Relay Pumping Tool

Relay Pumping Calculator

Plan relay distance, engine spacing, number of relay pumpers, and suggested PDP for long supply lays.

Inputs

Total relay distance (ft)

Desired flow (GPM)

Supply hose / C value

Custom C value

Max relay engine discharge PSI

Target intake at next engine PSI

Total elevation change ft (+ uphill)

Appliance loss per segment PSI

Training/reference aid only. Follow department SOPs, instructor direction, manufacturer data, and local conditions.

Results

Relay pumpers needed

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Engine spacing

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Suggested PDP each

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Total engines incl. attack

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Enter values and calculate.

Relay planning notes

This tool estimates how many relay pumpers are needed and how far apart to place them based on hose friction loss and desired intake pressure. Use conservative spacing when terrain, hose condition, hydrant capacity, or communications are uncertain.