What is the minimum uniform gauge pressure required for an air test on a drainage and vent system?

The minimum uniform gauge pressure required for an air test on a drainage and vent system is established to ensure the integrity of the plumbing system by verifying that it can withstand the necessary pressure without leaking. Specifically, a pressure of 5 PSI is set as the minimum threshold. This pressure level is sufficient to identify any weaknesses or potential failures in the system components.

Conducting the air test at this minimum pressure provides an effective means of assessing whether the drainage and vent system remains sealed adequately. If a lower pressure were used, it might not adequately reveal minor leaks or weaknesses. Therefore, while a higher pressure could be more stringent, maintaining a pressure at 5 PSI balances practicality and safety, making it a standard requirement within the International Plumbing Code.

In contrast, pressures lower than 5 PSI would not meet the code's intent for testing, while pressures higher than this threshold are not necessary for this specific test, thereby making them excessive. Therefore, 5 PSI is the accepted standard for ensuring the reliability of drainage and vent systems through air pressure testing.