An Archimedes screw used for movement of a peroxide solution, was suffering from corrosion particularly to the leading edges. Repair through metallurgy was prohibitively expensive and was not a solution to the corrosion issue. After inspection and assessment of the Archimedes Screw, it was proposed that the Corroglass 600 series coating system would be used to protect the externally wetted areas.
1. Machined surfaces were masked up and protected, prior to abrasive blasting and coating.
2. Abrasive blasted the externally wetted surfaces with new abrasive in accordance with ISO 8501-1, Sa2½ surface finish, to achieve a minimum surface profile of 50 microns.
3. Completed a final blow down, sweep and vacuum clean thoroughly, where required, to remove dust.
4. Applied Corroglass 600 series to achieve a total dft of 1.5mm.
5. Once cured, removed surface protection, dress edges and completed 100 % visual inspection.
6. Carried out thickness testing.
7. Spark tested at 20kv following adequate cure of the coating.
8. Packed for transport and delivery.
The bespoke coating of Corroglass 600 series offers exceptional levels of protection combined with extensive service life. The cost of the whole operation was considerably less than using metallurgy of the supply of a replacement screw. Added to this, the environment and carbon footprint impact of renewing the asset was negligible.