- What This Cheat Sheet Covers (and What It Does Not)
- The Exam Snapshot: Verified Facts Only
- Duties, Types and Terminology (Domains 1-3)
- Quality Control Systems (Domain 4)
- Design and Materials (Domains 5-6)
- Fabrication and Welding (Domain 7)
- NDE, Testing, Heat Treatment and Calibration (Domains 8-10)
- Data Reports, Stamping and Record Retention (Domains 11-12)
- The Required References You Must Navigate
- Sequencing Your Review Around the Domains
- Frequently Asked Questions
- The AI Commission exam from the National Board has 85 questions and follows the 12-heading NB-331-NC Revision 6 outline.
- No domain percentage weights are published, so treat all 12 content areas as testable.
- Required references: ASME Sections I, IV, V, VIII Division 1, IX; B31.1; QAI-1; and RCI-1/NB-263.
- Quality control appendices to know cold: Section I A-301, Section IV Appendix F, Section VIII Division 1 Appendix 10.
What This Cheat Sheet Covers (and What It Does Not)
This page condenses the National Board Authorized Inspector Commission (AI) content outline into a single scannable review. It is built from the National Board's detailed NB-331-NC Revision 6 outline, which organizes the exam into 12 numbered headings. If you are brand new to the credential, start with the broader AI study guide and come back here when you want a fast refresher on what must be memorized, what must be located in the Code, and what must be understood conceptually.
One caution up front: this is a review aid, not a substitute for the AI Commission course or for working knowledge of the ASME Boiler and Pressure Vessel Code. The exam is built around applying Code rules the way an Authorized Inspector actually would in a shop or field setting. For the full domain-by-domain treatment, see the complete guide to all 12 AI content areas.
The Exam Snapshot: Verified Facts Only
Many cheat sheets pad their exam facts with guesses. This one separates what the issuer confirms from what you need to verify yourself.
| Item | What Is Confirmed | What to Verify |
|---|---|---|
| Governing body | The National Board of Boiler and Pressure Vessel Inspectors | None |
| Number of questions | 85 | None |
| Course requirement | Attendance at the AI Commission course with a passing examination | Current course schedule and format |
| Content outline | NB-331-NC Revision 6, 12 numbered headings | Check for newer revisions before you test |
| Domain weights | None published | Not applicable |
| Exam timer | Not verified here | Confirm with the National Board |
| Current fee | Not verified here | Confirm with the National Board |
| Numerical pass mark | Not verified here | Confirm with the National Board |
For deeper context on these unknowns, the AI passing score article explains how to approach scoring uncertainty, and the AI certification cost breakdown covers the budgeting side. Eligibility questions are handled in the AI requirements guide.
Duties, Types and Terminology (Domains 1-3)
Domain 1: Responsibilities and Duties of the AI
This domain centers on the roles defined in RCI-1 and ASME QAI-1: the authorized inspection agency, the supervisor, and the inspector. It also extends to duties that appear throughout the other required references, so questions here can be woven into almost any other topic.
- Know who is responsible for what under RCI-1 versus QAI-1.
- Understand the distinct roles of the agency, supervisor and inspector, not just the inspector.
- Expect duty-based questions that surface inside design, welding and documentation scenarios.
Domain 2: Boiler and Pressure Vessel Types and Terminology
Before you can apply a rule, you must identify what you are looking at. This domain tests whether you can recognize boiler and vessel types and name their parts correctly.
- Distinguish power boilers, heating boilers and pressure vessels, since each falls under a different Code section.
- Learn part names precisely; a question may hinge on terminology.
- Connect each type to the Code section that governs it.
Domain 3: Code Structure and Content
This is a navigation domain. You need to know how the ASME BPVC is organized and where related requirements live so you can find answers efficiently.
- Know which section answers which kind of question.
- Understand how Sections I, IV, V, VIII Division 1 and IX relate to one another.
- Practice moving between the Code and related documents such as B31.1 for external piping.
Quality Control Systems (Domain 4)
Domain 4 is unusually concrete. The outline names three specific appendices, and each corresponds to a construction type:
- Section I, Appendix A-301: quality control for power boilers.
- Section IV, Appendix F: quality control for heating boilers.
- Section VIII, Division 1, Appendix 10: quality control for pressure vessels.
A strong cheat-sheet habit is to build a three-column comparison of these appendices: what each requires of the manufacturer's quality control system, and what the inspector verifies. Questions in this area reward candidates who can tell the three apart instead of blending them into a generic "QC manual" concept.
Design and Materials (Domains 5-6)
Domain 5: Design
Design is broad. It spans power boilers, heating boilers, external piping and pressure vessels, and the outline lists the components you must be ready to evaluate:
- Shells and drums
- Piping, headers and nozzles
- Formed and flat heads
- Braced and stayed surfaces
- Weld sizes
- Nozzle reinforcement
- Preformed and prefabricated pressure parts
- Flanges
- Joint efficiencies and ligament efficiency
Joint efficiency and ligament efficiency are classic places where candidates lose points by confusing when each applies. Make sure you can explain what each factor represents and how the Code uses it in a required-thickness or allowable-pressure context.
Domain 6: Materials
Materials questions test whether you can verify that what was purchased and installed is what the Code permits. Key topics include:
- Construction-section rules governing material selection
- Product-form tolerances
- Markings and marking methods
- Pressure parts versus nonpressure parts
- Non-ASME standards
- Repair of defective material
- Material certifications
Key Takeaway
For Domains 5 and 6, build a "why it matters to the inspector" note for each topic. The exam is written from the inspector's seat, so ask what you would check, what documents you would look at, and what would cause you to reject an item.
