Which step is necessary when performing a pressure control test?

Engaging the pump and setting it to operational capacity is essential when performing a pressure control test because this step allows you to assess how the system operates under actual conditions. By putting the pump into service, you can measure the pressure produced during normal operations, ensuring that it meets the required specifications for firefighting purposes.

This action directly impacts the results of the pressure control test, as it provides the necessary flow and pressure data needed to evaluate the pump's performance and the entire water supply system's efficiency. Proper operational readiness is crucial to understand the pump's capabilities and to confirm that it can deliver adequate pressure for firefighting efforts.

In comparison, testing the water tank for leaks, calibrating the pressure gauge, and inspecting discharge hoses, while important tasks, do not measure the operational performance of the pump itself under pressure. Each of those tasks addresses different aspects of the equipment's maintenance and functionality but does not focus on the crucial assessment that the pressure control test aims to provide.