Butterfly valves are very valuable to many industries, more common to automobile components. These valves come from a family of valves called quarter-turn valves. A quarter-turn valve is a valve that when the handle is turned a quarter of a turn, the valve inside opens or closes.
Butterfly valves consists of a metal disc, referred to as the butterfly, mounted on a rod. With the valve closed, the disc completely blocks the passageway. When the valve is opened, the disc moves a quarter turn so that it allows the passageway to be unrestricted. Thus, fluids or air can pass through. The disc position is affected by the outside of the valve.
There are many different types of butterfly valves. Resilient butterfly valves depend on the flexibility of rubber to work. This type has the lowest pressure rating. High-performance butterfly valves are composed of a slightly offset mounted disc. The offset mounting allows the valve to seal better and has the ability to wear less. This type of valve can be used in slightly higher-pressure systems. For more higher-pressure systems, a tricentric butterfly valve should be utilized. This valve has a metal seat that can be used to withstand a higher amount of pressure.
Although butterfly valves are used in many aspects, the most common use is in automobile parts. For example, a carburetor of a car utilizes a butterfly valve to work. The pedal of the car is pressed to open the valve that controls the engine's air intake. This allows air and gasoline to mix to maintain the proper ratio needed to pass through the intake valves to the combustion chamber, where it is ignited by the engine. When the car is just idling or running without pressing the pedal, the butterfly valve is partially opened, allowing a smaller amount of air to pass through to maintain idle speed.
