How do ball valves typically function?

Ball valves operate by using a spherical disc, known as a "ball," which has a hole through its center. This ball is capable of rotating within the valve body, allowing for control over the flow of fluid. The key aspect of their functionality lies in the design that enables a quarter-turn operation.

When the valve handle is turned a quarter turn (90 degrees), the ball rotates to either allow or block fluid flow, depending on the alignment of the hole. This quarter-turn mechanism is not limited to mechanical push-pull handles; it can also be actuated using switches that might be powered pneumatically, hydraulically, or electrically.

Thus, the correct answer emphasizes the versatility of operation with both mechanical and switch-based control, which is a fundamental characteristic of ball valves. This multi-faceted functionality makes them an essential choice in various applications, allowing operators to manage fluid flow conveniently and efficiently.