When should fire department connections be provided for a standpipe system?

• A. For each zone of the system
• B. Only at the main building entrance
• C. Only at the topmost zone
• D. Whenever hydrant pressure is low

Answer: (C)

Fire department connections exist to provide an external water source to the standpipe system so firefighters can pump water into the system when needed. In zoned standpipe arrangements, the system is divided into sections that can be isolated by valves. Placing a connection at the topmost zone ensures that the highest elevation of the standpipe can be fed from the outside, which helps establish pressure and supply to the entire vertical system during a firefighting operation. Once water is introduced into the top zone, it can spread through the interconnected risers to lower zones as needed, so a single exterior connection at the topmost zone can effectively serve the whole standpipe layout.

The other options aren’t as reliable in guiding external supply for firefighting. Providing connections for each zone would imply multiple exterior feeds, which isn’t required in many configurations and can complicate access. A connection only at the main building entrance or only at the top of the building isn't universally mandated by NFPA 14 and can fail to guarantee prompt, adequate supply to upper floors if the system isn’t fed from a suitable exterior point. The idea that a connection is needed “whenever hydrant pressure is low” isn’t a design rule for FDC placement; rather, it’s a matter of system design and AHJ requirements.