Podcast: How Does a Pneumatic Valve Actuator Work? Episode #6

A pneumatic valve actuator uses motive gas to drive a valve to its open or closed position. In this episode of Stuff You Should Know About Oil and Gas Production, Kyle Andrews answers the question, How does a pneumatic valve actuator work?

Topics for How Does a Pneumatic Valve Actuator Work?

  • What is an actuator? 
  • Why does a control valve need an actuator? 
  • What sources other than supply gas can be used?  
  •  Why do some producers use compressed air to power their valves? 
  • Why are the advantages and disadvantages of pneumatic valve actuators? 
Resources mentioned in this episode:

Pneumatic Valve Actuator podcastpodcast Valve Actuatorpodcast oil and gas valve

Curtis: Kyle, I wanted to talk a little bit about your recent job change. So you were an Account Manager with our Oklahoma City team, and now you’ve moved over to Product and Applications Trainer. Tell us a little bit about that new role.

Kyle: I’m going to be responsible for a few things, but mainly giving in-person training courses and developing an online training curriculum for our sales team.

Curtis: Very good. Well, I know you did a lot of that in your account manager role and you’ve taught me a ton, so I’m really excited about that change for Kimray. And I know we’re going to be offering even more training for our customers as well. So looking forward to seeing all you’re going to do with that.

Today we wanted to talk about another one of our blogs that gets a lot of web traffic, which is, “How does a Pneumatic Valve Actuator Work?” First let’s just talk about an actuator. What is an actuator?

Kyle: When it comes to control valves, the actuator is the driving force that moves the valve. A control valve doesn’t move on its own. It needs something to force it open and closed, and the actuator is what moves the valve stem open or closed.

Curtis: And obviously that’s going to need some kind of power to drive open or closed, but there are different types: mechanical pneumatic, and electric. So we’re talking about how does a pneumatic valve actuator work.

Kyle: A pneumatic actuator, when we say pneumatic, that can be air, natural gas, nitrogen, any kind of pneumatics as the driving force that the actuator uses to operate the valve.

Say we’re setting one of these up and we have a high pressure control valve. It’s got a pneumatic actuator on top, which is the kind of a saucer-looking thing on the top of our high pressure control valves. I can’t just set that up and expect it to work. What do I need to do to get gas or air into that valve for it to work? Well, the air or gas is coming to from a controller of some kind, whether that be a pneumatic pilot or a liquid level controller or even an I/P, it has to come from some type of controller monitoring the conditions and telling that valve to open and close.

Curtis: Okay. So what’s a common setup that you see?

Kyle: It depends on the application. For a dump valve, you’ll have a liquid level controller, like our Gen II liquid level controller. And the output of that level controller would go to the control valve being used as a dump valve.

So when liquid level rises and actuates the level controller, it then sends a pneumatic signal to the valve to open that way. It evacuates the liquid that’s in the vessel and the liquid level will lower. Once it gets to a certain point it’ll shut off the pneumatic signal going to the dump valve. And then the dump valve will close.

Curtis: Okay. So we talked about three types of actuation. We said there’s mechanical, there’s pneumatic. And there’s electric. What would you say one is the most common that you see out in the field?

Kyle: Pneumatic is definitely the most common.

Curtis: Why is that?

Kyle: I think because in oil and gas production, you always have some kind of pneumatics on location. You’re always going to have natural gas. And so it’s very available. It’s there. Also the variety of applications that pneumatics can be used for. If we’re talking about mechanical actuation, you’re limited to 500 PSI and below. With pneumatic actuation, you can have high pressure controls and they can also do low pressure. So it’s a wider range of applications can be done with pneumatic actuation.

Curtis: So they can take advantage of just the gas that’s in the production fluid. Whether they’re producing primarily oil or primarily natural gas, there’s going to be gas there that they can take and route it to a controller, which routes to the actuator.

Kyle: Correct. And you see a lot of producers now using compressed air as that motive gas for their pneumatic controls, because if that’s venting to the atmosphere, they don’t have to worry about environmental concerns.

Curtis: Yeah, well, that gets to my next question, which had to do with maybe some of the challenges with pneumatics. And one of those is emission venting, right?

Kyle: Yes. And so setting an air compressor on location, it does cost money. So, you know, a producer has to think about—I can either vent a natural gas to the atmosphere, or I can set a compressor, or I can try to go either capture the venting natural gas or use non-venting valves or controllers as another option.

Everybody’s trying to get away from venting any kind of emissions to atmosphere as much as they can. So again the options there are some type of vapor recovery unit to capture that, and Kimray makes non-venting valves and you can even convert your venting valves to non venting.

We have a good video on that over on the blog.

Curtis: I know one challenge that comes up quite a bit with pneumatics is wet gas.

Kyle: Yeah. So if you have wet gas on location and you’re using that for supply for your valve controller or your pilot, it can cause issues because, of internal elements like the pilot plug. All of our controllers have the pilot plugs that are designed for gas only. So if there’s a lot of moisture in your gas or debris it can keep that from operating like it should.

A couple of things you can do to help with that are just make sure the spot where you’re getting your supply gas is from the highest and driest spot possible.

Another thing you can do is use some kind of scrubber. We, we make a mini scrubber that helps dry out the gas So just an extra separation step to take it out the liquids from the gas before you use it.

Curtis:  Then kind of the big move that the industry seems to be making is toward electric actuation. Are you seeing that?

Kyle: Oh yeah, absolutely. You know, there’s, there’s lots of advantages to going with electric actuation. You’re getting a no-emission option, so there are no gas emissions with electric actuation. Then also you have the ability to automate processes and control processes remotely.

Curtis: Yes, there’s a lot of information available and some good videos on those electric products on the Kimray blog. Of course we’ll have links to the products mentioned and resources we talked about in the show notes. We’ll catch you next time on Stuff You Should Know about Oil and Gas Production.

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