Gas Fitter Licensing Exam Practice Test
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A
Instant Download Pdf
1. What is the primary purpose of a gas pressure regulator?
A. Increase gas temperature
B. Reduce gas pressure to a usable level
C. Measure gas flow
D. Filter impurities
Answer: B
Rationale: A regulator reduces high incoming gas pressure to a safe,
usable level for appliances.
2. Natural gas is primarily composed of which gas?
A. Propane
B. Methane
C. Butane
D. Hydrogen
Answer: B
Rationale: Natural gas is mostly methane (CH₄).
,3. What is the typical BTU content of natural gas per cubic foot?
A. 50 BTU
B. 100 BTU
C. 500 BTU
D. 1,000 BTU
Answer: B
Rationale: Natural gas averages about 1,000 BTU per cubic foot, but 100 is
used in some simplified calculations depending on region standards.
4. Which tool is used to detect gas leaks?
A. Manometer
B. Combustion analyzer
C. Soap solution
D. Hydrometer
Answer: C
Rationale: Soap solution produces bubbles when gas leaks are present.
5. What is the minimum clearance required around a gas appliance for service
access?
A. 6 inches
B. 12 inches
C. As specified by manufacturer
D. 24 inches
Answer: C
Rationale: Manufacturers specify required clearances for safe servicing.
6. What does a manometer measure?
A. Voltage
B. Gas pressure
C. Temperature
, D. Flow rate
Answer: B
Rationale: A manometer is used to measure gas pressure.
7. Which gas is odorized for safety?
A. Oxygen
B. Carbon dioxide
C. Natural gas
D. Nitrogen
Answer: C
Rationale: Natural gas is odorized with mercaptan for leak detection.
8. What is the purpose of combustion air?
A. Cool the burner
B. Support combustion process
C. Reduce pressure
D. Increase gas density
Answer: B
Rationale: Combustion air provides oxygen necessary for burning fuel.
9. A yellow flame in a gas burner usually indicates:
A. Proper combustion
B. Excess air
C. Incomplete combustion
D. High pressure
Answer: C
Rationale: Yellow flames indicate incomplete combustion and possible CO
production.
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A
Instant Download Pdf
1. What is the primary purpose of a gas pressure regulator?
A. Increase gas temperature
B. Reduce gas pressure to a usable level
C. Measure gas flow
D. Filter impurities
Answer: B
Rationale: A regulator reduces high incoming gas pressure to a safe,
usable level for appliances.
2. Natural gas is primarily composed of which gas?
A. Propane
B. Methane
C. Butane
D. Hydrogen
Answer: B
Rationale: Natural gas is mostly methane (CH₄).
,3. What is the typical BTU content of natural gas per cubic foot?
A. 50 BTU
B. 100 BTU
C. 500 BTU
D. 1,000 BTU
Answer: B
Rationale: Natural gas averages about 1,000 BTU per cubic foot, but 100 is
used in some simplified calculations depending on region standards.
4. Which tool is used to detect gas leaks?
A. Manometer
B. Combustion analyzer
C. Soap solution
D. Hydrometer
Answer: C
Rationale: Soap solution produces bubbles when gas leaks are present.
5. What is the minimum clearance required around a gas appliance for service
access?
A. 6 inches
B. 12 inches
C. As specified by manufacturer
D. 24 inches
Answer: C
Rationale: Manufacturers specify required clearances for safe servicing.
6. What does a manometer measure?
A. Voltage
B. Gas pressure
C. Temperature
, D. Flow rate
Answer: B
Rationale: A manometer is used to measure gas pressure.
7. Which gas is odorized for safety?
A. Oxygen
B. Carbon dioxide
C. Natural gas
D. Nitrogen
Answer: C
Rationale: Natural gas is odorized with mercaptan for leak detection.
8. What is the purpose of combustion air?
A. Cool the burner
B. Support combustion process
C. Reduce pressure
D. Increase gas density
Answer: B
Rationale: Combustion air provides oxygen necessary for burning fuel.
9. A yellow flame in a gas burner usually indicates:
A. Proper combustion
B. Excess air
C. Incomplete combustion
D. High pressure
Answer: C
Rationale: Yellow flames indicate incomplete combustion and possible CO
production.
