Skip to main content

Crop and Pest Management Guidelines

A Cornell Cooperative Extension Publication
44086

7.5 Selecting Nozzles from the Nozzle Catalogue - Airblast Sprayers

We need to select hollow cone discs with a core or whirl plate.

Nozzle output is based upon gallons/acre required above.

Gallons/minute =

GPA x mph x row width in feet

495

Where:

  • GPM = total sprayer output in gallons/minute
  • mph = travel speed in miles per hour
  • row width = width between rows of vines in feet
  • 495 = a mathematical constant to correct units of measurement

Example 1

We wish to apply a 50 gallons/acre. We have an airblast sprayer with 5 nozzles each side and a comfortable forward speed for our ground conditions is 3.5 mph. Rows are 9 feet apart.

Gallons/minute (GPM) =

GPA x mph x row width in feet

495

GPM =

50 x 3.5 x 9

=

1575

= 3.18

495

495

GPM =

3.18

= 1.59 per side

2

GPM per nozzle = 1.59 divided by 5 nozzles = 0.318

Using the hollow cone nozzle table in the Spraying Systems catalogues: # 49A, pages 40-41, #49, pages 38-41 or # 201, pages 10-11

  • Read along the pressure row at the top of the table.
  • Read down the column for 100 psi until you read 0.32 gpm, look across to the left, you will see we can choose a D6 disc with a DC 23 whirl plate or core.
  • Alternatively, you may read further down the column for 100 psi until you read 0.32 gpm, look across to the left and you will see we can choose a D2 disc with a DC45 whirl plate or core.
  • Alternatively, you may read down the column for 200 psi until you read 0.32 gpm, look across to the left and you will see we can choose a D4 disc with a DC23 whirl plate or core.

Example 2

We wish to apply a 100 gallons/acre. We have an airblast sprayer with 5 nozzles each side and a comfortable forward speed for our ground conditions is 3.5 mph. Rows are 9 feet apart.

Gallons/minute (GPM) =

GPA x mph x row width in feet

495

GPM =

100 x 3.5 x 9

=

3150

= 6.36

495

495

GPM =

6.36

= 3.18 per side

2

GPM per nozzle = 3.18 divided by 5 nozzles = 0.636

Using the hollow cone nozzle table in the Spraying Systems catalogues: # 49A, pages 40-41, #49, pages 38-41 or # 201, pages10-11:

  • Read along the pressure row at the top of the table.
  • Read down the column for 80 psi until you read 0.64 gpm, look across to the left, you will see we can choose a D5 disc with a DC 45 whirl plate or core. Sometimes it is difficult to find the exact flow rate, so a close alternative maybe chosen.
  • Alternatively, you may read down the column for 150 psi until you read 0.65 gpm, look across to the left and you will see we can choose a D5 disc with a DC25 whirl plate or core.
  • Alternatively, you may read down the column for 200 psi until you read 0.62 gpm, look across to the left and you will see we can choose a D4 disc with a DC25 whirl plate or core.

A better alternative to consider would be to use a one-piece hollow cone nozzle tip. These one-piece tips are easier to fit into the cap and are much easier to remove for cleaning, changing tips etc.

Example

To continue with the worked example from earlier for a nozzle tip with a flow rate of 0.64 gpm. As an example, using the Conejet hollow cone nozzle table in the Spraying Systems TeeJet catalogues: # 49A, page 39, or # 202, page15:

  • Read along the pressure row at the top of the table.
  • Read down the column for 90 psi until you read 0.648 gpm, look across to the left, you will see we need a blue TXVK-26 one-piece nozzle.