Week 14 challenge
BUTTERFLY VALVE
Butterfly valves are a family of quarter-turn rotational motion valves that are used in pipelines to shut off flow. It is often said that butterfly valves can be used to regulate the flow. However, we do not recommend doing this, as it can damage the valve disk and hurt the sealing properties. They are used in a wide variety of process media and industries, especially in water supply, collection, and distribution, as well as pumping stations, and have a broad range of use cases, especially in flow isolation. A couple of their key advantages over other valve families are their simple construction and compactness, resulting in the end products being of lighter weights and lower cost and with smaller installation footprints and faster actuation speeds.
Working principle
The construction of a butterfly valve is relatively simple, with the rotation of the valve disc controlling the fluid flow. In the closed position, the disc blocks the valve bore while in the open position, the disc is oriented perpendicular to the flow direction to allow flow. Butterfly valves generally provide bi-directional flow and shutoff capability. However, they are not full-bore, which renders them unsuitable for pigging or swabbing. The body material is ductile iron with an epoxy powder coat on both internal and external surfaces. The valves are typically operated by handwheels, gears, or actuators, or a combination thereof, according to the specific application requirement and technical specifications.
The butterfly valve is an assembly generally consisting of 6 subcomponents listed below:
- Body
- Disc
- Top flange/ Retainer
- Lever
- Nut
- Stem & Screws