PSI - Issue 22

Yaroslav Dubyk / Procedia Structural Integrity 22 (2019) 275–282 Yaroslav Dubyk / Structural Integrity Procedia 00 (2019) 000 – 000

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Using our statistical data, it is possible to determinate the probability of failure of Leak-Before-Break. This probability of failure is the probability that we get the critical crack in piping, and its leak rate will be less than a detectible leak. According to our calculations IGSCC crack are the most dangerous ones, for other type of crack the failure probability is less than 10 -6 . Considering Fig. 6 or Fig. 7 we can see, that transition from criterion 38 l/min to 3.8 l/min reduce the probability of failure of around an order of magnitude.

Fig. 6. Probabilistic analysis in K IC - σ ul space for IGSCC cracks, Normal Operation conditions, without crack morphology stochastic parameters.

Fig. 7. Probabilistic analysis in K IC - σ ul space for IGSCC cracks, Normal Operation conditions, with crack morphology stochastic parameters.