A urinal equipped with a flushometer valve must have an atmospheric vacuum breaker positioned how many inches above the highest part of the urinal?

The requirement that an atmospheric vacuum breaker must be positioned 6 inches above the highest part of the urinal when using a flushometer valve is rooted in the need to prevent the potential for backflow contamination. An atmospheric vacuum breaker acts as a safeguard against siphoning, which could occur if the water supply were to lose pressure. By ensuring that the vacuum breaker is placed at least 6 inches above the highest point of the urinal, it creates a sufficient air gap that prevents wastewater from being drawn back into the potable water system.

This distance is specified to ensure safety and compliance with plumbing codes, which mandate such measures to protect public health. It's important to adhere to these standards to avoid cross-contamination risks, especially in facilities where multiple plumbing fixtures may be used in close proximity. Proper installation of the vacuum breaker helps maintain the integrity of the water supply system and enhances overall plumbing safety.