Balancing Tap Line - frustrating 4 week experience

[Brewbum]

I can't seem to get these damn lines to balance is it because I am screwing with it too much?

We have a 55 foot run, we go up 8 feet back down 12 feet and back up to the taps 4 feet. So a total rise from bottom of keg of 4 feet. We carb our beers at 9 psi at 34 degrees. They are in the cooler at 40 degrees. Our line is the barrier tubing with 5/16 ID.

If we serve at 11-12 psi or so we usually get almost a pint poured and then it spews a little foam. If we raise the psi to eliminate that problem in a couple days the beers are overcarbonated.

What am I supposed to do. We are only open 3 days a week and by the time a week goes by the beer is a foamy mess. Also, usually by the time beer is about empty it is a foamy mess too.

I have since dropped the serving psi back down to 11 on all kegs but I anticipate the occasional burp of foam.

What am I missing? Do I need to have a nitro blender to serve at higher psi without causing overcarbing? New kegs pour great.

[spdbump]

You definitely need to add a blender panel. I would recommend a 70/30 mix. With that long of a run you are not putting enough co2 to the beers to pack the beer in the lines and pour successfully and by raising the co2 pressure you wind up overcarbing the beer. With a blender panel because of the mix of co2 and nitrogen you are able to raise the pressure without overcarbing the kegs. What is your elevation ?