PDP Calculator Guide – Engine Company Workflow (NP + FL + Elevation + Appliances)
Last updated:
PDP is where planning becomes operational. Use the PDP Calculator after you’ve sanity-checked hose friction using Friction Loss. Then standardize your results with Pump Charts so crews don’t do complex math under stress.
Open PDP CalculatorWater Supply & Hydraulics PillarPump Chart Generator
Operational note: PDP targets should match your department’s hose/nozzle packages and SOP/SOG. Use this as a decision workflow, not a one-size-fits-all chart.
What PDP Includes
- Nozzle Pressure (NP): the target pressure at the nozzle for your package.
- Friction Loss (FL): pressure lost through hose and flow. Use Friction Loss to estimate.
- Elevation: uphill adds demand; downhill reduces (use your local standard).
- Appliance Loss: wyes, manifolds, standpipes, master stream devices, etc.
60-Second Workflow
- Select the package: line + nozzle + realistic flow goal.
- Estimate routed length: corners, setbacks, stairs.
- Compute FL:Friction Loss
- Compute PDP: combine NP + FL + elevation + appliances.
- Stability check: if PDP is too high for stable operations, change the plan.
- Standardize: generate a pump chart for the package.
Examples (How to Use PDP as a Decision Tool)
- Long lay: PDP climbs quickly → consider larger hose to a gated wye.
- High-rise/standpipe: appliance + elevation dominate → use a dedicated standpipe playbook.
- Defensive flow: confirm supply first (Hydrant Flow / relay / shuttle).
Common Mistakes
- Using straight-line distance instead of routed length.
- Ignoring appliances or elevation.
- Forcing pressure instead of changing the hose layout/supply plan.
