Which of the following is true about the five-year flow test requirement for standpipes?

• A. Class 2 and 4
• B. Class 1 and 2
• C. Class 1 and 3
• D. Class 3 and 4

Answer: (C)

The five-year flow test is about proving that the standpipe system can deliver a large, sustained water flow to the farthest outlet for firefighting purposes. This requirement is specific to standpipe systems that are intended for firefighting use—Class I and Class III—because they must be able to supply high flow to multiple outlets for an extended period. Class I provides 2.5-inch outlets for fire department use, and Class III combines 2.5-inch outlets with accompanying 1.5-inch hose outlets, both needing substantial, reliable water supply. Class II systems are for occupant use with smaller 1.5-inch hoses and do not require the same high-flow, long-duration capability, so they aren’t subjected to the five-year flow test. Class IV refers to a different, less common configuration and isn’t the standard focus of this five-year test. So the true statement is that Class I and Class III systems have the five-year flow test requirement.