Draft beer lines

[panadero]

Hey all,
I am planning our draft lines, and have a question. I am trying to measure the resistance from gravity. I know it is about .5 pounds per foot, and with a keg you measure from halfway up the keg (or down!) for the starting point, and the tap as the finish point. What about serving tanks? I have eight foot tall serving tanks. I am guessing I still measure from the midpoint. So when the tank is full, it will have approx. 2 lbs (4') less pressure, and when almost empty 2 lbs more pressure than the system is set for.
Our serving cooler is directly below the barroom, and we will have about a fifteen ft height from center of tanks to the taps. Air cooled runs.
any thoughts?
Thanks!
David

[Frankentrostjim]

With kegs you would actually measure from the bottom, that is where the keg spear picks the beer up. With serving tanks measure from the outlet, that would be the maximum lift. If you get me lift, run (outlet to faucet), bright room temperature, and applied pressure I can get you the specs for the lines

[gitchegumee]

It won't matter much either way. Go for slightly more restriction and leave yourself room to tweak it if you can. You could also use the faucets that allow a slight increase in restriction. Or use a choker line of a certain length. It's less sensitive than you might think. Just make sure that your flow path is smooth (dont' like hose barbs for this reason--use JG fittings if possible), even, gentle, constant. Nothing sudden about temperature, pressure, or flow and you should be fine. Good luck!

[panadero]

The lift is fifteen feet from tank outlet (six inches from floor) to tap. The serving tanks will be at 37 F at 10 to 12 psi. depending on style (extra lengths for some lines) . The tap towers we got have six foot vinyl lines of 3/16ths id. I am guessing I should remove those as that is already 18 lbs resistance at 3lbs/ft?

My understanding was the actual pressure is measured from the liquid level in the tank/keg, and the halfway point gave an average you could use. That never added up to me, but I'll go reread the draft quality manual again...

My idea is to run the lines from the kegs/tanks to some kind of junction plate/manifold area where I can run them straight up to the taps, using a forced air blower. The towers are ten tap pass thru, so I was going to blow air up one side, and have it return from the other - the total air run being about 15 feet, plus the two right angles in the tower.

David

[gitchegumee]

Six feet of 3/16" vinyl tubing is standard supply for a tap faucet. It represents enough (if not too much) resistance to add a keg coupler and go. Tap beer in half an hour with a simple kegerator. For your specific situation, you have more work to do. Start with your lift. No way around that. 15 feet vertical up (yes from the midpoint)? So that's about 7.5psi right there. Then what type of faucet do you have? One with a long 1/4" SS shank on it? That adds more--something like another 3psi if I remember right. What is your main tubing diameter, material, resistance? Continue with this. Add them up. More than 13-15psi? Then increase the diameter of your main tubing to decrease the resistance per foot. You may have to chuck most, if not all of the 3/16" choker line that came with your taps. There are many great references for doing what you're doing. Seek them out and read until you have confidence you know exactly what you're doing. It's not that tricky. Good luck!

[Graydon]

http://www.brewersassociation.org/pa...quality-manual

Many of the questions asked on this board are best answered by publications from the BA. This Draft manual is free, and it tells you everything you need to know.

Graydon

[Frankentrostjim]

Assuming a total run of 20 feet with 15 foot lift, 1 foot of 3/16 vinyl choker line at tower then 19 feet of 5/16 barrier tubing. This will balance between 10-12 psi applied pressure. Pour rate is a bit slower than standard (gallon/minute) at 100 ounces/minute which will let you pour samplers with less waste. wall brackets will clean up install, serve as your junction block, and allow you to use more pliable vinyl beer line from tank to wall bracket. PM or call if you need more assistance. Cheers!

[Frankentrostjim]

Some additional info, the airshaft should be 4" and blower to move air should be 200 cfm or higher. Insulate the air shaft as good as possible outside of the cooler so return air is as cold aqs possible

[lhall]

I think the original poster was asking why you make your starting point halfway up the keg or serving tank. That is to take into account the hydrostatic pressure of the beer itself. By starting at the halfway point, it will average out. When the tank is full, the beer will flow a little faster through the line and when it is almost empty, it will flow a little slower.

[panadero]

Great help! Thanks.
The draft quality manual has been my primary resource, I was just trying to understand the whole concept a little better. Back up my ideas with positive reinforcement, so to speak.

Cheers!