The National Board of Boiler and Pressure Vessel Inspectors

NBIC 2025 Edition Changes

Print Date: 7/13/2025 7:28:27 AM

The 2025 edition is now available.

The 2025 edition of the National Board Inspection Code (NBIC) contains hundreds of revisions, ranging from editorial corrections and adjustments to entirely new sections and supplements.

Here is an overview of some major changes in the 2025 NBIC:

Changes in all Four Parts:

“Quality System” has been changed to “Quality Management System” throughout.
Definitions for Base Metal, Filler Metal, Temporary Location, Weld, Weld Metal, and Weld Consumable have been added to the glossary.

Part 1:

Form I-1, Boiler Installation Report, has been revised.
A new requirement for air intake installation in sealed combustion systems has been added to section 1.6.6.
New requirements have been added to sections 2.8.5 and 3.8.1.5 for low-water fuel cutoffs that are installed external to the boiler.
New drain system requirements have been added to section 3.6.3.
Sections 3.8.2.2 and 3.8.2.3 have new requirements for thermometers and temperature-sensing elements installed on hot-water heating and hot-water supply boilers.
Requirements in section 3.9.3 for set pressure and capacity for pressure relief valves on hot-water heating and hot-water supply boilers were updated to better align with ASME Section IV.

Part 2:

Requirements have been updated in section 1.4 regarding owners’ or users’ responsibility for addressing safety exposure for an inspector.
Several updates have been made to section 2.3.6.5 to revise inspection requirements for pressure vessels with quick-actuating closures.
Recommended inspection type/frequency for thermal fluid heaters was added to Table 2.5.8.
Several revisions were made to section 4.2 to better align the section with NBIC Part 3.
New inspection requirements for staybolts on historical boilers were added to section S2.10.4.1.
New sections S2.10.4.3 and S2.10.4.4 have been added to address maximum allowable working pressure (MAWP) calculations for curved stayed surfaces subjected to internal or external pressures in historical boilers.
Table S6.13.6 has been revised to match the latest U.S. Department of Transportation standards.
Supplement 14, Low-Pressure Boiler External Inspection List, is a new document.

Part 3:

Requirements for temporary locations have been added to section 1.4.1.
Paragraph j) in section 3.3.3 has been revised to clarify requirements for nozzle placement.
New requirements for flush patches have been added to section 3.3.4.6.
Welding requirements for plugging firetubes have been added to section 3.3.4.9.
Several updates and revisions have been made to section 4.2.
Section 5.2.2 has been updated to add guidance for “R” Certificate Holders with the “Design Only” scope.
Sections 5.2.5 and 5.2.6 have been revised to provide clarification on “NR” Certificate Holder responsibilities when completing Form NR-1 and Form NVR-1.
A new requirement has been added to section 5.7.1 to waive stamping or nameplate attachment requirements due to personnel safety or potential contamination risks.
Section S2.4.1 has been added to address reusing parts or attachments on historical boilers.
Section S2.13.4.1 has been added to address the replacement of through stays on historical boilers.
Several revisions have been made to the list of graphite pressure vessel routine repairs in section S3.3.
Section S3.5.4 has been revised to address block holes as well as tubes in graphite pressure vessels.
Section S3.5.6 has been added to provide a repair procedure for cross-drilled blocks on graphite pressure vessels.
Supplement 6, Repair, Alteration, and Modification of DOT Transport (Cargo) Tanks, has been updated to reflect the latest U.S. Department of Transportation requirements.
Supplement 10, Classifying Repairs and Alterations, has been added to provide a flowchart for determining if an activity would be considered a repair or alteration.
Supplement 11, Engineered Repairs and Alterations, has been added to provide a specific location for repair and alteration methods that require additional engineering considerations. The following methods have been relocated to this supplement:
- External Weld Metal Buildup
- Repair of Pressure-Retaining Items Without the Complete Removal of Defects
- Repair of ASME Section VIII, Division 2 or Division 3 Pressure Vessels
- Encapsulation
- Alteration of ASME Section VIII, Division 2 or Division 3 Pressure Vessels

Part 4:

Sections 2.5.1.6 and 3.8.2.3 have new requirements for thermometers and temperature sensing elements installed on hot-water heating and hot-water supply boilers.
Recommended inspection type/frequency for thermal fluid heaters was added to Table 3.2.6.
Section 3.3.4.1 has been deleted, and a new section 3.4, Annual Audits, has been added to replace 3.3.4.1.
Section 4.2.2 has been revised to clarify how ASME Code Cases are applied to the repair and conversion of pressure relief devices.

Any section in the book that received technical changes is marked with a (25) designator in the margin, next to the section’s heading. Refer to your copy of the 2025 edition for the specific details of these changes. If you have any questions about the NBIC, please contact the NBIC secretary at NBICSecretary@nbbi.org.