How far above the highest point of usage should a pressure vacuum breaker be installed?

The installation height for a pressure vacuum breaker is critical for ensuring its effectiveness in preventing backflow and maintaining proper system pressure. Specifically, it should be installed at least 12 inches above the highest point of usage to allow for the necessary air gap that prevents siphoning. This height creates a reliable barrier against potential contaminants that could enter the water supply due to backpressure or back-siphonage.

By maintaining this minimum distance, you ensure that any pressure fluctuations in the system do not compromise the integrity of the potable water supply. It also helps in the proper operation of the vacuum breaker by allowing it to function effectively when the system experiences changes in pressure. This regulation is a standard in plumbing codes to secure public health and safety related to water supply systems.