Small Diameter Pipe Inspections （小直径管检查）.pdfVIP

Improved Inspection of Small Diameter Pipe Welds Prepared by: Michael Moles Presented by: André Lamarre NDT in Canada 2010 and the 3rd International CANDU In-service Inspection Conference June 2010 – Toronto, Ontario Presentation Outline Issues with radiography Issues with manual and AUT Cobra – the ONDT solution Mechanical advantages Ultrasonic advantages Sample results Conclusions Typical Inspection Application Limited space during construction Even worse for In- Service applications. Problems with radiography Radiation safety Licensing Environmental side effects from chemicals Film storage Poor planar defect detection Comparatively slow Subjective interpretation Production disruption: For small diameter pipes in particular, =usually many welds in close proximity. Issues with Manual and Automated UT Manual ultrasonics – slow – operator dependent – no auditable record Automated ultrasonics – scanners must be small enough to fit – beam defocuses in small diameter pipes – cost generally high. Cobra – small diameter pipe inspections Low profile delivery system Operates with OmniScan ASME - Small Diameter Codes ASME B31.1 Code Cases 179 permits AUT of small diameter pipe girth welds CC 179 is workmanship-based Code Case ASME B31.3 CC 181permits AUT CC 181 Fracture Mechanics-based = B31.3 Code