As a general rule of thumb, it takes about a 1/2 lb of CO2 to dispense a 1/4 barrel of draft beer and 1 lb of CO2 to dispense a 1/2 barrel of draft beer. This table lists the approximate number of kegs that can be dispensed from each size of CO2 cylinder.
| |
2-1/2 lb Cylinder |
5 lb Cylinder |
10 lb Cylinder |
15 lb Cylinder |
20 lb Cylinder |
| Home Brew (5.00 Gallon) |
7-11 |
15-22 |
31-44 |
46-66 |
62-87 |
| Sixth Barrel (5.23 Gallon) |
7-11 |
14-21 |
29-42 |
44-63 |
59-83 |
| Quarter Barrel (7.75 Gallon) |
5-7 |
10-14 |
20-28 |
30-42 |
40-56 |
| Half Barrel (15.50 Gallon) |
2-4 |
5-7 |
10-14 |
15-21 |
20-28 |
A gas tank that is properly filled should read about 750 PSIG when the cylinder is at a 72° F temperature. CO2 gas pressure increases when it is exposed to heat, so if the gas tank temperature is above 72° F, the pressure will read higher than 750 PSIG. If the gas tank temperature is colder then 72° F, the pressure will read lower then 750 PSIG.
The tank pressure should read 750 PSIG until the liquid CO2 in the cylinder is gone, and the tank is almost empty. A decreasing pressure indicates the cylinder is nearly empty.