- The exam has 85 questions (75 scored, 10 unscored pretest) over 195 minutes, closed-book.
- Passing requires a scaled score of 400 on a 200-500 scale, not a fixed percentage correct.
- Required references include API 936 fifth edition, API 975, API 976, and four ASTM standards.
- No prior petroleum/petrochemical experience is mandatory to sit for the exam.
Understanding the API 936 Exam Structure
Refractory Personnel Certification (API 936) is administered by the American Petroleum Institute through its Individual Certification Programs (ICP) division. Before you open a single study reference, it helps to understand exactly what you're preparing for - because the format shapes how you should study far more than generic test-prep advice ever will.
The exam consists of 85 total questions delivered in a closed-book, multiple-choice format. Of those, 75 are scored and 10 are unscored pretest items mixed in to evaluate future exam content - you won't know which is which, so every question deserves your full attention. You have 195 minutes to complete the exam, whether you sit at a Prometric testing center or use ProProctor remote proctoring from your own location. API has also begun introducing alternative item types across its ICP exams, so don't be surprised if a question format looks slightly different from a straight four-option multiple choice item.
If you're still deciding whether this certification is the right investment of your time, our ROI analysis and salary guide can help frame the decision before you commit to a study plan.
The Four Domains You Must Master
API organizes the Body of Knowledge (BOK) for this exam into four content categories. Every scored question traces back to one of these domains, so your study time should map directly onto them rather than following a generic "read everything once" approach.
Domain 1: Roles and Responsibilities
Covers who does what on a refractory installation or inspection project - the relationships between owner-users, contractors, inspectors, and engineers.
- Understand the responsibilities assigned to each party under API Standard 936
- Know where inspection authority and sign-off responsibility sit in the workflow
Domain 2: Laboratory Testing Procedures
Tests candidates on the ASTM procedures used to evaluate refractory materials before and after installation.
- Be able to identify the purpose of ASTM C113, C133, C181, and C704 test methods
- Understand what each test measures - strength, density, drying behavior, or abrasion resistance
Domain 3: Materials and Installation Requirements
Focuses on the physical properties of refractory materials and the correct methods for installing them per API 936, API 975, and API 976.
- Know material classifications and their appropriate applications
- Understand installation sequencing, curing, and drying requirements
Domain 4: Installation Inspection and Quality Control
Covers how installed refractory linings are inspected and verified against specification.
- Know common defect types and how they're identified during inspection
- Understand documentation and quality control checkpoints throughout a project
For a more detailed breakdown of each domain, including how they interrelate, read our full API 936 Exam Domains Guide. If you're still trying to gauge overall difficulty relative to your background, our difficulty guide walks through what makes certain domains harder for different candidate profiles.
Registration, Fees, and Testing Logistics
Unlike some certifications, API 936 does not require you to already have petroleum or petrochemical industry experience - candidates entering the industry can apply directly, and a preparation course is not mandatory. That said, understanding the registration mechanics ahead of time prevents costly delays.
| Item | Member Rate | Nonmember Rate |
|---|---|---|
| Initial application fee | $450 | $625 |
| Recertification fee | $320 | $430 |
| Reschedule application | $200 | |
| Late application | $200 | |
Testing happens either at a Prometric center or remotely through ProProctor. If you choose remote testing, budget extra time before your appointment for a system-readiness check - connectivity issues discovered at the last minute can derail an otherwise well-prepared candidate. Test centers supply a physical calculator and scratch paper; remote sessions provide digital equivalents instead. No personal papers, notes, or reference materials are permitted at any testing location.
For the complete fee schedule and a discussion of value versus cost, see our API 936 Certification Cost breakdown. If you need help figuring out testing windows and deadlines around your work schedule, check API 936 Exam Dates before you register.
Key Takeaway
Register early enough to build in a buffer - a missed or rescheduled exam adds a $200 fee on top of whatever you already paid, so treat your target exam date as fixed once you commit to a study plan.
Building Your Reference Library
The current Body of Knowledge and publication effectivity window runs from April 2025 through December 2026, and it points to a specific, non-negotiable set of references. Study materials that aren't built around these exact documents will waste your time.
