Watts 774 OSY TS 12 Part of the 774 Series ADA Pad ZN1995 4NH ZN1995 4NH 50 Minimum Temperature Fahrenheit 33 Outlet Connection Size 8 IN Outlet Connection Type Flanged Joint Outlet Shutoff Valve Type Outside Stem And Yoke Gate Valve Outlet Thread Type Does Not Apply To Product Part Number F111630 Polymer Coating No Pressure Operation Continuous Protection Type Backpressure and Backsiphonage Seat Material EPDM Series 957RPDA Strainer No Technologies Flood Detection Tradename None Specification Sheet 957RPDA This 12 inch lead free double check valve backflow preventer assembly is designed to prevent the reverse flow of contaminated water of non potable quality from being pumped or siphoned into the potable water supply due to backsiphonage and or backpressure in accordance with national plumbing codes and water authority requirements spring loaded cam check valves