Air in Lines

[Hockeyhunter99]

I am pretty new to kegging so bear with the terminology.

I have three pin-lock kegs. i use long - "Foam Free" picnic taps from NB to dispense the brew. i keep having large head on my beer from one of my kegs. the taps on the other two kegs are fine. just this one seems wonky.

to explain in depth: there is always a bit of carbonation in this line. when i pour a beer, it shoots out an air bubble then blows foam. i get a glass full of head. then i see that there is carbonation in the line. non of the others does this. they keep really good pressure, no carbonation in the line, good pours with good head.

Specifics: 7-12 psi through 7.5ft line, force carb with rolling on ground at 30 psi then let sit for 24hrs. all beers are on the same tank with same pressure.

can the line have a leak to release pressure? too much carb? infection? might need to buy more hose?

worried

 

[raouliii]

There is an o-ring between the diptube and keg, under the post, that, when bad or poorly sealed, can allow CO2 to directly enter the beer line.

 

[Hockeyhunter99]

i will have to get a new set from LHBS and see if that is the case. if that is not the case, could it be something else?

 

[JuanMoore]

i will have to get a new set from LHBS and see if that is the case. if that is not the case, could it be something else?

The other possible cause is that the beer's overcarbonated. Unless you did something different with the carbonation for that one keg, it's most likely the diptube o-ring though. FWIW the diptube and post o-rings are good to have on hand, and 100 packs of each are only a couple bucks each from McMaster Carr.

 

[Hockeyhunter99]

new o-ring but still foaming. If it is overcarbed, (i have depressurized to put in the new o-ring) how else would i take the carbonation off?

 

[Hockeyhunter99]

This is what happens when i pour. Bubbles form inside the line at both ends and create a bubble that causes the foaming. the last pic is my glass after sitting for a minute.

any thoughts would be helpful

 

[JuanMoore]

new o-ring but still foaming. If it is overcarbed, (i have depressurized to put in the new o-ring) how else would i take the carbonation off?

Disconnect the gas and purge the pressure every time you think about it for a few days.

There's also a quick method, but it may reduce the carb level more than you want. Hook the gas line up to a liquid side QD, and connect it to the beer out side of the keg. Turn the gas on at a low pressure, hold the pressure relief valve open, and let the gas bubble up through the beer for 30 seconds or so.

 

[JuanMoore]

This is what happens when i pour. Bubbles form inside the line at both ends and create a bubble that causes the foaming. the last pic is my glass after sitting for a minute.

any thoughts would be helpful

If you pour a couple consecutive beers is it just the first one that's foamy, or all of them? Do the bubbles form in the line instantly, or do they form after the keg has been sitting for a little while? When you replaced the diptube o-ring did you notice any nicks or deformities in the underside of the lip on the diptube, or in the top of the post where it seals with the diptube?

 

[Hockeyhunter99]

The beer foams in the line. every glass is foam.

the o-ring was torn to shreds from the pinlock gas-in QD. I changed it out with a different QD and the o-ring got mangled again. this is getting frustrating. i am losing a great beer.

i tried a different hose (one that works fine with the other keg) and it foams up too.

 

[zachattack]

That's the post o-ring. Lubing it with keg lube (or any food safe lubricant) will keep it from getting mangled. Did you also check the dip tube o-ring? That requires taking off the post with a wrench.

 

[JuanMoore]

The beer foams in the line. every glass is foam.

the o-ring was torn to shreds from the pinlock gas-in QD. I changed it out with a different QD and the o-ring got mangled again. this is getting frustrating. i am losing a great beer.

i tried a different hose (one that works fine with the other keg) and it foams up too.

That doesn't sound like overcarbonation. Sounds like a bad diptube o-ring, which it sounds like you may not have replaced yet. As zach said, you need to use a wrench to remove the post, and then pull the diptube out to get the diptube o-ring off. It's part E in this exploded parts diagram-

 

[Hockeyhunter99]

Yes, i replaced the dip-tube o-ring. it was the mangled one. "E" in diagram is new and it the new one got wrecked as well. changed out the post completely. are there specific o-rings for pin-lock vs. ball-lock?

