CO2 leak, tried all traditional methods to find

I have a very slow CO2 leak that I have been trying to find for the last two nights with no luck. In the picture links you will see I have a primary regulator that runs at 40 PSI going to a T where it splits to a quick disconnect and a secondary regulator. The secondary regulator runs into a 4 way manifold (not pictured below – leak exists before the manifold). Both regulators have ball valves.

http://klwtx.com/uploads/CO2/CO2Rig.jpg

http://klwtx.com/uploads/CO2/CO2RigClose.jpg

My method of testing has been the following: 1) Close ball valve on the secondary regulator 2) open ball valve on primary 3) open CO2 tank to fill lines 4) close CO2 tank 5) monitor high pressure gauge and watch for pressure drop. I have done all of the usual methods of detecting leaks – soapy water from a spray bottle, starsan from a spray bottle, listening for leaks and finally last night I submerged the entire rig (regulators included :/) in a bathtub. Pressure drops to zero and still no luck finding a leak using any of these methods. It is a very very slow leak that takes about an hour to drop the pressure in the high gauge to zero. As you can see in the pictures the high gauge is already in the red but there is definitely still enough CO2 left in the tank for these tests.

I am at wits end and open to try any ideas anyone might have. I’m going crazy and starting to wonder if the leak could be so slow that when submerged in the bathtub the water is actually absorbing the CO2 as it leaks out before it can turn into a bubble? Thanks for taking the time to read.

Is that a check valve between the disconnect and the main hose in the second picture? I know you said you have a leak so this might not be the case at all but one time I installed a check valve backwards and it took me a while to figure out why there was no pressure going to the keg. They only work one way and having it on backwards was actually closing it instead of keeping it open.

I have a headache and probably should be trying to help right!

Yup that is a check valve between the disconnect - "unfortunately" it is working correctly :/

Maybe your gauge is broken?

And\or sometimes I've not gotten a good seal between the regulator and the tank itself. I use 10lb tank on my kegorator with two taps. One lasted for months (possibly a year at a rate of floating 2 5gal kegs a month). Then when it emptied, all I did was swap out the tank and it was empty within weeks. The next tank I bolted on (again nothing else changing down stream) and it has been holding just fine for almost a month now.

And I'm also thinking about the valve on the CO2 tank itself and weather or not some tanks are old, abused, and generally leaking from there...

Don't think it is the primary. I've had the entire rig submerged and not a bubble to be seen. Also, if I close the ball valve coming out of the primary and close the CO2 tank, the high pressure gauge holds indefinitely.

Open and close the main valve on the tank from full open to full closed 10 times. When you open it the last time make sure it is opened all the way until it stops. Some valves can leak if not fully opened, one of my tanks has a warning sticker with the instructions I just posted. I'm sure if it was a swapped tank the sticker has worn off or missing. Just another thing to check, probably the last place I would check. My other tanks have no problem with just being open a 1/2 turn and not leaking

Jrems - tried your idea a couple times over the last hour and still getting a slow leak.

If you submerged the hole rig and no bubbles,(Am I missing something?) then there is no leak. Maybe a gauge problem.

That is why I am so puzzled by it. According to the high pressure gauge there is a leak, yet nothing bubbles. Have gone from around 500 psi in the tank below 400 in the last 2 nights of testing. Will try replacing the gauge tomorrow and see what happens.

Have you checked the keg chimes?

AZ - Yeah the co2 isn't hooked up to kegs. Been testing with just the tank, primary going to a T that splits to a quick disc and a secondary

Have you made SURE that all the worm hose clamps are 100% tight/secure? As much as I liked the concept of using them, I've found that they really suck for making a 100% reliable connection every time. Far too often, I had to wind them up more than I would have liked JUST to get them tight enough to not leak (gas especially). I've since moved to using Oetiker clamps and have not had a single leak on any gas lines using them. You can get the straight crimping tool pretty cheap (under $10). The clamps themselves are cheaper than good hose clamps too (check out Keg Connection for them). Plus, I like how they clamp the full 360 degrees on the hose/tubing, unlike the hose/worm clamps.

I still use the worm clamps for 1/2" ID silicone tubing, and larger items. But if it's basically a connection I'll not be looking to change anytime soon, I'll use the Oetiker clamps on it.

I also do high pressure tests whenever I make a new line. I typically set the regulator to 30 psi (low side) then turn off the tank valve.

BTW, on the threaded fitting before the gas QD (off the T) do you have one of the white plastic tailpiece washers in place? You don't want to ever have metal on metal connections (the reason you use pipe tape on threads)... If you don't have the tailpiece washer where you have swivel nuts going to metal fittings, put them in place. If the washer is old/compressed/deformed, try replacing it with a fresh one.

Have double checked all the worm clamps, even got paranoid and replaced them all earlier tonight. Have all the plastic washers where they need to be. Think I'll give your clamps a try and put an order in tomorrow. What sizes do you usually go with? I have a couple larger than normal barbs so thinking I'll just got some of each, better safe than sorry for as cheap as they are. Thanks for the tips, appreciate the help.

Good news and bad news. Good, I think I finally found my leak. Bad, it's in the tank valve itself. Submerged the tank again, watched for about 10 minutes before I noticed two of the smallest bubbles I've ever seen float up from the part circled in red in the attached picture.
http://klwtx.com/uploads/CO2/LeakFound.jpg

Once I found it, about every minute or so two more tiny little bubbles would surface. Is this something I can take apart and fix if I purge the remaining CO2 in the tank? Or is it time for a new tank?

klemms0045 said:

Is this something I can take apart and fix if I purge the remaining CO2 in the tank? Or is it time for a new tank?

Click to expand...

You should be able to get the tank valve replaced. It is not something I would do myself, tank it to the place you get it fill and they should be able to do it or tell you where to go.

I've had a faulty valve before and when I brought it back to where I normally do my swap outs (AirGas store), I tell them the tank valve had a leak. Since I got the faulty tank from them they didn't even charge me for the gas on the swap out.