• Resiliently seated and inline OSY shutoff valves Dual-action check module for low-and high-flow performance Prewired supervisory switches Tamper-resistant test cocks

This 4 inch Ames Deringer(TM) 20GX Low Head Loss double check valve backflow preventer assembly is designed to prevent non-health hazard pollutants from entering the potable water supply system caused by backflow due to backpressure and/or backsiphonage conditions. Deringer 20GX features extra large body and checks for lower head loss, inline serviceable OS&Y gate valves, a stainless steel body, and Dual-Action(TM) checks for high performance at low-and high-flow rates. It may be installed under continuous pressure service to protect against both backpressure and backsiphonage. Maximum working pressure is 175psi (12 bar).