Butterfly Valve Actuator Types and Selection Guide
2024-09-14
Butterfly Valve Actuator Types and Selection Guide
Butterfly Valve Actuator Types and Selection Guide
Butterfly valve actuators determine which energy is used to operate the valve. This affects the valve's response time, actuation pressure rating, environmental suitability, and more. Sometimes, choosing the right actuator depends on the power supply available for the application. This article takes a closer look at the various actuator types for those who have some flexibility in which type to choose. Learn how different types of actuators work with industrial valves by reading our article on actuator sizing.
What is a butterfly valve?
A butterfly valve actuator is a device that is used to control the opening and closing of a butterfly valve. The selection of a butterfly valve actuator depends on various factors such as the application, the size of the valve, the type of the valve, the media that will flow through the valve, the required torque, and the environment in which the valve will operate
Types of Butterfly Valve Actuators:
-
Manual Actuator:
Manual actuation is the easiest way to drive a butterfly valve. The most basic design uses a lever to turn the stem, which is rotated to open or close the valve. Larger butterfly valves can have a handwheel connected to the gearbox. This is the easiest way to generate enough force to manually open or close the valve. The main advantage of manual drive is that it does not require an external power supply. However, since the user needs to open or close the valve, this actuation is not suitable for applications that require frequent actuation of the butterfly valve.
Manual butterfly valves work well in small water treatment plants. The valve controls the flow of water through different treatment process stages. Operators can use manual operations to adjust valves and control water flow as needed for treatment. Ideally, the valve is not adjusted very often.
-
Pneumatic Actuator:
Pneumatic actuators use air pressure to generate mechanical motion. The pressurized air in the actuator moves the piston or diaphragm, which rotates the stem. Butterfly valves with pneumatic actuators act quickly and reliably. They can be used in hazardous environments because they do not produce sparks. However, a compressed air source is required, and the drive speed is more difficult to control than with electric or hydraulic actuators.
Butterfly valve with pneumatic actuator work well in safety-critical natural gas treatment plants. Using valves that operate through air pressure rather than electricity reduces the risk of sparking, which can cause an explosion.
-
Electric Actuator:
Electric actuators convert electrical energy into mechanical torque. This torque rotates the stem to open or close the valve. Motorized butterfly valves are versatile because they can be programmed to respond to specific signals and can be controlled remotely. Electric actuators are relatively energy-efficient and easy to maintain. However, they are not suitable for use in high humidity or explosive atmospheres. It is suitable for applications where positional accuracy and repeatability are critical.
Electric Butterfly Valve work very well in large HVAC systems in commercial buildings. HVAC systems typically require precise airflow control to maintain an optimal indoor environment. Building management systems typically operate electric butterfly valves to provide this control. The system automatically adjusts the valve based on feedback from temperature and air quality sensors.
-
Hydraulic Actuator:
