Understanding the way a basic butterfly valve works is pretty simple. It can help you to learn more about the components of valves.
Butterfly valves are made of a number of components. The most important one is the metal disc. This metal disc is the one commonly
referred to as the butterfly. The butterfly is mounted on a rod and when the valve is closed it blocks passage of fluid. When the valve is fully open, the metal disc or butterfly moves a quarter turn. The passageway is unrestricted allowing fluids or air to pass.In essence, the movement of the disc will depend on whether the valve is open or closed either partially or completely. If the valve is opened partially, it means that the disc will not be rotated a full one quarter turn, thus it cannot provide unrestricted passage. This means that, smaller amounts of fluid or air will pass through.
However, if the valve is opened completely, the disc will be rotated 90 degrees then larger amounts of air or fluid will pass through.There are many other components that form the butterfly valve. They include the resilient seat, body, packing, a stem and an actuator. The resilient seat is mounted on the body of the butterfly valve in order to provide the proper seal. The packing provides an additional seal especially in case the resilient seat is damaged.
A pneumatiqc butterfly Valve is made of a pneumatic actuator and a butterfly valve.And there are Stainless steel pneumatic butterfly valve, hard seal pneumatic butterfly valve, soft seal pneumatic butterfly valve, carbon steel pneumatic butterfly valve.They have lots of advantages, auch as : simple structure, small size, light weight and low cost.