Tank to Pump

Hydraulics & Pressure

Elevation Pressure

EP

Elevation pressure is the pressure the pump must add or can subtract because the nozzle sits above or below the pump. Figure about 5 psi for each floor of rise, added on top of nozzle pressure and friction loss.

A vertical riser with a pump at the bottom and an adjustable nozzle partway up. A dashed height line shows elevation above the pump, and a live readout displays the pressure cost (in psi) with its direction — a loss to overcome going up, an assist going down.

Elevation pressure · interactive

LEVEL 0 psiThe nozzle is at the pump's level: elevation neither costs nor adds pressure.

Height mode

Every foot the nozzle rides above the pump costs pressure; drop it below the pump (negative) for a free pressure assist (5 ft steps). Values are training estimates from the same elevation formula the panel uses; follow your SOPs.

Elevation pressure is the pressure the pump must add or subtract because the nozzle is above or below the pump. Pick feet or floors, then drag the nozzle height to see the pressure cost in real time.

Water has weight, so lifting it costs pressure. Every floor the nozzle climbs above the pump is head the operator must add to the pump discharge pressure; a downhill lay gives some of it back. It is a real part of the PDP, separate from the hose's friction loss.

On a high-rise stretch, elevation can dominate the pump pressure calculation. That is why standpipe and high-rise planning treats a floor's worth of climb per level as a line item alongside the attack hose and the system allowance.

Formula

EP = 5 × (number of floors above the pump)

Training shortcut: about 5 psi per floor of rise. By height instead of floors, figure roughly 0.5 psi for each foot the nozzle sits above the pump.

Common questions

What is elevation pressure?
Elevation pressure is the pressure the pump must add when the nozzle is above it, or can subtract when the nozzle is below it. As a training shortcut, figure about 5 psi for each floor of rise.
How do you calculate elevation pressure?
Count the floors the nozzle is above the pump and multiply by about 5 psi per floor, or use roughly 0.5 psi per foot of height. Add that to the pump discharge pressure for an uphill lay and subtract it for a downhill one. These are simplified learning figures — follow your SOPs for real settings.

Where this shows up

See also