What kind of actuator does an air-to-open valve typically use?

An air-to-open valve typically uses a spring-to-open actuator. This design allows the valve to be closed by applying air pressure to the actuator, which compresses a spring. When the air pressure is released, the spring forces the valve to open. This is particularly advantageous in applications where it is critical for the system to default to an open state in the event of a failure or loss of control signal, ensuring that flow or pressure can be maintained as needed.

The operation of a spring-to-open actuator is based on the principle of using air to overcome the spring force. Once the air pressure is removed, the spring naturally returns the valve to its open position, which aligns with the functionality expected of an air-to-open design. This makes it a suitable choice in many automated process control systems.