One of the check valves may be an alarm check valve; how many check valves are required overall?

One of the check valves may be an alarm check valve; how many check valves are required overall?

• A. Two
• B. One
• C. Three
• D. Four

Answer: (A)

In backflow protection, having two check valves in series provides redundancy so that a failure in one valve doesn’t allow backflow. An alarm check valve is still a type of check valve; it just adds an alarm to signal movement or leakage. It can count as one of the two required check valves, with the other valve being a standard check valve. Therefore, the required total is two check valves. Using more than two isn’t necessary for meeting the typical requirement, and using just one would not provide the needed dual barrier.

In backflow protection, having two check valves in series provides redundancy so that a failure in one valve doesn’t allow backflow. An alarm check valve is still a type of check valve; it just adds an alarm to signal movement or leakage. It can count as one of the two required check valves, with the other valve being a standard check valve. Therefore, the required total is two check valves. Using more than two isn’t necessary for meeting the typical requirement, and using just one would not provide the needed dual barrier.