Surface Preparation
All tubes were filled with rubber bungs to protect them during the repair process. The substrate was then abrasive blast cleaned to achieve a surface cleanliness level of Sa 2.5 with a 75-micron profile. This preparation ensured that the repair materials would adhere effectively to the surface.
Application of UPS 200 EG CERAMIC REPAIR PASTE
Areas of pitting on the tube sheet were filled with UPS 200 EG. This step restored the integrity of the corroded sections, providing a smooth and solid foundation for the protective coating.
Application of UPS 225 HT HIGH TEMPERATURE CERAMIC
The entire surface of the tube sheet was then coated with two layers of UPS 225 HT. Both coats were applied by brush on the same day, each at a thickness of 500 microns. This high-performance coating was chosen for its ability to prevent future corrosion and withstand the high temperatures associated with the refinery's operations.