What is the minimum clearance required above the flood rim in a sink for an air gap?

The minimum clearance required above the flood rim in a sink for an air gap is 1 inch. This air gap is an essential element in plumbing design, as it helps prevent backflow and ensures that contaminated water does not flow back into the clean water supply. The one-inch clearance creates a physical barrier that separates the potential contaminant from the potable water source, thereby maintaining the integrity of the water system. Properly adhering to this requirement not only meets plumbing code regulations but also promotes public health and safety by reducing the risk of cross-contamination.