A water mist system air test must be conducted for _____.

A water mist system air test must be conducted for _____.

• A. 12 hours
• B. 24 hours
• C. 48 hours
• D. 72 hours

Answer: (B)

Testing the piping network with air checks its integrity by pressurizing it and watching how the pressure holds over time. The aim is to detect leaks at joints, fittings, or devices before water is introduced, so the system won’t fail once put into service. A 24-hour hold is the standard duration because it gives enough time to reveal slow leaks without unnecessarily delaying the project. Shorter tests, like 12 hours, may miss small leaks, while longer tests, such as 48 or 72 hours, usually don’t provide additional value beyond what a 24-hour test already shows.

Testing the piping network with air checks its integrity by pressurizing it and watching how the pressure holds over time. The aim is to detect leaks at joints, fittings, or devices before water is introduced, so the system won’t fail once put into service. A 24-hour hold is the standard duration because it gives enough time to reveal slow leaks without unnecessarily delaying the project. Shorter tests, like 12 hours, may miss small leaks, while longer tests, such as 48 or 72 hours, usually don’t provide additional value beyond what a 24-hour test already shows.