EVO-Z is a self-acting, adjustable, non-electric thermostatic operator and remote temperature sensor. It has adjustable max./min. temperature, selected temperature locking feature and can be shutoff completely if required. The symbol * protects against frost damage. Each EVO-Z thermostatic operator is individually calibrated and conforms to ASHRAE standardization rules for temperature regulation. The EVO-Z’s smooth shape and narrow air gaps gives a nice operation and makes it easy to keep clean. They can be mounted on all Macon NT series valves.
The sensor on the EVO-Z is wax-filled and the wax volume varies according to ambient temperature. The volume changes are transmitted to the valve stem via a liquid capillary system. The valve body has a return spring which closes the valve when the stem is under low pressure. When the force from the sensor and the return spring are balanced to the room temperature selected, the valve disc stops in that position to allow a certain amount of water or steam to flow through the valve. Ambient temperature changes cause the valve disc to change position and thereby continuously modulate the flow so that the room temperature is maintained at the desired temperature. The unit is secured against damage from over-pressure by a built-in pressure absorbing spring.