3ZV1 Series Zone Valves are ideal for flow control in hot and cold water HVAC systems. The 3ZV1 is electrically driven to open and spring to close. Units are available in 1/2″, 3/4″, and 1″; sizes with 24 or 120 VAC power supply. Easy to install these units are direct replacements for competitor units. Manual override lever is easily accessible externally. Consult factory for 220 VAC power supply, optional auxiliary switches, and BSP or sweat connections.