Disconnecting C02

[BigKutta]

Hey folks, its been a while. I hope all of your are safe and healthy. I recently tapped a keg of Veltins, and after a few days noticed the CO2 tank was completely empty. This tank was filled last summer, and usually my tanks will last a couple of years (5-6 kegs). I think there may have been a leak somewhere but I cant imagine as I tighten the ends fairly well. The only thing I can think of is that I am using a new M type couple which has a built in duck bill check valve (which I can see inside), so no check valve is required to me inserted at the end. Anyone know whats going one?

Anyhow, I will need to get a new tank and I was wondering if I can just disconnect the CO2 line at the coupler, and leave the coupler coupled to the keg? Or would I need to uncouple the thing to do this. Thanks!

[djc]

I am not familiar with an M coupler, but on a D coupler the check valve also acts like a washer on the connection between the line and the coupler. Do you have a shut off on your gas line after the regulator? If so, turn it off and then take the regulator off the tank. If you don't, lift the handle on the coupler then take the regulator off the tank. When you reconnect, run the pressure up to around 40 psi momentarily and you should hear if you have a leak. After that, turn the pressure back to a normal value and vent the keg.

[BigKutta]

I am not familiar with an M coupler, but on a D coupler the check valve also acts like a washer on the connection between the line and the coupler. Do you have a shut off on your gas line after the regulator? If so, turn it off and then take the regulator off the tank. If you don't, lift the handle on the coupler then take the regulator off the tank. When you reconnect, run the pressure up to around 40 psi momentarily and you should hear if you have a leak. After that, turn the pressure back to a normal value and vent the keg.

The M is just like a A coupler. Its a slider, except the pattern of the part that couples with the keg is slightly different. I was thinking the exact thing you are. The duck bill valve usually acts as a washer and that part is no longer there so there is no washer seal. Perhaps I should insert a washer next time?

Yes, I have a check valve after the gauge, so will shut off and remove.

Thanks

PS. I did get the tank filled, and tightened everything up, even added a washer to the connection where the duck bill valve goes. Turned on the gas, and of course could hear it initially as it made its way into the beer, but nothing out of the ordinary. How would I know its leaking?

Thanks

[Scott Zuhse]

Yes the "M" and "A" couplers are referred to as German sliders although are not interchangeable. Always conduct a leak test prior to setting pressure. Review this link for procedure.

[BigKutta]

Yes the "M" and "A" couplers are referred to as German sliders although are not interchangeable. Always conduct a leak test prior to setting pressure. Review this link for procedure.

Thanks for this link. I tried what it says there but nothing seems out of the ordinary there. Hope its a freak thing?

[BigKutta]

Could it be that the regulator is failing or leaking? This is the standard one I got with my kegerator 8-9 years ago.

[djc]

Did you run it up to 40psi and listen? If you don’t hear anything there may not be an issue.

[BigKutta]

Did you run it up to 40psi and listen? If you don’t hear anything there may not be an issue.

I did at first and could hear the gas going in the keg, but nothing out of the ordinary. What should I have been listening for? Thank you

[djc]

Hissing like a leak. If you went up to 40 psi and didn’t hear anything you should be good. Make sure to shut off the gas after that and vent the keg of the 40 psi. You will hear I’d refill when you turn the gas back on.

[Scott Zuhse]

If the procedures followed within link in above post did not result in the pointer on the high pressure regulator gauge dropping, you do not have a leak.

[BigKutta]

If the procedures followed within link in above post did not result in the pointer on the high pressure regulator gauge dropping, you do not have a leak.

Guys, thanks for all the advice but I'm pretty sure I have a leak. I looked at the high side pressure today and it has dropped. I've turned the gas off for now as filling up for $30 every week is not feasible. I tried every thing today, and I cannot hear anything. The only thing that has changed in my setup is a new coupler (M), which was loaned to me by the beer distributor as a courtesy. Its looks like a high quality coupler and even has their logo on it (Veltins Beer). The only thing different about this coupler is that the gas check valve is built into the couple and so a duck bill valve is not required at the gas inlet.

Thinking that this may be causing a slight leak (because I feel like the duck bill valve act as a washer too), I added a washer at the gas inlet at the coupler. That doesnt seem to have done anything. If my lines are ok, what could it be? See the picture attached. When I first connected the new tank on Monday, the high side pressure showed 800 psi (as in the pic). That same evening the pressure showed 600. And today, just 2 days later, the pressure is a bit over 500. Help!
IMG_3836.jpg

[djc]

You can spray the connection with soapy water and look for bubbles. Is this tank in the kegerator or outside? If it is in the kegerator, when the CO2 is cooled the pressure drops but you haven’t lost any gas.

[BigKutta]

Tank is in the kegerator. I understand the initial drop after the first 24 hours, but dropping after a couple of days? Anyway, I bought this epoxy putty that I applied to the connection points in the regulator itself (as shown in the pics). I will also try the spray test later today. Thank you.

Could there be loss at the coupler connection itself? Like a bad seal or gasket on the keg? Thanks

View album “Recents”.png

[djc]

There can be loss anywhere there is CO2, could even be a nick in the gas line. The coupler is one place and it is also the only new element in your set up. Run the pressure to 40 again, spray soapy water.

[BigKutta]

Will do that after work today. Thank you!