Hydrostatic tests of not less than 200 psi for 2 hours, or at 50 psi in excess of the maximum pressure, shall be conducted every how many years on manual standpipe systems and semi-automatic dry standpipe systems including piping in the fire department connection?

• A. 1 year
• B. 3 years
• C. 5 years
• D. 7 years

Answer: (C)

Hydrostatic testing verifies the piping network can withstand the design pressures without leaks or weaknesses. For manual standpipe systems and semi-automatic dry standpipe systems (including piping in the fire department connection), the test pressure is set at not less than 200 psi for two hours, or 50 psi above the maximum working pressure of the system, to simulate demanding conditions and reveal hidden defects along the entire system.

This testing interval—every five years—balances the need to catch corrosion, joint failures, or insulation deterioration before they become critical with the practicalities and costs of performing large-scale tests. Including the piping in the fire department connection in the test ensures every part of the standpipe network remains reliable for firefighting operations. Therefore, the required interval is five years.