Overview of the ASME Section XI Code Relating to NDE and Ultrasonic Examination Performance Demonstration

Abstract

Nondestructive examination (NDE) in Section XI of the ASME Boiler and Pressure Vessel Code has been an evolving process. The Code’s use of NDE for in-service inspection (ISI) to establish fitness for duty has brought about major changes in applied NDE philosophy and practice. The publication in Section XI, 1989 Addenda, of mandatory Appendix VIII, “Performance Demonstration for Ultrasonic Examination System,” sets a precedent for both NDE performance and recognition of the total NDE system (personnel, equipment and procedures). This paper highlights appropriate portions of Appendix VIII. Performance values such as probability of detection (POD) and flaw sizing accuracy are addressed. The use of flawed specimens for performance demonstration qualifies personnel, equipment and procedures, hence the “Ultrasonic System” qualification. Appendix VIII provides the opportunity for technique performance demonstration for assessment of material aging and qualification of components and systems for continued service. This article provides the background and justification for Code action to publish Appendix VIII.