Floating Ball Valve Vs. Trunnion Ball Valve: What is Their Difference

In this blog post, you’ll read:Ball valves are known for being compact, durable, and reliable, with quick on/off control. A ball valve controls the media flow by a hole (called a port) through the middle of the ball. Turning the ball 90 degrees’ lines up the port with the valve body and lets media pass through the valve. Turning the ball back 90 degrees to the closed position closes the valve. Seats are generally made of polytetrafluoroethylene (PTFE). It holds the ball in place and makes a tight seal so that media doesn't leak through the valve.
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Ball valves are known for being compact, durable, and reliable, with quick on/off control. A ball valve controls the media flow by a hole (called a port) through the middle of the ball. Turning the ball 90 degrees lines up the port with the valve body and lets media pass through the valve. Turning the ball back 90 degrees to the closed position closes the valve. Seats are generally made of polytetrafluoroethylene (PTFE). It holds the ball in place and makes a tight seal so that media doesn’t leak through the valve.

There are 2 main types of ball valve designs: floating and trunnion. It is most famous for industrial plumbing systems that use floating ball valves. When the seats on these valves start to wear down, the pressure from the fluid moves through the valve. It pushes the ball against the downstream seat to keep the seal tight. This article will explain the floating ball valve vs the trunnion ball valve. Let’s get started.

What Are Floating Ball Valves

Floating ball valves contain a ball that floats within the valve’s interior. The stem, which is actuated by a handle, is connected to the ball. The ball is connected to a lever that operates the valve’s opening and closing. Oil and gas, chemical refining, and water treatment are some industries that utilize floating ball valves.

brass floating ball valve body
brass floating ball valve body

Floating ball valves are employed in applications requiring high precision. The ball in a floating ball valve can move freely up and down. It allows it to create a secure seal. This makes floating ball valves suitable for applications where minimal leakage is permissible.

Floating ball valves are offered in different materials, such as brass, stainless steel, and plastic. The choice of material depends on the application for which the valve is used. For instance, a plastic movable ball valve would best suit an acidic environment. On the other hand, a brass ball valve would best suit a high-temperature application.

How Do Floating Ball Valves Work?

floating ball vs trunnion
floating ball vs. trunnion

                                                       Working mechanism

In the ball valve, the stem, or shaft, is connected to the top of the ball and turns it 90 degrees. This moves the floating ball valve. As the ball rotates, the wall of the valve body either covers or uncovers the port. This either passes the media run or stops it. There is enough space between the stem and the ball so that when it rotates on its axis.

Moreover, the flow pressure pulls it downstream against its seat, making a tight seal. In very low-pressure circumstances, moving ball valves might not close well after a certain amount of seat wear. This is due to the media not having enough pressure to push the ball against the seat downstream for a tight seal. Most of the pressure further downstream is enough to keep the seal tight long after the seats wear down.

Floating Ball Valve Applications

  • Distribution of water
Floating valve dn15 dn20 and dn25
Floating valve dn15 dn20 and dn25

                                            Floating Ball Valve for water tank

Water systems often need to keep air pockets from forming and ensure water flows smoothly. They need adequate pressure and excellent control features to handle high forces. Float ball valves are good for managing high water flow because they are pressure-sensitive.

  • Emergency shut-off systems

Because they respond very quickly, they are a great choice for emergency devices. Floating ball valves can flow fluids like fuels and water because they are not fixed or bonded.


  • The mechanism of the moving ball valve is simple, making it easy to understand and use. It works better because of this style.
  • The floating ball valve is perfect for pipes and systems circling heavy, thick fluids because it has little flow resistance.
  • Their flexibility lets them handle severe pressures. The moving ball valve is flexible enough to handle changes in pressure and temperature. This is because the ball can move inside the valve.
  • It seals well, so we don’t see any leaks when the system works since leaks are the main reason for losses in a company.


  • The weight of the floating ball tends to settle on the seal ring. It causes it to form irregularly, making it less effective.
  • The torque the ball creates depends on friction; if you get the wrong balance, the torque will not work.
  • The floating ball inside the valve can’t always handle high pressure, especially if the valve around it is too giant. It leaves too much area for materials to pass through.

What Are Trunnion Ball Valves? 

trunnion ball valve
Trunnion ball valve


Trunnion ball valves consist of a ball held in position by two trunnions. This design passes the ball rotate, allowing the valve to open or close. This ball valve is a specific valve used in various industries. The purpose of these valves is to provide superior performance in required applications. Trunnion ball valves are available in a range of diameters and pressure ratings to handle the needs of various industries.

The petroleum, natural gas sector, power generation industry, and chemical processing industry are industries that employ trunnion ball valves. These valves are also commonly used in applications requiring a high-quality valve. It can tolerate extreme temperatures and pressures.

