Water Distribution Grade 1 Certification Practice Exam

Which of the distribution valves is NOT classified as a rotary valve?

1. Ball valve

2. Butterfly valve

3. Gate valve

4. Check valve

The correct answer is: Gate valve

The classification of valves in water distribution systems is based on their design and operation. Rotary valves, such as ball valves and butterfly valves, operate by rotating a disc or ball to open or close the flow of water. This allows for efficient control of fluid flow with minimal pressure loss and straightforward operation. In contrast, a gate valve operates by lifting a gate out of the path of the fluid. This design does not involve any rotational movement to open or close the valve; instead, the gate moves linearly to either allow or stop flow. Therefore, it does not fit the classification of a rotary valve. Check valves are designed to permit fluid flow in one direction only and typically do not involve rotational movement for their operation, but they are not categorized under rotary valves. However, the key distinguishing factor here is specifically the operation of a gate valve, which is purely linear and not rotary. This is why the gate valve is not classified among rotary valves.