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A pilot valve is a small valve that controls a limited-flow control feed to a separate piloted valve. Typically, this valve controls a high pressure or high flow feed. Pilot valves are useful because they allow a small and easily operated feed to control a much higher pressure or higher flow feed, which would otherwise require a much larger force to operate; indeed, this is even useful when a solenoid is used to operate the valve.
Pilot valves are often used in critical applications (i.e., emergency and safety controls) and are human-operated. They can be set up as a push-to-activate or dead man's switch.
Video Pilot valve
See also
- Larner-Johnson valve
- Pilot-operated_relief_valve
Source of the article : Wikipedia