www . refrigerationandaircon . co . za RACA Journal I April 2024 41
Contributor that the tubes underwent the same production process . The low hardness values also suggest that the copper tubes did not undergo any hardening treatment / process .
CONCLUSION Based on the findings and discussion , the following conclusions were made :
• The failure of the heat exchanger was as a result of environmental corrosive attack , most likely from an external source .
• The overall construction of the heat exchanger suggests inappropriate material selection and / or fabrication techniques were utilised . A combination of improper material selection , welding and inappropriate paint selection / application increased the exposure of the copper tubes to the corrosive environment in which it operates . This allowed for corrosion to initiate and propagate throughout the whole heat exchanger , resulting in multiple leaks to occur over time .
RECOMMENDATIONS Based on the outcome of our investigation , One Eighty provided recommendations with regards to the failed heat exchanger .
These include : 1 . Review for appropriate material ( material selection ) 2 . Review weld procedures 3 . Review paint coating chemical composition for compatibility 4 . Review surface preparation and coating application
Successful implantation of the above-listed recommendations would minimise the overall risk for this type of failure from occurring in the future . The utilisation of the appropriate codes and / or standards should always be adhered to in any design in order to prevent unwanted failures due to lack of following the principle guidelines as set forth by the appropriate standardisation organisation . RACA
“ The low hardness values also suggest that the copper tubes did not undergo any hardening treatment / process .”
www . refrigerationandaircon . co . za RACA Journal I April 2024 41