Fabrication and Welding (Domain 7)
Domain 7 is the largest and most detail-heavy section of the outline, and it rewards careful, organized study. It divides naturally into forming and preparation, and welding.
Forming and Preparation
- Cutting and edge preparation
- Cold-forming limits
- Out-of-roundness limits for cylindrical, conical and spherical shells
- Formed-head tolerances
- Attachment of lugs and fittings
- Holes for screwed or threaded stays and tubes
Welding
- Welding responsibilities and processes
- Procedure qualification and welder/operator qualification (Section IX is central here)
- Surface cleaning and alignment tolerances
- Spin holes
- Finished joints and fillet welds
- Defect repair
- Peening
- Surface weld-metal buildup
Section IX governs welding qualification, so expect to cross-reference it with the construction sections. A common trap is knowing the tolerance but forgetting which party is responsible for verifying it. Tie each tolerance to the person or organization responsible, which loops back to Domain 1.
NDE, Testing, Heat Treatment and Calibration (Domains 8-10)
Domain 8: Nondestructive Examination
The NDE domain asks when examination is required, which methods are permitted, and how the methods compare. Section V is your core reference. Be ready to discuss:
- When NDE is required under each construction section
- Permitted methods and the advantages and limitations of each
- Procedure and personnel qualification
- Reports and what they must contain
A useful drill is to take a given defect type and ask which method is best suited to detect it, and which is poorly suited. That mirrors how applied questions are typically framed.
Domain 9: Testing and Heat Treatment
This domain covers impact testing, heat treatment and pressure tests, including exemptions and alternatives. The exemptions are where candidates stumble: knowing that a requirement exists is not enough, because you must also know the conditions under which it does not apply, and what alternatives are acceptable.
Domain 10: Calibration of Measurement and Test Equipment (M&TE)
Calibration is often under-studied because it feels administrative, but it has its own named subtopics:
- Calibration frequencies and methods
- Tolerances
- Master standards
- Identification of equipment
- Records, for both working and master measurement and test equipment
Understand the difference between working M&TE and master standards, since traceability runs from one to the other.
Data Reports, Stamping and Record Retention (Domains 11-12)
These last two domains are documentation-focused and tend to be the most "closed-book friendly" parts of the outline, because the rules are specific and checkable.
Domain 11: Data Reports and Stamping
Data reports and stamping vary by construction type, so a power boiler, a heating boiler and a pressure vessel each follow their own conventions.
- Know which report applies to which construction type.
- Understand what must be completed and signed before stamping occurs.
- Be able to spot an incomplete or inconsistent report.
Domain 12: Record Retention
Record retention is governed under ASME Sections I, IV and VIII. The exam expects you to know what must be kept, by whom, and for how long under each section.
- Build a simple table of retention requirements by section.
- Note who holds which records, manufacturer versus agency.
- Verify exact retention periods directly in the Code rather than relying on memory.
The Required References You Must Navigate
The National Board outline names a specific reference set. Familiarity with each is part of the preparation:
- ASME Section I: power boilers
- ASME Section IV: heating boilers
- ASME Section V: nondestructive examination
- ASME Section VIII, Division 1: pressure vessels
- ASME Section IX: welding and brazing qualifications
- ASME B31.1: power piping
- QAI-1: qualifications for authorized inspection
- RCI-1/NB-263: rules for commissioned inspectors
Because the exam is anchored to these documents, speed of navigation matters as much as recall. If you can open the right section quickly and read it accurately, you gain a real advantage. Our difficulty guide discusses why this navigation skill is often the deciding factor for candidates.
Sequencing Your Review Around the Domains
Rather than a generic schedule, order your review by how the domains depend on each other. Foundations first, details second, documentation last.
Roles, types and Code layout
- Domains 1-3: RCI-1/QAI-1 roles, vessel and boiler terminology, how the Code is organized.
- Do this first because every later domain assumes you know who is responsible and where to look.
Quality control and design
- Domain 4 appendices side by side, then Domain 5 component rules and efficiencies.
Materials and fabrication
- Domains 6-7, giving extra time to welding qualification and tolerances since Domain 7 is the densest.
Examination, testing and paperwork
- Domains 8-12: NDE methods, test exemptions, calibration, data reports and record retention.
- Finish with timed mixed practice across all 12 areas.
Adjust the pace to your experience and your course date. Candidates with shop or field inspection backgrounds may compress Domains 2 and 7, while those new to the field should lengthen them. When you are ready to test yourself, the AI practice test lets you drill by domain, and you can check testing windows and scheduling to plan your timeline.
Frequently Asked Questions
The issuer's examination information confirms 85 questions. Candidates also attend the AI Commission course and must pass the examination. Confirm the current timer and format with the National Board before your test date.
No percentage weights are published for the NB-331-NC outline. Treat every domain as testable and avoid skipping areas based on assumptions about their importance.
The required references are ASME Sections I, IV, V, VIII Division 1 and IX, plus B31.1, QAI-1 and RCI-1/NB-263. Section I covers power boilers, Section IV heating boilers, and Section VIII Division 1 pressure vessels.
A numerical pass mark is not verified here, so confirm it with the National Board. The AI passing score article explains how to prepare when exact scoring details are uncertain.
That depends on your career goals and employer. The ROI analysis and the earnings guide walk through the considerations without relying on invented figures.