scope:

This report covers one phase of the overall problem of reinforced openings in pressure vessels; specifically, the development of a design procedure for radial nozzles in spherical shells loaded with internal pressure. The design procedure is intended to define acceptable reinforcing details for radial nozzles in spherical vessels, hemispherical heads, torispherical heads provided the opening is in the spherical section sufficiently away from the toridal section, and ellipsoidal heads in the central section. Reinforcing, if any is required, is assumed to be continuous with the shells, as contrasted to "welded-on" pads. Since limit analysis is used to establish the design procedure, an implied assumption is that the material of the shells and the weld metal is ductile, e.g., is capable of withstanding several percent of local strain in a complex stress field at all temperatures at which the vessel may be loaded.