| Abstract: | This paper presents a brief summary of the technical basis for the recommended stress indices for 45 degree lateral connections under internal pressure and in-plane moment loadings.Starting with the historical background of the Pressure Vessel Research Committee's (PVRC) long range program on lateral connections, this paper highlights the various aspects intrinsic to this program such as model selection, analysis technique, finite element discretization, loading conditions, material properties and boundary conditions.A discussion of the stress index method and its application to the pressure vessel and piping design is offered as a prelude to the recommended code indices. Proposed changes to Par. NB-3338.2(C) (1) of Subsection NB of the ASME Code pertaining to lateral nozzles in cylindrical vessels and Par. NB-3650 relative to branch connections in piping systems are presented and discussed in detail.Besides, this paper discusses the need to develop additional data in the range of geometric parameters, 0.5 ≤ d/D ≤ 1.0 and 10 ≤ D/T ≤ 50, and under other remaining loading conditions to broaden the application of the stress index method. |
