Stuck Check Ball Water Only Keg Coupler

[djc]

As Mike said, the ball is the check valve in the liquid side of the coupler, and is designed to stop liquid flow from the tap side out of the coupler when you uncouple. The direction you would be sending gas if you were carbonating in the liquid side would be forcing the ball to seat and stop flow, just like it is designed to do. The standard check valve for the gas line is the duckbill. I don’t see a reason to be carbonating in the liquid side, so I’m going to assume you are carbonating in through the gas side, in which case you should check and clean, or replace the duckbill. BTW the ball check valves’ only job is to keep the two or three ounces of product in the liquid line from spilling when you are uncoupling, so it isn’t a required part.

[mikejferrari]

If you are sending gas through the liquid side of the coupler to carbonate, then you need to remove the check ball. If you're concerned about back flow into your gas line, install an in-line gas check valve.

[Waldner]

We keg and carbonate our own water for a non-alcoholic alternative. We try and keep a spare keg coupled and carbonated to swap them out when the other empties. On the spare keg coupler we have the product line capped and only CO2 feeding in to carbonate the keg. Often the keg fails to carbonate after weeks and we believe it’s because the check valve is getting stuck preventing any CO2 flow. It’s almost like the carbonic acid in the CO2 is reacting with the coupler and causing the ball to stick. We’ve considered removing the check ball altogether but are concerned about back flow. We clean regularly but it almost seems to happen daily preventing CO2 flow. Is there any way to resolve this another way? Thanks