Actuated Butterfly Valves
What is an Actuated Butterfly Valve?
An Actuated Butterfly Valve consists of two parts: an actuator and a butterfly valve. An actuator is a mechanism used for closing and opening a valve. The actuator uses air, electricity, or a spring to open and close the valve. The butterfly valve regulates or isolates flow, using a disk as a closing mechanism. Thus--in short--within an actuated butterfly valve, the actuated butterfly valve works by taking supplied energy from the actuator and moves the butterfly valve disc accordingly.
In the center of the pipe is a plate or disc. A rod, connected to the actuator, passes through the disc in the center of the pipe. When the actuator is turned (rotated), the disc will become either parallel or perpendicular to the flow. In an actuated butterfly valve, the disc will slightly open and close to establish or control the media’s flow rate. As the disc on the butterfly valve closes, the upstream pressure will increase, while the downstream pressure will decrease.
The disc can be iron, stainless steel, aluminum/bronze or nickel-plated. Materials for the stem include stainless steel or carbon steel.
The rotary stem of the butterfly valve moves to a maximum of 90 degrees. The design itself is compact; there are no pockets; thus, fluid cannot become trapped. This is the reason that butterfly valves are often used in sanitary applications, although they are not a true sanitary valve per se.
Uses and Advantages
Actuated butterfly valves are very common in the agricultural, water and wastewater treatment industries. Actuated butterfly valves can be used for water, gas, and air-cooling, for vacuum service, and high pressure/temperature water services.
Actuated butterfly valves are often small and are able to be opened and closed quickly. It’s compact, lightweight, and available in wide selection of sizes. In fact, some butterfly valves are so large, an average adult could stand completely upright within its orifice. However, the bigger the valve the larger the actuator is required. And, the size and weight of the valve package is definitely a factor in many applications. Thus, some manufacturers have gone to great lengths to reduces the size of the actuator on large automated valve packages. Vein actuators continue to grow in popularity, because they can significantly reduce the size of the actuator that is operating the valve(NOTE: For more information on vein actuation, visit our Easytork Valves page). Regardless of the actuator needed, butterfly valves have proven themselves to be reliable, precise, and require very little maintenance. If properly specified and maintained, they provide a tight, reliable, two directional shut off.
Slurry buildup can affect a butterfly valve’s performance. In addition, slurry can make the butterfly valve difficult to clean. For this reason, when dealing with extreme applications, it is recommended to use a double or triple offset butterfly valve.
If you found this overview interesting, please consider checking out the following resources offered by our valve store: