Lost CO2 due to blackout??

[Airborneguy]

I haven't poured a beer since saturday, and when I last checked, my CO2 tank was still about halfway full.

Today, after a 20 hour blackout, I went to pour a beer, which didn't happen, and found the CO2 completely empty!

Could the temperature change due to the blackout have allowed all of the CO2 to escape somehow? I did not touch the fridge at all once the power went out, and that includes opening either tap.

I want to fill my tank again tomorrow, but am afraid it may have been something else besides the temperature change.

 

[DavidHawman]

How did you know the tank was half full? Did you pick it up and weigh it or was the pressure at the half-way point pressure wise?

If you did the former then what was the temperature change? I doubt even a wild temp swing would cause the loss of any Co2.

If you did the later you were looking at nearly an empty tank, not a half full tank. Ignore this if you have heard this before but: a tank will show a constant pressure until all the liquid CO2 is boiled. Therefore you will you have a constant pressure and then the tank will suddenly go from ~900psi down to 0 rather quickly.

 

[Airborneguy]

I didn't weigh the tank, I was going off of the gauge. I never heard that before. You're not talking about the gauge which shows what PSI I have it set at correct? You mean the one which is supposed to read how much is left in the tank. That gauge reads a constant amount then drops quickly?

 

[Arkador]

the high pressure gauge is not a measure of how much liquid CO2 is in the tank. The pressure will be a variable depending on the temperature of the tank, but once equalized to the temp the tank will be stored at should remain relatively constant as long as there is liquid left.

Once the pressure starts dropping, all the liquid is gone, and there is only pressurized gas left, at this point, there isn't enough for more than a handfull of pints to be served before it will be empty.

 

[Airborneguy]

Ok... so tell me if my thinking is off here:

The gauge isn't exact, and it stayed constant because of the temperature. But the tank was already close to empty and that is why when the temperature changed, it immediately dropped.

Am I understanding here?

 

[Yooper]

Ok... so tell me if my thinking is off here:

The gauge isn't exact, and it stayed constant because of the temperature. But the tank was already close to empty and that is why when the temperature changed, it immediately dropped.

Am I understanding here?

Yeah, that's pretty much it. It'll say "500 psi" or something for a month. Then, it'll drop about 1/2 way, and boom! the next day empty. In my opinion, those gauges are useless.

 

[Arkador]

+1 yooper
I keep a 20oz tank handy to throw in when my main tank goes empty. keeps everything going for a couple days while i get my main tank refilled.

 

[Airborneguy]

Gotcha. So do you think that the fridge being out for 20 hours was just a coincidence of timing?

 

[klyph]

My tank pressure gauge used to work, until I knocked the tank over...

 

[mattd2]

The high pressure gauges with the "time to think about refilling" marks are used for compressed gases that do not liquify and therefor the pressure in the tank is an indication of the amount of gas left, unfortunatly CO2 is a gas that liquifies (as other have said already) and therefore yes those refill now gauges are pretty much useless for homebrewers. You could put a bathroom scale under you tank if you have the room.
I think it was just coincidence, but I would check for a slow leak in your system as you still should of had the same amount of gas in the tank.

 

[shortyjacobs]

Gotcha. So do you think that the fridge being out for 20 hours was just a coincidence of timing?

100% yes.

That gauge is useless.

 

[david_42]

Gotcha. So do you think that the fridge being out for 20 hours was just a coincidence of timing?

Yea, just the luck of the draw. At the same time, if you didn't tap a beer for 20 hours and the tank ran out, you might have a leak.

Having two CO2 bottles and two propane tanks are worth the extra cost.

 

[mkory]

I went into this thread thinking that you drank so much that you blacked out, and completely drained your CO2 tank doing so.

 

[wildwest450]

You did unplug your c02 tank during the black out, didn't you?

 

[mattd2]

Yea, just the luck of the draw. At the same time, if you didn't tap a beer for 20 hours and the tank ran out, you might have a leak.

Having two CO2 bottles and two propane tanks are worth the extra cost.

I like the idea of using the 20 oz "paintball" cylinders as a back up, I think I have even seen them from keg connection with the pinvalve removed and a regualr co2 threaded valve installed.

 

[rawlus]

the high pressure gauge is not like a gas gauge in the car that shows the amount of gas/liquid in the tank - the gauge merely shows the pressure of that gas liquid (it's mainly there to warn you of an overpressure situation). it will vary somewhat due to ambient temp, and when no more liquid is in the tank to turn into gas it will drop precipitously.

if you want to know "how much" CO2 liquid is left in the tank, weigh it and subtract the tare weight (which should be listed on the tank), or weigh the tank with gauges and fittings when you know it is empty and write that weight down, then you can weight when you get it filled, and do routine weighings along the way.

 

[Airborneguy]

You did unplug your c02 tank during the black out, didn't you?

No, I couldn't find the plug! Where is it on these damn things?

 

[mattd2]

the high pressure gauge is not like a gas gauge in the car that shows the amount of gas/liquid in the tank - the gauge merely shows the pressure of that gas liquid (it's mainly there to warn you of an overpressure situation). it will vary somewhat due to ambient temp, and when no more liquid is in the tank to turn into gas it will drop precipitously.

I think the problem is mainly from the fact that a lot of the regualtors are supplied with hi pressure guages with markings on them for indication of when to refill the bottle which are good for compressed gases but useless for liquafiable compressed gases (eg CO2). Most people would take it for granted that they have a guage is telling them when to refill their bottle, untill they ask the question "why is my guage broken?" and get told that the gauge is useless for CO2. IIRC aren't the "refill" pressure on these gauges around the vapour pressure of liquid CO2, 500PSI (not sure if I recall the pressure right?)? In otherwords even with a full bottle the guage would be telling you to refill it.

 

[Arkador]

I like the idea of using the 20 oz "paintball" cylinders as a back up, I think I have even seen them from keg connection with the pinvalve removed and a regualr co2 threaded valve installed.

I have a valve similar to this on my paintball CO2 tank (Which i also use for paintball)

 

[mattd2]

I have a valve similar to this on my paintball CO2 tank (Which i also use for paintball)

Does that replace the normal pin valve or does it screw into it. At the moment I am using sodastream cylinders as they are the least investment for me to get started (SWMBO has a couple of spares I can pinch) and I have just modified my regulator stem to include a pin to press down on the valve pin.

 

[BigTexun]

Gotcha. So do you think that the fridge being out for 20 hours was just a coincidence of timing?

It was pure coincidence. Rising temps make pressures rise, not decrease.

I would check for leaks though before putting a new bottle on... if you have a small leak that caused your demise, it will continue...