Hydro Flow NDJ Plastic Solenoid Valve 24V - 1 in Threaded w/ Flow Control. Control the flow of your irrigation lines using Hydro Flow's Irrigation Control Valves. It features low head loss at high flow rates, limits water hammer and comes equipped with a flow control handle for easy flow adjusting. Operating range: 15 to 40 PSI. Flow range: 2 to 35 GPM.