Which type of valve is commonly used to control flow based on a pneumatic signal?

A solenoid valve is specifically designed to control the flow of fluid using an electromagnetic solenoid to actuate the valve. When a pneumatic signal is applied, the solenoid energizes to open or close the valve, allowing for precise control of flow in pneumatic and hydraulic systems. This feature makes solenoid valves particularly useful in applications requiring automated or remote control.

In contrast, other types of valves, such as ball valves and gate valves, are typically manually operated or may require a different actuation method, such as a handwheel or lever. Check valves are designed to allow flow in one direction only and do not have an actuating mechanism for flow control based on a signal. Therefore, a solenoid valve is the most suitable choice for applications where flow control is needed in response to a pneumatic signal.