What is the minimum size of an air break?

The minimum size for an air break is 1 inch. An air break is installed to create a physical separation between the potable water supply and non-potable fluids, helping to prevent contamination through backflow. The requirement for a minimum size helps ensure that the air gap is effective in maintaining that separation under various operating conditions. A 1-inch air break is adequate to achieve the necessary clearance and provide the necessary protection in typical plumbing installations, as it allows sufficient airflow to prevent siphoning and ensures that any potential contaminants cannot reach the potable water supply. This is an essential safety consideration in plumbing design to protect public health.