This 6 inch reduced pressure detector backflow preventer assembly help stop the reverse flow of liquids due to backpressure or backsiphonage, where potential health hazard exists. Its compact modular design facilitates easy maintenance with a single access cover for in-line repairs. This assembly consists of a short lay length stainless steel body, test cocks, corrosive resistant stainless steel bottom mounted relief valve, torsion spring check valves, outside stem and yoke resilient seated gate valves and comes furnished with a gallon per minute meter to detect underground leaks and unauthorized water use. This backflow assembly contains a 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 relays a signal that triggers notification of potential flooding to service personnel. The add-on sensor connection kit is available for building management systems and cellular communication.