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.
Famous quotes containing the word pilot:
“Whenever the weather licks the pilot instead of him lickin’ the weather, he’s finished. The first time makes the second time easier. And the first thing he knows, he’s in trouble when the weather is perfect.”
—Frank W. Wead (1895?–1947)