Mechanical Calculation and Verification of Steam Generators and a Knock Out Drum

MAWP rerating study for a set of steam generators and a knock out drum, following API 510 Section 8.8 criteria, which required calculations based on the original 1969 design code allowable stresses since the equipment predates the 1999 ASME addendum. Under the new, higher target MAWP, several components were found overstressed under ASME VIII Div. 1 rules, including the small end cone to shell junction, channel flange, and shell side head. A detailed FEA study was then performed for these components, including the head, a nozzle, the cone, the tubesheet to flange connection, and a tailor made gasket, applying ASME VIII Div. 2 Part 5 elastic stress analysis and linearized stress evaluation under the governing load combination (pressure, static head, dead weight, and live load). This combined Div. 1 and Div. 2 approach enabled a safe MAWP increase for critical process equipment while rigorously validating structural integrity at every discontinuity point.