Pressure Vessel Fitness for Service
A major oil company revitalizing an Iraqi oil field called on Becht Engineering to review several hundred pressure vessels containing thinned regions to determine their fitness for service (FFS) per the API-579-1/ASME-FFS-1 Part 5 process for analyzing Local Thin Areas (LTAs). Using ultrasonic testing (UT) and visual inspection data, Becht Engineering customized its proprietary API-579-1/ASME-FFS-1 compliant General Metal Loss and Local Thin Area evaluation software to create a program capable of evaluating the maximum allowable working pressure (MAWP) of these pressure vessels in an efficient manner. The software is very easy to use and presents the results in a user-friendly format for evaluation by engineers and managers. Because of the extensive nature of the corrosion, large files containing UT scan data needed to be evaluated, and the software was enhanced to parse and analyze the LTAs in the large datasets. This highly efficient process allows rapid evaluation of LTAs, and most vessels were completed in less than one week’s time. Becht’s software modification has also included the COMPRESS vessel design software output as an input to these FFS assessments. Becht has performed Level 1 and Level 2 LTA analyses on various vessels, evaluated sections of vessels for total replacement, analyzed external damage caused by shrapnel from previous wars, and developed repair procedures within the means of the maintenance team for this remote oil field.