Tank running low ... high pressure?

[Jtvann]

So I've got a large CO2 tank that is running low. I've got it hooked into 2 kegs at room temp, set to 20 psi. For the last few days I've gone down and found that the pressure has risen to 30 psi on the regulator.

I know the regulator is good. It's never crept on me and carbonation levels always taste right. Now that the tank is on the verge of running dry, the pressure is rising.

Falling, I'd completely understand. Rising... wouldn't have expected that. Any ideas to what's happening?

 

[day_trippr]

Ime, that's normal behavior when the cylinder pressure is in the "red zone" (under ~250psi) and heading down.
I just had a tank kick today that I've been keeping an eyeball on for the last two weeks with daily tweaks to the pressure knobs (dual body).

It does seem strange that a "regulator" fails to regulate, and tbh I'm not sure about the reason for it, but one thing for certain is the control knob "spring pressure" gradually wins over the ever falling cylinder pressure when the latter gets very low...

Cheers!

 

[Pkrd]

Same experience here. Foam often means I'm getting low on CO2.

 

[Jtvann]

Thanks for the replies. I live so far out in the middle of nowhere that I never let a tank get this low before swapping it. Now I have a 3rd tank just for use as a spare, and I let the one in use fully die.