Comparative Study between Degradation Analysis and API 510 Remaining Life Evaluation Method for Feed Gas Filter Vessel Reliability Analysis

The objective of this study is to use the wall thickness data for degradation analysis of feed gas
filter vessel and compare the results with remaining life evaluation method provided in API 510. The
exponential model for degradation fitted best to the degradation (wall thickness) data. Extrapolation of
model gave the failure time for each thickness measurement location, thus providing a failure data set to be
analyzed for the reliability function. The results obtained show that the degradation model is more
optimistic than API 510 methods and thus it gives a failure free period of 690.33 years which is higher in
comparison to life evaluated by using API 510 short term and long term corrosion rates which were
calculated to be 510.43 & 628.75 years respectively. These results can be used as a good starting point for
Risk Based Inspection studies by estimating the probability of failure based on Weibull analysis.