What is Plug Valve?

What is Plug Valve?

The plug valve has a conical or cylindrical disc that can control fluid movement through one or more side passages through the plug. When the valve is opened, the hollow channel aligns itself with the flow so that the liquid can flow freely. Rotate 90 degrees to close the valve and readjust the plug to stop flow.  

Plug valves used for blocking, distributing or changing the flow of media are small and easy to use. Certain types of plug valves will also work in hot environments, but their primary use is in cold, medium or low-pressure environments.

The plug valve has a handwheel, compressor/actuator, and plug disc. When the operator operates the handwheel, the handwheel transfers motion to the compressor which further transfer its motion to the valve disc.

 The purpose of the ball and plug valves is to provide better control. In fact, they are called control valves because they guarantee an ideal seal for a wide variety of industrial applications. When choosing the right valve, it is important to understand the function of the valve.

Large valves are more expensive and heavier, but the focus is on the tightness of plug valves. However, ball valves are best for large applications that need to be easier to use.

Key Difference Between Plug Valve and Ball Valve

1) Function

Both the plug valve and ball valve are right angle rotary valves that can be opened and closed by rotating the actuator 90 degrees. Its main purpose is sealing and closing. However, the sealing surface of the plug valve is much larger than the sealing surface of the ball valve. That means a better seal quality, but also a higher torque and a higher operating effort.

Ball valves do not require torque and are lightweight, which makes them easier to use than plug valves. A small seal area can mean poor seal performance, but advances in seal injection and chemical sealants have addressed this shortcoming.

2) Maintenance 

Both types of control valves require regular maintenance to function effectively. The plug valve has a simple structure and few moving parts, so that maintenance is relatively easy. In addition, the plug can be removed and cleaned to facilitate access and cleaning of the remainder of the valve body.

It is more difficult to clean the ball valve because the ball or disc sits deep in the valve and is difficult to access. Over time, media particles can collect in the cavity of the ball valve body, which further increases the cleaning and maintenance problems.

In general, the cost of running a plug valve is less than the cost of running a ball valve. This is because the cone of the cone valve is mounted under the bushing to prevent the valve body and cone from wearing out. Replacing the bushing and top seal is sufficient to improve and maintain the best valve functionality and long-term service requirements.

3) Applications

The large surface area and unobstructed flow of the plug valves make them ideal for applications such as sludge, sludge and sewage. Reinforced plug valves provide a tight seal when handling aggressive or corrosive media. Its simple structure, ease of use and maintenance, and corrosion resistance provide reliable shutdown options for the most critical applications.

Multifunctional ball valves are popular in a variety of automated applications, such as: water supply, oil refining, hydrocarbons, cooling water, brewing and desalination, processing, high ph services.

Applications of Plug Valve

  1. The plug valves are used for different types of compressors to control the gas flow.
  2. They are also used for different pumps and boilers.