Stiffness Coefficients and Allowable Loads for Nozzles in Flat-Bottom Storage Tanks

Abstract

The stiffness coefficients presented in this paper simulate the actual local translational and flexural restraint of the nozzle connection due to the attached tank shell. These coefficients can be conveniently incorporated into the analysis of the attached piping system to determine the imposed reactions at the pipe to nozzle junction. It is felt that including the stiffness coefficient will have an appreciable effect on the results of the piping analysis and will give a realistic prediction of the end forces at the nozzle connection. The acceptability of these end forces can be evaluated using the proposed criteria. The stiffness curves given in this paper can also be utilized to determine the elastic deformations of the tank shell for the calculated end forces at the nozzle connection due to the attached piping.