API TR 939-D:2003 pdf download

API TR 939-D:2003 pdf download.Stress Corrosion Cracking of Carbon Steel in Fuel Grade Ethanol: Review and Survey.
Nevertheless, ethanol has been stored in more than 3(X)O tanks throughout the country throughout the last twenty years, without a reported case of SCC at manufacturers’ sites; and users area adding hundreds of additional tanks to ethanol storage. I)ue to the current and future tanks dedicated to ethanol storage: together with, the many pipelines and other storage facilities that are used in petroleum transport. the potential of repair associated with this or any issue affecting petroleum and ethanol storage cannot be dismissed.
4 Review of Published Literature
4.1 CORROSIVE AUACK IN ORGANIC MEDIA
In general. most practitioners of corrosion engineering and science are much more familiar with the basic principals of corrosion processes in aqueous solutions than they are with non-aqueous media such as organic solvents. I lowever, based on a review of the applicable literature, many of these principals are common. This section will present a discussion of important similarities and differences between aqueous and organic systems as applicable to understanding corrosion of metallic materials in ethanol.
For the most part, the similarities between organic and aqueous media dominate. Figure I shows the relationship between the electrode potentials of various materials in water and selected organic solvents, including methanol and ethariol. Ill While less data is available tirethaiiol. it appears that the trend is basically the same where the potential or the hydrogen electrode is similar for water, methanol and ethanol. l:or the most part. the behavior of the common metals Cu. Ph, Ti. Cd, Zn and Al are similar among these systems. and for methanol in particular. Ii is primarily in the region of Hg and Ag. which have a very high electrode potential in water, where a significant reduction in the electrode potential is observed. Additionally, water, methanol and ethanol are all protic media capable of sustaining electron transfer and ionization of the hydrogen atom. Therefore, in most cases, corrosion processes and galvanic interactions would be expected to be thennodynamically similar in water, methanol and ethanol with the following electrode potential ordering maintained:
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