Crop and Pest Management Guidelines

A Cornell Cooperative Extension Publication
34194

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, pages10-11

  1. Read along the pressure row at the top of the table.
  2. 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.
  3. 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.
  4. 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:

  1. Read along the pressure row at the top of the table.
  2. 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.
  3. Sometimes it is difficult to find the exact flow rate, so a close alternative maybe chosen.
  4. Alternatively you may read down the column for 150psi 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.
  5. 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:

  1. Read along the pressure row at the top of the table.
  2. 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.

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