Typical Fill Pressure

[Dan2539]

So I just got my new 5 lbs. CO2 tank filled for the first time from a local bar supply store yesterday. I let the tank warm up in my basement after filling (which is around 60 degrees). I'm only getting around a 750 PSI reading on my primary gauge. The tank capacity is rated at 1800 PSI. Is this a typical fill for a tank or did I get a pretty weak charge in my tank? I had it done while I waited in the store and the fill took a little less than 10 minutes. I've heard people say they have their tanks left overnight to fill at certain locations where the tanks are actually refrigerated before filling which supposedly increases the fill capacity. Is this the norm?

 

[remilard]

It should be filled to 5lbs above the tare weight.

The pressure reading is a function of the ambient temperature (until there is no liquid left).

 

[malkore]

It should be filled to 5lbs above the tare weight.

The pressure reading is a function of the ambient temperature (until there is no liquid left).

bingo. pressure inside the tank is dependant only on there being some liquid CO2 left in the tank, and the temperature of the tank.

weigh the tank and then subtract the tare weight that should be stamped on the tank.

my CO2 tanks are about 900psi at 75F and drop to 500psi inside my keezer at 43F.

 

[Dan2539]

It should be filled to 5lbs above the tare weight.

The pressure reading is a function of the ambient temperature (until there is no liquid left).

Sorry if I'm not understanding you right... Does this mean that the primary gauge is not a very helpful measuring tool of tank fullness until there is only gas and no liquid left inside the tank?

 

[shelly_belly]

750 PSI sounds about right for 60 degrees. Check out the graph in this link...
http://www.teamonslaught.fsnet.co.uk/co2_info.htm

So I just got my new 5 lbs. CO2 tank filled for the first time from a local bar supply store yesterday. I let the tank warm up in my basement after filling (which is around 60 degrees). I'm only getting around a 750 PSI reading on my primary gauge. The tank capacity is rated at 1800 PSI. Is this a typical fill for a tank or did I get a pretty weak charge in my tank? I had it done while I waited in the store and the fill took a little less than 10 minutes. I've heard people say they have their tanks left overnight to fill at certain locations where the tanks are actually refrigerated before filling which supposedly increases the fill capacity. Is this the norm?

 

[Dan2539]

Cool, lots of info and very helpful. Thanks everyone.

 

[HI_SALENITY]

The one I just exchanged has about 850-900 at 70f

 

[jonp9576]

Sorry if I'm not understanding you right... Does this mean that the primary gauge is not a very helpful measuring tool of tank fullness until there is only gas and no liquid left inside the tank?

that is exactly what were saying. since co2 is a liquid when its in the cylinder, the pressure will change depending on the temperature. if you put in out in the direct sunlight in the middle of the summer you might even see some readings over 2000psi.

generally the pressure will stay at the exact same point till the liquid is gone.

 

[nealperkins]

You should worry about the net weight of CO2 you received. It's fairly common for folks to attempt to fill 5# of CO2 into a warm tank...result, you get short changed. I'd suggest taking your scale in with you when you pick up your tank. Then only pay them for the pounds you receive. I WAS getting short changed by about 25%-30%...