A Probabilistic Lifetime Prediction Technique for Piping Under Creep Conditions

We outline here a simple approximate method of lifetime prediction for high-temperature, internally pressurized piping components that takes into account the very large scatter present in the creep data for commonly used piping materials. This scatter is so large as to make deterministic methods of life prediction quite problematic. The method presented here is based upon the well-known Monte Carlo technique, and makes use of the standard damage fraction as the basic measure of creep damage. The method yields predictions of the probability of failure after a fixed operating time, assumed to be large.