This residential and light commercial grade in-line valve replaces Rain Bird and other irrigation valves installed below ground with 3/4 in. female threaded inlet and outlet. It can be used with any 24-Volt AC irrigation timer. Its unique reverse-flow design helps prevent flooding in the event of internal diaphragm failure, keeping the valve closed and saving water. This valve can be applied with all types of watering devices including Rain Bird spray heads (1800, 600), and rotors (22SA, 32SA, 42SA+, 52SA, LG3 and AG5). Use in-line valves in locations where the use of a pressure vacuum breaker (PVB) or a double-check valve is required by code to protect against backflow. Check your local codes to determine what type of valve is required. After installation and before startup, always the flush system of dirt and debris manually using the valve's external bleed screw.