Abstract
Failure of domestic fuel oil tanks by perforation at the bottom as a result of internal corrosion has been a troublesome problem of the oil industry. Field investigation indicated the primary cause of corrosion to be the presence of small amounts of water in the tanks but did not provide a satisfactory explanation for the rapid localized attack that would occur sporadically. Laboratory data are presented which show that very rapid penetration can result from localization of the rusting .action of water if imperfect coatings are present on the surface of the steel. Examples of such imperfect coatings are mill scale with breaks in the scale, thin sludge deposits and dirt collected on the bottom of the tank. There was no indication that the fuel oil was contributing any corrosion accelerating acidic constituents.
Addition of an alkaline sodium nitrite mixture to the individual tanks has been proved to be an effective means of preventing these corrosion failures. Supporting laboratory data are presented.
