For a high-pressure water mist system, the minimum time for a hydrostatic test is which of the following?

For a high-pressure water mist system, the minimum time for a hydrostatic test is which of the following?

• A. 60 minutes
• B. 120 minutes
• C. 180 minutes
• D. 240 minutes

Answer: (B)

In hydrostatic testing, you’re verifying that the piping and fittings of a high‑pressure water mist system can withstand pressure without leaking or failing. To reliably spot leaks and weak joints, the system is pressurized and kept at test pressure for a sufficient period so even slow leaks become evident. Two hours is the standard minimum duration used in industry practice for this type of system, giving enough time to reveal any hidden weaknesses across the entire piping network, including small-diameter runs and connections. Shorter durations can miss slow leaks, while longer times don’t provide additional assurance that isn’t already required by the standard practice. Therefore, the minimum hydrostatic test time is two hours.

In hydrostatic testing, you’re verifying that the piping and fittings of a high‑pressure water mist system can withstand pressure without leaking or failing. To reliably spot leaks and weak joints, the system is pressurized and kept at test pressure for a sufficient period so even slow leaks become evident. Two hours is the standard minimum duration used in industry practice for this type of system, giving enough time to reveal any hidden weaknesses across the entire piping network, including small-diameter runs and connections. Shorter durations can miss slow leaks, while longer times don’t provide additional assurance that isn’t already required by the standard practice. Therefore, the minimum hydrostatic test time is two hours.