Class III standpipe outlets have which diameter combination?

• A. 1/2 and 1 inch
• B. 1 and 2 inch
• C. 1 1/2 and 2 1/2 inch
• D. 2 and 3 inch

Answer: (C)

Class III standpipe outlets are designed to serve both occupants and firefighters by providing two hose connection sizes at one point: 1 1/2 inch and 2 1/2 inch. This combination brings together the features of Class II, which uses a 1 1/2 inch hose for occupant use, and Class I, which uses a 2 1/2 inch outlet for fire department attack lines. The 1 1/2 inch port lets occupants or responders pull a smaller handline, while the 2 1/2 inch port supports high-flow attack with larger hoses, enabling rapid, versatile firefighting from a single standpipe. Because these are standard hose sizes, the setup is practical and widely compatible. Hence, the diameter combination for Class III standpipe outlets is 1 1/2 inch and 2 1/2 inch.