Introduction of ferrous sulfate into supply water of condensers cooled by water from St. John’s River had the effect of bringing tubing failures to a sudden halt. Experiments were made by City of Jacksonville’s electric utility and water department over several months on several condensers to establish proper amount of ferrous sulfate to be added, frequency with which additions must be made, relative effect of chlorination, acid cleaning in service and reestablishment of protective iron film and others. Initial difficulties were attributed to two things. The scale that forms on inside of tubes forms a large cathodic area. When any breaks occur in this scale, the small anodic areas exposed are open to attacks. This attack is augmented by the impinging flow of the water which wipes clean the area under attack, helping to bring about the rapid failure.
8.2.2, 7.4.2, 4.6.4, 5.8.2
