My 20 lb CO2 tank's pressure has dropped to just over 500psi.
How close to needing a refill is this?
How close to needing a refill is this?
CO2 tank pressure close to empty?
- Thread starter Denny's Evil Concoctions
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I've got the same question. My thought is that if you can still adjust your regulator to the desired pressure then the bottle is still good. Mine is down to 500 PSI for the first time so I'm in the same boat.
OP
OP
Yeah, well I know it's ok for carbing a batch but I want to push 5 gallons though a filter into another corny keg. Don't want to run out since it's the weekend. Didn't notice the co2 leval had finally dropped until after praxair had close for the weekend.
easy way to figure out how much co2 you have left is to weigh the tank. the tare weight should be stamped on the tank, and so you can figure out how many volumes of co2 you have just from the weight and see if that is enough for you to transfer with.
What temperature is the tank sitting at? CO2 has a direct pressure/temperature relationship. The tank pressure will stay exactly the same, at a given temperature, until all the liquid has been vaporized. Once only vapor exsists in the tank, the pressure will drop rapidly. Once all the liquid has been vaporized, weighing the tank to determine how much more you can do with the remaining vapor is useless.
Here is a pressure/temp chart for CO2. If your tank is sitting at a room temp of 70˚F and is reading any less than 850 psi then you only have vapor left and the tank will be empty very soon.
Here is a pressure/temp chart for CO2. If your tank is sitting at a room temp of 70˚F and is reading any less than 850 psi then you only have vapor left and the tank will be empty very soon.
Even with the leak I have in my kegger, when I hit the red zone (400 psi) on a five pound tank, there is enough gas for a week. That's with three ales and one soda water. I figure the soda water uses 80% of the gas since it gets refilled every ten days.
OP
OP
OK, HBS told me that when it drops from 800 lbs then you on vapour. I'm at 550 psi at ext temp of 70F. He figured with a 20lb tank that should be enough for a couple of kegs.
As long as it's enough to push 5 gallons into another corny and carbonate and dispense till Monday.
As long as it's enough to push 5 gallons into another corny and carbonate and dispense till Monday.
bikebryan
Well-Known Member
Of course it has mass.gnef said:
However, at that point, the weight is so small that it is basically negligible in weight.
So it sounds to me when the pressure drops into the red there is nothing but vapor and it won't be long before the bottle has little or no pressure. Is this correct?Dennys Fine Consumptibles said:
Are you just being sarcastic, or are you suggesting that I don't know that all matter, including light, have mass? Do you think that the the weight of CO2 vapor would even be measurable, or of useful interest to anyone other than a scientist in a lab?gnef said:
John
RichBrewer said:
It depends. If the tank was sitting at 35˚F the pressure would be very close to 500 psi, which would be where the "red zone" starts. If the tank was at 70˚F and the gauge was in the red zone then, yes, there would only be vapor left in the tank.
Also, even if the tank was at 35˚F, but the pressure was noticeably dropping, that would indicate that there was only vapor in the tank. The pressure will stay the same, at a given temperature, until all the liquid has been vaporized.
John
johnsma22 said:Are you just being sarcastic, or are you suggesting that I don't know that all matter, including light, have mass? Do you think that the the weight of CO2 vapor would even be measurable, or of useful interest to anyone other than a scientist in a lab?
John
wow. you sound smart.
mass is useful and measureable to people outside of a lab. you can't use a bathroom scale, but you can measure it and find out how much co2 is in it to find out how much exactly you have left and given no leaks in your system, can figure out how much longer the tank will be useful before it craps out on you and you need to swap or fill.
Where are the mods? We've got a FIGHT!
PSI as has been said is related to temp. I get my tank filled and it's at about 750 psi I think. Stick it in the fridge and after about 24h it's at just over 500 psi. If that gauge is starting to move down from it's "normal" psi you got a couple days left depending on kegs, dispensing etc.
You'll learn your equipment after 1-2 cycles... and yes, John has it 100% correct. I just repeated in my own words.
You'll learn your equipment after 1-2 cycles... and yes, John has it 100% correct. I just repeated in my own words.
Fatabbot
Well-Known Member
gnef said:wow. you sound smart.
