Which standpipe type is equipped with both 1½-inch and 2½-inch connections and allows simultaneous use?

• A. Class I Standpipes
• B. Class II Standpipes
• C. Class III Standpipes
• D. Class IV Standpipes

Answer: (C)

Standpipe effectiveness hinges on who can use it and how many connection sizes it offers. The key here is a system that provides both a 1.5-inch hose connection for occupants and a 2.5-inch connection for fire department use, so both groups can operate at the same time. This dual-access design is exactly what a combined standpipe is for: occupants can pull a 1.5-inch hose from the standpipe, while firefighters can connect a 2.5-inch supply line, enabling concurrent operations. The other types either supply only the larger 2.5-inch outlets for firefighters or only the 1.5-inch outlets for occupants, and thus don’t allow simultaneous use. The combined configuration, therefore, matches the description.