can't find CO2 leak

hi all,

a few weeks ago i had to get a new tank of co2. so i got another, hooked it all up and turned on the gas. the next morning i get up and its completely empty.
sooo...i get another tank, i've hooked it up just to the regulator..no kegs yet. i have turned on the gas and sprayed it down with soapy water and i see no leaks anywhere. is there somewhere else i should check on the regulator? i have in the past had an issue with one of kegs leaking, but i have since checked it before often and didnt see any leakage with the soap test. where else should i look? if i wake up again tomorrow with an empty tank i may lose it! specially because the place i get my tanks is only open from 8-5 so i can only get over there once a week because of work. so i have to wait a week everytime i screw up! some advice?

TIA,

M

Make sure you are sealing the keg lid with 20-30 psi. Also make sure you use keg lube on any orings. You can test the grew disconnects by placin them in a glass of water and looking for bubbles . Check you keg release valve too with starsan or soap.

What are you using as a basis that your keg is empty? Are you weighing it or looking at your pressure gauge? Is the tank inside or outside the kegerator.
If the tank is inside your kegerator and you are seeing it empty cause pressure gauge is at 0, it is NOT empty. You can't go by the p[pressure gauge. Weigh it on a scale.
If it weighs out empty, or you can open the valve on the tank with no reg or anything attached and nothing comes out, then get that starsan back out and spray spray spray. You will find it somewhere. Spray around the bottle's neck, all over the bottle's valve. Try leaving it with no reg connected to see if it still empties itself if it is. Leak could as easily be on the tank/valve, as anywhere else in the system.

JesseRC said:

Make sure you are sealing the keg lid with 20-30 psi. Also make sure you use keg lube on any orings. You can test the grew disconnects by placin them in a glass of water and looking for bubbles . Check you keg release valve too with starsan or soap.

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thanks for your reply. when you say sealing the lid, do you just mean the pressure that i am keeping on when not in use? i assume you meant the brew disconnects. i'm not sure i follow the placing them in the water thing.

as for the tank, i do keep it inside the kegerator. i was certain it was empty. when opened with no reg nothing came out.i will continue to search!

rhltechie said:

thanks for your reply. when you say sealing the lid, do you just mean the pressure that i am keeping on when not in use? i assume you meant the brew disconnects. i'm not sure i follow the placing them in the water thing.

as for the tank, i do keep it inside the kegerator. i was certain it was empty. when opened with no reg nothing came out.i will continue to search!

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After transferring beer to keg, and attaching the lid. You want to hit it with 20-30 psi , and then pull the pressure relief valve a few times to get rid of the left over o2 in there. THe high pressure also helps seal the lid and poppets. If you do have a leak on the keg, you'll notice it at this time.

The grey quick disconnect attaches to the keg post. If you have the reg set to something, just take the disconnect and stick it in a glas of water to see if it is leaking from the disconnect. Sometimes they need a little tightening.

Though not necessary, I always use Teflon tape on the threads.

homebrewer_99 said:

Though not necessary, I always use Teflon tape on the threads.

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Not necessary on flare fittings, but very necessary on NPT fittings.

I've never put teflon my kegs. Don't want it in my beer. Keg lube is all that is needed.

Installing an NPT fitting without some kind of sealant is a bad idea, IMO. They make specific tape to use for gas lines, otherwise pipe dope is a good way to go. I'm not necessarily saying it's needed on the post, as I don't know what kind of seal we're talking about there, but there are usually NTP fittings in the gas line somewhere.

From http://en.wikipedia.org/wiki/National_pipe_thread

"The taper on NPT threads allows them to form a seal when torqued as the flanks of the threads compress against each other, as opposed to parallel/straight thread fittings or compression fittings in which the threads merely hold the pieces together and do not provide the seal. However a clearance remains between the crests and roots of the threads, resulting in a leakage around this spiral. This means that NPT fittings must be made leak free with the aid of thread seal tape or a thread sealant compound. (The use of tape or sealant will also help to limit corrosion on the threads, which otherwise can make future disassembly nearly impossible.)"

If you're losing a full tank in a few hours the leak should be easy to find with a soap test. You just haven't checked the right place yet. Heck, you could probably hear a hissing with a leak that size.

Dp..................

There could be a leak on the hoses/fittings of the regulator. Check those connections and the connection of the regulator to the tank. Is there an O-ring in between the regulator and tank? Good luck.

JKoravos wrote:
Heck, you could probably hear a hissing with a leak that size.

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Set your regulator pressure above 60 psi you should hear a hissing sound.
Wait until the kids are in bed

Cheers,
ClaudiusB

I've had a problem in the past like this, It turned out to be the O-rings on the Ball lock post was worn out. This caused it to be an intermittent leak. Some time the gas connector would seal fine but if I moved the keg it would start to leak.

