To adjust actuator speed using a flow control valve, which arrangement correctly describes the direction to decrease or increase speed?

• A. Clockwise to increase; Counterclockwise to decrease
• B. Counterclockwise to decrease; Clockwise to increase
• C. Counterclockwise to increase; Clockwise to decrease
• D. Clockwise to decrease; Counterclockwise to increase

Answer: (D)

Controlling actuator speed with a flow control valve works by throttling the flow in the line. Turning the adjustment toward tighter restriction reduces the flow, which slows the actuator; turning toward looser restriction increases the flow, making the actuator move faster. So the direction that decreases speed is clockwise, and the direction that increases speed is counterclockwise. This is the standard convention for needle-type flow control valves in hydraulic and pneumatic systems.