Gas Fitter Licensing Exam 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 and maintain downstream pressure
C. Filter impurities from gas
D. Measure gas flow
Answer: B. Reduce and maintain downstream pressure
Rationale: Regulators ensure gas is delivered at a safe and consistent
pressure for appliances.
2. Which gas is commonly used in residential natural gas systems?
A. Propane
B. Butane
C. Methane
D. Hydrogen
,Answer: C. Methane
Rationale: Natural gas is primarily composed of methane.
3. What is the standard test pressure for low-pressure gas piping in
many jurisdictions?
A. 1 psi
B. 3 psi
C. 10 psi
D. 100 psi
Answer: B. 3 psi
Rationale: Many codes require low-pressure systems to be tested at
around 3 psi.
4. What tool is commonly used to detect gas leaks?
A. Ammeter
B. Manometer
C. Combustible gas detector
D. Hydrometer
,Answer: C. Combustible gas detector
Rationale: Electronic detectors identify the presence of combustible
gases.
5. What color is commonly used to identify natural gas piping?
A. Green
B. Yellow
C. Blue
D. Red
Answer: B. Yellow
Rationale: Yellow indicates gas piping per common industry standards.
6. What is the main hazard of incomplete combustion?
A. Oxygen buildup
B. Carbon monoxide production
C. Nitrogen release
D. Water vapor
Answer: B. Carbon monoxide production
Rationale: Incomplete combustion produces dangerous carbon
monoxide.
, 7. What is the purpose of a sediment trap?
A. Increase gas flow
B. Collect moisture and debris
C. Regulate pressure
D. Vent gas outdoors
Answer: B. Collect moisture and debris
Rationale: Sediment traps prevent debris from entering appliances.
8. Which fitting is used to change pipe direction?
A. Coupling
B. Elbow
C. Tee
D. Union
Answer: B. Elbow
Rationale: Elbows are used to change direction in piping systems.
9. What does BTU measure?
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 and maintain downstream pressure
C. Filter impurities from gas
D. Measure gas flow
Answer: B. Reduce and maintain downstream pressure
Rationale: Regulators ensure gas is delivered at a safe and consistent
pressure for appliances.
2. Which gas is commonly used in residential natural gas systems?
A. Propane
B. Butane
C. Methane
D. Hydrogen
,Answer: C. Methane
Rationale: Natural gas is primarily composed of methane.
3. What is the standard test pressure for low-pressure gas piping in
many jurisdictions?
A. 1 psi
B. 3 psi
C. 10 psi
D. 100 psi
Answer: B. 3 psi
Rationale: Many codes require low-pressure systems to be tested at
around 3 psi.
4. What tool is commonly used to detect gas leaks?
A. Ammeter
B. Manometer
C. Combustible gas detector
D. Hydrometer
,Answer: C. Combustible gas detector
Rationale: Electronic detectors identify the presence of combustible
gases.
5. What color is commonly used to identify natural gas piping?
A. Green
B. Yellow
C. Blue
D. Red
Answer: B. Yellow
Rationale: Yellow indicates gas piping per common industry standards.
6. What is the main hazard of incomplete combustion?
A. Oxygen buildup
B. Carbon monoxide production
C. Nitrogen release
D. Water vapor
Answer: B. Carbon monoxide production
Rationale: Incomplete combustion produces dangerous carbon
monoxide.
, 7. What is the purpose of a sediment trap?
A. Increase gas flow
B. Collect moisture and debris
C. Regulate pressure
D. Vent gas outdoors
Answer: B. Collect moisture and debris
Rationale: Sediment traps prevent debris from entering appliances.
8. Which fitting is used to change pipe direction?
A. Coupling
B. Elbow
C. Tee
D. Union
Answer: B. Elbow
Rationale: Elbows are used to change direction in piping systems.
9. What does BTU measure?
