In-Depth Discussion of the Significant Changes to ASME VIII-1 and ASME VIII-2, 2025 Edition

Introduction

The publication of the 2025 edition of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section VIII, Division 1 (ASME VIII-1) and Section VIII, Division 2 (ASME VIII-2) will be available in July 2025. Like previous editions, the standards will contain technical updates, clarifications to existing rules, and editorial revisions. However, there are significant changes that will be implemented in the 2025 edition which reflect years of planning, organizing, and execution to enhance the use and reach of these standards. The intent of this article is not to provide an exhaustive list or synopsis of changes but rather to focus on aspects of the changes that are shaping the direction of future updates of the standards as recommended by the ASME BPV Section VIII Reshape Project. The article will, however, highlight specific changes to ASME VIII-1, Appendix 47 associated with the requirements for pressure vessel designers and the removal of the two-class vessel structure of ASME VIII-2, which impacts industry.

This article is organized into four main sections: a historical review of initiatives of the ASME BPV Section VIII committee to provide the reader with a perspective of why the changes are being implemented, a summary of the specific changes that will be implemented based on the Reshape Project, specific changes to ASME VIII-1 and ASME VIII-2 that will have a significant impact on industry, and a forecast of opportunities that the committee is considering to further shape use of the standards.

ASME BPV Section VIII – A Historical Perspective

To provide a better understanding of the changes being implemented in the 2025 edition of ASME VIII-1 and ASME VIII-2, we must start with the rewrite of ASME VIII-2, which was published in the 2007 edition. The 2007 edition of ASME VIII-2 was considered a significant milestone in promoting the advancement of technology and a major upgrade to user-friendliness as compared to other ASME book sections. The rewrite provided a new allowable stress basis with a reduced design margin on ultimate tensile strength (UTS) of 2.4 justified with more stringent material requirements and enhanced examination requirements, introduced explicit design load combinations, and modernized design-by-analysis (DBA) techniques. Of the many development objectives, the ASME VIII-2 rewrite provided a clear and consistent writing style highlighted by a flat modular structure to better facilitate its use, maintenance, and implementation of new technologies, optimized code rules to balance technology, user-friendliness, and jurisdictional acceptance, and formatted the rules to facilitate computer implementation. The rewrite also introduced enhanced design–by–rule (DBR) procedures and provided harmonization of many common DBR methods found in ASME VIII–1.

A significant driver behind the ASME VIII–2 rewrite was the harmonization of the DBR in ASME VIII–1 and ASME VIII–2. The intent of harmonization of DBR between the two code books was to allow the “common rules” to reside in ASME VIII–2 and be referenced from ASME VIII–1. To further explore the common rule approach, the Task Group on Common Rules was initiated in 2010 by ASME BPV Section VIII. This effort was promoted to reduce the difficulty of maintaining two sets of common rules due to complexity and updates, minimize ASME Code volunteer time on maintenance activities and increase volunteer efforts to focus on technical advancements that may provide significant cost savings, and ease the use and clarity of code requirements. The initial phase of the task group established four objectives.

1. Develop a Code Case to permit use of the ASME VIII–2 DBR as part of ASME VIII–1 construction,
2. Modify ASME VIII–2 to include vessel classes,
3. Develop example problem manuals for ASME VIII–1 and ASME VIII–2, and
4. Obtain user feedback on the above-referenced initiatives and identify an initial set of common rules to be removed from ASME VIII-1 with reference to ASME VIII–2.

Subsequent phases were open-ended at the time of the charter development to the extent of obtaining feedback from the users based on the results of the initial phase. A summary of the actions taken by ASME BPV Section VIII to achieve the established goals follows.