Which component is used to control the flow of air and thereby influence system pressure?

• A. Filter
• B. Regulator
• C. Valve
• D. Sensor

Answer: (C)

The key idea is that pressure in a pneumatic system is set and kept stable by a regulator. A regulator’s job is to maintain a chosen downstream pressure by adjusting how much air can pass from the supply. It compares the actual downstream pressure to the desired set point and throttles the flow up or down to hold that pressure steady, even as the supply pressure or system demand changes.

Context helps: the filter cleans air so contaminants don’t affect performance, the valve simply opens, closes, or throttles a path for air and can influence flow locally but doesn’t automatically hold a specific pressure, and the sensor just measures pressure without controlling it. So, when the goal is to control flow to influence and stabilize system pressure, the regulator is the device designed for that purpose.