The paper is in two sections. The first section summarizes ten years of experience on two product lines operated by Shell Oil Company using alkaline aqueous solution of sodium nitrite as an internal corrosion inhibitor. Figures show the short and long time effect of nitrite inhibition, and reduction of cost by elimination of scraper operation and hay tank and strainer operation is discussed. This section includes a generalized statement of increase of capacity which can be expected from sodium nitrite inhibition.
The second section discusses the use of magnesium anodes as an external corrosion preventive on Shell’s products pipe line from Wood River to Chicago. The line is now 26 years old and was 21 years old with a moderately high leak frequency when anode installations were instituted. In order to analyze the effects of anode installations, pilot plant experiments were conducted, and the paper reports these pilot plant experiments and their results and the conclusions drawn therefrom. Included in this section of the paper are several sets of field tests conducted before anodes were installed, after anodes were installed, and over several years of life of anodes. Pictures and drawings support the conclusions drawn from pilot plant experiments, and results of field tests and experience during the five years of experimental work on the line are summarized. The conclusions drawn from this section of the report are that proper field testing and installation of magnesium anodes can control destructive corrosion sufficiently to extend the useful life of uncoated pipe lines to approximately double their unprotected life.
