Butterfly valves are used to control and regulate or throttle the flow. They are characterized by fast operation and low-pressure drop. They require only a quarter turn from closed to full-open position. Butterfly valves are produced in sizes ranging from NPS 2 (DN 50) to over NPS 160 (DN 4000). They are usually manufactured in flanged, wafer, and lug, or single-flange-type designs. The welding-end style is a specially engineered valve for a specific application. Threaded-end, grooved-end, and shouldered-end butterfly valves are also available to satisfy the joint type selected for the piping system. Butterfly valves are produced with metal-to-metal seats, soft seats, and with fully lined body and disc. The soft seats permit bubble-tight shutoff and the full lining enhances erosion and corrosion resistance. Butterfly valves are suitable for low-pressure and low-temperature applications as well as high-pressure and high-temperature applications. The term high-performance butterfly valve is intended to signify their suitability for moderate- to high-pressure and temperature services. The butterfly valves have a low-pressure drop and high-pressure recovery factor. They are suitable for low-pressure drop applications. These valves are extensively used in large water transmission, distribution, and cooling water lines.
- The compact design requires considerably less space, compared to gate, globe, or other valves.
- Light in weight
- Quick acting; as a quarter-turn valve, it requires less time to open or close.
- It is available in large sizes, ranging from NPS 2” (DN 50) to over NPS 120 (DN 3000).
- They have low-pressure drop and high-pressure recovery.
- Provide bubble-tight service.
- Throttling service is limited to low differential pressure.
- Throttling is restricted to a 30- to 80-degree disc opening. Location of valve, pipe routing, free, and closed discharge are to be considered while using a butterfly valve in a throttling application.
- Cavitations and choked flow are two potential concerns.
- The disc movement is unguided and affected by flow turbulence.
Concentric Or Low-Pressure And Low-Temperature Butterfly Valves, The High-Performance Butterfly Valves, Cover A Wide Range Of Applications. These Applications Include:
- Cooling Water, Air, Gases, And Other Similar Applications, Such As Fire Protection, Circulating Water, Etcetera
- Corrosive Services Requiring Lined Valves
- Food Processing, Chemical, And Pharmaceutical Services
- Slurry And Similar Services
- High-Pressure And High-Temperature Water And Steam Services.
- Throttling Service Involving Low Differential Pressures, As In Cooling Water Or Air Supply Systems
- Vacuum Service.
