PSI in 20lb Bottle

I just exchanged a 10lb(might have been 8lb) CO2 bottle for a 20lb. I cant remember what the regulator said when I hooked it up but I want to think it was around 800PSI. I have only pushed maybe 30 pints from a fresh keg and the PSI gauge is reading at about 690 PSI right now. The serving PSI is set to 10PSI. The tank is sitting at about 70 degrees, does that PSI sound correct for a full 20lb tank at that temperature? I checked for leaks and didn't find any.

Thanks,

David

Amount of CO2 in the tank needs to be weighed, tank pressure will vary with temperature, not amount of Co2 in the tank. Tank pressure will be constant as long as there is liquid co2 in the tank at a constant temperature. With temp constant, as soon as the tank pressure begins dropping you will be empty very soon as there is only gas left in the tank.

Tank is likely stamped net wt., amount over that is CO2.

No, if the tank is really at 70 degrees that is below where it should be for a full tank. It should be at about 850 psi at that temperature. Are you sure the bottle's not cold? They're generally very cold right after refilling due to the purging process. I agree that you want to weigh it. It's always possible they gave you an empty tank by mistake.

zachattack said:

No, if the tank is really at 70 degrees that is below where it should be for a full tank. It should be at about 850 psi at that temperature. Are you sure the bottle's not cold? They're generally very cold right after refilling due to the purging process. I agree that you want to weigh it. It's always possible they gave you an empty tank by mistake.

Click to expand...

Its definitely not cold. I guess I'll weigh it.

There should be a tare weight stamped on the bottle. Your mass should equal that weight+weight of CO2