Hydrostatic testing interval for a dry standpipe system is every how many years?

• A. annually
• B. every 2 years
• C. every 3 years
• D. every 5 years

Answer: (D)

Hydrostatic testing checks that the piping can hold a high pressure without leaking or failing, confirming the standpipe’s structural integrity. For a dry standpipe, the pipe is normally dry and only filled during testing or activation, so hidden corrosion or weak joints can develop over time. Performing a hydrostatic test at a higher-than-service pressure over a set period reveals these issues before they become a problem.

Standards for water-based fire protection systems specify this hydrostatic test at five-year intervals. This interval strikes a balance between ensuring safety and avoiding the disruption and cost of more frequent testing; it’s long enough to be practical, yet frequent enough to catch aging or hidden damage.

So, the correct interval is five years.