What is an Air Break in plumbing?

An air break in plumbing refers to a physical separation between a drainage outlet and the flood level rim of a fixture, appliance, or receptacle. This design creates a barrier that prevents backflow or contamination of the potable water supply. The air break ensures that wastewater cannot siphon back into clean water supplies because of the gap that exists. This is particularly important in preventing diseases and ensuring that the water supply remains safe for consumption.

In contrast, the other options describe different plumbing components or systems that do not serve the specific function of preventing backflow via a physical separation. For example, pressure relief valves are designed to relieve pressure in water lines to prevent over-pressurization, while support structures provide necessary stability for plumbing systems. Similarly, valves that control water flow do not inherently provide a barrier between wastewater and potable water. The unique function of an air break in maintaining clean water quality is what sets it apart in the context of plumbing.