CHARACTERIZATION OF EQUIPMENT DEFECTS AND IN-SERVICE DAMAGE USING NON DESTRUCTIVE MATERIAL EVALUATION TOOLS AND INSPECTION TECHNIQUES

摘要

The increasing regulatory requirements in a competitive market in the process industry are forcing plants to use their inspection and maintenance budgets more efficiently. Several approaches are available for inspection prioritization of plant equipment. In addition, nondestructive evaluation (NDE) methods are available for detection, quantification, and characterization of equipment damage using internal and/or external access. All of these methods; however, require knowledge of degradation mechanisms and where they occur in the plant, as well as the methods available for detection and characterization of damage. By using the available internal and external inspection techniques, fabrication related defects were distinguished from service induced damage mechanisms in 119 refinery pressure vessels in wet H_2S and other services. When the indications were characterized as fabrication related or cracking in an inactive stage, considerable savings were made by avoiding unnecessary vessel entries, eliminating the need for weld repairs, or even reducing the extent of magnetic particle testing in a vessel. A summary of case histories will be presented.