Zone valves are used to shut off the heat-transfer medium in air conditioning systems. When coupled with a thermo-electric actuator and controlled by 
a room thermostat, they automatically shut off the part of the plumbing circuit in which they inserted. They feature a high flow coefficient, which is why they are typically installed for zone control. Thanks to their special balanced obturator, they can work at high differential pressures. The valve is equipped with unions.