A plug valve with a one-piece top-entry construction resembles a one-piece top-entry ball valve in many ways. Technically, ball valves and plug valves are the same valves because they perform the same functions and have similar features, and have similar applications. Today, we’ll examine the differences between a plug valve and a ball valve.
Definition of Ball Valve vs. Plug Valve
A control valve is an integral part of every piping system. These valves are primarily use to control the flow of the medium through various sections of piping in a system. Control valves such as ball valves and plug valves perform similar tasks and are frequently interchangeable. In terms of their function and structure, however, they are still distinct.
Control valves come in so many types that it can be overwhelming to choose one. Installing the wrong valve in a system that has important applications can make it less efficient and even deadly. In this post, I’ll explain the differences between plug and ball valves so that you can make an informed decision about which is right for your application. Keep reading to find out more.
What Are Ball Valves and Plug Valves?
Let’s first understand what ball and plug valves are. Control valves with spherical discs inside are known as ball valves. This disc has a port, which is a hole. By aligning the port with both ends of the valve, the valve is open, allowing the medium to freely flow through it. When the port is perpendicular to the ends of the valve, the valve is close and the medium flow stops.
Water Ball Valve
Ball valves evolved from plug valves with a ball as their closing part; they revolve around the valve’s center to open and close and are mostly use to cut off, distribute, and change the direction of a flow. A ball valve can close firmly with just a 90-degree rotation or a small torque. Through the flow path for the medium, the entire horizontal cavity of the valve body provides no resistance.
Ball valves are characterize by their compact structure, ease of operation and maintenance, and suitability for water, acids, solvents, natural gas, and other general media. Additionally, it can handle harsh media such as oxygen, hydrogen peroxide, methane, and ethylene. The body of the ball valve can be made from one piece or multiple pieces. A ball valve is commonly thought to be best for opening and closing instantly, but new improvements have made them suitable for throttling and flow control as well.
Water Plug Valve
Plug valves get their name from the conical taper or cylindrical disc that looks like a plug. Plugs have one or more sideways openings that allow fluid to pass through. The valve opens when the bore passage aligns with the flow, allowing fluid to pass freely through it. The solid section of the stopper restricts the flow and thus closes the valve when it is turne.
The plug valve is a type of old-line valve that is also known as a cock valve or a spinning plug valve. The valve “plug” (usually conical or cylinder) is connected with the body of the conical hole surface, which moves around the centerline of the valve to achieve open and close. Mostly, it is use for cutting, distribution, and changing media flow.
Plug valves have a simple design and are small in size. They can only rotate 90 degrees to open and close. Commonly use in low-pressure, small-diameter, medium- to low-temperature situations. The plug valve’s sealing surface is easily worn away, and it is also easy to get stuck in high-temperature or high-pressure situations, making it unsuitable for flow regulation.
The ball valve and the plug valve are quarter-turn valves, which means that they can open or close by rapidly rotating the actuator 90 degrees. These are quick-acting valves that are use for sealing and shutting down processes. Both ball valves and plug valves are ineffective for throttling. It is possible to modify either valve’s design and construction to make it suitable for throttling, but it would be rather costly.
What Is the Difference Between Ball Valves and Plug Valves?
As far as function and use are concerned, ball and plug valves are very similar. Control valves are use in various piping systems to produce tight shut-offs. Each of them relies on a perforated disc to control the flow of the medium. They differ in several ways, though. These are some of the main differences between ball valves and plug valves:
At the center of both the ball and plug, valves are bored discs. Ball valves have a hollow center and a spherical disc. Through a plug valve, a conical or cylindrical disc is drilled with openings. The disc or ball in a ball valve is smaller than the disc or plug in a plug valve. As a result, a plug valve can provide a tighter shut-off than a ball valve. Plug valves are also smaller than ball valves. As plug valves have a smaller footprint, they can easily place in smaller units.
The plug valve was replace by the ball valve. Although both rotate at 90 degrees, the “plug” is either a plug or a ball with a circular hole or channel going through its axis. When the ball and ports are rotated by 90 degrees, the sphere will appear as a sphere at the intake and outlet, cutting off the flow. Plug valve upper sections, the conical plug, and pressure-formed conical body surfaces are seale with packing between the plug and the body space. Typically, plug valves are simple and cost-effective since they do not have bonnets and instead have the handle exposed outdoors at the end.
Plug valves outperform ball valves when it comes to cutting performance, but this isn’t immediately apparent. The plug valve’s sealing surface is much larger than that of the ball valve and provides a superior seal, although at the cost of more torque and a smaller diameter. It is preferable to use the ball valve as a medium switch rather than as a throttle valve to reduce medium erosion and valve tightening over time.
Plug valves are use when sealing requirements are stringent, but the diameter is small, while ball valves are use when the sealing effect is needed. is not stringent, but the diameter is large because, with the advancement of sealing technology, the sealing effect of the ball valve has greatly improved.
Plug Valve is Lower Cost
By completely covering the “plug” on the plug valve, the bushing prevents wear on the valve body and plug. It is possible to repair and update the valve by replacing the bushing and top seal, meeting the long-term service requirements of 300°C. The wide temperature range provides significant advantages over hard-sealed metal ball valves.
Additionally, only the top face and flange of the plug valve require processing; all other sections are cast in one stage, and the interior body does not need to be processed. In manufacturing MONEL, INCONEL, HAST alloy, and other exotic materials, the plug valve has an economic advantage over a ball valve.