Pull the O-ring off and take it to your LHBS, or Hardware store and match up the size. I've put a too small O-ring on before an leaked several pint's before I caught the problem.

JKoravos said:

If you're losing a full tank in a few hours the leak should be easy to find with a soap test. You just haven't checked the right place yet. Heck, you could probably hear a hissing with a leak that size.

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I thought so too!! i dont hear a thing. I just weighed it again after 2 hours and i have lost .5lb. I have drenched all of the connections and I see nothing. Now, the washer..I dont have one. never have. this is my connection to the tank:

http://smg.photobucket.com/albums/v510/rhltechie/?action=view&current=tank.jpg

I sprayed all around this connection but i see no bubbles and i hear no hissing. its drivin me nuts!!

the oring that is on the end is your washer. I have one just like it. Here's what you can do:
-connect the regulator to tank. Do not connect gas line to keg.
-Open valve on tank and set psi to 30 on reg.
-Now close the main valve on tank.
-Leave it for a few hours or all night
-if you have a leak on the co2 system, you will have less than 30 psi
-If it does leak , you can isolate further by closing the valve coming out the regulator (the one that feeds the gas line). Repeat steps above. If the pressure drops then the leak is between the shutoff valve an the tank, and you have ruled ou the gas line.

JesseRC said:

the oring that is on the end is your washer. I have one just like it. Here's what you can do:
-connect the regulator to tank. Do not connect gas line to keg.
-Open valve on tank and set psi to 30 on reg.
-Now close the main valve on tank.
-Leave it for a few hours or all night
-if you have a leak on the co2 system, you will have less than 30 psi
-If it does leak , you can isolate further by closing the valve coming out the regulator (the one that feeds the gas line). Repeat steps above. If the pressure drops then the leak is between the shutoff valve an the tank, and you have ruled ou the gas line.

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ok...i thought that was the only thing i was supposed to have but i was starting to doubt. i have been doing something like what you suggested since i posted earlier. i weighed the tank. left the gas lines off of the kegs. turned on the main valve of the tank and have been weighing it all day to see if it was leaking. i like your idea better cause i dont lose co2 constantly if it is leaking! the weight hasn't changed in hours BTW. its looking like it may be something at the keg end.

rhltechie said:

ok...i thought that was the only thing i was supposed to have but i was starting to doubt. i have been doing something like what you suggested since i posted earlier. i weighed the tank. left the gas lines off of the kegs. turned on the main valve of the tank and have been weighing it all day to see if it was leaking. i like your idea better cause i dont lose co2 constantly if it is leaking! the weight hasn't changed in hours BTW. its looking like it may be something at the keg end.

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THe weight may take a while to notice. If you try the steps outlined above and you have a leak, you'll notice the drop in the gauges from 30psi . I use my spare 5# co2 tank for sealing kegs and such. When I turn the main tank valve off, it stays at 30 psi for weeks. This means my reg, and gas lines aren't leaking.

JesseRC said:

THe weight may take a while to notice. If you try the steps outlined above and you have a leak, you'll notice the drop in the gauges from 30psi . I use my spare 5# co2 tank for sealing kegs and such. When I turn the main tank valve off, it stays at 30 psi for weeks. This means my reg, and gas lines aren't leaking.

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ok..so, it stayed at 30psi for 24 hours....so i suppose its some place where the disconnects meet the keg(s). guess its good that its narrowed down....more investigation!!

Just to check you test here.

You closed the tank valve and left alone for 24 hours, and the psi on gauge stayed the same?

-If so then yeah you're left with either a keg that is not sealing well at the lid, pressure relief valve or on the post when the QD is connected. Make sure the keg is sealing properly and that the post orings are not damage. Apply so keg lube if needed to lid oring and post orings.

JesseRC said:

Just to check you test here.

You closed the tank valve and left alone for 24 hours, and the psi on gauge stayed the same?

-If so then yeah you're left with either a keg that is not sealing well at the lid, pressure relief valve or on the post when the QD is connected. Make sure the keg is sealing properly and that the post orings are not damage. Apply so keg lube if needed to lid oring and post orings.

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yes...this is what i did. one thing though...the guage actually went UP...what is the deal with that?? also..the pressure gauge dropped WAY down. the weight of the tank is still the same though.

rhltechie said:

yes...this is what i did. one thing though...the guage actually went UP...what is the deal with that?? also..the pressure gauge dropped WAY down. the weight of the tank is still the same though.

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What gauge went up. There is a low pressure gauge and a high pressure gauge. The high pressure gauge reads co2 tank pressure. It can fluctuate with temperature changes, but otherwise should not have moved much. None of them should have moved much. If the High pressure gauge went way down. I suspect the regulator to co2 tank seal is at fault.

