Kegging beer line question

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Khirsah17

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Hello,

I am trying to get into kegging, and am slowly realizing how much initial planning there is to get started. Right now my biggest question is in regards to forced carbonation and beer lines. All the information I am using is from:

http://hbd.org/clubs/franklin/public_html/docs/balance.html


Case #1.
Fridge temp = 38F
Faucet height from keg = 2 ft
Volume of CO2 desired = 2.5

From chart - CO2 pressure = 11.2 psi

Using a 3/16 ID line with 2.7 avg resistance:
Beer line length needs to be about 3.4 ft to have serving pressure of 1 psi.


Ok, so thats totally doable... HOWEVER, let's assume theoretically, i only have a 1 keg fridge (i know, crazy). And now i want to serve a low CO2 volume british beer.


Case #2.
Fridge temp = 38F
Faucet height from keg = 2 ft
Volume of CO2 desired = 1.8

From chart - CO2 pressure = 3.9 psi

Using a 3/16 ID line with 2.7 avg resistance:
Beer line length needs to be about 0.7 ft to have serving pressure of 1 psi.

That wont do, so changing to a 1/4 ID line with 0.7 avg resistance:
Beer line length needs to be about 2.7 ft to have serving pressure of 1 psi.
That's more like it.


So basically, my questions are these:

1. It seems like once you pick a specific beer line length, you are pretty much stuck to a specific volume of beer. So are you master keggers always switching around line lengths and diameters to adjust for different volumes of CO2? In my example, i'd have to have two different beer lines, and just change them out for different styles of beer. I suppose i can change the fridge temp, but that doesnt seem to make *all* that much of a difference. Kegging seems like it can be a big pain in the butt if you want to serve different style of beer.

2. What difference is it going to make whether i use 3/16 ID or 1/4 ID line besides line length?

Thanks!!
 
the stated restriction is a generalization, and it actually changes, depending on the pressure.

you should also know that even though it seems that through these calculations, you can get to a point that no beer will flow, beer will flow, even if you have 30+ ft, albeit very slowly.

in my mind, 3 ft of beerline is way too short. i use 5 ft, and will soon be increasing that to 10 or so, that way my higher carbed beers don't just pour foam. my 'regular' beers will just pour more slowly.

there is a huge difference between 3/16'' and 1/4''. only use 3/16 for most close applications. the only time you want to use 1/4'' is for long runs where you need less restriction.

remember, it is easy to cut off tubing if there is too much. it is infinitely more difficult to add tubing back.
 
Yeah, I made the mistake of going with 5.5 feet on each of my faucets but I didn't factor in the lower faucet height on my chest freezer. If you're using a tower, you're adding a bit of resistance. I'm going to replumb with 8 feet and cut back from there if necessary.
 
I agree with Bobby, start with about 2 feet more than you think based on your equation. You can always shorten it.
 
The Jan/FEb 2006 Issue of Brew Your Own (Vol. 12, No.1) had a great article on calculating resistances for beer dispensing systems. I'm one of those sickos whos enjoy math and "story problems" from aglebra classs, so I filled about three or four pages with these type of calculations. :rockin:

For my system and temps and pressures, it calculates out to about 5 ft. of 1/4" hose from the keg to the tap. I'll increase it to 7 ft. per one of the above posts and shorten if necessary. My shanks can't accept 3/16" hose; wish I would've thought of this before I purchased the taps and shanks, however I can compensate with a just a bit more hose.

It's also amazing that the difference in resistance per foot of hose changes a LOT with just an added 1/16" ID, according to the information in the article.
 
The Jan/FEb 2006 Issue of Brew Your Own (Vol. 12, No.1) had a great article on calculating resistances for beer dispensing systems. I'm one of those sickos who enjoys math and "story problems" from aglebra classs, so I filled about three or four pages with these type of calculations. :rockin:

For my system and temps and pressures, it calculates out to about 5 ft. of 1/4" hose from the keg to the tap. I'll increase it to 7 ft. per one of the above posts and shorten if necessary. My shanks can't accept 3/16" hose; wish I would've thought of this before I purchased the taps and shanks, however I can compensate with a just a bit more hose.

It's also amazing that the difference in resistance per foot of hose changes a LOT with just an added 1/16" ID, according to the information in the article.
 
Do NOT get the 1/4" line. I'm telling you, you're going to get foam. Maybe you'll be OK if you leave your kegs at 8psi and you're running the line straight up to where your faucet is, 5 feet higher than the keg. Your shanks will indeed take 3/16" hoses, just warm them up in a cup of boiling water.

Also, if you think you'll be running a few different pressures like say an English Ale and a Hefe, make yourself up two lines, one of 6' 3/16" and one of 8' 3/16".

I'm serious, I bet if you took a poll, 95% of keggers here use at least 5 feet of 3/16" line per faucet.
 
Hmmm, most people here are pretty much in favor of the 3/16 ID line, which I'm totally cool with. Glad I asked before I ordered :) Overall, I was going to build a manifold with more ports than I had kegs, and the extra ports would have had the odd size tubing for the rare occasions that I brewed a lower carbonated beer. That way, I'd have more flexibility in the future without to much actual change.

However, I'm curious to know as to why the equations don't accurately reflect real life situations. Seems like not too many people take the equations seriously, but instead just use more hose and cut back based on the physical results. A guess and check method vs. a prior to ordering, "predictable" method.

Someone mentioned something about pressure?
 
I think you need slow down a sec. When you talk about manifolds, you're talking about the gas (CO2) distribution system to multiple kegs. The tubing size and length does not have any bearing. Use 1/4 at the shortest lengths you can get away with. Now, the lines from the kegs to the faucets... THAT is where the tubing diameter and length come into play. And yes, I do recommend getting 3/16" tubing and start with about 7' on each faucet. If the beer is carbed fine but it's pouring too slow or you aren't getting a big enough head, cut a foot off and try again. Throwing away a couple stray feet of tubing is cheaper than buying a whole new lot.
 
Yea, you're right. I'm not sure why I brought up the manifold. Thinking about too many things at the same time, haha. I really need to start making a plan on paper as opposed to doing it all in my head!

Either way, the original question I asked was what I meant to ask. I guess I'll be buying a bundle of 3/16 and testing it out.
 
It's interesting to see all the responses to this post.

I must admit that I'm in the design phase of my kegerator, and certainly appreciate all the replies from folks with practical experience.

The pressure balance calculations that I refer to were published in Brew Your Own in their advanced brewing section by Bill Pierce, who at that time wrote the Advanced Brewing column in each issue. His explanation, calcs, and reasoning made sense in terms of basic physics and chemistry. I'll give my system desing a "shot" based on what he published in that issue, and report back with total frankness about my results.

Again, appreciate all the responses.
 
Finished assembling the kegerrator last night with the 1/4" line. Tried running water through the taps to check the flow rate and, WOW. Kinda' like Niagra falls. :D

You folks were right; 3/16' ID line, about five feet, is what I need. I re-visited some other sources for calculating line length, and they were more in agreement with 3/16" line than 1/4" line for my system. My hard-worked beer woulda' been nothin' but foam if I tired running it through that 1/4" line.

Thanks for setting me straight, and keep it up. If no one ever tells me I'm wrong, I'll never learn anything. ;)

I'll post some pics of the kegerrator in the other forum shortly.
 
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