Spray Nozzle GPM & Broadcast GPA

Pressure-scaled nozzle output, broadcast application rate, tank coverage and boom height for ISO 10605 and TeeJet spray tips.

Pressure-scaled nozzle output

Spray Nozzle GPM & Broadcast GPA calculations for pressure-scaled nozzle output are computed deterministically from published formulas, so the same inputs always produce the same result and the same OAS-XXXX verification hash.

Broadcast application rate

Spray Nozzle GPM & Broadcast GPA calculations for broadcast application rate are computed deterministically from published formulas, so the same inputs always produce the same result and the same OAS-XXXX verification hash.

Boom height and overlap

Spray Nozzle GPM & Broadcast GPA calculations for boom height and overlap are computed deterministically from published formulas, so the same inputs always produce the same result and the same OAS-XXXX verification hash.

Engineering summary

Governing parameters for the Spray Nozzle GPM & Broadcast GPA silo.

Governing parameters and computed results for this calculation
Parameter Value
Tip families TeeJet · MEG · airless
Rated pressure 40 PSI (flat-fan)
Flow scaling Q = Qr·√(P/Pr)
Broadcast rate model GPA = 5940·Q / (S·W)
Target double overlap 30 %

Frequently asked questions

How does nozzle flow change with pressure?
Nozzle flow scales with the square root of pressure: Q = Qr·√(P/Pr). Doubling the pressure raises flow by about 41%, so a small pressure change moves the application rate noticeably.
What is the broadcast application rate formula?
GPA = 5940 · Q / (S · W), where Q is gpm per nozzle, S is travel speed in mph and W is nozzle spacing in inches. The 5940 constant folds the acre, mile and minute unit conversions.
How high should a spray boom run?
Set boom height for a 30% double overlap: H = S·(1−0.30) / (2·tan(θ/2)), where S is nozzle spacing and θ is the full fan angle. Too low and the pattern streaks; too high and drift and overlap increase.