How butterfly valves are operated .....?
The butterfly valve is opened and closed in several ways, depending on the torque required to open and close it .
1- Manually hand lever or hand wheel .
2- Gearbox
3- Pneumatic actuator ( Double acting, single acting ).
4- Electtric positioner 4-20 mA in order to control opening percentage .
5- Electric Actuator ( Quarter turn & multi-turn in case of large sizes)
6- Hydraulic actuators
