Project summary

The main scope included recoating of the azimuth thruster box coolers and cleaning of the seven coolers that were coated during a previous docking in Qatar. Pressure testing, tubesheet preparation, and gasket surface finishing were also added during execution.

How we worked

We began with chemical cleaning and high-pressure washing of all units. The four azimuth thruster coolers were sandblasted using Garnet Mesh 30/60, followed by double-layer coating with Säkatonit Extra AR-F. All tubesheets and gasket surfaces were cleaned and grinded as per our procedures.

For the cleaned units, all marine growth was removed using chemical baths and manual methods. All coolers were then pressure tested at 3 bar using custom covers and gaskets fabricated on-site. No leaks were found during the tests.

Results

All 11 coolers were successfully cleaned, coated, tested and delivered. Flanges and sealing surfaces were hand-finished for smooth assembly. The project was completed on schedule and all equipment was prepped for reinstallation onboard.

What we used

• Säkatonit Extra AR-F (2-coat system)
  
• Garnet Mesh 30/60
  
• NGP Marine Descaler
  
• HP washer, 80 bar
  
• Custom pressure test setup with fabricated gaskets
  
• Air and water flushing for all tubes
  

Reflections

This project shows the benefit of combining coating, cleaning and mechanical control in one complete service. The process ensured that all units are delivered with optimal protective coating and mechanical integrity, ready for duty.