluttering.
I now have another tap doing the same thing
I suspect sediment gets caught in the poppet valve.

Bru, Glad you found it!