• Integral shutoffs for shorter lay length and lightweight construction Dual-action check module for low-and high-flow performance Prewired supervisory switches Tamper-resistant test cocks

This 8 inch Ames Deringer(TM) 20 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 20 features integral Eccentric-Seal(TM) butterfly shutoff valves for a short lay length, integrated tamper switches, 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).