Bubbles coming from shank

[Duffman D]

Hi all,
I have a kegerator that overall seems to be running pretty well except for one thing. Right after I pour a beer I can see little bubbles coming into the beer line from the shank and after a while it creates a relatively large gap in the line (an inch or more). This occurs only at the shank. There are no bubbles coming from the coupler and no other gaps in the line occur. Once I pour past the initial "burp" it pours great. It just seems weird that the bubbles would be coming back out of the shank. I've changed faucets and made sure the beer line is connected to the shank securely and that the washer is in good shape and yet the problem persists. Do I need to replace the shank or is there something else I should check? Thanks in advance for your help.

[djc]

What’s your pressure? Beer temp?

[Duffman D]

Temp is 37.9, pressure is 14, line is 10 ft of 3/16.

[djc]

Do you have a duckbill on the gas side and a check ball on the beer side of the coupler?

[Duffman D]

Yes. Everything is good near the coupler. The bubble is 10 feet away from that. After I pour a beer I can literally see bubbles coming back into the beer line from the shank so I feel like the issue is on that end.

[djc]

I understand what end you are talking about, I was asking about the checks because if you had beer retracting towards the keg or into the gas line, it would be pulling it back from the faucet end causing what you are seeing. Does the gap that forms in the beer line go all the way to the shank, or is there beer in between the pocket and the shank?

Front closing or rear closing faucet?

[Duffman D]

Ah, I've got you regarding the checks. Makes sense. Unless there's some kind of a defect/issue with the duckbill or ball I should be good on that front.

The faucet is a Perlick 650SS--forward sealing with flow control. The gap is right up against the shank. No beer in between the gap and the shank.

[djc]

With no beer between the gap and the shank it seems to me like it might be air coming in rather than CO2 breaking out, but I can’t really figure out in my mind how or why that could be. Have you looked down in the top of the tower to see if you can pin point where the bubbles originate?

[Duffman D]

I don't have a tower, it's a fridge in which I poked a hole in the door. The farthest down the line that's visible is where the hose connects to the back of the shank, just inside the door. I just changed faucets again and still getting bubbles. I think maybe I'll get a new shank and see if that solves the issue. Thanks for your responses. I'll update once I get the new Shank.

[djc]

It could be CO2 break out if the shank and line through the door is getting warm. How much shank do you have sticking out into the cooled space? As temp rises the required pressure to keep CO2 in solution also rises. That area gets warm and can’t hold it’s CO2.

[Duffman D]

That's an interesting thought. I did recently replace the fridge though the rest of the setup is the same. In the new fridge the door is thicker so there's just enough of the shank poking through the door to screw the nut completely on. I ordered a shank that's about an inch longer. Generally speaking would longer be better?

[Duffman D]

The new shank arrived yesterday and as of this morning there is still a bit of a bubble but it's much smaller than it was. So maybe shank length is playing a role. Wondering if I should try a longer shank.

[djc]

You definitely want shank in the cooled space. A few inches in would be good because the steel is a better conductor of cold than the beer line. You can also boost the results by having a fan circulating cold air from the bottom of the fridge on to the shank.

[Duffman D]

Ok, I'll try that. Thanks. One other question, is shank bore diameter going to matter? When I installed the new shank I realized that the bore is 1/4" whereas the old shank is 3/16". Seems to pour ok but wondering if I should go back to 3/16" bore.

[djc]

The bore doesn't matter, as you've seen the 3/16" line still makes it on a 1/4".