What is an air break in a drainage system?

An air break in a drainage system refers to a piping arrangement where waste discharges below the flood-level rim but is not directly connected to the sewer line. This design allows for the prevention of backflow and protects against siphoning by ensuring that there is an air gap between the discharge point and the sewer system. This air gap acts as a critical safety feature that helps to prevent any potential contamination of the potable water supply. Understanding this concept is essential for ensuring compliance with plumbing codes and for maintaining the safety and integrity of a plumbing system.

While the other options involve aspects of plumbing, they do not accurately describe an air break. For instance, a direct discharge into a sewer line is characteristic of a different plumbing practice, and obstruction preventing drainage refers to a blockage issue rather than the method of discharge. Lastly, the vertical distance between two pipes does not encapsulate the concept of an air break, which specifically involves the relationship between waste discharge and sewer connections.