Spray Unit Washdown Process

Spray Unit Washdown Process
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Steps

  1. Target time
    30 minutes.
  2. Equipment and materials
    • Recently used Spray Unit attached to tractor.
    • Hose with clean water
    • Gurney / pressure washer
    • Gloves, earmuffs, eye protection.
  3. Method
    1. Ensure the spray unit tank is completely empty.
      • Remove the cap at the back of the spray unit and allow all residual liquid to drain.
    2. Rinse the tank thoroughly with clean water using a hose.
      • Allow water to run out of the bottom of the tank.
      • Ensure the filter basket inside the tank is also washed clean.
  4. Clean the Nozzles
    1. Remove all spray nozzles from the boom.
      • Each nozzle assembly consists of the:
      • holder in which there is:
      • a stainless steel filter basket
      • a black rubber 0-ring
      • the nozzle itself.
      • There are 12 nozzle assemblies in total.
    2. Take all nozzle assemblies to the gurney.
    3. Disassemble each nozzle assembly.
    4. Clean each nozzle: (opposite to the normal flow direction).
      • Use the gurney to blow water backwards through the nozzle
    5. Clean each stainless steel filter: direction to normal flow.
      • Hold the filter between thumb and forefinger.
      • Use the gurney to blow water through the filter in the opposite
    6. Reassemble all nozzle assemblies and set aside.
  5. Clean the Main Filter
    1. Remove the main filter:
      • Remove the red centre piece to stop water flow.
      • Unscrew the locking cover.
      • Remove the cover and extract the blue filter.
    2. Clean the blue filter thoroughly using the gurney.
    3. Set the clean filter aside temporarily.
  6. Flush, reassemble, and test
    1. With the main filter and nozzles removed, fill the tank with approximately 100 litres of clean water.
    2. Run the system to flush all lines.
    3. Check each line to ensure water is running clear.
  7. Reassemble the System
    1. Reinstall the main filter:
      • Reverse the removal steps.
      • Ensure the O-ring is properly seated and sealing.
    2. Reattach all nozzle assemblies.
  8. Check and Test
    1. Run the spray unit briefly.
    2. Check that all nozzles are spraying correctly.
    3. Adjust nozzles as necessary to ensure even spray patterns.
  9. Empty the Tank
    1. Drain any remaining clean water from the tank.
    2. Leave the spray unit ready for storage or next use.
  10. Quality checks and “definition of done”
    • Run the spray unit briefly.
    • Check that all nozzles are spraying correctly.
    • Spray unit is drained and ready for storage or next use.
  11. Troubleshooting and exceptions
    • Nozzles not spraying evenly: Remove and re-clean affected nozzle(s) and filter basket(s); re-test.
    • Water not running clear after flushing: Continue flushing; re-check tank, main filter, and nozzle filters for residue.
    If issues persist after re-cleaning and flushing, escalate to the spray unit owner/maintenance lead.