What is the most common type of valve found on lines?

The ball valve is the most common type of valve found on lines, primarily due to its distinctive features that make it advantageous in various applications. Ball valves consist of a spherical disc (the "ball") with a hole through the center, which allows for smooth and efficient flow when aligned with the pipeline. When the ball is turned 90 degrees, the flow is stopped, creating an effective seal.

One of the key reasons for the popularity of ball valves is their ability to provide a reliable shut-off capability with minimal pressure drop. This characteristic makes them ideal for quick on/off operations. Moreover, ball valves require less torque to operate compared to other valve types, which simplifies handling and installation.

In addition, ball valves are versatile and can be used across a wide range of applications, including water supply systems, gas distribution, and chemical processing. Their durability and resistance to wear also contribute to their frequent use in various industrial settings. Overall, the combination of efficient flow control, ease of use, and versatility explains why ball valves are the predominant choice for pipeline applications.