OVERVIEW: The cooling water system’s tube sheets, internals and sealing faces were suffering severe pitting corrosion due to a galvanic reaction between dissimilar metals. The Chem-tect™ RB 300 series was used to protect against sea water at temoeratures of up to 80°C.
INDUSTRY
ENVIRONMENT
Ambient sea water inlet side and 60-80°C outlet side
SUBSTRATE
Mild Steel water boxes & bronze tube sheets
CHALLENGE
The cooling water system was severely corroded and required refurbishment. The tube sheets were corroded due to a galvanic reaction between dissimilar metals. A 72 hour shut down period was utilised to complete the work. The tube internals required protection from abrasive blasting damage. Sealing faces were suffering severe pitting corrosion also.
SOLUTION
Tube internals were protected by inserting rubber bungs from internal damage the surface treatment process.
The entire face was abrasive blasted to ensure surface is clean and free of contamination. RB 300 was applied to tube-sheet face, followed by post machine sealing faces to ensure division plates mate, preventing interference and by-passing. Caps were removed. Chemcote also supplied nylon inserts to prevent tube end corrosion & cavitation.
PRODUCTS
OUTCOME
This client has become one of our regular customers. Chemcote has conducted numerous jobs for this client over the years, including multiple heat exchanger and condenser units. During a routine 4 year inspection, other cooling water systems coated with the same coating which showed no signs of deterioration.
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