Oklahoma Natural Gas Contractor Exam: Complete 2026 Study Guide
Getting your Oklahoma Natural Gas Contractor license is a significant career milestone — and the PSI exam standing between you and that credential is very passable with the right preparation. The exam tests real knowledge that protects public safety, so it's designed to be thorough. The good news? It's open book, and with 120 minutes for 40 questions, you have plenty of time if you know your reference materials well. This guide covers everything you need: exam structure, topic breakdowns, sample questions, approved study materials, and practical tips to help you pass on your first attempt. Start by taking our free practice exam to benchmark where you stand right now.
Oklahoma Natural Gas Contractor Exam Overview
The Oklahoma Natural Gas Contractor exam is administered by PSI and is required by the Oklahoma Construction Industries Board. Here's what to expect on test day:
- Questions: 40 scored questions
- Time limit: 120 minutes
- Passing score: 70% — that's 28 correct out of 40 scored questions
- Format: Multiple choice (and some true/false style questions)
- Open book: Yes — you bring your own approved references
- Testing: In-person at a PSI testing center
The open-book format is a double-edged sword. It gives you a safety net for specific code numbers you can't memorize, but it can slow you down if your books aren't well-organized. Candidates who tab and highlight their references before the exam consistently perform better than those who flip through unmarked pages under time pressure.
For full details on registration and requirements, review the official exam bulletin or visit the state licensing website.
Exam Topics: What the Oklahoma Natural Gas Contractor Exam Covers
The exam draws from four topic areas. Here's the breakdown by number of exam items — this tells you exactly where to focus your study time.
Pipe Installation — 15 Items (Heaviest Weight)
This is the largest section and covers the practical side of running gas lines: support requirements, clearances, materials, connections, joints, underground installation, and protecting structural components. With 15 of 40 questions here, this topic alone accounts for 37.5% of your score.
Pipe Sizing — 12 Items
Expect calculation-based questions requiring you to size piping systems correctly based on appliance input ratings, pipe length, and pressure drop. Altitude adjustments are also tested. This section rewards candidates who practice working through sizing tables — not just reading them.
General Fuel Gas Piping — Knowledge, Definitions, and Regulations — 10 Items
This section covers code definitions, combustion air requirements, appliance categories, and regulatory framework. Understanding key terms and the logic behind the code goes a long way here.
Safety — 3 Items
Three questions covering OSHA 29 CFR Part 1926 safety requirements. Fewer questions, but each one counts. Don't skip this section — a missed safety question is a missed point.
Sample Oklahoma Natural Gas Contractor Exam Questions
Here are five sample questions representative of what you'll see on the real exam. Work through them — but we won't be giving you the answers here. See how you do, then check your knowledge with our free practice exam.
Question 1 — Pipe Sizing
According to the IFGC, what is the basis for determining the volumetric flow rate of gas to be provided when sizing piping systems?
- A) The average input of all appliances served
- B) The sum of the maximum input of the appliances served
- C) 75% of the total connected hourly load
- D) The input rating of the largest single appliance
Question 2 — Pipe Installation
According to the Oklahoma Fuel Gas Code, the minimum dimension of air openings for combustion air shall be not less than:
- A) 1 inch
- B) 2 inches
- C) 3 inches
- D) 4 inches
Question 3 — Pipe Sizing
According to the IFGC, the volumetric flow rate of gas shall be adjusted for altitude when the installation is above what elevation?
- A) 1,000 feet
- B) 2,000 feet
- C) 3,000 feet
- D) 5,000 feet
Question 4 — Pipe Installation
According to the Oklahoma Fuel Gas Code, the building shall not be weakened by the installation of any gas piping.
(True / False)
Question 5 — General Fuel Gas Piping — Knowledge, Definitions, and Regulations
Under the Oklahoma Fuel Gas Code, the minimum required volume of indoor air for combustion using the Standard Method is:
- A) 25 cubic feet per 1,000 Btu/h of appliance input rating
- B) 50 cubic feet per 1,000 Btu/h of appliance input rating
- C) 75 cubic feet per 1,000 Btu/h of appliance input rating
- D) 100 cubic feet per 1,000 Btu/h of appliance input rating
Notice the pattern: some questions require precise code recall, others test your understanding of calculation methodology, and at least one tests a fundamental installation rule. That variety is exactly what Oklahoma natural gas contractor exam questions look like on the real thing.
What Types of Questions to Expect
Here's a topic-by-topic breakdown of the kinds of problems you'll encounter.
