| ABSTRACT: | SAMPLING AND RISK ASSESSMENT METHOD FOR METALLURGICAL INSPECTION OF
PIPES AND TANKS
M.Brochu, B. Godin, and F. Lefebvre
XperX inc, Montreal, Canada.
This paper gives a general overview of a method developed to optimize NDT inspection planning and results
analysis. The proposed system offers sample size calculation, statistical analysis and life prediction tools. In
each step, calculations are driven by equations developed using data gathered from previous expertise.
These equations are updated as new case studies are added to the system database. The method was initially
developed for radiographic and ultrasound techniques. It can be described in eight steps:
1) Assessment of degradation severity
2) Determination of inspection method
3) Initial sample size calculation
4) Field testing
5) Results analysis
6) Probability and reliability calculations
7) Predictions and degradation pattern
8) Results presentation.
Steps 4 to 7 can be recomputed to get a better confidence index. Calculation and results presentation are
customized based on a questionnaire fill by the project engineer.
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