This week’s post takes up right where last week’s post left off in our discussion on Corrosion Management and Control (CM&C) Management Systems. As I have said previously, this information is based off a series of articles I did on PEI&R MS, which you can reference here. Here are the next four:
#5 External Corrosion Control
We come to external corrosion and corrosion under insulation (CUI). This is another of the many CM&C issues in which the C/M engineer/specialist needs to input to the inspection and maintenance plans, especially with regard to areas of susceptibility to CUI and placement of CMLs to detect CUI. Additionally there is a large amount of good guidance on where to look for external and CUI in the API 510 and API 570 Codes on Pressure Vessel and Piping Inspection, as well as their sister recommended practices, API RP 572 and API RP 574.
#6 Materials Selection
Next is Materials Selection. Clearly the input of a C/M engineer/specialist is generally needed for materials selection, not only for design purposes, but also for replacement and repair decisions after a piece of pressure equipment has failed to perform as expected or has leaked. Excellence in materials selection is the foundation for avoiding breaches of containment, and is another issue that should be well documented in the Corrosion Control Documents mentioned above. Both the API and NACE have a number of useful publications and recommended practices dealing with materials selection for the refining and chemical manufacturing industries. One of the most useful is API RP 571, Damage Mechanisms Affecting Fixed Equipment in the Refining Industry, which has recently been updated and expanded in the 2nd edition. Don’t be misled by the title, the document also covers most of the damage mechanisms in other hydrocarbon and chemical processes.
#7 Coatings and Linings
Coatings and Linings, an offshoot of Materials Selection, covers a wide variety of corrosion barriers including external paints and coatings, polymeric linings, metallic linings, and refractory linings. In my experience, this is clearly the purview of a C/M engineer/specialist, without which the operating site may fall victim to “good vendor salesmanship” rather than being able to select the best i.e. most cost effective coating or lining to meet their needs over the entire life cycle of the equipment. Some of the larger operating sites and companies have-in house coatings and linings engineer/specialists, but those that don’t may need to seek guidance from competent third party, independent consultants for applications where failure could be very costly, not to mention result in safety or environmental incidents.
#8 Corrosion Control Standards
Next is Industry Standards for Corrosion Control. Previously, I mentioned the numerous API and NACE standards for materials selection, but there is an even larger body of standards and publications from not only API & NACE, but also from other Standards Developing Organizations (SDOs), like the ASTM andASME that cover corrosion control and materials selection topics. Each operating site should have access to the latest edition of those standards/ publications that apply to the type of processes and fluids handled. Each SDO has catalogs and on-line listings of available publications covering corrosion control topics. Participation as a member or just as an interested party at the numerous meetings of the API and NACE can be very useful in helping sites understand and appreciate the volume of literature available on corrosion control in the refining and chemical manufacturing industry.
Next week I will cover the last two Management Systems for Corrosion Control.