Replacing PR53SD steam wash nozzle - PR53 - PR53AC - PR53AP - PR53GC - PR53GP - PR53M - PR53SD - PR53W

PR53 Series User Guide

Document code
Document type
User guide

Follow these instructions to replace the PR53SD steam wash nozzle assembly.

WARNING Process refractometers may be installed in processes that have hot, cold, caustic, or otherwise hazardous liquids. When installing or removing the refractometer from the process, use personal protective equipment (PPE) adequate for the process medium and according to the requirements of the installation site.
WARNING If you have a wash system in place or are planning to install a wash system, make sure to familiarize yourself with safety regulations related to hot steam and water. For more details, see the related wash system user guide.
WARNING Surfaces on the equipment are hot. Use suitable personal protective equipment (PPE).
  • PR53SD steam wash nozzle (Vaisala item DRW258211SP)
  • 46 mm wrench
  • 9/16 in wrench
Figure 1. PR53SD steam wash nozzle assembly
Figure 2. PR53SD steam wash nozzle parts
Steam wash nozzle fitting
Shut-off steam valve
Safety pin
Wash nozzle nut
Wash isolation valve
  1. Familiarize yourself with the safety instructions of the installation site.
  2. Make sure the process line is depressurized and empty.
  3. Close the shut-off steam valve (2).
  4. Disconnect the steam hose using a 9/16 in wrench.
  5. Remove the safety pin (3).
  6. Loosen the wash nozzle nut (4) 2 turns using a 46-mm wrench. Do not fully loosen the nut.
  7. Pull the steam wash nozzle out until it stops.
  8. Close the wash isolation valve (5).
  9. Loosen the wash nozzle nut (4) fully using a 46-mm wrench.
  10. Pull out the steam wash nozzle.
  11. Push the new steam wash nozzle into the wash isolation valve (5).
  12. Tighten the wash nozzle nut (4) a few turns using a 46-mm wrench. Do not tighten fully.
  13. Open the wash isolation valve (5).
  14. Push the steam wash nozzle fully into the process.
  15. Reinstall the safety pin (3).
  16. Tighten the wash nozzle nut (4) with a 46-mm wrench to approx. 40-45 Nm.
  17. Clean the threads with a brush to remove any remaining PTFE‑tape.
  18. Add 2‑3 rounds of PTFE‑tape to the threads of the new steam wash nozzle fitting (1).
  19. Connect the steam hose. Tighten with a 9/16 in wrench.
  20. Open the shut-off steam valve (2).
  21. Recycle removed parts according to the recycling instructions in PR53 Prism Wash System User Guide (M212808EN).