The butterfly valve actuator selects the power source that is used to operate the valve. This affects the valve’s reaction time, actuation pressure rating, environmental compatibility, and other factors. Choosing the appropriate actuator might be influenced by the available power source(s) for the specific application. This post provides a detailed analysis of several actuator types, catering to users who possess a certain degree of freedom in choosing the kind that best suits their needs. Keep reading our page on actuator types to get insight into the operational mechanisms of various actuator types in relation to industrial valves.
Butterfly valves control pipe fluid flow. This valve operates like a ball valve and shuts off quickly. Butterfly valves have revolving stems with discs. The disk stops fluid flow when the valve closes. To enable practically unfettered fluid flow, the valve is completely open and the disc spun a quarter turn. Between totally closed and fully open, the disc permits proportionate flow. Manufactured by the top butterfly valve manufacturers, these valves are easy to use, reliable, and inexpensive.
Butterfly valve actuator selection
System components and needs determine butterfly valve actuator selection. Operators can actuate a butterfly valve manually, electrically, pneumatically, or hydraulically operate a butterfly valve. Manual butterfly valves are ideal for tiny, seldom opening and closing valves. Larger valves have gearboxes for manual operation.
- Depending on type and construction material, butterfly valves range in cost from least to most expensive: manual, electric, pneumatic, and hydraulic
- Pneumatic and hydraulic actuators cost more because they need compressed air or hydraulics
- Large butterfly valves may need a hydraulic actuator for effective opening and closing
- For high-system pressure applications, hydraulically operated butterfly valves may be essential
- Pneumatically operated butterfly valves provide rapid reaction time for certain applications
- Manual butterfly valves are the easiest to install and operate since they do not need an external power supply
- Electrically operated butterfly valves are not suited for damp or explosive settings.
Butterfly valve actuator types
Manual, electrical, hydraulic, and pneumatic butterfly valve actuation are the main ways. Electric, hydraulic, and pneumatic butterfly valves typically feature manual actuation options.
Manual butterfly valve
Designed and produced by the leading butterfly valve manufacturers, butterfly valves are easiest to use manually. The simplest version employs a lever to move the valve stem, which opens or closes the valve disc. Hand wheels may link to gearboxes for larger butterfly valves. This is the simplest technique to manually open or shut the valve. Manual operation’s main advantage is that it does not need any electricity. For frequent butterfly valve actuation, this actuation type is not optimal since a user must open or shut the valve.
Electric butterfly valve
An electric valve actuator generates torque from electricity. This torque turns the valve stem to open or shut. Programmable and remote-controlled electrically operated butterfly industrial valves are versatile. Electric actuators are energy-efficient and easy to repair. They are not ideal for explosive or high-moisture conditions.
Hydraulic butterfly valve
- Butterfly valve hydraulic actuators generate force from fluid
- A piston in the cylinder moves as the hydraulic pump presses oil
- The valve stem opens or closes with piston action
- Hydraulic actuators can operate high-pressure valves with considerable force
- However, the hydraulic power unit and fluid reservoir complicate and expense the system.
Pneumatic butterfly valve
Air pressure powers pneumatic actuators. Actuator air presses a piston or diaphragm to spin the valve stem. Butterfly valves with pneumatic actuators are rapid and dependable. They don’t ignite, therefore they’re safe in dangerous conditions. The actuation speed is harder to regulate than electric or hydraulic actuators and requires a compressed air supply.
Industrial valve actuator standards
Butterfly valve actuators must fulfill international standards. Valve actuators that violate these criteria may break prematurely, damaging a system and endangering workers. Some common industrial valve actuator standards include the following:
- ISO 22153: ISO 22153 defines industrial valve actuators’ fundamental specifications
- ISO 5211: ISO 5211 specifies actuator requirements for part-turn valves, which have a stem that spins less than 360° to open or shut. Actuators with or without gearboxes are standard
- BS EN 15714: This standard specifies part-tun valve pneumatic actuators.
Actuator specific applications
The following examples are applications typically suitable to one type of butterfly valve actuation method. Use the following examples to help determine which type of actuator a different application may require.
Manual butterfly valve
Manual butterfly valves work well in small-scale water treatment plants. The valve controls the flow of water through different treatment process stages. Operators can use manual operation to adjust the valve and control water flow depending on treatment needs. Ideally, this valve will not be adjusted frequently.
Electric butterfly valve
Electric butterfly valves work very well in large-scale HVAC systems in commercial buildings. HVAC systems typically require precise airflow control to maintain the optimal indoor environment. The building management system typically operates the electric butterfly valve to provide this control. The system automatically adjusts the valve based on temperature and air quality sensor feedback.
Pneumatic butterfly valve
Pneumatic butterfly valves work well in gas processing plants where safety is essential. Using a valve that operates via air pressure rather than electricity reduces the risk of sparks which can cause explosions.
Hydraulic butterfly valve
Hydraulic butterfly valves work well in hydroelectric power plants. The valve controls flow in the penstock leading to the turbine. This is a high-pressure application that other actuator types likely could not produce enough force to work under.
Concluding Remarks
Butterfly valves are like ball valves but have benefits. Small and pneumatically operated, they open and shut swiftly. The disc valve needs less structural support than a ball valve of equal diameter and is lighter. Butterfly valves are accurate, making them useful in industry. They are durable and low-maintenance.
Butterfly valves work pneumatically, electrically, or manually. Pneumatic valves are the fastest. Electronic valves need a gearbox signal to open or shut, whereas pneumatic valves may be single or double-actuated. In the event of a power loss, a single-actuated valve springs back to a closed state. Non-spring-loaded double-actuated pneumatic valves need a signal to open and shut.
Automation makes pneumatic butterfly valves dependable and lasting. Reduced wear extends valve life, reducing operational expenses from valve maintenance hours.
