Backflow preventer assembly, ASSE 1022, brass, is vented, has dual check valves, 10-200 PSI rating, flow rate 2.4 GPM at 15 PSA, and 3/8" male flare (MFL) x 3/8" male flare (MFL) connections. It protects the connected plumbing and drinking water from the corrosive effects of CO2 gas. The CO2 gas mixed with water in a carbonator tank downs