Analysis of stresses in tank walls and bottoms with a penetrating connecting pipe

Abstract

Tanks and equipment used in chemical and petroleum engineering have structural units in the form of a branch pipe or nozzle attached to a cylindrical tank wall or an ellipsoidal or hemispherical bottom. One such unit is a branch pipe, which partially penetrates inside the tank. In the standards, a penetrating pipe is assumed to be a reinforcing element of the wall or bottom. However, the geometric parameters for which this is true are now shown. It also should be noted that no stress analysis of such elements exists in the domestic literature. Spherical and ellipsoidal bottoms with a radial penetrating tube have been analyzed analytically for axisymmetric component shell designs. An analytic solution is not feasible for other designs, for example, a slanted pipe on a bottom or a pipe on a cylindrical wall. The structural joint of a tank wall (bottom) with a branch pipe is an intersection of shells. The stress state of such shell structures is conveniently calculated using shell theory. In considering the complex geometry of intersecting shells, the most usual approach is a numerical analysis. Here we present results of the stress state from an internal pressure (the usual operating load) on a cylindricalmore » tank wall and an ellipsoidal or a spherical bottom with a penetrating branch pipe.« less