Minnesota Boiler License Practice Exam

Which valve is used where flow in one direction only is desired?

1. Gate

2. Globe

3. Check

4. Butterfly

The correct answer is: Check

The check valve is specifically designed to allow fluid to flow in one direction only, preventing backflow. This is vital in systems where the maintenance of flow direction is critical, such as in boiler systems or any piping systems that require unidirectional flow to maintain operational integrity. When fluid attempts to flow backward, the check valve automatically shuts, creating a seal that blocks the reverse flow. This function is essential in protecting equipment from potential damage or operational failures that could occur if the flow were to reverse. The other types of valves mentioned serve different roles: the gate valve is primarily used for isolation and does not inherently prevent reverse flow; the globe valve is used for regulating flow rather than controlling flow direction; and the butterfly valve, while it can be used for isolation and flow regulation, does not prevent backflow in the way a check valve does. Thus, the check valve is the appropriate choice for situations where one-way flow is necessary.