This high sensitivity, direct acting, 3-Way positioning pilot is actuated by a pressure responsive diaphragm, which tends to reach equilibrium with the set spring force. The pilot directs flow and pressure between its ports:
- When sensed pressure is above set point, It connects port “C” to “0”
- When sensed pressure is equal to set point, it blocks connections between all ports
- When sensed pressure is below set point, it connects port “C” with “A” and “Z”
An integral needle valve restricts flow through port “Z”