Since 1914, the American Society of Mechanical Engineers’ (ASME’s) Boiler and Pressure Vessel Code (BPVC) has served as a worldwide model for assuring the safety, reliability, and operational efficiency of boilers. In July, ASME will release the 2019 version of its BPVC code, updating each of the “living document’s” 12 sections.


Past, Present, and Future

ASME issued its first standard, “Code for the Conduct of Trials of Steam Boilers,” in 1884. This paper evolved into “Rules for the Construction of Stationary Boilers and for Allowable Working Pressure” – the first edition of ASME’s Boiler and Pressure Vessel Code (BPVC) – which was issued in 1914 and published in 1915.

The BPVC has grown over time to include 31 books and 17,000 pages covering industrial and residential boilers as well as nuclear reactor components, transport tanks, and other forms of pressure vessels. It is kept current by nearly 1,000 volunteer technical experts — drawn from a balance of interests among industry, government, and R&D — who operate in a fully open and transparent manner via a consensus process.

“Updating this code is a comprehensive process,” said Steve Rossi, secretary, ASME. “Each committee has a standards committee that consists of 30-40 members. Underneath the standards committees are a range of four to 10 subcommittees. Under those are task groups, which could consist of as many as a dozen task groups per section. Everything starts with the task groups and then funnels up. At the top is the ASME board. It all goes through an approval process at each level. By the time this is released, a lot of eyes will have seen these changes.”

Code updates are issued every two years. The ASME committee has proposed numerous changes to each of the code’s sections in its 2019 update.

“There are a lot of factors that determine what changes in each update,” Rossi said. “So far, there are 42 changes occurring in 2019 — some major and some minor. That said, a minor change to one person or company can be a major change for another.”

Thomas Molfetto, director of marketing, ASME, said code changes occur for a number of reason.

“The code is driven by the market demand,” he said. “As things change in the world, the wording in the code will change. This can be driven by regulatory changes, new technologies, jurisdiction limits, etc. For example, if there is a new welding procedure, we have to update the code to reflect that. As the world evolves, so does the book.”

Here are a few of the proposed changes.


Section I – Power Boilers:

  • Developed a new non-mandatory appendix for fabrication of dissimilar metal welds (DMW) for CSEF steel to austenitic materials;

  • Section PW-38 has been rewritten, incorporating non-mandatory appendix A-100, detailed rules for preheating and inter-pass temperatures, and interruption of welding and preheat; and

  • Added a new figure for code jurisdictional limits for piping for fire-tube boilers.


Section II – Materials:

  • Added four new “for information only” tables for BPV IV stress values (Tables 6A-6D). The intention is for these tables to become mandatory in the next edition; and

  • Mandatory appendix 5 in Section II, Part D, was revised to include a provision for wrought allowable stresses to be applied to HIP powder metallurgy material/components of the same grade in the time-independent range.


Section III – Nuclear Family Components:

  • The major change for BPV XI will be Division 2 – Requirements for Reliability and Integrity Management (RIM) Programs for Nuclear Power Plants. Division 2 provides an alternative approach to the current ISI activities needed to accommodate the new advanced nuclear reactor designs other than light water reactors. Division 2 RIM will be replacing the current Division 2 and Division 3.


Section IV – Heating Boilers:

  • Stress values for SA-268 S44400 & TP349 materials were added in Table HF-3001;

  • Language was added to parts HC-403, HC-520, HA-404, and HA-504 to allow for the use of electronic signatures; and

  • Guidance for the use of HLW or PRT designators together with the certification mark for marking parts was added.


Section V – Nondestructive Examination:

  • A new mandatory appendix was created for Full Matrix Capture (FMC);

  • A new non-mandatory appendix was created for examination of welds using FMC; and

  • Adoption of the 2016 edition of ASNT SNT-TC-1a and a new mandatory appendix that outlines the exceptions and additional requirements noted.


Section VI – Construction of Heating Boilers:

  • Para. 6.3, mounting was updated to add consistent verbiage to that of BPV Section IV; and

  • F & T Trap high level “spill” was revised to Steam Trap (optional) in Figure 5.9.1


Section VIII – Construction of Power Vessels:

  • Paragraph U-2(g) of Div. 1 was revised with rules to allow usage of Div. 2 for design methods not provided in Div. 1 as well as other recognized standards or codes. New appendix 46 was created to provide a means for the designer to use the rules given in Div. 2;

  • UG-14 was revised to improve clarity and allow for the production of hollow cylindrical components with a greater range of diameters under qualifying conditions; and

  • Nameplate markings between Divs. 1 and 2 have been aligned by reducing the “construction type” markings that are mandatory on the nameplate for Section VIII.


Section IX – Welding and Brazing:

  • A major addition was made to Table QW/QB-422: EN base metal grades were added to Table QW/QB-422 with the same P-number and group-number previously assigned to the corresponding ASME adopted and modified EN material specifications designated with the SA/EN prefix;

  • Revisions to Tube-to-Tubesheet rules include revising QW-193 and QW-288 to arrange essential variables into a tabular format for both procedure and performance qualifications. QW-303.5 has been replaced by a new paragraph in QW-387. Variables were added or revised in Article IV to accommodate this revision as well; and

  • Qualification requirements were added for personnel supervising welding qualifications in Para QW-106.


Section X – Fiber-reinforced Plastic Pressure Vessels:

  • The inspection process with regard to acoustic emission examination has been streamlined but still provides a proper and meaningful inspection result. The changes are based on an improved understanding of the inspection process gained through experience in assessing production vessels;

  • Currently, ASME Section X can be interpreted to allow intermediate valves between the vessel and the test gage. Compared to Section VIII, Division 1, that does not allow intermediate valves between the vessel and the test gage. Wording similar to Section VIII, Division I, has been added; and

  • The requirements for the qualification test for cyclic fatigue has been reduced to be more reflective of those in other industry standards that are less severe yet have proven safe for more than 25 years since their incorporation in the early 1990s. The previous requirements were unnecessarily severe, thus creating an artificial barrier to qualification of Section X Class III pressure vessels.


Section XI – Inservice Inspection of Nuclear Power Plant Components:

  • A major editorial alignment of Division 1, Class 2 and Class 3 requirements were completed. Comparisons were made between corresponding paragraphs in Subsections NB and NC in order to align them in areas of divergence;

  • A revision of Division 5, Subsection HA Subpart B — General Requirements for Graphite Materials — was revised to include ceramic composite materials; and

  • A new Division 5, Subsection HH Subpart B for Class SN Nonmetallic Core Components was added.


Section XII – Construction and Continued Service of Transport Tanks:

  • A new non-mandatory appendix to build QC Manual per B620 was introduced;

  • Vacuum jacket requirements were added to non-mandatory appendix E;

  • New rules for the traceability of multi-page data report forms were established; and

  • Requirements from BPV II Part D; Tables 1A & 1B general notes (c) and (d) and Table 3 General Notes (b) and (c) to BPV XII TD-210 were incorporated.

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