We were recently given some unfortunate customer feedback when one of our heat exchangers (HX) was used in a sea water application and "failed". The HX tube material in contact with the sea water was 90/10 Cu/Ni. According to some expert we never got to talk to, "the constant flow of sea water leached out copper from the tube, causing it to fail within a very short amount of time, because the HX was never properly commissioned". Our Cu/Ni HX was replaced with a competitor's titanium model, which is supposedly working well. I know of no more specific details of the failure than what was quoted above, for the HX was not returned to us, nor were we given access to this expert to ask clarifying questions. However it seems possible to me that this "commissioning" referred to must be somehow allowing an initial build up of a surface corrosion film, which would have then deterred additional, more serious corrosion underneath. As long as the film was not eroded away by contaminants or excess velocity, the HX should have lasted for many years instead of only weeks. Since then I have been looking for some guidance we could give our customers on the proper "commissioning" of HX for use with sea water. Can anyone help us?

Thank you for your response, Dave. Even though you state you do not know what was meant by "commisioning", you include in your response phrases such as, "precleaning and inhibition is conducted to make sure that a protective film is established" and "initially establish the protective film". Well that SOUNDS like some sort of commisioning to me. How exactly does one go about "inhibiting" and "establishing"? What did YOU mean when you say those things? Also I forgot to mention a question about sea water leaching the copper out of the Cu/Ni. Is this possible? Thanks, Brian