CO2 Regulator Help

[Crosley623]

I just recently made the switch to kegging after purchasing a nice 3 keg setup. I checked all of the check valves at the manifold and replaced one of them, so it looks like everything past the regulator is sealed. Onto the regulator.... The low pressure gauge is working well, but I cannot seem to get the high pressure gauge working. I contacted the company and they sent me a new gauge, I installed it and am having the same problem. This gauge is supposed to show how much gas is left in the tank, with the valve open or closed. When my valve is closed the gauge shows completely empty (just below the red area) and when I open the valve the gauge shows it's about time to refill (just above the red area)
Does anyone have any thoughts on this, I'd like to be able to know how much gas I have left in the tank but I have no clue where to begin troubleshooting.

Thanks

 

[bucfanmike]

high pressure gauges are horribly inaccurate and for the most part useless. It cant work at all with the valve closed, as it is reading pressure from the tank, which wont be there with the valve closed.

 

[nasty_rabbit]

You don't mention if you filled the CO2 tank before attaching the regulator. If you are unsure of the amount in the tank, it may be accurate.

 

[nasty_rabbit]

Are there numbers on the gauge or just color codes? If there are numbers, a full 5 pound tank would register around 900 psi.

 

[user 4295]

I suspect that you have the CO2 tank in the fridge, right? Actually, the high pressure gauge will still read accurately at fridge temps. It will just read lower due to the pressure/temperature relationship of CO2 in a liquid/vapor state, but it still doesn't tell you anything about how much liquid CO2 is left in the tank.

CO2 in a liquid/vapor state has a direct pressure/temperature relationship, as can be seen in the chart below. The pressure will stay the same, at a given temperature, until all the liquid has been vaporized. Once only vapor exists, the pressure in the tank will drop rapidly. The only way to know for sure how much liquid CO2 is left in the tank is to weigh the tank, and subtract the tare weight that's stamped on the side of the tank.

Also, fwiw, When you keep the CO2 tank in the fridge the elastomer that is used for the regulator's diaphragm will be slower to respond to changes in output pressure when it's cold.

For example. If you have the regulator in the fridge and set to 10 psi and then you change the output pressure to 12psi, you may find that when you come back in a couple of hours that the new output pressure may be 15 psi. This "creeping" effect is due to the cold temps effecting the diaphragm. I've learned to compensate for the "creeping" effect by setting the new output pressure just slightly lower than my intended pressure. It will then creep up to my new setting after some time. Usually not very long.

 

[Crosley623]

Thanks for the responses guys. This regulator has shown the exact same pressure since I got it, from completely full tank to bone dry tank. Yes it is in the fridge so I know the reading will be off, but as it stands it is completely worthless as I have no clue how much CO2 is in the tank

 

[user 4295]

Thanks for the responses guys. This regulator has shown the exact same pressure since I got it, from completely full tank to bone dry tank. Yes it is in the fridge so I know the reading will be off, but as it stands it is completely worthless as I have no clue how much CO2 is in the tank

The high side gauge will never tell you how much liquid CO2 is left in the tank. It will read EXACTLY the same pressure, at a given temperature, until all of the liquid CO2 has been vaporized. Once the liquid is gone, the high side gauge will start to drop.

The ONLY way to know exactly how much liquid CO2 remains in the tank is to weigh the tank and subtract the tare weight stamped on the side of the tank from that number.

 

[seanybubbles]

I just pretend the second gauge isn't there.

 

[JuanMoore]

...... but as it stands it is completely worthless as I have no clue how much CO2 is in the tank

Now you're starting to get it.

Sorry that you expected the high pressure gauge to do something that it doesn't do. As mentioned, you'll need to weigh the tank if you want some idea of how much gas you have left.