JesseRC said:

What gauge went up. There is a low pressure gauge and a high pressure gauge. The high pressure gauge reads co2 tank pressure. It can fluctuate with temperature changes, but otherwise should not have moved much. None of them should have moved much. If the High pressure gauge went way down. I suspect the regulator to co2 tank seal is at fault.

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maybe i am just using the wrong terms here. ok, i have a dual reg with the third guage being the pressure from the tank. two being the psi that goes to the kegs. one of the gas line guages actually went up to 40 psi, the other stayed at 30 psi. but the guage that reads the pressure from the tank has steadily dropped and is almost bottomed out right now. does that make sense?

Yeah, it sounds like you may have a bad connection to your tank. I would check the oring/plastic washer to make sure it it good and making a seal. All the other connections are low pressure. THis is actually a high pressure connection and can leak a lot of co2 quickly if not sealed right.

JesseRC said:

Yeah, it sounds like you may have a bad connection to your tank. I would check the oring/plastic washer to make sure it it good and making a seal. All the other connections are low pressure. THis is actually a high pressure connection and can leak a lot of co2 quickly if not sealed right.

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I dunno what to do with this at this point. I am so frustrated with this. I have sprayed and sprayed and looked an listened. Nothing! The o ring looks fine. Are there places that do leak tests for you? I haven't been able to drink my brew for weeks. Therefore I can't brew cause I am so stocked! Killin me!!

Gee, at this point fill up your tub with water, turn on the gas set to 60 psi on greg and dunk the tank, reg, and gas line. Maybe someone can chime in here, but I think the reg should be fine, not sure, maybe the gauges shouldnt be submerged. I'd just go back and start retesting every bit along the way. Maybe take the setup to a welding supply place .

Did you try replacing the plastic crush washer between the tank and regulator? Did you try to replace the Oring's on the ball lock posts?

Maybe you could fill up your bath tub and put the whole thing under water, you will get water in your regulator, so you will have to get it dried out after, but it might help you pin point the leak.

From what It sounds like, and all you have tried you have a tough one on your hands.

Here's what NOT to do...

Quite a while back I had a leak I couldn't find and man I was getting very frustrated. So I finally reached a point where I stopped and thought, "wait, when I need to check a scuba reg I just immerse it!" So like a complete idiot and without actually thinking at all, I submerged a 4-bank of regulators in a bucket of water....

I found the leak.... lol... It was in one of the connections between regs.

The never really worked right again. I know: big shocker huh?

JesseRC said:

Yeah, it sounds like you may have a bad connection to your tank. I would check the oring/plastic washer to make sure it it good and making a seal. All the other connections are low pressure. THis is actually a high pressure connection and can leak a lot of co2 quickly if not sealed right.

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He was saying he was losing an entire tank overnight. If it was a leak on the high pressure side of his reg. the high pressure gauge would have dropped to zero almost instantly, not overnight.

I still think it's on the low pressure side.

JKoravos said:

He was saying he was losing an entire tank overnight. If it was a leak on the high pressure side of his reg. the high pressure gauge would have dropped to zero almost instantly, not overnight.

I still think it's on the low pressure side.

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If you re-read his statements he has 3 gauges. 2 Low pressure and 1 high pressure for the the tank. Neither of the 2 low press gauges dropped (1 actually went up) the 3rd gauge (high pressure tank gauge) went down and almost bottomed out. Am I missing something.

I have a 2 gauges on a spare tank i use for purging. I close the valve on my tank, I can come back a month later and neither gauge has moved.

Find your leak yet??

nope....havent found it yet. i have been so busy with work. i have the day off so i am going to take the whole friggin thing apart and recheck it..AGAIN!!!

JesseRC said:

If you re-read his statements he has 3 gauges. 2 Low pressure and 1 high pressure for the the tank. Neither of the 2 low press gauges dropped (1 actually went up) the 3rd gauge (high pressure tank gauge) went down and almost bottomed out. Am I missing something.

I have a 2 gauges on a spare tank i use for purging. I close the valve on my tank, I can come back a month later and neither gauge has moved.

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If he had a bad connection between his tank and regulator, and the leak was big enough to lose a tank over night, as soon as he closed his tank valve the needle on the high pressure gauge would bottom out almost instantly. He said his high pressure gauge bottomed out after ~24 hours, indicating a small leak on the high pressure side. The amount of gas left in the regulator after closing the tank valve is probably a few cc. It wouldn't take much of a leak to lose that over 24 hours.

So, he does have a leak on the high pressure side of the regulator somewhere, but it's small. Actually, based on his description, the low pressure gauge that went up in pressure could be caused by gas getting past the diaphragm of that regulator and raising the pressure on the low pressure side.

Well good luck, hope you find it.