What is the minimum flow that a single sprinkler can provide for combined systems?

• A. 50 gpm
• B. 75 gpm
• C. 125 gpm
• D. 100 gpm

Answer: (D)

In combined standpipe and sprinkler systems, there is a minimum flow requirement for a single sprinkler head to ensure that, even with other hose outlets or heads in use, a sufficient volume of water can reach one head for effective suppression. The standard sets this minimum at 100 gpm to provide a meaningful discharge rate from one sprinkler under worst‑case piping configurations and supply conditions.

This 100 gpm baseline accounts for the friction losses and possible water drawn by hose connections in the system. If the flow from a single sprinkler were allowed to be less than this, a small or developing fire might not receive enough immediate water to control it, especially when other demands are present. While higher flow rates can occur when more heads open or hose streams are used, the 100 gpm figure represents the minimum guaranteed flow from one sprinkler in a combined system.

Hence, the best choice is 100 gpm because it reflects the minimum discharge requirement that ensures reliable performance for a single sprinkler head in a combined system.