Pump Discharge Pressure
Required PDP from nozzle, friction, elevation.
Example
You enter
- Nozzle pressure (psi) 100
- Total friction loss (psi) 25
- Elevation change (ft up positive) 20
You get
- Pump discharge pressure 135 psi
- Elevation contribution 10 psi
Checked against published worked examples from: NFPA.
Details, formula, and sources
Formula or tablePDP = NP + FL + EL + AFL where NP is nozzle pressure, FL is hose friction, EL is elevation pressure (0.5 psi/ft, the NFA fire-ground shortcut), AFL is appliance friction.
Source and editionNFA training materials by name; IFSTA Pumping Apparatus Driver/Operator Handbook by name.
Free accessNFA materials free at usfa.fema.gov; IFSTA licensed.
What governsEstimate. AHJ and licensed fire protection engineer govern.
API field namesnozzle_pressure_psi, friction_loss_psi, elevation_ft, pdp_psi, elevation_psi
- Elevation factor 0.5 psi per ft of head -- the NFA / IFSTA fire-ground shortcut this tile applies, deliberately about 15% above the exact 0.434 psi/ft water column so a pump operator's mental math errs high on pressure rather than lowNFA / IFSTA Pumping Apparatus Driver/Operator training materials
- Not the exact hydrostatic value 1 ft of water is 0.434 psi at 60 °F; the elevation-pressure-loss tile reports the exact figure alongside the 5-psi-per-floor rule, and the standpipe / relay / eductor tiles in this module use 0.434 rather than the shortcutphysical fact (1 ft H2O = 0.434 psi at 60 °F)