Refrigeration Plant Operator B Practice Test

How many turns does a basic type of ball valve require to go from fully open to fully closed?

1. Half turn

2. Quarter turn

3. Full turn

4. 3/4 turn

The correct answer is: Quarter turn

A basic type of ball valve is specifically designed for quick and efficient operation. It typically requires only a quarter turn to move from fully open to fully closed. This design allows for immediate and complete isolation of the fluid flow, making it ideal for applications where a rapid shutdown or start-up is necessary. The quarter-turn operation is advantageous because it minimizes the time and effort required to operate the valve, enhancing overall system efficiency. In contrast, other types of valves, such as gate valves or globe valves, may require multiple turns to achieve the same function, which involves more complex mechanical movements. The simplicity of the ball valve's design is what sets it apart, making it a preferred choice in many refrigeration and HVAC systems.