Backflow Prevention Practice Exam

The air inlet valve not sealing properly is indeed a potential failure point for an atmospheric vacuum breaker. This type of device relies on a combination of atmospheric pressure and water flow to function correctly. When the air inlet valve fails to seal, it can lead to back siphonage, allowing contaminated water to mix with the potable water supply. This failure typically occurs due to debris or sediment buildup, wear over time, or incorrect installation. Proper sealing is crucial to maintain the integrity of the device, ensuring it effectively prevents backflow.

In contrast, while deterioration of the body material, installation height, and entering water temperature can influence the overall performance of an atmospheric vacuum breaker, they do not directly represent a failure in sealing which is essential for preventing backflow. Deterioration may lead to structural failure over time, and incorrect installation height or excessively high water temperatures can affect performance, but it is the sealing of the air inlet that is directly responsible for failure to prevent back siphonage.