Texas Commission on Environmental Quality (TCEQ). Class C Water License Exam

What is the most commonly used valve for isolating a water leak?

1. Ball valve

2. Gate valve

3. Butterfly valve

4. Check valve

The correct answer is: Gate valve

The gate valve is the most commonly used valve for isolating a water leak due to its simple design and effective sealing capabilities. When fully open, gate valves provide minimal resistance to flow, which helps maintain a smooth and uninterrupted flow of water. This characteristic is particularly important in cases where isolating a section of piping is necessary to stop a leak while allowing other sections of the system to function normally. Using a gate valve enables quick closure and isolation of sections of a water distribution system, making it a practical choice for maintenance and emergency situations. The design of a gate valve allows for a tight seal when closed, which helps prevent any leakage, ensuring that the area remains isolated until repairs can be made. While other valves like ball valves and butterfly valves also have their advantages in various applications, gate valves remain the industry standard for isolation purposes. Check valves, on the other hand, are designed to prevent backflow and are not used for isolation.