Tank to Pump

Formulas

Pump Discharge Pressure Formula

The pump discharge pressure formula adds nozzle pressure, friction loss, appliance loss, and elevation pressure into the target the operator pumps to. It is the recipe that turns a tip-pressure goal into a panel setting.

Build the target from the tip backward: start with the nozzle pressure the tip is designed for, add the friction loss of the hose at the planned flow, add any appliance in the lay, then add or subtract elevation. The sum is the pump discharge pressure.

Working the formula in that order keeps the operator from forgetting a term. Each piece is a separate line item, and leaving any of them out — especially appliances or elevation — sends the line out under target.

Formula

PDP = NP + FL + AL + EP

NP = nozzle pressure; FL = friction loss (C × Q² × L); AL = appliance loss; EP = elevation pressure (add uphill, subtract downhill).

Common questions

What is the pump discharge pressure formula?
The pump discharge pressure formula is PDP = NP + FL + AL + EP: nozzle pressure plus friction loss plus appliance loss plus elevation pressure. It turns a tip-pressure goal into the number you set on the discharge gauge.
In what order do you work the PDP formula?
Build it from the tip backward. Start with the nozzle pressure the tip is designed for, add the friction loss of the hose at the planned flow, add any appliance in the lay, then add or subtract elevation. Taking the terms in that order is what keeps an operator from forgetting one.

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See also