Valve control mechanisms such as a ball and plug valve is use to start and stop the flow of a medium. A plug valve’s sealing surface is significantly larger than a ball valve. As the valve’s cylindrical or conical stopper has a larger surface area, it offers a better seal. On the other hand, a larger surface area translates to more torque. The valves are stiff as a consequence of the tremendous torque.
On the other hand, ball valves do not require any torque to operate. Despite their reduced surface area, ball valves can experience poor sealing performance. However, advances in chemical sealants and seal injections mean this is no longer an issue. Plug valves tend to be heavier than ball valves.
Since plug valves are expensive to manufacture and can become quite heavy, plug valves are typically use in smaller applications.
To function properly, control valves must be regularly maintained. Ball valves are difficult to maintain because the ball is positioned deep within the valve and cannot be easily accessed. One of the most common criticisms of ball valves is that the valve’s body cavity accumulates particles from the medium, making their removal difficult.
Plug valves are easier to maintain since the plug can be removed and cleaned quickly. The rest of the valve body can also be easily accessed, making maintenance a breeze. Plug valves have a simpler design and fewer moving parts than other valves. They’re also much smaller than ordinary valves. Repairs and maintenance are much easier.
Ball valves are a type of control valve that can use in many applications. Depending on their structure and function, they come in a variety of shapes and sizes. This is why they are one of the most widely use valves in the pipe industry. There are ball valves with full and reduce bores. The full bore ball valve permits unrestricted medium flow. In reducing bore or reducing port valves, the bore is smaller than the pipeline diameter, thus limiting the flow of the medium.
Floats and trunnions can equip with ball valves. A floating ball valve is use when a bi-directional shutoff is required. Ball valves mounted on trunnions are using in high-pressure, high-temperature applications.
The types of plug valves are fewer than those of ball valves. The majority of plug valves, particularly rectangular port valves, have full bores. Reduce bores are also possible with round port and diamond port valves, but these can only is use in low-pressure situations.
Plug valves can categorize into two categories: lubricate plug valves and non-lubricated plug valves. Normally, lubricated plug valves are made of metal and have a lubricant chamber that ensures the plug remains lubricated at all times. Lubricate plugs are easier to move, have less friction, and resist corrosion. Lubricate plug valves can is use for larger applications and high-temperature services.
In non-lubricated plug valves, an elastomeric sleeve is inserte between the plug and the valve body. This sleeve reduces friction between the plug and the body. The valve, however, cannot use in high-temperature applications due to the non-metallic seat.
The lifetime of a ball valve is longer than that of a plug valve. The plug valve must be able to handle more torque and has a larger surface area in contact with the medium. The valve has been subject to more wear and tear, making it more prone to corrosion. A ball valve has special features that prevent the medium from coming into constant contact with the disc. Due to the low torque, there is less wear and tear, even though there are more moving parts.
Manual, electric, pneumatic, hydraulic, and other types of actuators can use to operate ball valves. Even when operating under high-pressure conditions, they are easy to open and close and require very little force. Both manual and electric actuators can use to operate plug valves. Pneumatic actuators can use as well, but they are quite expensive to install. Plug valves are notoriously difficult to open and close in high-pressure applications due to their high torque. The reason plug valves aren’t usually use in larger applications is because of this.
Both ball and plug valves can be adjusted to meet individual needs. On the other hand, ball valves can be adjusted much more easily than plug valves. There are so many types of ball valves on the market, so you have a lot of options. There are unidirectional, bidirectional, and multidirectional ball valves. They can have several ports and a one-piece, two-piece, or three-piece body. Ball valves are available with top-entry, end-entry, side-entry, or split-body designs. Bleed and double block capabilities can also be added to ball valves.
Plug valves can also be customized, but only to a limited extent. Because of their simplistic structure, they leave little room for improvement. Multiple-port plug valves are available in a variety of sizes, ranging from two to five ports. Multiport valves should use with caution since they may not produce a very tight shut-off. Other types of plug valve adaptations, such as using electric or pneumatic actuators or adding anti-friction components, are quite expensive.
What Are the Differences Between Ball Valve and Plug Valve?
Ball and plug valves are widely use in a variety of pipeline applications. To enable bubble-tight shut-off, plug valve is use in fluid services such as air, gas, vapor, hydrocarbon, and others. In slurries, mud, and sewage applications, plug valves are typically use because they have a large surface area and allow for unrestricted medium flow. When dealing with corrosive or hard materials, fortified plug valves are employed to ensure a tight seal. Due to their anti-corrosion properties and basic operational structure, they provide the most reliable shutdown choice in critical applications.
There are many applications for ball valves. The turbine skid, compressor skid, gas feed line, generator skid, crude oil plants, polymer plants, separator skids, field gas plants, LNG plants, industrial gas processing plants, tank farms, hydrocarbon processing, oil refinery feedstock lines, and automated processes are just a few of the applications in which they use. The subsea, underground, and cryogenic industries all require high-pressure ball valves. In addition to cooling water, petroleum refining, feedwater, desalination, and brewing all require stainless steel ball valves.
Also, read How does the Butterfly Valves Work?
In a variety of applications, control valves such as ball valves and plug valves provide bubble-tight seals. The plug valve seals better, but it’s difficult to use and too heavy and expensive for large-scale applications. Despite their limited sealing abilities, ball valves are simple to operate and can scale up for bigger applications. Moreover, with the addition of technology and systems, their sealing capacities can improve. Our catalogs offer a wide selection of ball and plug valves.
Aira Euro Automation is a leading valve manufacturer in India, Aira has a wide range of pneumatic and manually operated industrial valves. They export their products to more than 20+ countries including Gulf countries.