CO2 drained overnight?

[Buckeye_dad15]

I have 4 kegs in my converted fridge. I have a 5lb tank running them. Put the 4th keg on last week and set the pressure to carbonate. Tapped it on Friday and had a few pints, regulator was still reading just shy of full. Saturday evening a few friends stopped by and had some beer. By Sunday evening when I checked the bottle was down to almost empty and by Monday it was.
I'm not really sure how it disappeared so quick because I would think if there was a leak, then I would have seen the guage slowly going down after I hooked the last keg up to it. Plus I had checked for leaks. But it seemed like it didn't empty until after the new keg started getting used. When I filled the keg the week before, there wasn't a lot of headspace in it. I was wondering if after, say, a couple gallons was dispensed that's where the CO2 went to fill the space?
I always check for leaks everytime I put a new bottle on and will again tonight when I put this one on, but didn't know if anyone might have ever had the same thing happen.

 

[theseeker4]

I have 4 kegs in my converted fridge. I have a 5lb tank running them. Put the 4th keg on last week and set the pressure to carbonate. Tapped it on Friday and had a few pints, regulator was still reading just shy of full. Saturday evening a few friends stopped by and had some beer. By Sunday evening when I checked the bottle was down to almost empty and by Monday it was.
I'm not really sure how it disappeared so quick because I would think if there was a leak, then I would have seen the guage slowly going down after I hooked the last keg up to it. Plus I had checked for leaks. But it seemed like it didn't empty until after the new keg started getting used. When I filled the keg the week before, there wasn't a lot of headspace in it. I was wondering if after, say, a couple gallons was dispensed that's where the CO2 went to fill the space?
I always check for leaks everytime I put a new bottle on and will again tonight when I put this one on, but didn't know if anyone might have ever had the same thing happen.

CO2 in a cylinder is a liquid, with CO2 gas above it. This means that whether you have 4.5 pounds of liquid CO2, or 0.1 pounds of liquid CO2, the pressure on the regulator will read the same, just about full. This is because the gas and liquid are in an equilibrium, determined by the pressure of the gas in the cylinder and the temperature. The temperature of the cylinder is pretty much the only thing that will change the reading of the gauge while liquid remains in the cylinder. Once all the liquid in the cylinder is gone, as gas is drained during normal use and more liquid converts to gas, the pressure reading starts dropping, since the liquid is gone and no more liquid CO2 is vaporizing to keep the pressure steady. This means your cylinder might be completely full, or almost empty, and you won't know until the pressure starts dropping. That happens only when your cylinder is almost completely empty of CO2.

How many kegs have you served from that 5 pound bottle of CO2? You might have just run out normally, without a leak. Good luck!

 

[Yooper]

Here's the weird thing about c02 gauges. They aren't like a fuel tank, where the gauge is actually useful and tells you when you're running low.

They measure pressure. And the pressure of a 5# tank will be around 500 psi at room temperature when it's full. And the pressure of a 5# tank will be around 500 psi when it's nearly empty. And then, once it's nearly empty, the reading will start to drop. It will go to 0 very very quickly.

I always joke that the best way to incorporate that gauge into your keg system is to put duct tape over it.

The only way to know how much co2 you have in your tank is to weigh it. Subtract the tare weight stamped on the outside from the total, and that's how many pounds of co2 you have left. A 5# tank should dispense 5-8 kegs or so, depending on your usage.

 

[stella_tigre]

We got two bottles (a 10 and a 5) just to make sure we don't run out unexpectedly! We're out in the country so refilling a CO2 bottle is not necessarily easy to do. We're new at kegging so still on our first 10 lb bottle but the fiver is standing by!

 

[Chanoc]

Pressure will remain fairly constant as long as there is liquid inside the tank.
Once all iquid vaporized into gas, remaining CO2 is very little.
I'm order to know how much CO2 remains, you need to weigh the cylinder and compare to here weight

 

[Revvy]

I've "never seen the gauge going down" when I've had leaks, it just happens, with no grand announcement. You wake up, go to pull a beer and nothing. It happens to all of us.

Don't over analyze it, you have a leak, find it and fix it. At least once a year I have a leak, things come loose, poppet o-rings break, you don't happen to seat the lid right on the keg, or you mix them up when cleaning, and the one that happens to fit perfectly on just that keg is on the wrong one, a hose clamp worked itself loose, whatever. Kegging can be just as much a pain in the ass as bottling sometimes.

Fill a spray bottle with dishsoap and water, get a new bottle of gas, turn it up to 30-40psi, and spray everything, and look for bubbles. In fact I keep a tiny spray bottle of soap/starsan and water in the keezer and always spray the hookups of whatever keg I fill or swap in, just to make sure.

 

[Chanoc]

.duh..!
Too slow....

 

[Revvy]

.duh..!
Too slow....

This was an "unanswered thread" when I started writing my answer, I hit post and there were 6 responses. LOL

 

[Buckeye_dad15]

Thanks everyone for the answers. Thinking about it, I have been through a few kegs with it, so, by Yooper and theseeker4's explanation, it might have just ran out, unless, like Revvy said, somehow I developed a leak Saturday after leak testing everything a week ago when I put the last keg on. Either way I'll retest everything this evening when I refill and go from there, it was just something I haven't had happen yet so it caught me by surprise lol Thanks again!

 

[FVillatoro]

Using starsan in a spray bottle and wetting the connections with it and spotting for bubbles is a great way to see if you have a leak (I spray all the hoses and fittings as well as the top of the kegs if I suspect a leak).
Dish soap and water work even better, but you have to clean it off well.

I once developed a leak on one of my check valves and it drained a 20# tank in about a day
From spraying around I noticed that a valve leaked when I closed it and stopped leaking with I opened it - a keg kicked and I pulled it out and tada...

 

[jpakstis]

I had this happen to me, where it would just be gone within a couple of days. When I took the tank to get refilled and to get looked at for leaks (I even took the regulator), the guy there said that the vast majority of the time, its because people don't put a rubber gasket in the regulator hook-up to the tank. He gave me a couple of them and I haven't had to refill it since (its been seven months). I've since learned to put a gasket or washer anytime metal connects with metal. It only took me like 3 refills to figure it out!