What is the definition of a pneumatic valve actuator? Pneumatic valve actuators are devices that are designed to control the flow of media such as gas or liquid in a system by opening and closing valves. They are usually powered by compressed air, and can be used in a variety of industrial and commercial applications. Pneumatic valve actuators are specially designed to operate quickly and accurately, and are commonly used in applications where rapid response is needed. For example, they are often used in process control applications in chemical or petroleum industries to control the flow of fluids. Additionally, pneumatic valve actuators can be used in medical or dental facilities for controlling the flow of gases or liquids. Pneumatic valve actuators are characterized by their ability to quickly and accurately open or close valves, as well as to regulate the flow of media. They are built with precision, and can be operated manually or electrically.