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NBBI NB 23 (NBIC) National Board Inspection Code - Part 3 Repairs and Alterations

NBBI NB 23 (NBIC) National Board Inspection Code - Part 3 Repairs and Alterations (25th) — available for instant access at Publications Office.

National Board of Boiler and Pressure Vessel Inspectors 25th

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NBBI NB 23 (NBIC) Part 3 – Repairs and Alterations is the volume of the National Board Inspection Code that establishes rules, methods, and documentation requirements for repairing and altering pressure‑retaining items and their pressure relief devices in service. It is the primary post‑construction standard used when restoring or changing the pressure boundary of boilers, pressure vessels, and related equipment. Purpose and scope NBIC Part 3 covers work performed on existing pressure‑retaining items after initial construction, including repairs to correct damage and alterations that change the design or operating conditions. It applies regardless of the original construction code (e.g., ASME BPVC) and provides an accepted basis for jurisdictional approval, certification, and stamping. The scope typically includes boilers, pressure vessels, pressure piping, and associated components, as well as repairs and alterations that impact pressure relief protection. Major topics covered NB 23 (NBIC) Part 3 generally addresses: Definitions, responsibilities, and certification Clarifies what constitutes a repair versus an alteration, and defines the responsibilities of the owner‑user, repair organization, and inspector. It sets out the requirements for organizations holding National Board “R” or similar certificates of authorization and the role of the authorized inspector in overseeing work. Repair methods and procedures Provides rules for mechanical repairs and welded repairs, including defect removal, weld joint preparation, welding processes, qualification of procedures and personnel, preheat and postweld heat treatment, examination, and testing. It also recognizes specific repair techniques that have proven successful in service. Alterations and rerating Describes the requirements for design changes that affect the original pressure boundary or operating conditions, such as increasing or decreasing allowable pressure or temperature, adding nozzles or reinforcements, or modifying geometry. It includes engineering analysis, calculations, and documentation needed to support rerating and revised nameplate data. Examinations, testing, and acceptance Specifies nondestructive examination (NDE) and pressure tests required for repairs and alterations, along with acceptance criteria. It links examination and testing to the scope and risk of the work performed and provides guidance on when full code‑level requirements may be modified or supplemented with alternative methods. Documentation, stamping, and records Covers the use of National Board “R” stamps or other applicable markings, completion of repair/alteration forms, and retention of records. It ensures there is a traceable history of work performed on each pressure‑retaining item, supporting future inspections and integrity assessments. Typical users and applications NBIC Part 3 is used by: Certified repair organizations performing weld repairs, component replacements, or alterations on boilers and pressure vessels. Authorized inspectors and jurisdictional authorities who must review and accept repairs/alterations and verify that they meet recognized standards. Owner‑users and plant engineers planning scope, methods, and acceptance criteria for repairs and alterations within integrity management programs. Engineering firms evaluating rerates, design modifications, or life‑extension projects for in‑service pressure equipment. Role within the NBIC set Within the NB 23 NBIC 4‑volume set: Part 1 – Installation establishes correct initial conditions for equipment that may later require repair. Part 2 – Inspection identifies the damage or degradation that drives repair or alteration decisions and verifies fitness‑for‑service. Part 3 – Repairs and Alterations defines how that work must be designed, executed, examined, and documented. Part 4 – Pressure Relief Devices provides parallel rules for repair and alteration of pressure relief devices themselves or related system changes. Together, NBIC Part 3 provides a structured, recognized framework for safely restoring or changing pressure‑retaining items while maintaining regulatory compliance and long‑term equipment integrity.