 

[JuanMoore]

Yes, i replaced the dip-tube o-ring. it was the mangled one. "E" in diagram is new and it the new one got wrecked as well. changed out the post completely. are there specific o-rings for pin-lock vs. ball-lock?

The post o-rings (part D) are very slightly different (thicker for pin-lock), although a lot of people use them interchangeably. The diptube o-rings are the same though. If the diptube o-ring is getting mangled just from being installed, then there's something seriously wrong. Nothing moves against that o-ring when connecting or disconnecting the QD, so the QD shouldn't mangle it. Like I asked before, are there any nicks on the underside of the flare on the diptube, or on the top of the keg where the post screws on?

I'm still not 100% convinced we're talking about the same thing based on the way you've described things. Just to be clear, you unscrewed the post and removed it, which looks like this-

then removed the long liquid side diptube, and then replaced the o-ring that sits against the flare at the top of the diptube, here-

 

[Hockeyhunter99]

Yes, the dip tube o-ring. took the wrench and unscrewed the pin-lock. took it off completely. pulled the dip tube out and the o-ring looked like it had gone through the threads of the post to get it mangled. The o-ring under the flared dip tube is torn up

 

[JuanMoore]

Yes, the dip tube o-ring. took the wrench and unscrewed the pin-lock. took it off completely. pulled the dip tube out and the o-ring looked like it had gone through the threads of the post to get it mangled. The o-ring under the flared dip tube is torn up

You need to install a new one in a way that it doesn't get mangled. First you need to inspect the surfaces it contacts to ensure there's no nicks or deformities in the metal. Assuming everything looks good, use some keg lube or star-san solution to give a little slip so that it doesn't bind if the diptube spins when the post is being screwed on.

 

[Hockeyhunter99]

well i can't get new o-rings until after the holidays. got the last two from the LHBS and shipping won't come soon enough. will they sell o-rings at home depot or lowes that are food grade??

 

[somedudefromguam]

Have you tried relieving the pressure and waiting overnight, then bring the keg back up to serving pressure, then pouring.

When you crank the reg up to 30 psi and carb, you could have over carbonated the brew, if the serving pressure is a lower pressure than the beer in the keg it could cause this.

An easy way to see would be to crank your regulator up a few psi at a time and try pouring, this will bring the serving pressure closer to the pressure of the brew and if it does not eliminate the problem, it should make it foam a little less. Although this can cause foaming also, if your lines are too short, the beer will just fly out of the tap and foam up as it hits your glass.

http://www.kegworks.com/faqs/Draft-Beer-Quality-Manual.pdf
This PDF really helped me when I was learning to balance my keg system. I used to have bad dreams about it...

I guess it could be the o ring you are talking about.... but probably not if you already replaced it. I have 8 kegs that all get used heavily, I have noticed that some of the same o rings you are talking about are also kinda chewed up from the threads, they all work fine.

Another idea... you could switch the two o rings that are on the one problem keg... The one on the gas side is identical from the beer side...

Sorry to hear about your beer woes... Good luck!!!

 

[JuanMoore]

well i can't get new o-rings until after the holidays. got the last two from the LHBS and shipping won't come soon enough. will they sell o-rings at home depot or lowes that are food grade??

Not sure they'd be labeled "food grade", but I don't think there'd be an issue using o-rings from the hardware store. Any buna-n or silicone o-ring should be fine. I'm pretty sure the diptube is size 109, but you might want to check with the McMaster o-ring list linked in the sticky kegging faq's just to be sure.

 

[Hockeyhunter99]

got some new 0-rings and keg lube, flipped the posts and blew CO2 down the liquid dip tube. purged air and dropped the psi.

i think it helped. i will check tonight after it has sit for a while.

 

[Hockeyhunter99]

MUCH BETTER:rockin: