What is the minimum height requirement for an atmospheric vacuum breaker above the highest part of a urinal with a flushometer valve?

The minimum height requirement for an atmospheric vacuum breaker above the highest part of a urinal with a flushometer valve is 6 inches. This is a crucial installation guideline to ensure that the vacuum breaker operates correctly and provides adequate backflow prevention. The atmospheric vacuum breaker is designed to protect the potable water supply from contamination due to back-siphonage, and positioning it at least 6 inches above the highest part of the fixture helps achieve this.

By adhering to this height requirement, plumbing systems maintain compliance with health and safety standards, preventing potential cross-connections where non-potable water could enter the drinking water supply. This particular measurement is standardized in plumbing codes to ensure that all installations meet the necessary safety requirements and function effectively in preventing backflow scenarios.