Stress Analysis of Reactor Nozzle to Head Junction

Abstract

Spherical heads are widely used in pressure vessels and piping systems of petrochemical and power plants. Under different loading conditions, the stress will occur at the nozzle to head or shell junction area. Due to discontinuity of the geometry, defect will occur and the junction region will become the weakest point which will be the failure source of the whole structure. Thus a reliable and accurate analysis method for head or shell to nozzle junction is necessary. In this paper, stress analysis is carried out for nozzle to head junction subjected to applied external load, internal pressure and moments. Stresses at reactor nozzle to head junction are obtained using Welding Research Council (WRC) 107 and PVCodeCalc software (2008) with and without stress indices. It is observed from the analysis that with the case of stress indices stress are very high in nature. So, an attempt is made to do the stress analysis of reactor nozzle to head junction using FEA software (ANSYS 12), as per ASME Section VIII Division 2.