Spray Equipment And Calibration
MEDIUM
40 CFR § 171.103(d)
To double the output (Gallons Per Minute - GPM) of a hydraulic spray nozzle solely by adjusting operating system pressure, by what factor must the pressure (PSI) be increased?
Multiple Choice Options
40 CFR § 171.103(d)
Official Manual Chapter: Chapter 9: Application Equipment & Chapter 10: Calibration
Nozzle flow rate varies in proportion to the square root of pressure: (GPM1 / GPM2) = sqrt(PSI1 / PSI2). Therefore, to double output (2x GPM), pressure must be increased by 2 squared = 4 times. Adjusting pressure to make large changes in output is undesirable because high pressure creates dangerously small, drift-prone droplets.
Official EPA Core Study Domain
Spray Equipment And Calibration
Practice All Domain Questions →