Which statement about check valves is correct?

Which statement about check valves is correct?

• A. They must be installed in series
• B. Independently operating check valves
• C. If one fails, the other will automatically open
• D. They are mechanically linked and move together

Answer: (B)

Check valves are one-way devices that open to allow flow in the forward direction and close to prevent backflow. Each valve responds to its local pressure difference and has its own moving part, so they operate independently. You can have multiple check valves in a system for redundancy or in different sections without any mechanical linkage between them—their operation doesn’t require them to move together or be in a specific order like series. Also, a failure in one valve doesn’t automatically cause another valve to open; failure modes vary, and independence is what preserves function in parallel arrangements. That’s why independently operating check valves best describe how these devices work.

Check valves are one-way devices that open to allow flow in the forward direction and close to prevent backflow. Each valve responds to its local pressure difference and has its own moving part, so they operate independently. You can have multiple check valves in a system for redundancy or in different sections without any mechanical linkage between them—their operation doesn’t require them to move together or be in a specific order like series. Also, a failure in one valve doesn’t automatically cause another valve to open; failure modes vary, and independence is what preserves function in parallel arrangements. That’s why independently operating check valves best describe how these devices work.