How can a plumbing inspector verify the integrity of underground piping?

• A. Visual inspection only
• B. Pressure testing and visual inspection
• C. Smoke testing
• D. Water flow testing

Answer: (B)

To ensure the integrity of underground piping, a plumbing inspector should utilize pressure testing and visual inspection. Pressure testing is a critical evaluation method where the piping system is filled with water or air and then pressurized to check for leaks, ensuring that the system can withstand the operational pressures without failure. This method not only confirms the integrity of the pipes but also detects weak points where potential leaks could occur.

Visual inspection complements this by allowing the inspector to observe exposed sections of the piping and surrounding areas for any signs of distress or improper installation. While visual inspection alone may provide some insights, it cannot effectively detect leaks or internal defects within completely buried or underground piping systems. Therefore, a combination of both pressure testing and visual inspection offers a comprehensive approach to confirming the structural integrity of the piping.

Other methods like smoke testing or water flow testing serve different purposes, such as identifying leaks in venting systems or determining the flow rates through the system. However, they do not directly verify the integrity of underground piping in the same effective manner as pressure testing combined with visual inspection does.