bubbles forming in my draft line

Not knowing your set up, it sounds like the lines are warming and perhaps you are getting the co2 to come out of solution while it sits in the lines.

 

almost certainly your line is too warm.
check the temp of the first pour. then check the temp of the second pour. if they are not exactly the same then you can be certain. this is a very common problem.

warm liquid holds less gas. the bubbles are CO2 gas coming out of solution. it is very unlikely you have air entering the line. if you have a place for air to enter, then you a place for beer under pressure to escape. so unless you have a leak, it's not air entering your line.
Cheers.

 

you have CO2 coming out of solution.
1. check your temps. the keezer is not a uniform temp from top to bottom. if the temp probe has been moved, that is your problem. you may very well have some other problem, but since bubbles in your dispense line are the result of gas coming out of solution, rule out temperature variation.

2. did you change the pressure on the regulator? is the regulator working properly? if the pressure has been reduced gas will equilibrate to the lower pressure within the keg. you will have gas bubbles creeping up the line as you describe. be sure your regulator is ok.

Cheers.

 

You can't have an air leak in your line without liquid coming out, it would get pushed out your keg before it managed to get in the line.

It's co2 coming out of solution. I'm assuming you have picnic taps. They are getting warm or you have a change in pressure somehow.

 

One other possible source of the problem... solid crud collecting in the dip tubes or lines. Solids may form nucleation sites for CO2 to cause a foam up. Try cleaning the lines with PBW then flushing with water.

I've had the bubbling issue before with my beer gun, even with new lines. To get around it I pre filled the line with Starsan (diluted in water) and assembled the picnic tap, line and beer connection in the star san solution making sure to get no bubbles in the line and then sealed it. After I hooked it up and ran it, no bubbles in the line.

 

A general setup for kegging is 5-10 feet of line, (3/16"ID), 10-15 PSI, 40-45F, and a 10-12 second pour. You'll pour from about 18-24" from the center of the keg.

If you are getting foamy, it's time to turn up the cold, and or turn down the PSI. Try one or the other before both and find something that works well for your kegs.

 

When cleaning the keg out, run some hot BLC or Oxyclean through the line. See how it runs and trace back to the tap. Good luck.

 

38 in the kegerator.
what is the temp in the glass?