Code Case 2235-3 A Major Opportunity for Advanced Ultrasonic Inspection

摘要

In 1996, Code Case 2235 was approved by the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code Committee. The Code Case allowed for ultrasonic examination in lieu of radiographic examination of ASME Section VIII Division 1 and Division 2 vessels whose wall thickness exceeded 4" (107.6mm). Two subsequent revisions have been made to the Code Case. Revision 1 provided clarification on the use of digitized ultrasonic inspection systems, specifically those employing Time-of-Flight Dim-action (TOFD) techniques. Revision 2, published in May 2000, revised the minimum wall thickness figure down to 0.5" (12.7mm), thus allowing the use of the Code Case for most pressure vessels manufactured for use in industrial applications. This paper describes the main features of the Code Case and goes on to describe what is believed to be the first Code compliant inspection performed to Code Case 2235-2 by AEA Technology in Italy in June 2000, using a combination of TOFD, (main weld body), Pulse Echo, (weld root & cap) & Creeping Waves (upper surface/sub surface). Subsequent to the above further minor amendments have been incorporated within CC2235-3 which do not affect the above philosophy.