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Maryland Journey Natural Gas Fitter — Practice Exam

What This Practice Exam Covers

The Maryland Journey Natural Gas Fitter licensing exam consists of 40 questions answered in 90 minutes, with a passing score of 70% (28 correct). The exam draws from five topic areas: General Piping, Pipe Sizing/Math, Chimney and Flues, Combustion, and Appliances — all based on the 2018 International Fuel Gas Code (IFGC) and Mathematics for Plumbers and Pipefitters.

This practice exam gives you two ways to prepare:

• Free practice exam: 10 questions per attempt, drawn from a limited pool. You can retake it as many times as you like to get a feel for question phrasing, answer structure, and the code's level of detail. It costs nothing and requires no account.
• Full practice exam: 40 questions, 90-minute timer — identical in structure to the real exam. Questions are pulled from a pool of 188+ items, so each attempt presents a unique set. No two sittings are the same, which means repeated attempts build genuine readiness rather than answer memorization.

Start with the free exam to calibrate, then use the full practice exam for serious test prep.

What You'll Be Tested On

General Piping — 15 Questions (37.5% of the exam)

This is the heaviest topic and the one most candidates underestimate. Questions cover:

• Allowable pressure drop and maximum operating pressure — you need to know the specific pressure limits for low-pressure indoor systems (typically ½ psi or less) and where medium-pressure rules apply.
• Approved piping materials — steel pipe, copper tubing, CSST, polyethylene (for underground), and aluminum each have distinct code approval conditions. Know which materials are prohibited in which locations.
• Joints, fittings, and connection methods — threaded, brazed, welded, press-connect, and flared connections all have specific application requirements. The exam will ask which method is code-compliant for a given situation.
• Installation requirements — prohibited locations include elevator shafts (2018 IFGC, Page 20, Section 301.15) and concealed spaces where the code restricts certain materials. Underground burial depth, corrosion protection requirements, and rules for protecting pipe from physical damage (such as the 3½-inch roof elevation rule from Section 404.9, Page 72) all appear here.
• Pressure testing — test medium (air, nitrogen, or inert gas — not natural gas for new systems), required test pressure, duration, and acceptable leak detection methods. See 2018 IFGC, Pages 74–75 (Sections 406.4, 406.4.1, 406.4.2, 406.5, 406.5.2).
• Purging procedures — the sequence for safely purging air from new piping before placing it in service.

Pipe Sizing/Math — 10 Questions (25% of the exam)

The second-largest topic requires actual calculation, not just code recall.

• Pipe sizing methods — longest length, branch length, and hybrid pressure drop methods. You must be able to read sizing tables and apply the correct method for a given system layout.
• Maximum gas demand — converting appliance BTU ratings to cubic feet per hour (CFH). The formula is CFH = BTU/h ÷ heating value of the gas.
• Equivalent lengths for fittings — adding fitting allowances to pipe runs before entering a sizing table.
• Fitting allowances — threaded, copper (solder cup depth), and welded fittings each use different formulas. Slip-on flanges are a specific tested case (see Mathematics for Plumbers and Pipefitters, Pages 54–56, Unit 14).
• Offset calculations — 45°, 60°, and 22.5° angle constants are used to find diagonal length, travel, and offset. These constants appear directly in exam questions. See Mathematics for Plumbers and Pipefitters, Pages 94–98 (Unit 25).
• Grade and percent grade — calculating drop over a given run, or finding percent grade. Use the formula: % grade = (drop ÷ run) × 100. See Mathematics for Plumbers and Pipefitters, Pages 126–128 (Unit 33).

Chimney and Flues — 5 Questions (12.5% of the exam)

• Venting categories and system selection — Category I, II, III, and IV appliances vent differently; the exam expects you to match category to system type.
• Termination height and location — Type B, BW, and L gas vents have specific minimum heights above the appliance draft hood or flue collar. The 5-foot minimum above the highest connected appliance draft hood (IFGS, Section 503.6.6) is directly tested.
• Vent connector materials, slope, and clearances — connectors must slope upward toward the vent; slope and clearance minimums are tested.
• Masonry chimney requirements — lining materials, inspection requirements, and what must be done before connecting a new appliance.
• Sizing Category I systems — using IFGS tables (Table 503.4, Table 503.8) to determine correct vent diameter.
• Gas vent types — Type B (double-wall), Type BW (wall furnace), and Type L each have distinct installation rules.

Combustion — 5 Questions (12.5% of the exam)

• Combustion air methods — indoor vs. outdoor source methods per the IFGC, including when each is required (IFGC 2018, Chapter 3, Sections 304.5 and 304.6).
• Opening sizing — minimum free area calculations expressed in square inches per Btu/h of appliance input.
• Flammability limits — natural gas has a lower flammable limit (LFL) around 5% and upper limit (UFL) around 15% in air. Propane has a narrower range. These percentages appear on the exam.
• Gas properties — natural gas is lighter than air (specific gravity < 1.0); propane is heavier than air. Both are odorized; neither is toxic in the same way as carbon monoxide.
• Combustion products — definitions of complete vs. incomplete combustion, CO vs. CO₂ production, and flue gas composition.
• Burner definitions — main burner, power burner, and induced-draft burner are defined terms (IFGC Section 202, Pages 12–17).

