- What API 936 Certification Actually Is
- Who Hires API 936-Certified Personnel
- The Four API 936 Exam Domains
- Exam Format, Scoring, and Testing Options
- Required References and the BOK
- Registration, Fees, and Eligibility
- Maintaining the Certification
- A Domain-Aware Approach to Preparation
- Frequently Asked Questions
- API 936 is administered by API's Individual Certification Programs, not a separate testing body.
- The exam has 85 total 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.
- Four domains structure the content: Roles and Responsibilities, Laboratory Testing Procedures, Materials and Installation Requirements, and Installation...
What API 936 Certification Actually Is
Refractory Personnel Certification (API 936) is one of the American Petroleum Institute's Individual Certification Programs (ICP). It exists to verify that a person working around refractory linings - the heat-resistant materials used in furnaces, reactors, and other high-temperature process equipment - understands the standards, testing procedures, and inspection practices that govern proper refractory installation and quality control.
Unlike a training certificate you receive for attending a class, API 936 is a credential you earn by passing a proctored, closed-book examination administered through Prometric testing centers or API's ProProctor remote-proctoring platform. It is a standalone individual certification tied to a specific body of knowledge, and it must be periodically renewed to stay active.
If you're comparing this credential to other things that share the "API 936" label, note that this article - and this entire site - refers only to Refractory Personnel Certification (API 936) as published by the American Petroleum Institute. For a plain-language breakdown of the acronym and scope, see What Is API 936? and API 936 Meaning.
Who Hires API 936-Certified Personnel
Employers in refining, petrochemical processing, and related heavy-industrial sectors look for this certification when staffing roles connected to refractory design review, materials procurement, laboratory testing, field installation oversight, and quality assurance inspection. Because the credential doesn't require a minimum years-of-experience threshold to sit for the exam, it's used both to validate incoming technical staff and to formally recognize experienced refractory specialists, inspectors, and engineers who already do this work daily.
Roles that commonly value the credential include refractory inspectors, quality control technicians, materials engineers, and contractor personnel who need a portable, industry-recognized way to demonstrate competency across employers. For a closer look at where this certification tends to open doors, see API 936 Jobs, and for a broader discussion of career payoff, Is the API 936 Certification Worth It? Complete ROI Analysis 2026 walks through the tradeoffs in more depth.
The Four API 936 Exam Domains
The API 936 body of knowledge organizes exam content into four domains. Understanding what each one covers - and how they interact - is more useful than memorizing isolated facts, because scenario-based questions often blend concepts from more than one domain.
Domain 1: Roles and Responsibilities
Covers who does what across a refractory project - owner-operator, contractor, inspector - and the responsibilities each party holds for specification compliance, documentation, and sign-off.
- Distinguishing inspection authority from installation authority
- Documentation and communication expectations between parties
Domain 2: Laboratory Testing Procedures
Focuses on the ASTM test methods referenced by API 936 - covering properties like modulus of rupture, permanent linear change, cold crushing strength, and abrasion resistance - and how those results inform material acceptance.
- Matching ASTM test methods to the property they measure
- Interpreting laboratory results against specification limits
Domain 3: Materials and Installation Requirements
Addresses refractory material types, mix design, storage, and the installation methods (casting, gunning, ramming, brick setting) appropriate to each application.
- Material selection based on service conditions
- Correct handling, curing, and dryout practices
Domain 4: Installation Inspection and Quality Control
Covers what an inspector checks during and after installation - anchor spacing, joint quality, thickness verification, and documentation of nonconformances.
- Inspection hold points and acceptance criteria
- Common installation defects and their causes
Each of these domains draws directly from API Standard 936, API 975, API 976, and the referenced ASTM standards - not from generic construction or inspection knowledge. For a domain-by-domain study breakdown with more granular subtopics, see API 936 Exam Domains 2026: Complete Guide to All 4 Content Areas.
Key Takeaway
Because questions frequently combine a laboratory result (Domain 2) with an installation or acceptance decision (Domain 3 or 4), study the domains together rather than in isolation.
Exam Format, Scoring, and Testing Options
The API 936 exam consists of 85 total multiple-choice questions delivered in a closed-book format over 195 minutes. Of those 85, 75 are scored and 10 are unscored pretest items used by API to evaluate future exam content - candidates cannot identify which questions fall into which category, so every item should be treated as scored. API has also indicated it is gradually introducing alternative item types across its ICP examinations, so candidates shouldn't assume every question will be a traditional single-best-answer format.
Scoring is reported on a scaled range of 200 to 500, and a scaled score of 400 is required to pass. This is not the same as needing roughly 80% correct - because the scale accounts for item difficulty across different exam forms, the relationship between raw questions answered correctly and the scaled score isn't one-to-one. For a full explanation of how this works, see API 936 Passing Score 2026: Exactly What You Need to Pass.
