Butterfly Valve

A butterfly valve is from a family of valves called quarter turn valves. The butterfly valve is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway. When the valve is open, the disc is rotated a quarter turn so that it allows unrestricted passage. The position of the disc is effected from outside the valve. Butterfly valves are utilized in many aspects of our lives. One of the most common examples of a butterfly valve is in the carburetor of car. In a carbureted car, the "gas" pedal actually operates a butterfly valve that controls the engine air intake. When the driver depresses the gas pedal all the way to the floor the butterfly valve opens all the way as described above to allow air to pass freely into the carburetor combustion chambers, where it is ignited by the engine