The Taco Z075T3-2 3-Way Zone Sentry Valve is a 3/4-inch NPT, 24V motorized valve designed to regulate fluid flow in hydronic HVAC systems. It operates by using an electric actuator to position the three-way valve, directing heated or chilled water between system circuits according to zone control requirements. The valve is commonly used with boilers, chillers, radiant heating systems,... https://www.partshnc.com/z075t3-2-taco-3-way-sentry-zone-valve-3-4-npt-24v