1st Time Keg - Slow Leak?

Greets All,

I bought a used keg system with CO2 tank and two corny kegs. I replaced all the rings with fresh ones, filled them with 5 gallons of water, hooked up the gas line and brought the keg up to 20 lbs psi, then turned it off at the tank and walked away (gas line still connected). When I checked back a few hours later the regulator gauge was down to 0 psi. So I took it back up to 20 psi, turned off the tank, and the next morning again, back to 0 psi. I tried several variations on this for a while - including removing the line after pressurizing, in case there's an inline leak - and wound up with some great soda water but the keg doesn't seem to hold the pressure. When I pull the release valve after several hours of sitting no air comes out. I can't find any leaks using leak-detector soap, and this evening I submerged the entire keg in the bathtub and pressurized it but didn't see any bubbles. And yet it makes soda water (...shouldn't it have gone flat?) . . . will it make, and hold, carbonated beer?

Thanks for your comments!

The water is absorbing the the CO2 and there is probably a check valve that is preventing the CO2 from leaking back to the regulator. The first thing to do is tighten the nut at the tank about 1/8th turn.

Both of my regulators have slow leaks, so I'm constantly turning the CO2 on and off. A pain, but I've never been able to track the leaks down they are so slow.

why do you keep turning the regulator off?

set it at serving PSI and leave it there for a few weeks

It is my understanding that if you turn off the tank, your primary regs will eventually depressurize due to the design of the needle valve on the tank. Perhaps your entire system is depressurizing when you do this?

I am not sure how you can serve soda water from a keg yet not have any pressure in the keg. Perhaps you should bubble test your system again.

If you do have a small leak then you will find a little keg lube goes a long way on all your gaskets and fixes most leaks but it does sound like your water is just carbonating which is sucking up the C02.

Turning off the valve on the CO2 tank will allow CO2 to leak back past it. This is NOT a good test. The valve on the CO2 tank is rear seating, so it only seals when opened fully. Here's some pics to explain: