I added a second faucet to my draft system a while ago. I have my CO2 line going to a dual distribution port. The CO2 regulator is reading 9-10 PSI. When I have one keg on tap, that faucet pours perfectly. When I add a second keg, the new keg pours foamy. The keg that poured normally before adding the second keg gets a little wild. When one keg blows, the other keg pours perfectly. I’ve changed lines, switched disconnects and changed faucets; nothing seems to work. Just doesn’t make sense.
I just put in a perlick setup with 10’ of 3/16" lines (1/4" shank) and all four poured foam the first two weeks. I checked for leaks and found 2-3 very small ones in gas connections due to worm gear clamps. Next I set my pressure to 11-12 psi and fridge temp to 42 F. After about two weeks the foam stopped and they all pour much better now.
I am beginning to wonder if the culprit was starsan foam/bubbles in the lines that was getting trapped in different high points of my beer line loops.
There are several things that this could be. If you have some leak on the beverage side of keg #2 it would make it pour foamy (like a bad dip tube o-ring). Keg #2 could be overcarbed, and if you don’t have a check valve for each line this could be filling the headspace of keg #1. You may just have a line length that is too short, and don’t notice the pour on keg #1 because it is undercarbed.
Have you tried pouring just from the good keg through both faucets? Likewise for the bad keg, see if the problem stays with the keg or with the line. How long are your dispense lines? A good rule of thumb is 7-10’ of line for 10-12 psi dispense pressure, which is a lot higher than what your average online calculators will (incorrectly) recommend.