Butterfly Valve
https://youtu.be/EUANR3-EyTg This video is a part of industrial valve video clip which describes butterfly valve.
https://youtu.be/EUANR3-EyTg This video is a part of industrial valve video clip which describes butterfly valve.
https://youtu.be/IYyBRnShVyc This video is a part of industrial valve video clip which describes these phenomena.