NBIC NB-23 Part3-2025 PDF

Full title and description

St NBIC NB-23 Part3-2025 — National Board Inspection Code (NB-23), Part 3: Repairs and Alterations, 2025 edition. This document provides the requirements, recommended practices, and verification/documentation guidance for performing repairs and alterations to pressure-retaining items (boilers, pressure vessels, and associated components) when original construction code requirements cannot be met or when post-construction work is required.

Abstract

Part 3 of NB-23 (NBIC) is the 2025 edition guidance and rules for repair and alteration of pressure-retaining items. It covers acceptable repair methods, alternative examination and testing techniques, heat-treatment considerations, welding procedures (including guidance on alternatives to post-weld heat treatment where applicable), stamping and documentation requirements, and responsibilities of repair organizations and inspectors. The Part is intended to promote safe, uniform post-construction practices across jurisdictions.

General information

• Status: Current (2025 edition — active).
• Publication date: July 1, 2025.
• Publisher: The National Board of Boiler and Pressure Vessel Inspectors (National Board).
• ICS / categories: Pressure equipment / pressure vessels and associated components (commonly classified under ICS 23.020 / related 23-series categories).
• Edition / version: 2025 edition (NB-23, Part 3).
• Number of pages: Not consistently published as a single-page-count by all distributors; page count varies by file/print format (publisher volumes are typically provided as Part 3 standalone or as part of the four-volume NBIC set). Estimated page count varies by printing/format and is not specified here.

Scope

This Part provides requirements, alternative methods, and guidance to perform, verify, and document acceptable repairs and alterations to pressure-retaining items regardless of the original code of construction. When original code requirements cannot be met, the Part supplies proven repair methods, non-destructive and destructive examination options, testing procedures, heat-treatment guidance, and administrative requirements (stamping, reporting, and forms). Jurisdictional regulations take precedence where they conflict with NBIC provisions.

Key topics and requirements

• Acceptable repair and alteration methods for boilers, pressure vessels, and associated piping/components.
• Welding procedure requirements and guidance on alternatives to post-weld heat treatment (PWHT) for certain materials and repair types.
• Inspection and examination methods (visual, NDE techniques, acceptance criteria) and documentation requirements.
• Testing and verification (hydrostatic testing, leak testing, proof tests), and heat treatment guidance where applicable.
• Stamping, reporting, and use of National Board forms and the “R”/“NR” stamping program for repaired items.
• Requirements for repair organizations, certificate holders, and inspector responsibilities including jurisdictional precedence.
• Special considerations for historical boilers, fatigue/creep, corrosion, and material-specific repair limitations.

Typical use and users

Used by: boiler and pressure-vessel inspectors, repair and alteration shops, owner-users, maintenance and reliability engineers, welding shops, jurisdictional authorities, insurance and inspection companies, and consultants. Typical uses include planning and performing repairs, qualifying repair procedures, preparing required documentation and stamping, and ensuring compliance with jurisdictional rules for in-service pressure equipment.

Related standards

Commonly referenced alongside: ASME Boiler and Pressure Vessel Code (construction rules and original code requirements), other NBIC Parts (Part 1 — Installation and Part 2 — Inspection), applicable jurisdictional regulations and codes, and material- or process-specific standards (welding codes, NDE standards). Where jurisdictional regulations differ, those regulations govern.

Keywords

NBIC, NB-23, Part 3, National Board, repairs, alterations, pressure vessels, boilers, welding, PWHT alternatives, inspection, non-destructive examination, stamping, R-stamp, NR-stamp, documentation, 2025 edition

FAQ

Q: What is this standard?

A: It is Part 3 of NB-23 (the National Board Inspection Code) — the National Board’s published guidance and rules for repairs and alterations to boilers and pressure-retaining items (2025 edition).

Q: What does it cover?

A: It covers acceptable repair/alteration methods, examination and testing options, welding and heat-treatment guidance (including alternatives in some cases), documentation and stamping requirements, and the responsibilities of repair organizations and inspectors. Jurisdictional rules take precedence when conflicts occur.

Q: Who typically uses it?

A: Inspectors, repair shops, owner-users, maintenance engineers, certifying authorities, and jurisdictional regulators use it to plan and verify repairs and alterations and to prepare required National Board documentation and stamping.

Q: Is it current or superseded?

A: The 2025 edition is the current edition (published July 1, 2025); it follows prior editions (for example, the 2023 edition) and constitutes the active NBIC Part 3 at this publication date. Check with the National Board or authorized distributors for any interim interpretations or corrigenda.

Q: Is it part of a series?

A: Yes — NB-23 (NBIC) is published in parts; Part 1 covers installation, Part 2 covers inspection, Part 3 covers repairs and alterations, and Part 4 addresses pressure relief devices. The parts are intended to be used together as appropriate.

Q: What are the key keywords?

A: Repairs, alterations, NBIC, NB-23, R-stamp, NR-stamp, welding procedures, post-weld heat treatment, NDE, hydrostatic test, stamping and documentation, pressure vessels, boilers, 2025 edition.