ASME PRESSURE VESSEL INTERNALS AND THEIR DESIGN CODE

It is common for designers to use the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME) when designing vessel internals (i.e. process trays, bed supports, bolted connections, etc). Typically the ASME allowables are directly applied to internals without any regard to the member geometry or failure modes. The ASME code was developed for modes of failures experienced in the pressure boundary and was not intended to be utilized for the design of structural components. ANSI/AISC 360-10 "Specification for Structural Steel Buildings" (AISC) addresses the failure mechanisms experienced in structures based on their geometry and boundary conditions. This paper will provide several examples along with a direct comparison between structural members designed to the AISC and ASME codes. This paper will also provide guidance for using the AISC methodology with material properties at design temperature from ASME Section II Part D for robust design of internal structures.