1-1/2" Backflow Preventer, Reduced Pressure, Bronze with Ball Valves and SAE Test Cocks APOLLO 4A207A2F1 1 2" Backflow Preventer, Reduced Pressure, Bronze with Ball Valves and SAE Test Cocks APOLLO 4A207A2F DESCRIPTION The Apollo Model RP4A Series Reduced Pressure Backflow Preventers provide maximum protection against back siphonage or backpressure from substances that are hazardous to the potable water supply. The top accessed modular check valve cartridges provide captured springs, replaceable seats and reversible silicone seat discs. This Made in