Fire Protection · NFPA-13
Fire-Ready
A looped fire ring main with a Q=K√P sprinkler grid: over-deliver the design density, clear the 7-psi minimum, and prove the demand point sits under the supply curve.
The system
A looped ring main with a sprinkler grid
A city main backed by a fire pump feeds a looped DN100 ring main wrapping the building; two risers tap the remote corner and feed a grid of ten K=8.0 sprinklers over the NFPA-13 Ordinary-Hazard-Group-2 design area (0.20 gpm/ft² over 1500 ft²). DekEn solves the whole network with the production Q=K√P emitter engine.
- System
- Looped DN100 ring main + fire pump
- Design area
- OH-2, 0.20 gpm/ft² over 1500 ft²
- Sprinklers
- 10 × K = 8.0 emitters
- Solve
- Hazen-Williams (NFPA §22.4) + Q=K√P emitters, converged in 3 passes
The result — it passes, with margin
Over-delivers the density, clears the minimum, sits under the supply curve
The system delivers 0.266 gpm/ft² against the 0.20 gpm/ft² requirement, every nozzle stays above the 7 psi NFPA minimum, and the §28.4 demand point — 596 gpm at 30.3 psi, including a 250 gpm hose allowance — sits on the available water-supply curve, with headroom above the required operating point. The ring genuinely shares load, roughly 173 gpm each way, meeting at the remote corner.
Source: the production GGASolverSparse Q=K√P emitter solve (converged in 3 passes, mass-balanced).
What this proves vs the competition