What is the minimum vertical distance that constitutes proper separation for an air gap fitting?

The minimum vertical distance that constitutes proper separation for an air gap fitting is 1 inch. An air gap is a critical component in plumbing systems designed to prevent backflow, ensuring that contaminated water does not enter the potable water supply. The 1-inch vertical separation allows for sufficient air to act as a physical barrier between the potable water and any potential source of contamination, thus effectively mitigating the risk of back siphonage or backflow.

This standard is widely accepted in plumbing codes and practices to ensure safety in water distribution systems. Maintaining this minimum distance is crucial to safeguarding public health and complying with plumbing regulations. While larger separations may provide additional safety, 1 inch is the established standard that balances safety and practicality for most applications.