#WishIknew – What’s a control valve actuator?

Valves

When you have a question about process automation that needs a short answer, let us know with #WishIknew and @Visaya! We’ll reply with a #WishIknew post. It’ll give a quick explanation, then some related articles, videos, or reviews if you want to know more.

I wish I knew what a control valve actuator is!

The control valve actuator is one of the three main components of control valves. If you want to know about the others, you can read our other #WishIknew on them here, here and here. We have tons of valve actuators on the market with various operations, but this overview should give you a place to start if you want to know more.

The actuator adjusts the valve position using information from the positioner. You can operate the valve actuator in many ways. For instance, a pneumatic actuator converts air pressure to a linear or rotary movement. If you have an electrical actuator, a motor converts electrical energy into mechanical torque. And a hydraulic actuator works like a pneumatic, only it uses liquids instead of air.

Courtesy of Samson

Valve actuators can work backward or forwards, too. We call that direct or reverse action. For direct action, the input will push down the valve stem and the spring will push it up. For reverse action, the input will push the valve stem up and the spring pushes it down. Makes sense, right?

If you have a pistol actuator, then those come in linear or rotative versions. The linear actuator works with linear valves, naturally, and the rotative actuator with butterfly valves and such.

See? We have a lot of variations, but they all do the same thing – move the valve to increase or decrease the flow of product. Dead simple but super important!

Watch the video to learn more about how actuators work:

Related tags: #WishIknew Actuator Basic Control valves devices English Final Element Principle valves
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