During an annual pressure test, what is used to pressurize the piping system and for how many hours should the pressure be maintained?

The correct choice involves the use of installed pumps to pressurize the piping system during an annual pressure test, along with maintaining that pressure for a duration of 2 hours. This method is preferable because installed pumps can provide a consistent and reliable source of pressure that is necessary for an accurate test.

Maintaining pressure for 2 hours is standard practice in ensuring that any potential leaks or weaknesses in the piping system can be identified without overstraining the materials or compromising safety. This duration is considered adequate for the test while minimizing risks associated with prolonged pressure exposure, which could lead to equipment deterioration or unsafe conditions.

In contrast, the other options involving a hand pump, while feasible, may not ensure the same level of precision and ease of pressure maintenance as installed pumps can offer. Additionally, maintaining pressure for 4 hours generally exceeds the requirement, potentially complicating the test process and equipment integrity checks. The combination of using installed pumps and a 2-hour test period ensures both accuracy and safety in the assessment of the piping system's integrity.