General Fuel Gas Piping — Knowledge, Definitions, and Regulations
These questions test code definitions, combustion air calculations using the Standard Method, appliance categories, and regulatory scope. Expect questions that ask you to identify the correct definition of a term or determine minimum volume requirements for a given appliance input rating.
Pipe Sizing
This is a math-heavy section. Questions cover determining flow rates, reading sizing tables, adjusting for altitude, and selecting correct pipe dimensions for given scenarios. You'll need to be comfortable working through the IFGC sizing tables under time pressure.
Pipe Installation
The broadest topic. Questions address pipe support spacing, materials allowed for different applications, joint types, underground burial depth, protection from physical damage, structural integrity requirements, and combustion air opening sizes. Expect scenario-based questions where you identify whether an installation meets code.
Safety
Drawn from OSHA 29 CFR Part 1926, these questions cover construction-site safety requirements relevant to gas work. Think fall protection, trenching requirements, and general safety compliance.
All four areas are represented across our full pool of 192 practice questions. Start with the free practice exam to get a feel for the format, then consider the full practice exam for topic-by-topic scoring that pinpoints your weak spots.
Required Study Materials for the Oklahoma Natural Gas Contractor Exam
This is an open-book exam, and the state specifies exactly what you can bring. Get these materials, study them thoroughly, and organize them well before test day.
Required References
2024 International Fuel Gas Code (IFGC) (2018 edition accepted through December 13, 2026)
This is the primary reference for the exam. The IFGC covers pipe sizing, installation requirements, combustion air, and appliance connections. Most of your exam questions will trace back to this code. Get familiar with how it's organized — particularly the sizing tables in Chapter 4 and the installation requirements in Chapter 4 and Appendix.
OSHA 29 CFR Part 1926
Required for the safety section. This covers OSHA standards for the construction industry. You won't need to memorize the entire document, but know the sections relevant to gas work, trenching, and general construction safety.
Recommended Organizational Tools
Since your books can be tabbed and highlighted (but not written in), tabbing them yourself as you practice is a real competitive advantage: every tab marks a section you've already found once.
Redi-Tag Permanent Colored Tabs
These 100 laser-printable tabs in five colors (purple, green, blue, dark blue, and orange) are ideal for color-coding your references by topic. Tab your pipe sizing tables in one color, installation requirements in another, and combustion air sections in a third. When you're in the exam under time pressure, you want to land on the right page in seconds — not minutes.
Sharpie Tank Highlighters
A pack of 12 in assorted fluorescent colors. Highlight key code thresholds, minimum dimensions, and table headers before the exam. The chisel tip works well for underlining specific values within tables. Let ink dry before turning pages to avoid smearing.
Study Tips for Oklahoma Natural Gas Contractor Prep
Prioritize by exam weight. Pipe Installation accounts for 37.5% of the exam — nearly four in ten questions. That's where your study time should be concentrated first, followed by Pipe Sizing (30%), then General Knowledge (25%), and Safety (7.5%).
Work the sizing tables until they feel automatic. The Pipe Sizing section is where candidates lose points because they're slow with the tables, not because they don't understand the concept. Practice locating values quickly.
Rule out wrong answers first. On tough multiple-choice questions, eliminate the options you know are wrong before choosing. Narrowing down to two choices sharply improves your odds even when you're genuinely unsure.
Use practice tests as a diagnostic tool. After each practice session, note which topics you miss most and focus your next study block there. Re-testing weak areas produces far more score improvement than re-reading sections you already understand.
Trust your first instinct — but not blindly. Stick with your first answer unless you have a real reason to change it: you misread the question, or a later question gave you a clear correction. Considered changes often help; second-guessing out of nerves rarely does.
Tab as you practice. Every time a practice question sends you hunting, tab or highlight what you found, so by test day your tabs mark the sections you actually use. You're allowed permanent tabs and highlighting — use both, and check the night before that every tab is permanent.
You're Ready to Start
The Oklahoma Natural Gas Contractor exam is challenging but straightforward when you know what to expect. Study to the topic weights — lead with Pipe Installation and Pipe Sizing, since together they make up two-thirds of your score. Get your reference books organized with tabs and highlights before test day. And use practice questions to find your weak spots early, while there's still time to fix them.
Start right now with our free practice exam — 10 questions, no account required, instant results. It's the fastest way to see where you stand. When you're ready to go deeper, the full practice exam mirrors the real test with detailed topic-by-topic scoring so you can walk into the PSI testing center confident.
Good luck — you've got this.