What is the maximum spacing between sprinklers on a branch line absent special conditions?

What is the maximum spacing between sprinklers on a branch line absent special conditions?

• A. 100 ft
• B. 150 ft
• C. 80 ft
• D. 120 ft

Answer: (C)

The spacing between sprinklers on a foam-water branch line is set to ensure the foam solution is effectively distributed across the protected area with the required application rate. When no special conditions are present, eighty feet is the standard maximum distance. Keeping sprinklers no farther apart than this helps maintain adequate coverage between heads, ensures the farthest sprinkler still receives the design flow and foam proportioning, and reduces the risk of gaps in the foam blanket. If spacing were greater, coverage could drop below the intended density, and the system might not meet the design requirements for the hazard class. Special conditions—such as higher hazard, larger unprotected areas, obstructions, or different proportioning needs—could lead to closer spacing or alternative design approaches.

The spacing between sprinklers on a foam-water branch line is set to ensure the foam solution is effectively distributed across the protected area with the required application rate. When no special conditions are present, eighty feet is the standard maximum distance. Keeping sprinklers no farther apart than this helps maintain adequate coverage between heads, ensures the farthest sprinkler still receives the design flow and foam proportioning, and reduces the risk of gaps in the foam blanket. If spacing were greater, coverage could drop below the intended density, and the system might not meet the design requirements for the hazard class. Special conditions—such as higher hazard, larger unprotected areas, obstructions, or different proportioning needs—could lead to closer spacing or alternative design approaches.