What is the purpose of a vacuum breaker?

The purpose of a vacuum breaker is to allow air into a system to prevent a vacuum. In plumbing systems, a vacuum can occur when there is a sudden drop in water pressure, which can lead to the backsiphonage of contaminated water into the potable water supply. A vacuum breaker works by introducing air into the system when a vacuum is detected, thus breaking the vacuum and preventing any backflow of potentially harmful substances. This is especially important in situations where there could be a risk of cross-connection with non-potable water sources.

By preventing the formation of a vacuum, the vacuum breaker ensures the integrity of the drinking water supply, maintaining safe water quality standards. This mechanism is vital for protecting plumbing systems and public health, reinforcing why option B is the accurate choice.