Appendix 46: Leveraging Division 2 Rules for Division 1 Vessels

The vast majority of pressure vessels are designed and built to ASME Section VIII, Division 1. While Division 2 typically requires its own separate code stamp, ASME allows designers to apply certain Division 2 design rules to Division 1-stamped vessels under Appendix 46. To maintain the standard Div. 1 safety factor, Appendix 46 requires that allowable stresses from Div. 1 are used. However, by utilizing the more precise formulas found in Division 2, designers can often reduce component thickness and nozzle reinforcement requirements. For vessels fabricated from expensive alloys, these material reductions can translate into significant cost savings. Appendix 46 is a powerful tool for producing a truly optimized vessel design.