Podcast: How a Pressure Control Valve Works | Episode #7

If you’re in oil and gas production, it’s critical to know how a pressure control valve works. In this episode of Stuff You Should Know about Oil and Gas Production, Kyle explains how to identify the key components of a high pressure control valve package and what each does to support operation of the valve.

Topics for How a Pressure Control Valve Works

  • What are the key components of a high pressure control valve?
  • Explain how a pressure control valve works
  • Which components are required for production different applications?
  • Ideas for repurposing a pressure control valve
Resources mentioned in this episode:

Podcast pressure control valvepressure control valve podcastcontrol valve podcast

Transcript

Curtis: Our subject today is High Pressure Control Valves. There are several components you need around that valve in order to make it work. So we want to address these and help explain what all they are, and what you need depending on your application. So, Kyle, can you explain how a pressure control valve works?

Kyle: Kimray makes a couple of different kinds. We make a stem-guided and then a cage-guided. The control valve doesn’t do much on its own though. It’s going to go to a fail position and it’s going to stay in that position until it is told to do otherwise by some type of controller. 

That makes this valve really versatile. It can be used in a lot of different applications. It can be used as a dump valve, pressure regulator, suction controller, recirculation valve on a compressor, and even in plunger lift applications. 

Curtis: So these things are all over the place, these and the back pressure regulators you see everywhere.

Kyle: Anytime you’re driving down the highway and see a site almost always you can count on a red valve, either a back pressure or a high pressure control valve in some application. And with the high pressure control valve, it’s really the components that you pair it with that determine its function and the application that you use it in.

Curtis: Okay. Yeah. Let’s jump into that. So there are four primary components that you see used with the high pressure control valve. So what are they? 

Kyle: The pilot, the supply gas regulator, drip pot, and sense line protector.  

The pilot is what is controlling where the valve is positioning, if it’s open or closed. It is monitoring either downstream pressure or upstream pressure, depending on the application. And then it is changing the valve position to keep a set point. 

For an example, in a back pressure application it’s monitoring upstream pressure. If the pressure goes over the set point, the pilot is going to make a change to its output, to change the position of the valve to help to regulate and maintain that set point.

Curtis: So it will have pressure coming into it, right? 

Kyle: Correct. It’ll have supply gas coming through to the pilot itself. It’ll have an output going to the actuator of the valve and then it’ll have the sense line that is monitoring the controlled pressure. 

Curtis: Okay, so it sends an appropriate amount of pressure to the valve telling it to open or close. So next, the supply gas regulator. 

Kyle: The supply gas regulator takes unregulated pressure, so it could be pressure coming from the valve body itself, which could be high pressure. It could be 2,000 PSI, could be 200 PSI, but we must regulate that down to 30 PSI.

That pressure is what our pilot uses to open and close the valve. Our actuators have a maximum pressure of 45 PSI, but 30 PSI is enough to fully actuate the valve. So, you don’t want to go over that pressure, and you need something to regulate that pressure down to 30 PSI. And that’s what the supply gas regulator does.

Curtis: All right. Get it down to where the pilot can use it on the actuator. 

Kyle: Correct. 

Curtis: Next the drip pot. 

Kyle: The drip pot will be a step before the supply gas regulator. The gas you’re using for supply will come into the drip pot, and that just gives a place for any free liquids to fall out.

You don’t want to send a wet or dirty gas to the pilot. It can cause issues. So, we’re going to try to knock out some of the moisture that’s in the gas with the drip pot and then from the drip pot, it goes to the supply gas regulator. 

Curtis: The issues that it causes are with the pilot plug right? 

Kyle: Yes. The pilot plug and some of the other small areas within the pilot can get clogged up with any bit of moisture that gets in there. It can keep it from seating and sealing properly. 

Curtis: One of the most common pieces of advice I hear given is check your supply gas. Is it wet or dirty? Is it coming from a high and dry spot? 

Kyle: Yeah. And the drip pot helps with that, just helps clear out any remaining liquid. It gives it a place to go and to settle. Now you do have to drain those because they can fill up. You have to make sure that you’re draining those to keep giving that wet gas a place to fall out. 

Curtis: Okay, number four, the sense line protector.

Kyle: A sense line protector will be installed before the pilot. And what that does is it protects the pilot from being over pressured. So if you’re using a 30 HPG pilot, it’s rated for 300 pounds, but if there’s potential for more pressure to get to the pilot than 300 pounds, and if that’s in a failure scenario or whatever the case may be, you want to be able to protect that pilot from being over pressured.

So if it’s set for 300 pounds, as soon as it sees over 300 pounds, it will close and not allow that pressure to go by until it’s back down below 300 PSI. 

Curtis: Okay. Great. So these four components are important to the operation of your high pressure control valve. You can’t just set up a control valve and it’s going to work on its own. Right? 

Kyle: Right. 

Curtis: So, let’s say somebody calls up and they’re going to order a high pressure control valve from us. And they want us to build up that package. Is there a standard buildup that we do with these components?

Kyle: Yes. Our standard buildup is going to include all four of these pieces, or five pieces if you count the control valve. And that’s because we don’t know where it’s going or what it’s being used for. There are certain things that you can do if you are building this yourself, or if you’re repurposing a valve.

Maybe you don’t necessarily need a supply gas regulator or drip pot if you already have supply gas there on location that you can pull from another regulator. So those aren’t always necessarily required. 

And then with the sense line protector, if the working pressure of the pilot is higher than the valve’s working pressure, you don’t need a sense line protector because the potential for the pilot to be over pressured isn’t there because the pressure on the valve itself isn’t going to exceed the working pressure of the pilot. So, you don’t have to worry about it being over pressured. 

Curtis: We were talking about this earlier. Can you give me a numerical example of what that might look like? 

Kyle: Yeah. Again, let’s use the AHJ pilot as an example. It’s a 300 pound pilot. If you were using a 2,000-pound valve with the 300-pound pilot, you need to protect that pilot because the potential is there for there to be 2,000 PSI on the valve body or on the monitored pressure. So, you need this sense line protector in that scenario. 

But what if your valve body doesn’t exceed the working pressure of the pilot—let’s say you have a control valve with 150 raised face flanges, but your pilot is a 150 PG pilot. That’s a 1,500 pound pilot. You don’t have to worry about the pilot being over pressured because it far exceeds the working pressure of the valve. 

Curtis: And that’s because of the flanges specifically, correct? 

Kyle: Yes, that’s because of the connection type. 

Curtis: Gotcha. Okay. So, some money-saving opportunities possibly if you either have some of these onsite or you look at your application and you don’t need that supply gas regulator or sense line protector, right?

Kyle: Yep. So definitely give us a shout if we can help you talk through some of these things. We can help you repurpose valves and tell you what components you’re going to need for your application. 

Curtis: You’ll find links to the products and resources we mentioned on this episode in the show notes, and we’ll catch you next time on Stuff You Should Know about Oil and Gas Production.


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