When conducting an air test of a rough plumbing installation requiring a gauge pressure of 5 psi, what is the required gauge increment?

• A. 0.05 psi
• B. 0.10 psi
• C. 0.20 psi
• D. 1 psi

Answer: (B)

The required gauge increment for conducting an air test at a pressure of 5 psi is 0.10 psi. This increment is appropriate because it allows for a precise and reliable measurement while ensuring that the pressure can be closely monitored during the testing process.

Using a gauge increment of 0.10 psi strikes a balance between sensitivity and practicality. A smaller increment, such as 0.05 psi, may not be necessary, as it might not provide actionable insights within the context of typical rough plumbing installations. Meanwhile, a larger increment, such as 0.20 psi or 1 psi, could reduce the visibility of minor pressure fluctuations, potentially obscuring small leaks that need to be detected during testing.

Therefore, the selected gauge increment facilitates the identification of pressure drops that could indicate issues within the plumbing system.