Commentary and Justification for Modifications to Mandatory Appendix 47 in the 2025 Edition of ASME Section VIII, Division 1

With the 2021 edition of ASME Section VIII, Division 1 (VIII-1), Mandatory Appendix 47 was published as a new requirement for Manufacturers that focused on the requirements for persons who are designers of pressure vessels. The new appendix contained prescriptive requirements for education, training, experience, and oversight of these personnel including the explicit requirement that Responsible Charge be satisfied for pressure vessels built and certified by the Manufacturer. However, the new requirements of Mandatory Appendix 47 created significant misunderstanding and frustration in the industry, particularly concerning the requirements of Responsible Charge. As a result, a complete rewrite of the appendix was successfully undertaken for the 2025 edition of VIII-1. To address the issues with Responsible Charge and the prescriptive requirements, a number of changes were implemented. First, any reference to Responsible Charge and associated requirements were eliminated. Next, the requirements for Certifying Engineers and Engineers were eliminated in favor of a single requirement for a Designer. Additionally, more flexible wording was incorporated to simplify how engineering/design oversight is accomplished, and prescriptive education and experience requirements have been replaced with performance-based requirements. Also, clear distinctions for the certification of the pressure vessel by the Manufacturer were made to separate out any User or jurisdictional requirements. Finally, to establish who has final responsibility, the appendix shifts the burden of certification of the design away from a designer and back to the Manufacturer while maintaining some basic designer responsibilities. This paper presents commentary on the intent of the original requirements of the 2021 edition as well as the modifications for the 2025 edition. Additionally, a summary of the justification for the requirements that remain in the appendix is discussed. Finally, a comprehensive comparison of the original and current requirements is provided.