CHEMICAL APPLICATION AND OPERATING VARIABLES
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6. Spraying Solutions other than Water
Most calculations are based on spraying water. A
conversion factor must be used to determine
application rates of chemical solutions that do not
use water as the carrier because other solutions
will be heavier or lighter in density than water.
To determine the proper size nozzle for the
solution to be sprayed, convert the desired GPA or
GPM of solution to a water rate using the
conversion factors. Then use the new converted
GPA or GPM rate to select the proper size of
nozzle tip.
Example:
a. The chemical manufacturer’s recommended
rate of application for a solution of 28%
nitrogen is 8.5 GPA.
b. A solution of 28% nitrogen has a specific
gravity of 1.28 and a conversion factor of
1.12. The converted GPA is therefore 9.52
for a solution with water.
8.5 GPA X 1.12 = 9.52 GPA
c. Refer to the conversion chart and locate the
equivalent GPA for a solution of water based
on the ground speed and pressure.
Conversion Chart
lbs./US gallon
7.0
0.84
0.92
8.0
0.96
0.98
8.34
1.00
1.00
9.0
1.08
1.04
10.0
1.20
1.09
10.65
1.28
1.12
11.0
1.32
1.14
12.0
1.44
1.20
14.0
1.68
1.29
SPECIFIC
GRAVITY
CONVERSION
FACTORS
WEIGHT OF SOLUTION
kilograms/liter
0.84
0.96
1.00 - Water
1.08
1.20
1.32
1.44
1.68
1.28
