The flow of liquids and gases can be controlled using valves in a variety of settings. Valves come in a variety of types, functions, porting, durability, and control capabilities. On the other hand, plug valves and ball valves serve the same purpose. They both regulate the flow of gas or liquid using either a straightforward on/off function or a multipath function. So, what are the differences between those valves?
In this post, I want to share the differences between ball valves and plug valves in terms of body structure, function, application, and maintenance. And on the last post, we will learn how to choose the right one. Before we jump into the difference between those valves, let’s learn some basics about ball valves and plug valves.
What Are Ball Valves?
Ball valves are valves with an internal spherical disc. There is a port, or hole, in this disc. When the port and both ends of the valve are lined up, the valve is in the open position, enabling the medium to freely flow through it. When the port is perpendicular to the ends of the valve, the valve closes, and the medium flow stops.
The ball valve characteristics are small design, simplicity of use and maintenance, and suitability for water, acids, solvents, natural gas, and other general. Additionally, it works well with corrosive media including oxygen, hydrogen peroxide, methane, and ethylene. The body of the ball valve may be made of one piece or many sections. Although it is typically believed that ball valves are better for opening and shutting instantly, recent advancements have made them acceptable for throttling and flow control.
What Are Plug Valves?
The cylindrical disc with a conical taper or conical shape that resembles a plug is what gives plug valves its name. The plug features a side opening or apertures on either side that let fluid pass through. The valve opens, enabling fluid to flow freely through it as soon as the bore passage lines up with the flow. When the valve is turned, the solid portion of the stopper blocks the flow and shuts the valve.
The plug valve is small and has a simple construction. To open and shut, it can only be turned 90 degrees. It is commonly used in conditions of low pressure, small diameter, and medium to low temperature. The plug valve is not suitable for flow regulation because its sealing surface is easily worn, and it is easily to become stuck in high-temperature or high-pressure conditions.
Differences between Ball Valves and Plug Valves
Body Structure
A ball valve features a spherical disc with a hollow core. A plug valve is composed of a conical or cylindrical disc with drilled apertures. The disc or ball in a plug valve is larger than the disc or ball in a ball valve. This enables a plug valve to provide a tighter shut-off than a ball valve. Plug valves are also more compact than ball valves. Plug valves’ reduced footprint makes it simple to install them in smaller units.
Function
Both plug valves and ball valves operate with a rapid 90-degree rotation of the actuator, making them quarter-turn valves that open and close. Their main function is sealing and shut-off procedures. The plug valve’s sealing surface, however, is substantially greater than a ball valves. Better sealing properties result from this, but it also entails higher torque and more work during operation.
Ball valves are somewhat simpler to operate than plug valves because of their torque-free functioning and small weight. Despite the possibility that their reduced sealing surface may result in poor sealing performance, developments in chemical sealants and seal injections have helped to solve this flaw.
Application
Plug valves are the best option for applications involving mud, slurries, or sewage because of their increased surface area and unrestricted flow capabilities. Fortified plug valves offer tight sealing when working with corrosive or hard materials. They are a reliable shutoff choice for the most of critical applications because to its simple construction, convenience in use and maintenance, and anti-corrosion properties.
For a range of automated applications, such as gas flow lines, crude oil, LNG, and more, the adaptable ball valves are a popular option. High-pressure ball valves are a great option for subsea and cryogenic services while stainless steel ball valves are good for cooling water, petroleum refining, feed water, brewing, and desalination.
Maintenance
Both plug valves and ball valves require routine maintenance to operate properly. Plug valves contain fewer moving components and a simpler construction, making them relatively easy to maintain. Additionally, you can simply reach the rest of the valve body for hassle-free cleaning after removing and cleaning the plug.
Ball valves are more difficult to clean since the ball or disc is buried deep inside the valve and is difficult to access. The ball valve’s body chamber may gather significant debris over time, adding to the problems of cleaning and maintaining it.
Longevity
In general, ball valves have longer lifespan than plug valves. Greater torque must be handled by a plug valve, and more of its surface area comes into contact with the medium. This indicates that the valve is more susceptible to corrosion.
Ball valves are equipped with unique devices that stop the medium from coming into continual contact with the disc. Despite having more moving components, it requires less maintenance because of the low torque.
How to Choose?
Plug or ball valves may be required, depending on the material. Ball valves might be more adaptable, although plug valves are simpler to maintain and clean.
Plug valves have better tight sealing properties while being more costly and heavy for larger scale. However, it is true that they are difficult to operate. Ball valves are a preferable option when you have a larger application that requires for simpler operation. However, keep in mind that they do not have the same tight sealing properties as plug valves. You could require more modern technologies and updated mechanisms to increase a ball valve’s sealing capacity for your large-scale application.
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