How Does a Trunnion Ball Valve Work?

trunnion ball valve parts
Trunnion ball valve parts


Trunnion ball valves are quarter-turn valves that are used to stop or initiate the passage of a fluid through a pipe. The most prevalent variety of ball valves features a “free-floating” design, so the trunnion type represents a change in structure. The ball attaches to the stem on one end of a trunnion ball valve, while the other end connects to a trunnion-shaped shaft. This modification to the design holds the ball securely in position. The ball in a floating ball valve is only attached to the stem and is therefore referred to as floating.


  • Chemical industries 

Trunnion ball valves are optimal for various chemical industries due to their superior safety, dependability, and sealing capabilities.

  • Oil and gas industries

Trunnion ball valves are suitable for various oil and gas industry applications. Several oil and gas enterprises utilize trunnion-mounted ball valves. It includes gas feed lines, industrial gas processing plants, field gas plants, oil refinery feedstock, and crude oil plants.

  • Pipeline industries

Trunnion ball valves are incredibly useful in the pipeline industry. These valves can handle various applications, such as gas, slurry, and fluid transmission.


  • They feature spring-loaded seats that allow the industrial valve to manage high and low pressures without manual adjustments. These springs help restore equilibrium when pressures drop or abruptly increase without warning.
  • It can be used in high-pressure situations because the object is less likely to pass. This ensures the valve maintains a correct closure on both sides without adding torque to the shaft. This gives it the necessary strength to withstand high pressures.
  • Operating a trunnion-mounted ball is less expensive because the steam and trunnion promptly absorb any additional pressure applied to the valve. This primary mechanism substantially reduces torque, reducing the need to install a large actuator.


  • Due to the fixed nature of the trunnion ball valve, it isn’t very easy to repair or perform maintenance on it. The only option is to shut down the system by manipulating a single valve component. This is a counterproductive action.
  • Without appropriate maintenance, the welded sections of the trunnion ball valve begin to operate with increased friction. Moreover, this has a negative impact on the valve’s efficiency due to the increased torque and energy consumption.
floating ball valve vs. trunnion ball valve
floating ball valve vs. trunnion ball valve

Floating Ball Valve Vs Trunnion Ball Valve: What Are the Key Difference?

Ball valves include both floating ball valves and trunnion ball valves. Ball valves are valves that utilize a ball to regulate fluid passage. The ball’s central opening enables fluid to pass through when the valve opens. When the valve is fully closed, the ball is rotated to obstruct the opening, preventing fluid from passing through.

  • Sealing

Since the ball of a floating ball valve floats, the ball will move against the downstream seat when subjected to the pressure of the medium; therefore, the floating ball valve seal is a single-side seal. In contrast, the ball of the trunnion ball valve is immovable, so both sides must be sealed.

  • Appearance

The appearance of the floating ball valve and the trunnion ball valve are readily distinguishable. If the valve body has a fixed axis at the bottom, it is a trunnion ball valve; otherwise, it is a floating ball valve.

  • Operation

Both floating ball valves and trunnion-mounted valves have the common characteristic of employing a rotating ball mechanism to regulate the start or stop of fluid flow. The operation of these entities varies, as does their design requirements, which are influenced by factors like pressure, class, bore size, and other relevant variables.

  • Risk of leakage

The leakage rate and maintenance requirements of floating ball valves are lower than those of trunnion ball valves. They’re less costly. However, trunnion ball valves can withstand more significant pressures and have better flow characteristics.

  • Design

While discussing a floating ball valve vs a trunnion ball valve, what are the key distinctions between a trunnion valve and a floating valve? The primary distinction lies in the ball’s design. The ball in a floating ball valve is unrestricted to float within the valve’s body. This aligns the ball with the mount to create a close seal. However, in a trunnion ball valve, the ball is fixed to a short, cylindrical portion of metal called a trunnion. The trunnion serves as a focal point for the projectile. It helps the valve and prevents the ball from cracking under extreme pressure.

  • Pressure

Floating ball valve balls exhibit greater adaptability to variations in pressure due to their ability to move freely in response to changes in valve pressure. In contrast, trunnion ball valves are better suited for situations where pressure remains relatively constant.

Floating Ball Valve Trunnion Ball Valve: Which is Better for Your Application?

When picking between a trunnion ball valve and a floating ball valve, there are many considerations to consider. Both have pros and cons, so the best choice for what you want will depend on many factors. I’ve compiled a quick summary of these two types of floating ball valves vs trunnion ball valves to help you make the best choice.

  • The majority of floating ball valves cost less than trunnion ball valves. The durability makes trunnion-mounted ball valves a popular choice for heavy-duty uses.
  • Floating ball valves help regulate water and work with chemicals.
  • A floating ball valve has a ball that floats on a seat. This makes it a lesser probability that it will damage the ball. When you connect a ball to a trunnion, it makes the valve more durable.

Floating Ball Valve Vs Trunnion Ball Valve: Conclusion

There are a few essential aspects to know about floating ball valves vs trunnion ball valves. Because they can handle more pressure, trunnion ball valves work better in high-pressure situations. These valves are better for conditions where leaks are concerned because they are less likely to leak.

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