How many kegs per CO2 fill?

[RichBenn]

OK, I know this question was probably asked before, but after 15 minutes of trying to find the right search string.....

Let's assume carbing via CO2, how many kegs for a 5 lb tank before a refill is needed?

Rich

 

[mosquitocontrol]

5-8 is the going rate.

 

[Arkador]

I get about 1keg per # of CO2 including force carbonating. I loose some in cleaning and such, since i use it to flush lines and stuff.

 

[JonW]

Are we talking 1/2 bbl kegs or home 5 gal corny kegs??

 

[mattjmac]

I'm pushing my 8th corny keg of beer right now. I know it's gotta' be getting low, but the damn thing just keeps on going. I force-carbed all 8 kegs. And I use the tank to push cleaner/sanitizer when I do the lines. I'm pretty amazed how long it's lasted, actually.

Edit - I have a 10 lb. tank so I guess according to the above posters it's not that amazing, after all.

 

[RichBenn]

Are we talking 1/2 bbl kegs or home 5 gal corny kegs??

corny kegs

 

[shataway]

I get about 1keg per # of CO2 including force carbonating. I loose some in cleaning and such, since i use it to flush lines and stuff.

I am new to kegging with a 5lbs tank. My last fill was to 750 psi at 75 deg at the keg store. By weight it was only 1-2 pounds the best I could tell by my scale. I assume that most of my fill was gas and not 5 lbs of liquid CO2.

Now that I have force carbed one corny keg, I see the needle moving into the red zone which means that I am out of liquid CO2.

Based on this, I have to agree with the above statement. Now I need to find a bigger tank and someone who can do a good liquid fill...

 

[shortyjacobs]

6-8 for me

 

[Arkador]

I am new to kegging with a 5lbs tank. My last fill was to 750 psi at 75 deg at the keg store. By weight it was only 1-2 pounds the best I could tell by my scale. I assume that most of my fill was gas and not 5 lbs of liquid CO2.

Some places just top off the tanks. to measure a proper fill you need to know the empty weight of the tank, then weigh it again when filled, it should weigh 5# more full. If they aren't using a scale to tell how full it is, go somewhere else for your refills.

Ignore the pressure, espically when it is in the keezer. CO2 pressure is temperature variable. at 100deg it is something like 950PSI, and at 36, mine is just above the red line.

 

[shortyjacobs]

I am new to kegging with a 5lbs tank. My last fill was to 750 psi at 75 deg at the keg store. By weight it was only 1-2 pounds the best I could tell by my scale. I assume that most of my fill was gas and not 5 lbs of liquid CO2.

Now that I have force carbed one corny keg, I see the needle moving into the red zone which means that I am out of liquid CO2.

Based on this, I have to agree with the above statement. Now I need to find a bigger tank and someone who can do a good liquid fill...

Liquid and gas both have mass, (and weight). If your weight of the tank was only 1-2 lbs over the tare weight, (tare weight is stamped on the cylinder), then you got swindled.

Ignore the high pressure gauge, mine is in the red as soon as I buy it and still lasts 6-8 kegs.

 

[nicnic]

Mine is ready for its first refill after going through 9 kegs.

 

[pjcampbell]

Does the pressure affect how much co2 you use to force carb it or do you just need more pressure (same volume?) to get it into warmer fluid?

 

[Walking_Target]

At STP ~44 grams (one mole) of CO2 will occupy about ~22.2 liters of volume. a proper 5lb co2 fill has about 50 moles of CO2 gas.

This works out to about 1100l of CO2 at STP.

Working at STP, a 2 volume batch of beer will use approximately 46l of CO2. That yields a theoretical value of 46 kegs per fill for force carbing.

Practically, if you're getting a full fill, carbing at refrigerator temps and only using the bottle for force carbing, you could potentially force carb up to 15 kegs, accounting for losses from disconnecting, purging and molecular porosity of tubing and etc. I bet you could probably really stretch these numbers by building a ridiculous manifolded setup with very short line lengths to the keg using high quality tubing with low porosity using the passive 'set it and forget it' keging method.

If you're serving from the same keg, you have to use pressure to force liquid, which immediately cuts that number in half, so 7-8 kegs per fill.

Yes, some of my math is fuzzy, because it's very difficult to accurately measure CO2 used in an open system. This is the same problem I had with calculating total shot numbers for my paintball markers, I could use rough stoichiometry to measure the volume of CO2 ejected per shot, but those volumes changed based upon fractions of a degree of ambient temperature.

 

[RichBenn]

Does the pressure affect how much co2 you use to force carb it or do you just need more pressure (same volume?) to get it into warmer fluid?

Yes, just use the carb charts.

 

[TrubDog]

+1 for 6 to 8 kegs with a 5lb tank.