Any production arrangement where one needs to monitor, regulate, or alter the flow of a liquid media through various piping sections of a system must include control valves. Every piping system needs control valves as a crucial component.
Control valve types include ball and plug valve models that carry out comparable functions and are frequently used interchangeably. They remain unique in terms of the overall structure, function, and applied applications. This guide lists all the major differences between plug vs ball valve and other relevant information that can help people in choosing the ideal valve type for the desired applications from reliable industrial valve suppliers.
What Is Plug Valve
A plug valve rotates in a 90-degree turn and it regulates flow using a tapered or cylindrical stopper. The disc has a path for the flow to pass through and is shaped like a plug. The bore passage is in the flow while it is open. The heavy part of the stopper restricts the flow when it is swiveled 90 degrees from the open position.
In situations where speedy operation is necessary, it is utilized in place of a gate valve. Typically, plug valves are chosen for low-pressure and low-temperature applications. For usage with corrosive chemicals, plug valves that have body linings made of polytetrafluoroethylene (PTFE) can be utilized.
What Is Ball Valve
Ball valves are on or off mechanisms with a quarter-turn. The valve’s movable ball, which is located in the center, regulates the flow of gas or fluid media. The rotary ball, which serves as the pivot, is made with a hole in the middle. The ball is swiveled to open or shut down the valve via a stem on its top. The stem can be swiveled manually or automatically using levers.
Steel, bronze, iron, brass, or PVC are the materials that ball valves are most frequently composed of. Multiple ports, or apertures in the valve, are possible with ball valves. Two-port ball valves are utilized for conventional on or off control and retain double ports. Applications that need more than one media source or that require diverting media in various directions employ multi-port valves, such as 3-way valves, 4-way valves, etc.).
Plug Valve Vs Ball Valve: Major Differences
Check out the main differences between ball valves and plug valves.
Different Types of Valve
The different types of plug valves vs ball valves are listed below.
- Plug Valves
Most plug valves are full bore, especially rectangular port valves. Round port and diamond port valves can also be used, but their usage is quite limited to low-pressure applications. Lubricated plug valves and non-lubricated plug valves are the two types of plug valves.
The plug of lubricated plug valves is typically made of metal and possesses a lubricant chamber that maintains lubrication all the time. The lubricated plug moves more easily, experiences less friction, and is corrosion-resistant. Lubricated plug valves can deal with larger and high-temperature applications.
- Ball Valves
A form of control valve that has numerous applications is the ball valve. In accordance with their construction and purpose, they are available in a variety of sizes and shapes. Because of this, they are currently among the valves used most frequently in the pipe industry. There are ball valves with full and reduced bores.
Full bore ball valves enable unrestricted medium flow. As the bore is less than the diameter of the pipeline, reduced bore or reduced port valves restrict the media flow. Ball valves can be mounted on a float or trunnion. Floating ball valves are utilized in applications where a bi-directional shut-off is necessary. High-pressure, high-temperature applications use ball valves with trunnion installation.
Structure Of The Valves
The structural difference between plug and ball valve is mentioned here.
- Plug Valves
A plug valve, which has a conical tapering or cylindrical disc, regulates the flow of liquid through one or additional sideway-moving passageways. The hollow tunnel aligns with the flow when the valve is open, enabling the liquid to flow freely. The plug is realigned to restrict the flow after a 90-degree rotation shuts down the valve.
The plug valve is a compact, straightforward device that alters the flow of media by cutting or dispersing. Although some specialized varieties of plug valves can function in high-temperature situations, their primary applications are in medium or low-pressure and low-temperature environments.
- Ball Valves
The ball valve is an altered plug valve that has a spherical disc and a circular bore channel. The port is a hole that exists in the disc. The valve is open, and the medium seeps through it when the port is in line with the dual ends of the valve. The flow ceases when the port is vertical to the valve ends.
Ball valves are useful for a range of systems due to their small structure, simple use and upkeep, and compatibility with water, acids, natural gas, and solvents. Even in the extreme operating environments of media like hydrogen peroxide, oxygen, methane, or ethylene, ball valves are an excellent choice. Traditional gas shutdown ball valves are best suited for open and close operations, while more sophisticated or customized models also deliver flow control and throttling features.
The 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 is substantially greater than a ball valve. Better sealing properties result from this, but it also entails greater torque and more work during operation.
Ball valves are somewhat simpler to regulate than plug valves because of their torque-free functioning and lightweight feature. Despite the possibility that their tiny sealing surface may result in poor sealing performance, developments in chemical sealants and seal injections have helped to address this flaw.
Both plug and ball valves have bored discs in the middle. A ball valve features a spherical disc with a hollow center. 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, and it 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 can be effortlessly positioned in tinier departments because of their low footprint.
The plug valve gave rise to the ball valve. They both rotate at 90 degrees, and based on whatever “plug” is being used, it can be a plug or a ball with a circular through hole or channel running through its center. The ball and ports should be arranged so that the sphere will appear as a sphere at the intake and outlet to stop the flow when rotated by 90 degrees.
