Pipe Service Tests on Baltimore Water

Theory of corrosion for engineers

“…Fundamentally the rusting or corrosion process is one in which electrons arc lost by metallic atoms which then become positive ions. Fe = Fe + + + 2 electrons (Reaction 1) The area where the metallic atoms lose electrons and become ions is called the anodic area and this reaction the anodic reaction. The area where the electrons are used is another chemical reaction called the cathodic area and this reaction the cathodic reaction.…”

“…The area where the electrons are used is another chemical reaction called the cathodic area and this reaction the cathodic reaction. Since metals are good conductors of electrons these areas may be separated if environmental conditions warrant such.2 ' Present address, Hancock Research Foundation, University of Southern California, Los Angeles, California, 1 All corrosion is essentially electrochemical in nature since elections are always transferred from the metal to some reducible substance but some prefer to view corrosion as electrochemical only when the anodic and cathodic areas are separated by a discernible distance. If the corrosion is uniform over the entire surface they prefer to call it direct chemical attack.…”

“…Let us recall the two conditions necessary for corrosion to take place: (1) Electrons that tend to be lost by the metal in the anodic reaction cannot be lost unless they can be used in some other chemical reaction which we call the cathodic reaction. (2) The ions formed by both the anodic and cathodic reactions must be removed from where they are formed or must combine with ions of opposite charge so no great accumulation of charge occurs in any area.…”

Über die Heißwasser‐Druckkorrosion von Zink

“…Neben dem Maximum bei etwa 60 bis 70' C zeigten sich bei Kurzzeitversuchen bei geringen Sauerstoffkonzentrationen auch Andeutungen eines Maximums bei 30' C (2). Die heute wahrscheinlichste Erklarung der Ursache des 60 bis 70' C-Maximums diirfte ein Wechsel der Morphologie der adharierenden Korrosionsprodukte in Abhangigkeit von der Temperatur sein, mit der auch Veranderungen des Potentials verbunden sind (1,2,(4)(5)(6)(7)(8)(9).…”

Discussion

“…To date no city has used a sufficient feed of Calgon to afford adequate protection to the hot water tanks of the consumers. Such quantities of a similar glassy phosphate, Micromet, have been supplied to several thousand hot water tanks, particularly in Little Rock, Engineering at Johns Hopkins University (1).…”