The 3" Watts 909RPDA Series Reduced Pressure Detector Assemblies were manufactured from 1990 and are still currently in production. The 3" 909RPDA is a cast iron bodied device with a bronze relief valve. It features two check covers and a seperate relief valve cover. Check valves are self contained and the relief valve is a stem type. In 2010, the LF909RPDA was introduced to comply with the new "Lead Free" laws. All repair parts were converted to lead free in 2013. Lead free repair parts will fit both regular 909RPDA and lead free LF909RPDA models. All 909RPDA models have replaceable seats and require no special tools for repair. The 909RPDA features a bypass assembly to meter water usage. The bypass backflow preventer was changed over the years and may be a 3/4" Watts 909, 3/4" Watts 009, or 3/4" 009M2. Please check the bypass device I.D. tag before ordering parts.