Continuous leakage from test cock #2 during a test of a pressure vacuum breaker is likely due to what issue?

Continuous leakage from test cock #2 during the testing of a pressure vacuum breaker typically indicates a problem with the inlet shut-off valve. If this valve is leaking, it can introduce continuous water flow into the system, which can manifest as leakage from test cock #2. This valve controls the flow of water into the pressure vacuum breaker assembly, and if it is not sealing properly, it prevents the necessary pressure differential from being maintained, leading to leakage.

In the context of pressure vacuum breakers, the purpose of the test cocks is to allow for the testing of backflow preventers to ensure they function properly. A proper seal is necessary for accurate testing. If the inlet shut-off valve does not seal correctly and allows water to pass through continuously, it disrupts normal function and leads to an observable leak at test cock #2.

This understanding highlights the importance of checking the inlet shut-off valve for any leaks during pressure vacuum breaker tests, as leakage from this valve can directly affect the integrity and performance of the backflow prevention assembly.