Structural Integrity and Creep-fatigue Assessment by ASME-NH for Hydrogenation Equipment at 454 ̊C

For pressure vessels constructed with low alloy steels which operate at temperatures above 371 ̊C, the fatigue design and exemption rules provided in ASME Boiler & Pressure Vessel Section VIII are no longer applicable. High temperature structure design codes which consider creep effect at elevated temperatures have to be used. An illustration of the assessment procedure of ASME-NH was given in detail based on thermal and structural finite element analysis results of hydrogenation equipment. The influences of primary load, temperature, weldment and the size of transition fillet on creep-fatigue damage evaluations were investigated by numerical analysis.