A butterfly valve actuator is a device used to open and close a butterfly valve, which is a type of valve that is used to control the flow of liquids and gases. Butterfly valves are designed with a disc-shaped plate that is attached to a rod, which is then connected to an actuator. The actuator is the part of the valve that is responsible for opening and closing the valve, and it can be powered by a variety of sources, including electric, hydraulic, or pneumatic power. The actuator works by rotating the disc-shaped plate to either open or close the valve, allowing or preventing the flow of the liquid or gas. Butterfly valve actuators are often used in industrial settings, such as in water treatment plants, chemical plants, and power plants, as they are reliable and easy to maintain.