BeerGas to push beer through regular tap

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Straight6TT

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I have a nitro setup and stout tap right now. I was given an extra normal tap and was wondering if I can use a splitter on the gas line to use beer gas to push another keg. My regulator is set to 25psi, and I figured I could run a longer beer line for the second regular tap to combat the high pressure needed for the stout tap. Will this work and is their an easy way to calculate how long of a line I would need for this. I naturally carb.
 
Or I could use smaller than 3/16" tubing to shorten the line length some. That would give me more resistance to push the beer and not have such a long line.
 
Using this calculator it says that my ideal line length at 25 psi would be only 12 feet. I dont feel this is correct. First off considering the formulas ask you to plug in the pressure in the keg (assuming that keg pressure inside and your regulator are set to the same thing) When one is using beergas the pressure in the keg and the number set on the regulator are different.

Would I add the two different pressures together to get my desired line length in the equation? For example:
P = L*R+H/2

Normal co2 to carb the equation would look like:
12psi = L*2+2/2
L = 5.75 feet of tubing

So for me do I need to add 12 psi in the keg from natural carbing plus the pressure on my regulator (25 psi) to give me a total pressure of 37psi? If thats the case the equation would be

37psi = L*2+2/2

L = 18 feet of tubing (closer to what I expected but I still thought it would be 25 feet of tubing or so)
 
I think you'd need a lot more than 12 feet, but more importantly the other keg will lose carbonation as you go through it since you aren't maintaining the proper head pressure of CO2. CO2 will break out of solution in the lines, and even if you manage to balance the pressure (I'd guess you'd need at least 20-25 feet of 3/16" ID) you'll have foamy pours and very undercarbed beer after a little while. If it's a stout and you want very little carbonation, you might be OK. But I'd really just invest in a CO2 setup.
 
Why am I not maintaining the proper head pressure with my example? Most people split their lines to push beer with co2, and run 3 or 4 kegs or more from one tank. Why is my example different?
 
Why am I not maintaining the proper head pressure with my example? Most people split their lines to push beer with co2, and run 3 or 4 kegs or more from one tank. Why is my example different?

Because you're pushing with beergas, which is not pure CO2. So the pressure of CO2 over the keg will be too low to maintain anything above a minimal carb level.
 
I am new to this so bear with me, but restaurants push all of their beer with beer gas, so why do theres not lose carbonation? Is it because they drink them faster?

My kegs are naturally carbonated to the proper volume, but being served with beergas, you are saying they will lose pressure i.e. go flat over time?
 
My kegs are naturally carbonated to the proper volume, but being served with beergas, you are saying they will lose pressure i.e. go flat over time?

That is what I'm saying. If you want 2.5 volumes of CO2 in your beer, and you serve at 40 degrees, you need to maintain ~12.3 psi of CO2 over your beer. If you have 75/25 beergas and you're applying 25 PSI, that means you have 6.25 psi of CO2 over your beer. That's only 1.9-2 volumes of CO2, which is undercarbed for many styles. If you're serving an English style ale or a stout, that might be fine, but for an American style ale, a Belgian, Hefe, IPA, etc. it's pretty low. If you crank down the temperature in your kegerator you can sneak some more carbonation into it with the beergas, but then your stout (or whatever you're pushing through the restrictor faucet) is going to be overcarbed and you'll probably get too much foaming when you pour. And like I said, the pours will be foamy until the carb level drops, which might take a little while.

I'm not totally sure how a restaurant/bar does it, but my guess is they blend the beergas themselves. So they have a tank of nitrogen and a tank of CO2, and they'll keep enough CO2 pressure on the keg to maintain the carb level, then apply nitrogen pressure as needed to push it up to the faucets.
 
Very strange, I work in a bar and we push all of our beers with beer gas pre blended and they don,t go flat. However we go through beer much faster than I would.
 
I'm not sure then. What kind of beers does your bar serve? What blend of beergas? If they're mostly serving generic BMC, the carb level is close to the same across the board and they might just run it all the same. They might have it set up to serve at 2.7 volumes of CO2 at 33 degrees, or something like that. If they serve any craft beer, I'm surprised they can't control the CO2 pressure.
 
Think of the partial pressure of CO2 as what controls the carbonation level and partial pressure of Nitro only used to boost the total serving pressure. It's possible, but I'm not sure how customary it is, to order specific beergas blends based on the serving pressure required for a given tap system.
 
When one is using beergas the pressure in the keg and the number set on the regulator are different.

This doesn't sound right to me. Why would this be the case? Do you mean the partial pressure of CO2 in the keg is different than the total pressure set at the regulator?


Straight6TT said:
So for me do I need to add 12 psi in the keg from natural carbing plus the pressure on my regulator (25 psi) to give me a total pressure of 37psi?

No, don't do this. The total pressure in regards to balancing line length will 25psi.
 
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