Methodology for Seismic Analysis of Electrically Operated Globe Valve

Abstract

The purpose of our thesis is to define a comprehensive seismic stress analysis methodology for a globe valve in context of the new guidelines after the Fukushima accident. Load combinations are performed as per ITER:s load specification guidelines. Loads are divided into primary loads, secondary- and accidental loads or occasional loads. Equipment is checked for strength and pressure integrity within stress limits and acceptance criteria. For seismic analysis, a modal analysis is performed to find the valves natural frequency and mode shape. Critical locations are considered for stress linearization to classify stresses. The stress classification is performed to satisfy the stress limit requirements of ASME BPVC, Section III, Sub-section NC.