How is the discharge of waste from a temperature relief valve required to be set up according to the code?

The correct answer highlights the importance of ensuring that the discharge from a temperature relief valve is appropriately set up to maintain safety and compliance with building codes. Specifically, the requirement to fully terminate through an air gap is designed to prevent backflow, which can potentially contaminate the potable water supply. By having a proper air gap in place, any discharged water will fall freely and, therefore, cannot siphon back into the water system, protecting against the risk of contamination.

An air gap creates a clear distance between the end of the discharge pipe and the surface it discharges onto, ensuring that no pressure can draw the water back into the system. This measure is essential in safeguarding public health, as temperature relief valves can release extremely hot water under conditions of excessive pressure in systems like water heaters. The setup maximizes safety by ensuring that any scalding water released does not pose a risk to individuals or infrastructure.