- API Standard 936, fifth edition (March 2024) - the core standard covering refractory materials and installation for petroleum and chemical process industry equipment
- API 975, first edition (November 2021)
- API 976, first edition (March 2018)
- ASTM C113-14 (2019), C133-97 (2021), C181-11 (2018), and C704-15 (2022) - the four laboratory test methods behind Domain 2
Because the exam is closed-book, your goal isn't to memorize page numbers - it's to internalize the logic and terminology of each document well enough to recognize correct answer patterns under time pressure. Our API 936 Cheat Sheet condenses the highest-yield facts from these references into a single-page review you can use in your final week of prep.
A Domain-Driven Study Schedule
Rather than a generic weekly template, structure your preparation around the four domains in the order they build on each other - roles and terminology first, then technical testing procedures, then materials and installation detail, and finally inspection and QC, which draws on everything before it.
Domain 1 - Roles and Responsibilities
- Read API 936 sections defining owner, contractor, and inspector duties
- Build a simple chart mapping each responsibility to the party who holds it
Domain 2 - Laboratory Testing Procedures
- Study ASTM C113, C133, C181, and C704 one at a time
- Write a one-line summary of what each test measures and why it matters
Domain 3 - Materials and Installation Requirements
- Work through API 975 and API 976 installation sequencing
- Compare material classifications side by side to avoid confusing similar terms
Domain 4 - Installation Inspection and Quality Control, plus full review
- Study common defect categories and inspection checkpoints
- Take timed practice sets covering all four domains together
Use spaced repetition for terminology you keep forgetting, and revisit Domain 2's ASTM details more than once - technical test-method facts fade faster than conceptual material. Practice under timed conditions on our practice test platform so the 195-minute pacing feels familiar before exam day, not foreign.
Exam Day: Format and Mindset
With 85 questions and 195 minutes, you have roughly two minutes per question on average - enough time to think carefully, but not enough to agonize over any single item. Since 10 of those questions are unscored pretest items you can't identify, the only sound strategy is to treat every question as if it counts.
Whether you're at a Prometric center or testing remotely via ProProctor, arrive (or log in) with time to spare. Remote candidates should complete the system-readiness check well before their scheduled start time rather than at the last minute. Remember that scratch paper and a calculator (physical or digital, depending on format) are provided - you don't need to bring your own, and you're not permitted to bring in outside materials of any kind.
Key Takeaway
Because passing is scaled (400 on a 200-500 range) rather than a flat percentage, don't panic if a section feels harder than expected - difficulty weighting is already built into the scoring model.
For candidates weighing how competitive the exam actually is, our API 936 Pass Rate article reviews the latest reported statistics in context, and our difficulty guide breaks down where most candidates lose points.
After You Pass: Recertification Timeline
Passing the exam isn't the end of the certification lifecycle - it's the start of a three-year cycle. You can renew by submitting a renewal application and fee, and employment verification is not required at renewal. Applications can be submitted starting 90 days before your certification expires, and if you miss that window, a 90-day grace period exists afterward, though it carries a late fee. Miss the grace period entirely, and you're back to submitting a brand-new application and sitting for the full examination again.
Every six years, instead of the standard renewal, you'll complete an online open-book recertification quiz: 25 questions, up to four hours to finish, with up to three pauses allowed and one retry if needed. This is considerably lighter than the initial 85-question closed-book exam, but it still requires you to stay current with any updates to the referenced standards.
If you're researching whether this credential fits your career trajectory or hiring needs, take a look at API 936 Jobs and API 936 Requirements for a fuller picture of who pursues and hires for this certification, and API 936 Training for structured preparation options beyond self-study.
Frequently Asked Questions
No. Applicants of any experience level, including people entering the petroleum or petrochemical industry for the first time, may apply. A preparation course is not mandatory.
The exam has 85 total questions - 75 scored and 10 unscored pretest items - administered over 195 minutes in a closed-book, multiple-choice format.
You need a scaled score of 400 on a 200-500 scale, not a fixed percentage of correct answers. See our Passing Score guide for details.
API Standard 936 (fifth edition, March 2024), API 975 (2021), API 976 (2018), and ASTM C113, C133, C181, and C704 in the editions listed in the current Body of Knowledge.
Certification is valid for three years. You can renew via application and fee without employment verification, apply up to 90 days before expiration, and use a 90-day grace period with a late fee if needed. After that, you must reapply and retake the full exam.
Preparing for API 936 comes down to matching your study effort to the exam's actual structure: four defined domains, a specific set of required references, and a scaled scoring model. Work through practice questions on our practice exam platform, review the domain breakdown in our full domains guide, and revisit the study guide overview as your exam date approaches.