After repairs to the piping system following a pressure test, what needs to be tested?

In the context of the National Fuel Gas Code, after repairs have been made to a piping system following a pressure test, it is essential to conduct tests specifically on the affected piping. This is crucial because the goal of retesting is to ensure that any modifications or repairs made do not introduce leaks or weaknesses in the system.

Targeting the affected piping allows for a focused assessment of the repairs, ensuring that the integrity of those specific areas is intact and that they meet safety standards. Testing only the affected sections avoids unnecessary disruptions to parts of the piping system that were not involved in the repairs, which can save time and resources while still ensuring safety.

The other options, while potentially relevant in different contexts, are not specifically required immediately following repairs. For instance, testing the entire piping system or newly installed appliances may be warranted at different stages of a project or system overhaul, but the immediate concern after localized repairs is to confirm the integrity of the affected sections. Thus, the focus remains on verifying that the repaired sections comply with safety regulations and function properly before the system is put back into service.