NDTnet 1998 Aug, Vol.3 No.8

Full-Text - Abstract

The driving force for the developments in NDT techniques has been the need for more reliable, simpler and cost-effective inspection. The developments in automated inspection technology and the growth of Fitness For Purpose (FFP) inspection have propelled emerging techniques like the Ultrasonic Time-Of-Flight Diffraction (TOFD) technique to the forefront in industry. The use of TOFD for weld inspection is being increasingly applied both as a replacement to radiography, for rapid, more reliable, real-time inspection and to offer a higher quality of inspection which ensures FFP inspection requirements.

Several international round-robin exercises have taken place over the last two decades. The first phase saw the validation of the technique as an accurate defect sizing tool. The second phase helped in confirming the usefulness of the technique as a rapid defect detection tool as well. The third phase involved the validation of TOFD as an alternative inspection tool leading to its widespread application in the industry. This phase saw the validation of TOFD for a wide range of applications which include, high temperature measurements, duplex steel inspections, thin plate inspections and complex geometry inspections. Other developments during this phase include the validation of TOFD for piping inspection confirming to ASME Xl, appendix 8, the publication of a British Standard for TOFD and the validation by Lloyds Register to use the AEA Sonomatic TOFD procedures for the inspection of welds up to 300 mm. The fourth phase of trials underway at this moment should lead tothe development of international standards for TOFD.

As a direct result of all these four phases, TOFD is widely being used as a solution providerfor a wide range of inspection problems. This paper will discuss in detail the specific results of thevarious trials undertaken and look at the ramifications to the industry, if the conclusions areimplemented. The significance of the practical experience gained through the various projects undertaken will be highlighted to assess the contribution of TOFD in improving inspection quality. The necessity of personnel qualification, standardization and the development of acceptance criteria will also be analysed to identify future growth potential of this technique in the industry.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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