Fire Department Connection Calculator

Determine FDC requirements including size, inlets, and location per NFPA 13, 14, and local fire department standards.

Total system demand including hose allowance

FDC Inlet Guidelines

System Demand Min Inlets FDC Size
Up to 500 GPM2 x 2.5"4" min
500-750 GPM2 x 2.5"4-6"
750-1000 GPM2-3 x 2.5"6"
1000-1500 GPM3-4 x 2.5"6"
> 1500 GPM4+ x 2.5"6-8"

FDC Installation Considerations

Accessibility

FDC must be accessible to fire apparatus. Wall-mount or post-mount near fire lane. Clear of obstructions.

Check Valve

Ball drip or automatic drain required between check valve and FDC inlets to prevent freezing.

Protection

Breakable caps (aluminum or plastic) prevent debris. Knox caps may be required in some jurisdictions.