Appliances — 5 Questions (12.5% of the exam)

• Listing and labeling — appliances must be listed and labeled by an approved testing agency; installation must follow the listing conditions.
• Clearances to combustibles — heating appliance clearances are specified by the listing and supplemented by code minimums.
• Clothes dryer exhaust — duct material (rigid metal), maximum length, and termination location requirements (IFGC Section 614, Pages 126–127).
• Unvented room heaters — input rating limits, required oxygen-depletion safety shutoff (ODS), and locations where these heaters are prohibited (IFGC Section 621, Sections 621.3, 621.6, 621.7).
• Cooking appliances — vertical clearances above cooking surfaces and installation requirements.
• Water heaters — installation requirements and conditions under which a water heater may also serve a space-heating function (IFGC Section 623.2, 623.7).

Worked Sample Questions

Sample 1 — General Piping

A journeyman gas fitter is installing above-ground outdoor gas piping that must cross a roof surface. What is the minimum elevation of the piping above the roof surface?

• A. 2 inches
• B. 6 inches
• C. 3½ inches
• D. 3 inches

Correct Answer: C — 3½ inches

Section 404.9 (2018 IFGC, Page 72) requires outdoor piping to be elevated not less than 3½ inches above grade and, when crossing a roof surface, not less than 3½ inches above that roof surface. The same 3½-inch clearance applies in both contexts. Answer D (3 inches) is a common trap — it sounds reasonable but is short of the code minimum.

Sample 2 — Pipe Sizing/Math

For a slip-on flange, how is the fitting allowance determined?

• A. It equals 1.5 times the pipe size plus ⅛ inch for weld penetration
• B. It equals the center-to-face measurement minus the depth of the solder cup
• C. It equals the pipe wall thickness plus one-half the gasket thickness
• D. It equals 1 times the pipe size plus ¼ inch for weld penetration on both sides

Correct Answer: C — pipe wall thickness plus one-half the gasket thickness

For a slip-on flange, the pipe is withdrawn slightly from the flange face to create an internal welding surface. The fitting allowance is therefore the pipe wall thickness (how far the pipe is set back) plus one-half the gasket thickness, measured to the gasket centerline. This is covered in Mathematics for Plumbers and Pipefitters, Pages 54–56 (Unit 14, Table 14-1). Answers A and D describe butt-weld or fillet-weld formulas — common confusions on this question.

Sample 3 — Chimney and Flues

What is the minimum vertical height above the highest connected appliance draft hood or flue collar for a Type B or Type L gas vent termination?

• A. 12 feet
• B. 3 feet
• C. 2 feet
• D. 5 feet

Correct Answer: D — 5 feet

IFGS Section 503.6.6 sets this minimum at 5 feet of vertical height above the highest connected appliance draft hood or flue collar. The 12-foot figure in Answer A is specific to Type B-W vents (measured from the bottom of a wall furnace) — a frequently confused pairing. Knowing both numbers, and which vent type each applies to, is exactly how this question discriminates between prepared and unprepared candidates.

How to Read Your Score

The passing score is 70%, which means 28 out of 40 questions correct on the real exam.

Treat your first practice attempt as a diagnostic, not a verdict. If you score in the 50s or low 60s, that is not a failure — it tells you exactly which topics to prioritize before your next attempt. A topic-by-topic breakdown is more useful than an overall percentage: scoring 60% on General Piping (the 15-question topic) has a bigger effect on your total than scoring 60% on any 5-question topic.

Scoring near 70% on practice should not be read as exam-ready. Practice questions come with more time to think than the real exam's pacing allows, and familiarity with a question pool inflates scores over repeated attempts. A comfortable margin — 78–80% or above — gives you a real buffer for test-day conditions.

Retake the full 40-question practice exam multiple times. Because it draws from 188+ questions, each attempt surfaces different items and forces you to recall code details rather than recognize them.

Where Candidates Lose Points

General Piping is where most points are won or lost, simply because it carries 15 of the 40 questions. Common mistakes include confusing test pressure requirements with operating pressure limits, or mixing up acceptable test media (the exam is specific: air or inert gas, not natural gas, for new piping). Candidates also confuse the burial depth rules with the elevation rules — they are different sections with different numbers.

Pipe Sizing/Math trips up candidates who skip steps. A multi-step CFH calculation that starts with the wrong conversion factor — or a pipe sizing problem where you forget to add equivalent fitting lengths before entering the table — produces a confident wrong answer. Offset calculations are lost when candidates mix up which constant applies to which angle (45° vs. 60° vs. 22.5° each have distinct multipliers).

Chimney and Flues questions punish candidates who mix up Type B, Type BW, and Type L termination heights. The numbers are different; the code is explicit.

Combustion questions often involve memorized values — the flammability percentage limits for natural gas and propane, and the specific gravity relationship (natural gas rises, propane sinks). Confusing the two gases on a single question costs a point immediately.

Time management is real: 40 questions in 90 minutes is 2 minutes 15 seconds per question. Math questions in Pipe Sizing can take 3–4 minutes, which means you must move quickly through definition and code-recall questions to protect that time.

Exam Quick Facts