Fire Sprinkler Pipe Sizing

Size fire sprinkler piping using pipe schedule or hydraulic calculation methods

Design Area

Most remote design area

System Configuration

Design Requirements

Branch Line Size --
Cross Main Size --
Feed Main/Riser --
Design Density --
Sprinklers Operating --
Min Sprinkler Pressure --
Estimated System Flow --
Note: Pipe schedule method shown. Hydraulic calculation required for most installations.

Design Density Requirements

Hazard Density Area
Light0.10 GPM/sf1,500 sf
Ordinary 10.15 GPM/sf1,500 sf
Ordinary 20.20 GPM/sf1,500 sf
Extra 10.30 GPM/sf2,500 sf
Extra 20.40 GPM/sf2,500 sf
Per NFPA 13 Figure 19.3.3.1.1

Important Notes

  • Must be designed by licensed fire protection engineer
  • Hydraulic calculations required for most systems
  • Add hose demand per NFPA 13
  • Verify water supply adequacy
  • Submit to AHJ for approval

Pipe Schedule - Light Hazard (Steel Pipe)

Pipe Size Max Sprinklers (Steel) Max Sprinklers (Copper) Max Sprinklers (CPVC)
1"222
1-1/4"333
1-1/2"555
2"101210
2-1/2"304030
3"606560
4"UnlimitedUnlimitedUnlimited
NFPA 13 pipe schedule tables. Reduce by 30% for Ordinary Hazard.