Cross Connection Practice Exam

During the field test of a Pressure Vacuum Breaker Assembly, when should the air inlet valve open?

1. At or below one psid

2. At or above one psid

3. Only when pressure exceeds three psid

4. It should not open during testing

The correct answer is: At or above one psid

The air inlet valve of a Pressure Vacuum Breaker Assembly is designed to open under specific pressure conditions to prevent a potential backflow situation in the system. It opens at or above one psid (pounds per square inch differential) to allow air into the system and break the vacuum that could otherwise cause siphonage. This feature is crucial because if a negative pressure condition occurs, the air inlet valve's function is to immediately allow air into the assembly, thereby mitigating the risk of backflow and ensuring the safety of the water supply. Compliance with this standard helps maintain proper functioning of the cross-connection control measures in place. The other choices describe scenarios where the air inlet valve would either not function effectively or misalign with industry standards for backflow prevention. Therefore, understanding the operational threshold of one psid is essential for effective backflow prevention measures in water systems.