What is the difference between trunnion mounted ball valve and floating ball valve?

The world of valves can be complex, especially for those who are not familiar with the various valve types. Two common ball valve types are the trunnion ball valve and the floating ball valve. While both perform the same function of regulating flow, there are differences in their design and functionality that make them suitable for specific applications.

A trunnion ball valve has a fixed shaft that holds the ball in place. The ball is held in place by a trunnion or bracket that allows it to rotate in a controlled manner. The shaft extends through the valve body, providing support and stability. As a result, trunnion ball valves are able to handle higher pressures and flow rates, making them a popular choice for industrial applications that require reliability and durability.

On the other hand, a floating ball valve has a spherical ball that floats within the valve body. The ball is free to move and seals against the valve seat under fluid pressure. Floating ball valves are designed for low-pressure and low-flow applications that require lower torque to operate the valve.

The main difference between these two types of ball valves is the way the ball is held in place. Floating ball valves rely on seals to hold the ball in place, while trunnion mounted ball valves use a fixed stem. This design difference affects the suitability of each valve for different applications.

Trunnion mounted ball valves are frequently used in the oil and gas industry, especially in pipelines and high-pressure applications. Its design allows for the use of larger balls and higher torques, making it ideal for handling high-pressure conditions in these environments. It is also widely used in other industrial applications, such as chemical processing, mining, and pulp and paper.

However, floating ball valves are more often used in low-pressure applications where smaller size and lower cost are advantageous. It is commonly used in residential and commercial plumbing and in the water treatment industry. Its smaller size and ease of use make it ideal for these applications.

In summary, it is crucial to understand the differences between trunnion mounted ball valves and floating ball valves when selecting the right valve for a specific application. While both perform the same function of regulating flow, their design and functional differences make each valve suitable for certain applications.