Beer backing up to regulator while carbonating

[ManSkirtBrew]

I've recently been having a problem with beer backing up through my GW Kent carb stones and up through the flow meter.

The check valve holds beer back without the gas connected, but once the head space reaches equilibrium with the setting on the regulator, I'm guessing it's allowing the check valve to stay open just enough to let beer creep back up into the lines and fill up my flow meter.

I've done some looking around for backup in-line check valves without much success. I was going to switch the ball valves on the regulators with ball-check valves, but I'd still love to hear any suggestions, especially if you've experienced this.

Here's the flow meter, in case anyone is curious:

[TGTimm]

I use a Parker C4005 in-line check valve between the QD for the stone and the line going to the regulator. It has an SS body and ball, so brewery compatible.

I also have several CVs that are built into push-fit fittings. Just be sure you get the right orientation for which end of the line you want to place it at.

[gitchegumee]

I always install check valves directly to the stone. Use a high quality SS instrument valve. When I buy from GW Kent, I add check valve P/N 85-619 to the assembly.

[HogMountain]

I've had the same problem and have a ruined flow meter. I searched for the Parker valve referenced above but it is not on their site. Can someone recommend another make and model?

[TGTimm]

I sourced the Parker valves from Nether Industries. Those folks have a huge inventory of brewery equipment, fast shipping and good prices.