Which statement about Class III standpipes is true?

• A. Class III provides both 2.5-inch fire department outlets and 1.5-inch occupant outlets on a single outlet
• B. Class III outlets are 4-inch only
• C. Class III are only used for exterior hydrants
• D. Class III are the same as Class I

Answer: (B)

Class III standpipe outlets combine two sizes on one connection: a 2.5-inch outlet for fire department use and a 1.5-inch outlet for occupant use. This design lets firefighters connect large-diameter hoses while occupants (or trained staff) can use a smaller hose from the same outlet. The other statements aren’t correct because Class III is not limited to 4-inch outlets, it isn’t restricted to exterior hydrants, and it isn’t the same as Class I (which provides only 2.5-inch outlets for firefighters).