You can sit the exam at a Prometric testing center or remotely through ProProctor, API's remote-proctoring platform, which requires a system-readiness check beforehand. No personal papers or reference materials are allowed in either setting; test centers supply a calculator and scratch paper, while remote sessions provide digital equivalents.
| Exam Detail | Specification |
|---|---|
| Total questions | 85 (75 scored, 10 unscored pretest) |
| Time allowed | 195 minutes |
| Format | Closed-book, multiple choice (alternative item types being phased in) |
| Passing score | 400 on a 200-500 scaled range |
| Delivery | Prometric test center or ProProctor remote proctoring |
Because the exam blends four content areas within a single sitting and applies a scaled passing threshold, many candidates want a realistic sense of difficulty before scheduling. How Hard Is the API 936 Exam? Complete Difficulty Guide 2026 examines this in detail, and API 936 Pass Rate 2026: What the Data Shows reviews the most recently reported pass-rate data from API's own statistics.
Required References and the BOK
API 936 exam content is drawn from a defined set of required references, and the current body of knowledge (BOK) and exam reference set are effective from April 2025 through December 2026. The required documents are:
- API Standard 936, fifth edition, March 2024
- API 975, first edition, November 2021
- API 976, first edition, March 2018
- ASTM C113-14 (2019)
- ASTM C133-97 (2021)
- ASTM C181-11 (2018)
- ASTM C704-15 (2022)
Notice that four of the seven required documents are ASTM test-method standards - a direct reflection of how heavily Domain 2 (Laboratory Testing Procedures) factors into the exam. Candidates who skim the ASTM methods and focus only on API 936 itself often find themselves underprepared for questions on test procedures and acceptance criteria.
Registration, Fees, and Eligibility
One notable feature of API 936 is its open eligibility policy: applicants may have any level of petroleum or petrochemical experience, including people entering the industry for the first time. There is no mandatory prerequisite course, though API and third-party providers offer preparation resources.
Current fee structure (initial certification):
- Initial application: USD 450 for API members, USD 625 for nonmembers
- Recertification application: USD 320 for members, USD 430 for nonmembers
- Reschedule fee: USD 200
- Late application fee: USD 200
For a complete cost breakdown, including how membership status affects total spend, see API 936 Certification Cost 2026: Complete Pricing Breakdown. If you want to confirm eligibility details and application timing before you commit, review API 936 Requirements 2026: Eligibility, Prerequisites & How to Qualify and API 936 Exam Dates 2026: Testing Windows, Deadlines & Scheduling.
Maintaining the Certification
API 936 certification is valid for three years from the date it's issued. Renewal at each three-year mark is handled through a recertification application and fee - no employment verification or work-hours log is required, which simplifies the renewal process compared to some other credentials.
Every six years, instead of the standard paperwork renewal, certificants must complete an online, open-book recertification quiz consisting of 25 questions with a four-hour time limit. That format allows up to three pauses during the session and one retry if needed - a notably different structure from the original closed-book exam.
Applications for renewal can be submitted starting 90 days before the certification's expiration date. If it lapses, a 90-day grace period follows, during which renewal is still possible but carries a late fee. Once that grace period passes without renewal, the certification lapses fully, and the individual must submit a brand-new application and retake the complete original examination - not just the shorter recertification quiz.
Key Takeaway
Mark your calendar 90 days before your three-year expiration date - missing the grace period entirely means starting over with the full 85-question exam.
A Domain-Aware Approach to Preparation
Generic study habits like spaced repetition or timed practice sessions only help if they're pointed at the right material. Since Domain 2 draws from four separate ASTM standards and Domain 4 depends on knowing inspection hold points from API 936 itself, it makes sense to sequence your review so that reference-heavy domains get more calendar time early, and scenario-based domains get more practice-question time closer to your exam date.
Foundations and Roles
- Read API Standard 936 in full, noting scope and definitions
- Work through Domain 1 responsibilities and hand-off points
Laboratory Testing Deep Dive
- Study each ASTM method (C113, C133, C181, C704) and the property it measures
- Practice matching test results to acceptance criteria
Materials and Installation
- Review API 975 and API 976 alongside installation method differences
- Compare casting, gunning, and ramming applications
Inspection, Review, and Timed Practice
- Focus on Domain 4 inspection checkpoints and nonconformance handling
- Take full-length timed practice exams under 195-minute conditions
A structured plan like this is covered in more depth in API 936 Study Guide 2026: How to Pass on Your First Attempt, and if you want a condensed reference for the final days before your exam, API 936 Cheat Sheet 2026: One-Page Review of Must-Know Facts summarizes the highest-yield facts across all four domains. Running full-length practice tests on our practice test platform before exam day is one of the most direct ways to gauge whether your pacing across 85 questions and 195 minutes is realistic.
Frequently Asked Questions
No. API Standard 936 is the technical document describing refractory installation quality control; API 936 certification is the individual credential you earn by passing an exam based partly on that standard along with other references.
No minimum experience level is required. Applicants may have any level of petroleum or petrochemical industry experience, including newcomers, and 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 format.
You need a scaled score of 400 on a 200-500 range, not a fixed percentage of correct answers. See API 936 Passing Score 2026 for a full explanation.
You have a 90-day grace period after your three-year expiration to renew with a late fee. After that window closes, you must submit a new application and retake the full original examination.
For related definitions and quick answers, you can also browse What Does API 936 Stand For?, What Is A API 936?, and What Does API 936 Mean?, or start practicing directly on the main practice exam site.