Pressure Based Sprayer Principals

Liquids Revolution – Sprayer Basics: Pressure, Flow & Speed
Operator Training

Pressure, Flow & Speed — How to Stay on Target

Built in the Great White North · Liquids Revolution

1) What are we trying to do?

Your job is to hold a steady application rate (GPA) while you drive. Whether you go faster or slower, the sprayer must deliver the right flow (GPM) to stay on target.

Flow moves with speed and width

Flow (GPM) ∝ Speed (km/h) × Width (m)

Nozzles follow the square-root law

Q₂ / Q₁ = √( P₂ / P₁ ) → P₂ = P₁ × (Q₂/Q₁)²

  • Small speed changes need small PSI changes.
  • Big speed jumps need a lot more PSI (because pressure scales with flow squared).
Two ways to stay on rate:
  1. Manual pressure: watch speed and set PSI from the chart.
  2. Fixed PSI + PWM: keep ~30 PSI and trim with PWM (if equipped).

2) What numbers does the chart assume?

  • Single-pass sidewalk width: 1.5 m (59.1") coverage
  • Center bar: 48" with 5 StreamJet nozzles, 1.5 GPM @ 40 PSI
  • 3-Zone wide: 14 ft total (center + two BoomBuster 265 5R wings, 8.0 GPM @ 40 PSI) sharing one regulator
  • Use the table below to pick your Model, GPA, and Speed, then set System PSI.

3) How to use the calibration lookup

  1. Select your Model (Single-Pass 1.5 m  or  3-Zone 14 ft).
  2. Choose your Target GPA (70/80/90/100) and Speed (5–14 km/h).
  3. Set the System PSI shown. On 3-Zone, center + wings share this pressure.
  4. Run a 60-second catch test. If wings are high/low, correct with PWM or restrictors until wing flow ≈ target.

Tip: If conditions change (ice, temp, traffic), adjust speed or PSI and re-check with a quick catch test.

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