What Is a Plug Valve and How Do You Use It?
If you work in an industry that relies on hydraulic systems to function, then we’d be surprised if you haven’t run into a plug valve. Plug valves are an essential part of a hydraulic system and work to keep the system functioning efficiently.
If you’re looking for a plug valve refresher course, keep reading. We’re going over what a plug valve is, how it works, its common applications, and more.
Let’s get started.
Basics of the Plug Valve
A plug valve comes in either a cylindrical or a conical shape. Inside the valve is one or more hollow chambers that allow for flow through the valve when it’s in the open position.
Plug valves are most commonly a “two port” system with an “open” position that allows for flow through the hollow passages, and a “closed” position that stops the flow.
It’s controlled with a rotator that has a manual handle for control. Turning the handle will rotate internal components that will either leave the passages open or close (“plug”) the passages to stop the flow.
These valves are most often used for horizontal flow with a single quarter turn of the rotator to adjust the valve’s internal passage flow.
Plug Valve Symbol
The plug valve symbol on plans or logistical documents is an upsidedown triangle with an “L” shaped bracket on top. You can see a list of valve symbols, including the plug valve symbol, on this page.
Types of Plug Valves
There are particular types of plug valves that have special features, are made of certain materials, and that are made for certain industries. Some of the different kinds are:
- Lined plug valves
- Lubricated plug valves
- Expanding plug valves
- Eccentric plug valves
- Taper plug valves
- Elastomer sleeved plug valves
- Lift-type plug valve
Each of these different types of plug valves has different applications that we will detail more in the next section.
Common Uses for Plug Valves
Plug valves don’t get clogged, and they can handle high-pressure situations. They can also handle corrosive and dangerous materials, which also means they require a lot of maintenance and replacement.
Here are some of the most common applications of plug valves:
High-Pressure Flow Lines
Since plug valves are able to handle high pressure, they’re often used in high-pressure applications like cementing, high-pressure/temperature materials, coiled tubing, acidizing, etc.
Dirty Upstream Applications
This is where most lubricated plug valves find their home. These valves won’t get clogged, can handle abrasive/corrosive materials, etc.
They do require maintenance more often because of these conditions.
Because of the “plugged” and “open” configuration that’s easily controlled, plug valves offer great flow control and isolation of materials. These valves can easily seal and separate liquids to avoid contamination or mixing, which is also crucial for certain high-pressure applications.
Sewage, Mud, Oil, Coal Slurries, etc
Plug valves don’t get clogged, so they can handle these abrasive types of materials. These valves are also great at control and isolation, as we just went over, which also makes them useful for working on flow lines with these materials.
The Plug Valve: Final Thoughts
This gives you a brief overview of the plug valve along with just a few of their uses. However, this list is far from a comprehensive one on the topic.