What defines a Class III standpipe system?

A Class III standpipe system is unique in that it is designed to be utilized by both firefighters and the occupants of the building. This dual accessibility is a key feature of Class III systems, which are typically found in larger buildings where both trained fire personnel and untrained occupants may need to use the system in an emergency.

The system includes both a 2.5-inch (65mm) hose connection, which is primarily intended for firefighters, as well as a smaller 1.5-inch (38mm) connection that can be accessed by building occupants. This ensures that in the event of a fire, trained firefighters can efficiently fight the blaze while also enabling building occupants to utilize the system for self-defense, if needed, until help arrives.

The other definitions provided do not encompass the collaborative nature of Class III standpipe systems, which is the fundamental differentiator. This multi-use capability makes these systems particularly valuable in emergency situations where effective response is crucial.