A Butterfly valve is a quarter-turn rotational motion valve, that is used to stop, regulate, and start flow.

Butterfly valves are easy and fast to open. A 90° rotation of the handle provides a complete closure or opening of the valve. Large Butterfly valves are usually equipped with a so-called gearbox, where the handwheel by gears is connected to the stem. This simplifies the operation of the valve, but at the expense of speed.

Typical applications of Butterfly valves

A Butterfly valve can be used in many different fluid services and they perform well in slurry applications.
The following are some typical applications of Butterfly valves:

• Cooling water, air, gases, fire protection etc.
• Slurry and similar services
• Vacuum service
• High-pressure and high-temperature water and steam services

Advantages of Butterfly valves

• Compact design requires considerably less space, compared to other valves
• Light in weight
• Quick operation requires less time to open or close
• Available in very large sizes
• Low-pressure drop and high-pressure recovery

Disadvantages of Butterfly valves

• Throttling service is limited to low differential pressure
• Cavitation and choked flow are two potential concerns
• Disc movement is unguided and affected by flow turbulence