Elevation

Elevation Pressure

Account for pressure lost or gained when water moves vertically.

What It Tells You

How vertical height changes the pressure required at the pump.

Formula

EP = height × 0.434 PSI per foot

What the Variables Mean

EP
elevation pressure PSI
height
vertical distance above or below the pump feet
0.434
pressure change for each vertical foot of water PSI per foot

Plain-Language Explanation

Pumping uphill uses pressure to lift water. Pumping downhill adds pressure at the lower end, so the elevation value becomes a gain.

Worked Example

The nozzle is 50 vertical feet above the pump.

  1. EP = 50 × 0.434
Add about 22 PSI

Fireground Takeaway

Use vertical height, not hose length, when calculating elevation pressure.

Practice This Formula

Open Reverse Flow and start a Practice Quiz filtered to this topic.

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