Prognostics for Small Bore Piping Undergoing Fatigue Degradation

Abstract

Prognostics of Small Bore Piping (SBP) degrading due to fatigue deals with estimating its remnant useful life (RUL). This manuscript elaborates the RUL prediction procedure for SBP. Physics-based model is utilized to estimate the RUL, and the uncertainty in the different parameters of the Paris law are quantified and propagated. According to Paris law, crack growth per cycle is proportional to Stress Intensity Factor (SIF) which in turn depends upon initial crack size (ICS) and stress range. ICS is generally estimated using the Non-Destructive Examination techniques while the stress acting at the interface of SBP and the mainline piping is determined using Fluid Structure Interaction (FSI) performed using ANSYS software to couple CFD and FEA analysis. Finally, the predicted RUL is employed to estimate reliability and frame inspection interval for SBP which shall ensure mitigation of hydrocarbon leak at the process facilities.