Which term describes a valve that operates another valve or control?

• A. Pilot Valve
• B. Live Load
• C. Twist
• D. Shuttle Valve

Answer: (A)

This question tests how a valve can control another valve in a hydraulic or pneumatic system. A pilot valve is a small valve whose job is to actuate or pilot the main valve. It receives a signal (pressure, electric, or mechanical) and creates a pilot pressure or signal that shifts the main valve’s spool, thereby controlling a much larger flow or force with a small input. The pilot valve enables precise, low-power control of a larger valve, which is essential when the main valve handles high pressures or flows but you want accurate control or remote operation. The other terms don’t describe this role: live load is a type of load in a system, twist isn’t a standard valve term, and a shuttle valve is a device that selects between two sources rather than controlling another valve.