Beer gas usage per keg

[FloppyKnockers]

Just a quick question for those using beer gas - I recently got a new nitro set-up and a new tank of beer gas to boot. I took my inaugural voyage with my peanut butter porter. It was waaaay more gooderer than it ever was on CO2. I carbed it up to a modest level with CO2 first, then put it on beer gas at ~30 psi to serve. It poured great and got all the cascadiness I was promised. When I first hooked it up I recall the pressure being 2100 -2200 ish psi. When its life came to its natural end (RIP oh great porter) I took note of the regulator stating 1700 psi. My question is: does a normal 5 gallon keg take 500 psi to push through its couple week life or may I have a slow leak somewhere?

Edit: it's a 5lb (22cf) tank

 

[Vale71]

We need to know the actual volume of the tank. It cannot be 22cf as that translates to 164 U.S. gallons and that's impossible.
With beer gas there is no liquid in the tank so the "5lb" is meaningless as well.

 

[day_trippr]

I'm guessing it's a "five pound" cylinder filled with beer gas, which I think I've read equates to 22cf at STP.

I wish I had a pat answer wrt the life span of a fill but all I can provide is anecdotes. To wit, I have a 10 pound beer gas cylinder (which is something like 40cf at STP) always have my stout on tap (probably a decade running now) and I actually can't remember the last time I had it filled. Had to be at least two years ago. In fact I'm betting it'll need a hydro cert next time I get it filled...

Cheers!

 

[NTexBrewer]

Maybe contact the company or Homebrew store that you bought the BeerGas regulator from. They may have experience of typical usage.

Or maybe a national company like Kegerators, Wine Refrigerators, Water Coolers, Beer Taps, Compact Refrigerators | BeverageFactory.com

I‘ve never used BeerGas so just thinking out loud. Typically I run my CO2 system at 12psi so at 30psi I’m guessing you will use more gas. Also, if you have a leak in your system you will lose gas faster at 30psi compared to 12psi. Would make sense to check your system for leaks along with the serving keg.

 

[doug293cz]

Just a quick question for those using beer gas - I recently got a new nitro set-up and a new tank of beer gas to boot. I took my inaugural voyage with my peanut butter porter. It was waaaay more gooderer than it ever was on CO2. I carbed it up to a modest level with CO2 first, then put it on beer gas at ~30 psi to serve. It poured great and got all the cascadiness I was promised. When I first hooked it up I recall the pressure being 2100 -2200 ish psi. When its life came to its natural end (RIP oh great porter) I took note of the regulator stating 1700 psi. My question is: does a normal 5 gallon keg take 500 psi to push through its couple week life or may I have a slow leak somewhere?

Edit: it's a 5lb (22cf) tank

30 psi gauge is equal to 3 atm absolute, and a 5 gal keg has a total volume of about 20 L, so to push a full 5 gal you need the equivalent of 60 L of gas at 1 atm. From what I have been able to find, a 20 CF gas cylinder has an internal volume of 3.5 L. 500 psi is equal to 500/14.7 = 34 atm. 3.5L * 34 atm = 119 L. Thus it looks like you used about 2X too much gas to push your porter.

Could be a slow leak, or could be erroneous pressure readings.

Brew on

 

[BrewerBrad82]

Keep in mind that Nitrogen does not liquify as CO2 does at typical cylinder pressures. CO2 is measured in lbs because it does liquify, while gasses like Nitrogen and Argon do not, so they are measured volumetrically. 22cf is the amount of space the gas would occupy at atmospheric pressure, not in the cylinder. Also, did you take the first psi measurement while the cylinder was at room temp, and the psi measurement after the keg was gone with a cold tank? That would explain Doug's estimation that you used more than calculated.

 

[doug293cz]

Keep in mind that Nitrogen does not liquify as CO2 does at typical cylinder pressures. CO2 is measured in lbs because it does liquify, while gasses like Nitrogen and Argon do not, so they are measured volumetrically. 22cf is the amount of space the gas would occupy at atmospheric pressure, not in the cylinder. Also, did you take the first psi measurement while the cylinder was at room temp, and the psi measurement after the keg was gone with a cold tank? That would explain Doug's estimation that you used more than calculated.

Yeah, a temp drop could explain 100 - 150 psi of the tank pressure drop.

Brew on

 

[FloppyKnockers]

Ya, know. I didn't even think about the temp variable because I didn't put it in the fridge. However, I did bring it home in the middle of one of our hottest days this year into an air conditioned house (the tank was warm to the touch). So not from room temp to cold, but from hot to room temp. Next time I serve up a nitro I will do a leak test and take note of the before and after pressures. Thanks guys.

 

[bracconiere]

I didn't even think about the temp variable because I didn't put it in the fridge.

LOL, why i keep my co2 tank on a scale...it was cold last night, and my HP gauge dropped.....but my scale tells no lies and it says it weighs the same...so i know it's not a leak....

 

[bracconiere]

to do a favor bestown upon me in my how many ounces of co2 thread, here's the calculator i was answered with...it says 5 gallons of nitrogen weighs 23 grams or so...


https://www.aqua-calc.com/calculate/volume-to-weight

you'ld have to do the math for the beer gas and what not....