CO2 line size, does the ID/OD size matter?

So--I'm setting up a chest freezer for carbing/serving, and also a portable rig so I can take 3 cornies to baseball tailgates and serve (Opening Day in Detroit soon!).
My LHBS sells everything gas-line related in 3/8" sizes, the people I talk to there swear by 3/8" standard line for gas-to-keg lines. If I go to stores online, I find 1/4" sized gear way cheap. I obviously want to brew and serve the best I can, does the difference in the two sizes matter? Some say yes, some say no. Pros/Cons, anybody? To illustrate the difference, setting up something in 3/8" line from LHBS to carbonate 3 kegs and serve 3 would be around 200 dollars all-told. Online the 1/4" soda equipment would cost around 75 bucks, by my math, and in my tax bracket $125 really matters.

I've been kegging for years (Just a data point) and I use 3/16" beer line for both dispensing the beer (line resistance really matters here) and for delivering the co² to the keg (line size does not matter in any way shape or form in delivering gas in a very low volume need like carbonating or dispensing beer).

I think they are pushing the S--- they have in stock and standing by the fiction.

I'd suggest 3/36" lines all around. This way, with a standard that you have chosen, you can swap lines at will without issues.

I'd definitely agree with P-J here, 3/16 lines really matter for beer line but CO2 can be whatever you want. I use 5/16 lines for all my CO2 mainly because thats how my setup started and it got difficult to change. That said, I have often come across the problem of needing to rig up new lines(new keezer FTW!) and have run out of the proper diameter line to fit my gas fittings.

Thanks for the advice PJ and Germanicus--why do you say 3/16" firm for beer? I've been sold 1/4" and it seems to work fine (of course, relative fine.)

Angeloboot said:

Thanks for the advice PJ and Germanicus--why do you say 3/16" firm for beer? I've been sold 1/4" and it seems to work fine (of course, relative fine.)

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This chart might help:



You can see a radical difference in back pressure between 3/16" and 1/4" beer line.

as far as i know gas line diameter can be whatever. i use 5/16 and it works fine. Beer line however is a standard 3/16 for the most part.

CO2 lines really don't matter. 5/16 is common because that's what beverage companies use on dispensing systems, and what you'll find on a factory sanke system. 1/4 is what my LHBS recommends (I have NO idea why).

I use nothing but 3/16 beverage tubing for everything, including gas, because I can take any line and use it for any purpose. I also use flare fittings everywhere, so I have a couple of extra hoses laying around for making "Out to Out" hoses and the like. Another perk is I don't have to have a pile of different tubing in the garage.

Ok, thanks all so far--this is starting to make a little more sense! I'm going to go ahead and use 1/4" all around for gas (I found a bank of 4 secondary regulators for around 60 dollars, all have 1/4" flares--should keep me busy for a while!). I'll follow the advice here and go to 3/16" for beer out, but this just leaves one question kind of unresolved: I'll have secondary regulators to adjust, sooooo, if I hook my keg of wheat and carb to 3.5 volumes, how do I dispense at that low flow rate suggested on the chart? My last keg I did was a porter, and I left it at 14psi for 2 weeks, but when I dispense at 14 psi, I got all foam. If the dispense psi is different than the carbed amount, won't gas come out of solution as I drink through the keg?

Angeloboot said:

Ok, thanks all so far--this is starting to make a little more sense! I'm going to go ahead and use 1/4" all around for gas (I found a bank of 4 secondary regulators for around 60 dollars, all have 1/4" flares--should keep me busy for a while!). I'll follow the advice here and go to 3/16" for beer out, but this just leaves one question kind of unresolved: I'll have secondary regulators to adjust, sooooo, if I hook my keg of wheat and carb to 3.5 volumes, how do I dispense at that low flow rate suggested on the chart? My last keg I did was a porter, and I left it at 14psi for 2 weeks, but when I dispense at 14 psi, I got all foam. If the dispense psi is different than the carbed amount, won't gas come out of solution as I drink through the keg?

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I also have all 1/4" flare fittings on the co² side. The 3/16" line slides on the barbs easily if you just soak the line in a cup of hot water. That allowed me to just buy one line size for everything.

Regarding carbonating and dispensing pressures, I believe that they should be one and the same. Controlling the pour then becomes the issue. Lets take the example of your wheat carbed to 3.5 vols: With a temperature of 40°F 3.5 vols would require a pressure of 23 psi for carbonation and dispensing. Now comes the complex part. With a very highly carbonated beer like this one, it is critical that the pour rate be fairly slow. I'd want it to take at least 10 to 12 seconds to fill a pint glass. To accomplish, this you need to match the line back pressure with the tank pressure that is being applied. At that pour rate we are looking at a back pressure of 9.4 per 10' of line. Now with a pressure of 23 psi & that flow rate, we are looking at about 24 feet of 3/16" line.

I know, I know - that's a lot of line. There is another way around this very long beer line issue. You can create a reasonable back pressure within your keg so that the line length can be more reasonable and easier to manage. Please check out this Thread for some information on how to accomplish this.

This link Carbonation_Table.xls will give you a full carbonation chart.

I hope this all makes sense and helps you.

I read the "cure for short hose" thread a couple of days ago, and thought that was a brilliant idea! I appreciate your help, PJ--looking online involves lots of thread digging, haven't really found a good authoritative source yet. So let's say I cut 20' of line to serve wheats/whatnot on, doesn't that preclude me from using the line for anything else? I can't very well push a 14psi porter through 24' of line if it loses 9.4 psi per 10'. Which leads me to curiosity: how do the people on here who show off 3 keg dispensers but list a rotation of like a dozen beers cope with this? I can't imagine everyone has dispensing lines cut from 5' to 24' with little disconnects on all--would be quite an investment, no?

And we resurrect another one from the depths of time..... Anyone have an answer??

It's kinda up to you. Some people have stout taps and serve with nitrogen. Others just serve stouts from the same tap as any beer. Some have one line pressure for multiple line and others have individual regulators for each line. If you have the space and really want to, who's gonna stop you from having a dedicated wheat line?
Generally, most beers are fairly close in carb level and you can adjust the line pressure to make up the difference, or not.