AR GA Gas Fitter Contractor
Exam Questions and Correct
Answers (Verified Answers)
Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary function of a gas pressure regulator in a fuel-
gas system?
A. To increase the heating value of the gas
B. To remove all moisture from the gas
C. To reduce and maintain gas pressure within the required operating
range
D. To increase the gas flow regardless of pipe size
,Rationale: A gas pressure regulator reduces the pressure supplied by
the utility or an upstream system and maintains a suitable
downstream pressure for appliances. Stable pressure helps ensure
safe combustion and proper appliance operation. A regulator does not
increase the fuel's heating value or compensate for improperly sized
piping.
2. Which property of natural gas is most important when determining
how it behaves after an indoor leak?
A. Its natural color
B. Its relative density compared with air
C. Its electrical conductivity
D. Its freezing point
Rationale: Natural gas is primarily methane and is lighter than air
under typical conditions. It tends to rise and can accumulate in high
areas when ventilation and room geometry permit. However, gas
movement is also affected by temperature, airflow, and enclosure
conditions. Propane is heavier than air and can collect in low areas.
3. What is the primary purpose of adding an odorant to commercially
distributed natural gas?
A. To increase its flame temperature
,B. To reduce the gas pressure
C. To prevent corrosion in steel piping
D. To make otherwise difficult-to-detect gas leaks noticeable
Rationale: Natural gas is naturally odorless, so an odorant is added to
help people recognize a possible leak. The familiar sulfur-like smell is a
warning, not a measurement of gas concentration. A person should
not rely on odor alone because odor fatigue, masking, or odorant-
related problems may prevent reliable detection.
4. Which instrument is commonly used to measure gas pressure in
inches of water column?
A. An ammeter
B. A tachometer
C. A manometer
D. A megohmmeter
Rationale: A manometer measures pressure by comparing the height
of a liquid column or through an electronic pressure sensor calibrated
for the application. Inches of water column are commonly used for
low-pressure residential fuel-gas systems. An ammeter measures
, electrical current, while a megohmmeter tests electrical insulation
resistance.
5. What should a gas fitter do before disconnecting an existing gas
appliance for replacement?
A. Immediately loosen the appliance connector
B. Increase the gas supply pressure
C. Shut off the gas supply and verify that the work area is safe
D. Remove the appliance vent before addressing the gas supply
Rationale: The gas supply must be isolated before disconnecting an
appliance to prevent uncontrolled fuel release. The fitter should follow
the applicable isolation procedure, verify conditions, and use
appropriate tools and leak-control practices. Work must also account
for ignition sources, ventilation, and the possibility of gas remaining in
the piping.
6. Which material is commonly approved for certain fuel-gas piping
applications when installed according to the applicable code?
A. Ordinary garden hose
B. Unlisted vinyl tubing
C. Standard drainage pipe
Exam Questions and Correct
Answers (Verified Answers)
Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary function of a gas pressure regulator in a fuel-
gas system?
A. To increase the heating value of the gas
B. To remove all moisture from the gas
C. To reduce and maintain gas pressure within the required operating
range
D. To increase the gas flow regardless of pipe size
,Rationale: A gas pressure regulator reduces the pressure supplied by
the utility or an upstream system and maintains a suitable
downstream pressure for appliances. Stable pressure helps ensure
safe combustion and proper appliance operation. A regulator does not
increase the fuel's heating value or compensate for improperly sized
piping.
2. Which property of natural gas is most important when determining
how it behaves after an indoor leak?
A. Its natural color
B. Its relative density compared with air
C. Its electrical conductivity
D. Its freezing point
Rationale: Natural gas is primarily methane and is lighter than air
under typical conditions. It tends to rise and can accumulate in high
areas when ventilation and room geometry permit. However, gas
movement is also affected by temperature, airflow, and enclosure
conditions. Propane is heavier than air and can collect in low areas.
3. What is the primary purpose of adding an odorant to commercially
distributed natural gas?
A. To increase its flame temperature
,B. To reduce the gas pressure
C. To prevent corrosion in steel piping
D. To make otherwise difficult-to-detect gas leaks noticeable
Rationale: Natural gas is naturally odorless, so an odorant is added to
help people recognize a possible leak. The familiar sulfur-like smell is a
warning, not a measurement of gas concentration. A person should
not rely on odor alone because odor fatigue, masking, or odorant-
related problems may prevent reliable detection.
4. Which instrument is commonly used to measure gas pressure in
inches of water column?
A. An ammeter
B. A tachometer
C. A manometer
D. A megohmmeter
Rationale: A manometer measures pressure by comparing the height
of a liquid column or through an electronic pressure sensor calibrated
for the application. Inches of water column are commonly used for
low-pressure residential fuel-gas systems. An ammeter measures
, electrical current, while a megohmmeter tests electrical insulation
resistance.
5. What should a gas fitter do before disconnecting an existing gas
appliance for replacement?
A. Immediately loosen the appliance connector
B. Increase the gas supply pressure
C. Shut off the gas supply and verify that the work area is safe
D. Remove the appliance vent before addressing the gas supply
Rationale: The gas supply must be isolated before disconnecting an
appliance to prevent uncontrolled fuel release. The fitter should follow
the applicable isolation procedure, verify conditions, and use
appropriate tools and leak-control practices. Work must also account
for ignition sources, ventilation, and the possibility of gas remaining in
the piping.
6. Which material is commonly approved for certain fuel-gas piping
applications when installed according to the applicable code?
A. Ordinary garden hose
B. Unlisted vinyl tubing
C. Standard drainage pipe
