Yesterday’s problem: Electrochemical corrosion of sliding faces

Con­vert­ing the water chem­istry from alkaline to com­bi­na­tion or neutral op­er­a­tion and using in­creas­ingly powerful feed water pumps caused elec­tro­chem­i­cal cor­ro­sion which con­sid­er­ably reduced the op­er­at­ing periods of me­chan­i­cal seals at many power stations. This damage phe­nom­e­non, which leads to the de­struc­tion of face ma­te­ri­als, had been par­tic­u­larly observed in large boiler feed pumps with high cir­cum­fer­en­tial ve­loc­i­ties.