OVERVIEW: Deep pitting was found in many areas of the 35 year old oil cooler water box requiring pit filling and reinforcement using composites. Water boxes needed to be coated on site with minimal disruption to adjacent turbine hall.
Our solvent-free epoxy glass-flake filled coating has excellent resistance to the 60°C Salt Water environment.
INDUSTRY
ENVIRONMENT
60°C Salt Water Immersed
SUBSTRATE
Cast Iron
CHALLENGE
To refurbish and extend the operating life of extensively corroded, 35 year old, oil cooler water box.
Deep pitting was found in many areas requiring pit filling and reinforcement using composites. Water boxes needed to be coated on site with minimal disruption to adjacent turbine hall.
Prepare, coat, cure and complete in a duration of four days.
SOLUTION
We recommended coating with RA 532, a solvent-free epoxy glass-flake filled coating, which has excellent resistance to this particular environment
SCOPE
Water Boxes – Onsite
Needle gun difficult to access areas
Remove graphitised materials with high pressure water blast at 20,000psi
Assess damage and apply one coat of RS 500P integrated with a fibreglass matting to cope with low pressure
Application of two coats of RA 532
Conduct QA, DFT and high voltage spark test to ensure continuity at required voltage
Covers – Workshop
Abrasive blast to AS1627.4 Sa2.5 with a nominal surface profile of 75µm
Hot wash to reduce presence of metallic salts to <25ppm and re-abrasive blast
Application of RB 332
PRODUCTS
OUTCOME
The first unit was coated in 2006 with an expected operating life of two years due to plant redundancy. This unit has continued to remain online and in great condition for a substrate that is more than 60 years old. It is expected to last another ten years.
The newly coated water boxes were completed without incurring costs for abrasive blasting, encapsulation and were carried out with reduced downtime.
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