The upper components of the plug valve, the conical plug, and the body surface created by the conical pressure are sealed with packing in the space between the plug and the body. Since plug valves typically do not retain bonnets and the handles are exposed outdoors at the end, they are easy to use and frequently inexpensive.
A number of actuators, such as manual, pneumatic, hydraulic, electric, and other types, can be used to operate ball valves. They are easy to open and shut down and need little force, even while functioning in high-pressure circumstances.
Plug valves can be opened and closed manually or electrically using actuators. Despite being relatively expensive to install, pneumatic actuators can also be utilized to regulate them. Plug valves in high-pressure applications may be challenging to open and stop due to the substantial amount of torque. Because of this, plug valves are rarely used in larger applications.
The plug valve costs considerably less than ball valves. The “plug” is completely covered by the bushing, which deters wear on the valve body and plug. By changing the bushing and top seal, which can withstand 300°C of continuous use, the valve can be updated and repaired.
All other components of the plug valve are cast in a single step, and only the top face and flange need to be processed. However, the internal body does not need processing. Comparing the plug valve to the ball valve, there is a clear cost advantage of choosing plug valves.
In general, ball valves last longer than plug valves. A plug valve possesses a bigger surface area in contact with the medium and is required to deal with more torque. It shows that the valve has undergone greater deterioration and is more vulnerable to corrosion.
Ball valves have unique features that stop the medium from constantly contacting the disc. Even though there will be more moving parts, the low torque ensures that it will last longer with little to no wear and tear.
- Check Valves
Even though it is only partially achievable, plug valve customization is also an option. It is possible because of their basic design, which offers little potential for development. There are many sizes of multi-port plug valves, varying from two to five ports.
Multiport valves need to be used carefully because they might not create a very tight shut-off. The expense of all additional plug valve modifications, like the addition of electric or pneumatic actuators or anti-friction components, is relatively expensive.
- Ball Valves
Compared to plug valves, ball valves offer a significant increase in adjustability. It is because there are so many different types of ball valves accessible in the marketplace. Ball valves come in unidirectional, bidirectional, and multidirectional varieties.
They can retain one, two, or three pieces with one or more ports. Ball valves with split-body, top-entry, end-entry, and side-entry options are accessible. Ball valves can also be equipped with double block and bleed capacities.
Both ball and plug valves require routine upkeep to operate effectively. Plug valves contain fewer moving components and simpler construction, making them relatively easy to maintain. Additionally, you can simply reach the remaining valve body for easy cleaning after eliminating and cleaning the plug.
Ball valves are more difficult to clean since the ball or disc is buried deep inside the valve and is hard to access. The ball valve’s body chamber may gather significant debris over time, adding to the problems of cleaning and maintaining it.
In comparison to ball valves, plug valves provide low-cost operations. It is so that the valve body and plug would not wear out as the plug fits underneath the bushing with a plug valve. In order to update and maintain the valve’s optimal function and long-term service needs, only the bushing and top seal need to be changed.
Are Plug Valves Better Than Ball Valves
Here are the top three primary reasons that explain why the plug valves are better compared to ball valves:
- Plug valves cannot be replaced by ball valves, but the plug valves have the capacity to replace ball valves.
- Plug valves are simpler to use. Contrarily, ball valves have a space between the body and the ball. Some medium stays in the void after the ball valve is placed and is shut down. The medium must be cleaned before the machine is put back into operation. It is a common issue in chemical and food manufacturing facilities. Ball valves become worthless in critical situations where the medium cannot be thoroughly cleaned due to a prolonged stop period.
- Plug valves have a full port, meaning that the entire flow is permitted. However, ball valves can have a full port or a limited port.
Plug Valve Vs Ball Valve: How To Choose
By understanding the type of valve application, it can become easy to choose between ball valves and plug valves.
- When To Acquire Plug Valves
For bubble-tight shut-off, plug valves are used in liquid applications like vapor, air, gas, hydrocarbon, and others. Since they have a larger surface area and provide unrestricted medium flow, plug valves are frequently employed in slurries, sewage, and mud applications.
In order to ensure good sealing while working with corrosive or hard materials, strengthened plug valves are used. Because of their straightforward operational structure and anti-corrosion qualities, they are the most dependable shutdown option in sensitive applications.
- When To Acquire Ball Valves
There are many applications for ball valves, and they are used in a variety of equipment, including generator skids, compressor skids, gas feed lines, crude oil plants, LNG plants, industrial gas processing plants, polymer plants, field gas plants, hydrocarbon processing, oil refinery feedstock lines, tank farms, separator skids, and automated process applications.
High-pressure ball valves are necessary for cryogenic, subterranean, and subsea applications. In addition, ball valves made of stainless steel are necessary for brewing, desalination, feedwater, cooling water, and petroleum refining.
Valves come in a variety of types, sizes, lifetime, purposes, and control capabilities. Plug valves and ball valves have the same purpose. They both regulate the flow of gas or fluid using either a straightforward on or off function or a multipath feature.
Due to their flexibility in high-pressure applications, ball valves are excellent choices. Whereas the plug valves can be maintained easily since they have easy construction and not too many moving components. It is possible to acquire ball valves and plug valves in bulk orders from a professional valve manufacturer.