Sprinkler / Standpipe systems should be supplied by using 3 inches or ___ hose.

• A. 2 inches
• B. 2 1/2 inches
• C. 3 inches
• D. 4 inches

Answer: (B)

The size chosen to supply sprinkler and standpipe systems is driven by a balance between flow needs and how easily a firefighter can handle the hose. Two and a half inches is the standard attack hose size for these systems because it provides enough flow to effectively fight most fires while remaining manageable to carry, connect, and maneuver. It also matches the common standpipe outlet connections, minimizing the need for adapters.

A three-inch hose, while capable of delivering more flow, is heavier and stiffer, making it harder to advance and control. A two-inch hose would be lighter and easier to handle but typically cannot deliver the necessary flow for standpipe operations. So the practical, widely used choice is two and a half inches.