Balancing my system.

[apo09283]

Ok, I think I have my feeble mind wrapped firmly around the whole issue of balancing my kegerator but I used several different sources for info and three questions come to mind.
1. One source says to account for gravity by measuring vertically from the center of the keg to the faucet. Another says to measure from the bottom of the keg to the faucet? For me it is only a difference of one foot. Which is it? In my calculation below I measure from the bottom.
2. One source mentioned a compensation factor for altitude in the volumes of CO2 chart. It says to add one PSI for every 2000 feet of altitude. I'm at 2250ft ASL. If I've got it right I need to add one pound of regulator pressure to compensate. Is this correct and do any of you bother compensating for altitude?
3. Does my math below look ok? From reading here in the forum it looks like many of you use 7ft of line but the math here calls for 3.8ft in my system. Should I start with more line and cut if necessary?

Beer @38F I want 2.5-2.6 volumes of CO2. System is just an old fridge set up with 6 Perlick taps in the door 27" above the bottom of the kegs. Liquid line is superflex 3/16" ID.

I need 12.5 PSI at the gauge to maintain correct CO2 volume. (13.5 if I add for altitude)
Resistance in my system due to gravity is: 27" or 2.25ft so 2.25 x .45= 1.0125PSI.
Beer line resistance is 3PSI per ft.
So I need to add 11.48lbs of resistance to the system. So 11.48/3 = 3.8ft or 45.5".
With no altitude compensation and measuring from the bottom of the keg to the faucet instead of the middle means I need to make my lines 45.5" long.


So, does this sound correct?
Thanks,
Bill

 

[jaobrien6]

Should I start with more line and cut if necessary?

Yes. It's so much easier to shorten a line than put in a new longer one.

Having said that, regarding your question, none of the formulas I found worked correctly for me. The calculations all said that just under 5' was perfect. I thought this was great because I had 5' lines (that's what my tower came with). I had foaming problems, and not just first glass problems but consistent problems. Switched to 10' lines, no more problems.

IMO, rather than doing a bunch of math, just buy longer lines than you think you need and try 'em out. The KISS approach worked better for me.

 

[jeffmeh]

To be precise, I believe the head pressure is the vertical distance from the surface of the beer and the tap, plus friction due to lines and fittings. So the pressure increases as the keg drains. That being said, +1 on buying longer lines and figuring it out through experimentation.

If you have not done so already, keeping the lines cold makes a huge difference on the first pour. Use a fan, or passive cooling with copper pipe, or for the big money by recirculating chilled glycol. I am happy with the passive cooling solution.

 

[Got Trub?]

As others have said start longer and then shorten if/as needed.

Why 38F?

Most beer styles should be served warmer than that.

GT

 

[HeyNoPie]

I have a system with a 12' or so rise and thought I would never get it right. From what I've seen, a little too much resistance is better than not enough. Here are a few items to cross check your setup:

They say a pint (12 oz) should pour in about 6 seconds. Mine takes probably around 10-15, but its perfectly clear.

If you get clear beer followed by a shot of foam about halfway into the glass, your regulator is too low. In this case, CO2 is escaping the keg and getting into the line.

I did this (http://www.maltosefalcons.com/tech/resistive-gate-draft-beer-flow-control) to add resistance to my lines and that solved everything to me. Ideally, you'd balance the system with proper line length, but I don't know how appealing it is to have 10' of line coiled up. I'm sure not all would agree with this approach though it was great for me.

All in all, your approach looks right, but I agree with the others who say to leave your lines a little too long and slowly cut away. You might setup one tap with experimentation and then you know what the others need to be.

 

[thisjrp4]

The whole keg balancing situation really bums me out. I have a home-made Sanyo mini-fridge kegerator with a 2 tap tower. I carb to 12 psi and serve with 5' of 3/16" line. I get bad foaming, particularly as the keg gets empty. I pour a huge glass of foam, then when the glass clears the beer is left flat - and flat beer just isn't as tasty as well carbed.

Like Bill I do the calcs and they say I need about 4' of line. Then you read that 10' gives more restriction and no foam. So which is it? I just kegged last night and put some of those epoxy mixing things in the dip tube to see how that works. Since the verdict is still out wether or not we are all going to die from using those, I'd rather have more FDA approved 3/16" line.

So...what stops the foam - 4' of line for 12 psi, or 10'???

 

[RichBenn]

I too have had to use much more line than the calcs would say. I believe there are three factors that explain this:
1. The resistance of the line per foot is MUCH lower on most quality beer lines than the formula would indicate.
2. The temperature of your beer may be different than you think(what the regulator says). In my own case, the temp regulator allows too much variation as well, which explains sometimes foamy, sometimes not.
3. The gauge on the regulator may be off.

Out of these, #1 is probably the main factor you are experiencing. There is a thread for using inserts that add resistance to your keg's outlet; check that out. Seems universally a workable fix for this problem.

Edit - Oh, and three more things - if you have any, even minor leaks in your system, you can get foam. (Symptom - the CO2 will give out too soon). And second, the beer line is supposed to slope only up from the keg to the tap to avoid CO2 bubbles in the line when you shut the beer off. And third, if the tap is not cold, the first pour will be foamier (is that a word?).

And we all thought kegging would simplify things....

 

[HeyNoPie]

In my situation, I needed more restriction than the calculations would say, so 10' might be better than 4'. Rich brings up some good points. You likely don't know the exact resistance of your line but are relying on general guidelines, so the numbers in your calculations may not be 100%. Your temperature will always vary a bit over time but hopefully not too extensively. You might use a separate thermometer to verify the fridge temp. As a rule, I let a keg sit in the fridge for 24 hours before tapping and usually try to wait a few hours after tapping to serve. I don't expect that is all entirely necessary and may be a little overkill, but it certainly helps to know the keg is not agitated in any way.

If subsequent pours get better, you likely have a temperature problem. If the foaming symptoms are consistent, I'd say it is a pressure/resistance problem.

 

[Soulrebel]

the flow restrictor from the Maltose Falcons site will fit in the dip tube of your keg.

 

[HeyNoPie]

Good point. That might be easier if you're running corny kegs.

I was originally running commercial kegs when I setup my system, so I have the restrictors in my 1/4" line held in place by worm drive hose clamps. I put the epoxy mixers in a separate section of line about 1' long and splice it in using 3/8" John Guest unions.

 

[apo09283]

I sincerely appreciate all the responses. So far so good! I increased the pressure in the kegs to about 15psi for two more days then reduced it to 12.5psi. I blew all the excess pressure off of each keg.

What a difference! Each beer tastes noticeably better especially a tangerine ale which is dramatically better! The temp is a bit low a 36 degrees but I'm slowly dialing it in. Pour times seem to bee about 6-8 seconds so I think I'm there.
Cheers,
Bill

 

[HeyNoPie]

I'm glad you're in good shape. How are you setup now?