The WATTS ACV Solenoid Control Valve with High Capacity Pilot System and Hydraulic Check Feature is designed to open fully or close drip-tight as commanded by a 3-Way Solenoid Pilot, and close drip-tight when downstream pressure becomes greater than upstream pressure. The solenoid may be activated by a pressure switch, level probe, or any other electrical on-off device. The valve also has provisions for manual operation in the event of power outage. Engaging the Solenoid Manual operator simulates power to the solenoid, manually controlling the main valve. Disengaging the Solenoid Manual operator returns the valve to electrical on-off service.