This 1/2 inch stainless steel reduced pressure zone backflow preventer assembly is designed to prevent the flow of polluted water from entering into the potable water supply due to backsiphonage and or backpressure. It is ideal for typical applications that are found in industrial plants, medical diagnostic equipment, reverse osmosis systems, carbonated beverage machines, brewing distillers, paper and pulp industries, chemical plants and aggressive atmospheres. This assembly consists of NPT end connections, quarter turn ball valve shutoffs with tee handles, top mounted vandal resistant EZ-test cocks with covers, two in-line independent check valves, captured springs, replaceable check seats, corrosion resistant internal parts, and a hydraulically operated differential pressure internal relief valve for reduced space requirements. This backflow assembly includes flood sensor with SentryPlus Alert(R) technology to detect excessive water discharges from the relief valve. When activated through an add-on sensor connection kit, the flood sensor can send an alert to notify the user of potential flooding. Add-on sensor connection kits are available for both BMS and cellular communications.