Keg line lengths? There are diff opinions. - Home Brew Forums

 Home Brew Forums > Keg line lengths? There are diff opinions.

03-12-2013, 06:36 AM   #1
spaceyaquarius
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I'm researching kegged beer line length. I've read so far that many people just go with 10 foot lines and claim that the foaming is not an issue.

There are several website that use this equation:
Length = (serving pressure – 1 – (elevation/2))/resistance per foot.

I have also found this equation (reportedly from commercial tap installers):
Length = (keg pressure + 5)/resistance per foot.

Assuming that you use a normal serving pressure of 10 PSI, and have an inner diameter vinyl tube of 3/16" (which is 2.7 resistance), then you'd require 3.14 feet of line with the 1st equation, and 5.55 feet with the 2nd equation.

I have 4.7 foot length lines at 10 PSI and I am getting too much foam.

Any ideas???

03-12-2013, 06:55 AM   #2
emjay

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Longer lines. It's always best to err on the side of "too long", because not only can they be cut shorter, but the only real disadvantage to a long line is that it will pour a bit slower. I'd recommend starting at 10-12 feet and going from there.

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03-12-2013, 07:06 AM   #3
spaceyaquarius
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I agree. I think the line length equation is completely unnecessary. You could calculate a length of 3.5 feet for one type of beer, and then another length of 5.5 feet for another type of beer. There's no way to adjust it back after you've cut the line.

Slow pours wouldn't bother me, and I guess you can always pour more vertically if there's not enough head from the pour.

03-12-2013, 09:17 AM   #4
mjdonnelly68
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Agree with the advice that longer is better (TWSS).

Had six foot lines in my three tap kegerator and often had problems with foaming.

Switched out to ten foot lines for all three and never have a problem now.
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03-12-2013, 10:38 AM   #5
Travestian

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Quote:
 Originally Posted by spaceyaquarius Slow pours wouldn't bother me, and I guess you can always pour more vertically if there's not enough head from the pour.
Technically pouring more vertically is better anyways for the flavor of the beer. A pour right down the middle of the glass helps break up some of the proteins in the beer and releases a lot of aroma. And we've all heard and know that smell is a very important factor in taste. I look at beer totally differently now that I pour down the middle instead of sneaking the side.

Sorry for the post hijack.

03-12-2013, 11:14 AM   #6
Dr. Francois

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You can also turn down to 8psi. I keep my regulator set to about 7psi, but I'm kind of a porter nut. If you love fizzier beers, I would add line length.

5 foot lines and never a worry of overfoaming unless the beer was overcarbed to begin with.

The only beer I've had trouble with so far is one I burst carbonated to get ready for a party. I overshot my target and it was a foamy mess until half way done. I think "set and forget" is the best way to go.
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03-13-2013, 06:16 AM   #7
JuanMoore

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Quote:
 Originally Posted by spaceyaquarius I'm researching kegged beer line length. I've read so far that many people just go with 10 foot lines and claim that the foaming is not an issue. There are several website that use this equation: Length = (serving pressure – 1 – (elevation/2))/resistance per foot. I have also found this equation (reportedly from commercial tap installers): Length = (keg pressure + 5)/resistance per foot. Assuming that you use a normal serving pressure of 10 PSI, and have an inner diameter vinyl tube of 3/16" (which is 2.7 resistance), then you'd require 3.14 feet of line with the 1st equation, and 5.55 feet with the 2nd equation. I have 4.7 foot length lines at 10 PSI and I am getting too much foam. Any ideas???
Those equations are both flawed for a variety of reasons. First, line resistance is not a constant for a particular line, it actually varies depending on flow rate. The table where you got the 2.7psi/ft figure assumes a flow rate of ~1gal/min, which is usually ok for commercial systems where the beer is kept under 38° and the carb level under 2.8 vol, but may not work well for a home system. The warmer the beer is stored or more carbonated it is, the slower it needs to be poured to prevent foaming. The places you got those equations likely misled you into thinking that they calculate the "ideal" line length, and anything other than that ideal length would cause foam. The fact is that all they do is calculate the length required to result in a particular flow rate, typically 1gal/min. The only side effect to a longer line is a slightly slower pour, and IMO an extra long line that can handle a wide variety of serving temperatures and carbonation levels is a whole lot more "ideal" than a length that results in an arbitrary flow rate.

The only halfway decent line length calculator I've seen is the one created recently by Mike Soltys found here-http://www.mikesoltys.com/2012/09/17...our-kegerator/
The only hard part is determining the pint fill time that won't result in excessive foam. IMO it should be at least 10sec to give a little system flexibility, and FWIW mine is set for a 13.5 sec pint fill.

Keep in mind that you'll want to use the highest pressure and slowest pint fill rate that you'll use for any of your beers, not simply the figures for your current batch. That way your lines will be long enough to handle any of your future brews too.
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03-13-2013, 06:33 AM   #8
Gitmoe

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Quote:
 Originally Posted by mjdonnelly68 Agree with the advice that longer is better (TWSS). Had six foot lines in my three tap kegerator and often had problems with foaming. Switched out to ten foot lines for all three and never have a problem now.
+1 on this exactly. Was running a 6ft line on my kegorator and when I added the 3 new faucets I made all 4 faucets 10ft lines. Poured much better at all pressures. I suggest to all my customers at work (LHBS) to run 10ft lines now. They all think I'm crazy but when they come back they thank me for the suggestion.

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03-13-2013, 07:30 AM   #9
spaceyaquarius
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Sounds good. I was thinking that the equation was not making sense. 10 foot lines are in the mail now. Trial and error.

03-13-2013, 05:42 PM   #10
H22W
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