A Summary of ASME Section VIII, Division 1 Appendix 47
The 2021 Edition of Section VIII, Division 1 of the ASME Boiler & Pressure Vessel Code has added Mandatory Appendix 47, “Requirements for Pressure Vessel Designers”. This mandatory appendix specifies the qualification requirements of those individuals involved in the design of pressure vessels.
This article provides a general summary of Appendix 47 from the 2021 Edition of the ASME Boiler & Pressure Vessel Code. It includes a few tables that may prove helpful in quickly understanding the requirements. Please note that this article does not discuss all of the requirements of Appendix 47, namely those concerning documentation. Appendix 47 of the applicable Code edition should be consulted for complete information.
Appendix 47 classifies persons in responsible charge of design activities as Designers, Engineers, or Certifying Engineers. The appendix refers one to the National Society of Professional Engineers (NSPE), Statement No. 1778 for information concerning the meaning of responsible charge. NSPE Statement No. 1778 defines responsible charge as “the direct control and personal supervision of engineering work”. It further states that engineering decisions are made by the person in responsible charge or by others over which the person provides supervisory direction. Importantly, the Statement also specifies that “reviewing drawings or documents after preparation without involvement in the design and development process does not satisfy the definition of Responsible Charge.”
The requirements for Designers, Engineers, and Certifying Engineers vary with respect to experience, education, and whether or not the individual has to have an engineering license. Table 1 below lists the qualification requirements for persons performing or supervising design activities.
Interestingly, 47-2(b) and 47-2(c) specify the minimum number of required years of experience designing pressure vessels for Designers and Engineers, but 47-3(a) and 47-3(b) permit the Manufacturer to specify an alternate minimum number of years of experience for Designers and Engineers.
Appendix 47 also specifies additional qualification requirements for Designers and Engineers for specific design activities. These activities include:
Performing numerical analyses (such as finite element analysis)
Conducting fatigue assessments
Design for seismic reactions (specifically response history procedure)
Design of quick-actuating closures
Performing design activities not specifically addressed by Section VIII, Division 1.
Certifying Engineers do not have to meet these additional qualification requirements. Table 2 below summarizes the additional qualifications for these specific design activities.
Of particular note is Designers and Engineers performing numerical analysis must have received instruction in the use and understanding of the numerical analysis computer program, and that all fatigue assessments must be performed by a Certifying Engineer or under the responsible charge of a Certifying Engineer.
In conclusion, prior to the 2021 Edition, Section VIII, Division 1 of the ASME Code was largely mute concerning specific qualification requirements of those individuals involved in the design of pressure vessels. With the addition of Appendix 47 to the Code, this is no longer the case. Smaller manufacturers who do not have a Certifying Engineer on staff may find the requirements of this new appendix impact their design operations and bottom line. Since this is a new appendix affecting all manufacturers of pressure vessels, revisions and/or clarifications to this Appendix, whether enacted with a new Edition of the Code or as an ASME Code Committee interpretation, are likely.