Which statement about pilot-operated valves is true?

• A. They Require a Continuous Electrical Power Source
• B. They Are Only Suitable For Direct-Acting Configurations
• C. They Are Single-Acting Devices
• D. They Use A Pilot Signal To Activate The Main Valve

Answer: (D)

Pilot-operated valves control the main valve with a smaller pilot signal. The pilot acts as the control element—when it’s energized or actuated, it creates a pressure change that shifts the main valve. Once moved, the main valve’s position is maintained by system pressure rather than continuous power, so you don’t need constant electrical power to keep it open or closed. That’s why using a pilot signal to activate the main valve is the correct description.

The other statements aren’t universally true. The pilot can be pneumatic or electric, and not all pilot-operated valves require constant power to stay in position. They aren’t limited to direct-acting configurations, and they aren’t restricted to single-acting designs; many configurations exist.