TM 5-3740-218-13&P
NOZZLE SELECTION AND SYSTEM CALIBRATION
G-1.
SELECTING NOZZLES FOR CALIBRATION
To properly select a nozzle, it must first be determined how many gpm each nozzle will have to put out. Once this is
known, the chart for nozzle selection will aid in finding a nozzle with the right gpm. The formula for finding the
gpm/nozzle is:
GPM/NOZ = GPA x MPH x SW
# NOZ x 495
Example: An operator wants to fly on 10 gallons per acre and fly 50 mph. The spray boom has 58 nozzles and the swath
width is 90 feet. How many gpm will each nozzle have to put out?
10 x 50 x 90 = 1.56 GPM/NOZ
GPM/NOZ = GPA x MPH x SW =
# NOZ x 495
58 x 495
Answer: Each nozzle will have to put out 1.56 gpm/nozzle. By looking at the charts in the section for nozzle selection, a
D-8 will meet this requirement. A D-8 equals 1.56 gpm/nozzle at 30 psi.
G-2.
NOZZLE SELECTION
The basic idea of nozzle selection is to find a nozzle that will perform to the application in the psi range available.
By listing all nozzle flows in gallons per minute at 30 psi, the job of nozzle selection can be simplified. With the following
formulas, nozzles can be selected from the Spraying Systems and DeLavan charts regardless of the pressure at which
they will be used.
GPM/NOZ at 30 PSI = GPA x MPH x Nozzle Spacing
5940 x Conversion Number for New PSI
or
GPM/NOZ at 30 PSI = GPA x MPH x Nozzle Spacing
495 x Conversion Number for New PSI
or
GPM/NOZ at 30 PSI = GPA x MPH x SW
# NOZ x 495 x Conversion Number for New PSI
The PSI Conversion Numbers Chart is used to obtain the "conversion for new psi." The conversion number should
correspond to the psi the nozzle will be performing at in its application.
The conversion number represents the formula: new PSI = 30 PSI
