0391012 - 2 In Lead Free Silicon Bronze Reduced Pressure Zone Backflow Preventer Assembly, Qua2 In Lead Free Silicon Bronze Reduced Pressure Zone Backflow Preventer Assembly, Quarter Turn Shutoff Valves This 2 inch reduced pressure zone backflow preventer assembly with its exclusive design incorporating the patented air in and water out principle for protection during an emergency condition prevents the flow of polluted water from entering into the potable water supply due to backsiphonage and or backpressure in accordance with national