Is my co2 tank empty?

Hello... I was just wondering how long after a co2 tank comes outta a cold fridge(about 45 degrees) does it take the pressure to come back up to the true volume/pressure? Mine is well into the red(ORDER GAS) and is still there 24hrs later??? Not sure if I have a leak or not and its a 20lb'er. Oddly it was reading 700psi just the other day now its in the red!!

thanks.

Jamie.

That certainly does sound like a leak. Don't you have something you can throw on there with a gauge? Or even better, when you open it up, does gas coming shooting out?? Haha

If you're wondering how much (if any) gas remains in the tank, you could always remove the regulator, weigh the cylinder, and compare that weight against the Tare weight stamped on the cylinder.

Of course, if the gauge went "in the red" before you pulled the tank out of the cold, you probably already know the tank is empty...

Cheers!

ryansanders said:

That certainly does sound like a leak. Don't you have something you can throw on there with a gauge? Or even better, when you open it up, does gas coming shooting out?? Haha


www.betterbeerkits.com

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A pressure gauge only tells you when you have run out of liquid CO2. With ANY liquid in the tank, the pressure is a function of temperature, and nothing else. This is a physical property that applies to all gas/liquid equilibrium situations. It's why pressure seems pretty constant for a long time, and then all of a sudden it starts dropping very quickly.

Once the pressure drops below the equilibrium value (at the temperature of the tank) you are out of liquid, and you will be out of gas very quickly.

As stated above, the only way to know how much CO2 is in the tank is to weigh it.

Brew on

I'm thinking my pressure relief valve was leaking but I'm not sure. The pressure relief seemed to be loose and I screwed it in as its threaded and I'm unsure if it's fixed or not.

if I refill my tank will shutting off the main tank valve prevent leaking while I'm trying to figure out if there is a leak or not....assuming the leak in in the regulator?

Forgive the lame questions I'm new to kegging and never used gas before.

Thanks.

newfiebrew said:

I'm thinking my pressure relief valve was leaking but I'm not sure. The pressure relief seemed to be loose and I screwed it in as its threaded and I'm unsure if it's fixed or not.

if I refill my tank will shutting off the main tank valve prevent leaking while I'm trying to figure out if there is a leak or not....assuming the leak in in the regulator?

Forgive the lame questions I'm new to kegging and never used gas before.

Thanks.

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Yes. Shutting off the main tank valve will prevent CO2 loss from the tank due to a leak elsewhere in the gas plumbing.

Spraying soapy water or Star San on the various plumbing parts and looking for bubbles blowing or foam growing is a way to find gas leaks. Need to open the main tank valve when looking for leaks.

Brew on

Being in the "order gas" area is not a problem. Even after filling my 5# tank, that is where it is, as that is the pressure and not like a fuel gauge. It's not like your car's gas tank that shows full, 1/2 full, and empty. The high psi regulator shows the pressure in the tank. Co2 is a liquid, dispensed as a gas, so my tank says "order gas" at about 500 psi for weeks and weeks- and then in one day, goes to "empty" when the gas is gone.

I say that the best use of the "high pressure gauge" is to remove it, or cover it with duct tape and everyone would be happier! It's only useful to confirm that you are out of gas. That's about it.

You should also check the keg post o-rings, I can't figure out how to check that for a leak.
I just had a leak, thankfully with my smaller tank, after getting the tank filled I again checked everything with starsan... No joy. I added some keg lube to the o-rings on the posts and looked at them pretty good, with the white keg lube on the black o-ring I could see a crack that I couldn't feel.
I changed out those two o-rings and it's been on co2 for about a week now. My 20lbs tank is getting close to the red but has been holding there for the past few weeks, a touch closer tonight with the temp drop, keezer out in the garage.
Good luck, leaks suck, but we have all been there.

Yooper said:

I say that the best use of the "high pressure gauge" is to remove it, or cover it with duct tape and everyone would be happier! It's only useful to confirm that you are out of gas. That's about it.

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You can also use it to determine the temperature of the CO2 cylinder. All you need is a chart that shows the liquid/vapor equilibrium temperature as a function of pressure. Only works if you actually have liquid in the tank tho.

Brew on

Thanks guys I'll weigh the tank tomorrow (gotta buy a scale). After that I'll check for leaks again.got to hurry tho because I have a ipa dry hopping now and weds it will be a week so I need to keg it soon!

sooo I was reading through this post and remembered that my gauge was going down pretty quick since a week or so. It was really unusual. I did the star san spray and found a leak on a tee connector. Grrrrr. Tank is almost empty now ! First leak in 8 years though... a bad hose clamp tore through the thin hose when I tightened it. Lesson learned : always check for leaks when replacing tank/after modifying system.


Cheers !

doug293cz said:

Yes. Shutting off the main tank valve will prevent CO2 loss from the tank due to a leak elsewhere in the gas plumbing.

Spraying soapy water or Star San on the various plumbing parts and looking for bubbles blowing or foam growing is a way to find gas leaks. Need to open the main tank valve when looking for leaks.

Brew on

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So I don't need to hook up my freshly refilled tank to find any leaks in the regulator etc????

doug293cz said:

Yes. Shutting off the main tank valve will prevent CO2 loss from the tank due to a leak elsewhere in the gas plumbing.

Spraying soapy water or Star San on the various plumbing parts and looking for bubbles blowing or foam growing is a way to find gas leaks. Need to open the main tank valve when looking for leaks.

Brew on

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So I don't need to hook up my freshly refilled tank to find any leaks in the regulator etc????

Would I still see bubbles without the gas on? I guess there is some O2/co2 in there?

So someone mentioned I don't need to hook up the gas to find any leaks is this so?

newfiebrew said:

So someone mentioned I don't need to hook up the gas to find any leaks is this so?

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You need to pressurize the system to find leaks.

Besides looking for leaks, instead of buying a scale, just go out and buy another 5 lb tank. I always have a full tank as backup just in case. Worst case scenario is if you have party going and you run out of gas....no beer to pour.....party ends at 9pm

newfiebrew said:

So someone mentioned I don't need to hook up the gas to find any leaks is this so?

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No, you have to have the gas hooked up and on to find the leaks. Turning the tank valve off just prevents more loss when you aren't actively looking for leaks.

Sorry, I didn't mean to imply that you could find leaks with the gas off.

Brew on

Just weighed the tank at work and it was 26 lbs exactly and the weight on the tank is TW 24.2 so I only got 1.8 lbs in the tank...gotta get a refill this week if I can.

Thanks guys.

Hopefully I'll find that damn leak!

So guys I possibly may have found my problem but it's just a quess at this point. I noticed before that when I turned up the psi to say 25psi or more I'd hear a gushing air sound coming from the relief valve on my regulator and once reduced it to say 10 psi it went away. Upon closer inspection I noticed that the relief valve itself screws into the regulator and it was loose and not totally screwed in (it was threaded). I have since tightened this valve and hope this was the issue!

Anyone else ever have such an issue with a relief valve on there regulator???

Thanks

Jamie

The last time I forced carbed my beer at 30psi, the relief valve popped open. This doesn't happen with serving pressure. Upon doing research, I found out that alot of cheaper regulators come with relief valves that max out ~25psi. I just bought a $4, high pressure one from HD and the problem was fixed.

newfiebrew said:

So I don't need to hook up my freshly refilled tank to find any leaks in the regulator etc????[...]

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You missed where he said you "Need to open the main tank valve when looking for leaks."...

Cheers!