What defines an Air Gap in drainage systems?

An air gap in drainage systems is specifically defined as the vertical space between the end of a drain pipe and the flood rim of the receptacle it discharges into, such as a sink, tub, or basin. This space is crucial because it prevents the backflow of sewage or contaminated water into the potable water supply. By maintaining this gap, it ensures that there is no direct connection between sewage and clean water, thus safeguarding public health and complying with health codes.

The other options do not accurately describe the definition of an air gap. The length of drain pipes, the angle of the pipes, or the type of material used for piping do not relate to how the air gap functions or its purpose within drainage systems. The focus of the air gap is solely on maintaining a physical separation to prevent backflow, making the distance between the waste pipe and the flood rim the only correct definition in this context.