CO GAS PIPING CONTRACTOR EXAM QUESTIONS
AND CORRECT NSWERS (VERIFIED ANSWERS) Q&A
2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of a gas piping system?
A. To transport potable water
B. To distribute fuel gas safely to appliances
C. To remove combustion products
D. To supply electrical power
Correct Answer: B. To distribute fuel gas safely to appliances
Rationale: Gas piping systems are designed to safely convey
fuel gas from the supply source to approved appliances.
2. Which property of natural gas is intentionally added to
make leaks detectable?
A. Color
B. Odor
C. Moisture
D. Pressure
Correct Answer: B. Odor
Rationale: An odorant is added to natural gas so leaks can be
detected by smell.
3. What should be done first when a strong gas odor is
detected inside a building?
A. Turn on electrical lights
,B. Operate a telephone inside the building
C. Avoid ignition sources and leave the area
D. Start a ventilation fan
Correct Answer: C. Avoid ignition sources and leave the area
Rationale: Ignition sources can ignite accumulated gas.
Occupants should move to a safe location and follow
emergency procedures.
4. Which gas is commonly used in residential and commercial
fuel-gas systems?
A. Oxygen
B. Natural gas
C. Nitrogen
D. Carbon dioxide
Correct Answer: B. Natural gas
Rationale: Natural gas is widely used as a fuel for heating,
cooking, and other appliances.
5. What is the purpose of a gas shutoff valve?
A. Increase gas pressure
B. Stop gas flow
C. Filter combustion air
D. Reduce pipe diameter
Correct Answer: B. Stop gas flow
Rationale: A shutoff valve allows gas flow to an appliance or
piping section to be stopped.
,6. Which organization publishes the National Fuel Gas Code?
A. NFPA
B. OSHA
C. EPA
D. ANSI alone
Correct Answer: A. NFPA
Rationale: NFPA 54 is the National Fuel Gas Code, developed
and published through NFPA's standards process.
7. What is the purpose of a gas pressure regulator?
A. Increase pipe size
B. Control gas pressure
C. Remove water from combustion air
D. Measure gas temperature
Correct Answer: B. Control gas pressure
Rationale: Regulators control gas pressure to keep it within the
range required by the downstream system or appliance.
8. Why must gas piping be properly supported?
A. To increase gas temperature
B. To prevent excessive movement and stress
C. To increase gas pressure
D. To eliminate the need for valves
Correct Answer: B. To prevent excessive movement and stress
Rationale: Proper supports keep piping stable and reduce
mechanical stress on pipe, joints, and appliances.
, 9. What is the primary concern when selecting a material for
gas piping?
A. Its decorative appearance
B. Its compatibility and approval for fuel-gas service
C. Its ability to conduct electricity
D. Its weight only
Correct Answer: B. Its compatibility and approval for fuel-gas
service
Rationale: Piping materials must be approved and suitable for
the gas, pressure, environment, and installation method.
10. What does pipe sizing primarily determine?
A. Paint color
B. The amount of gas that can be delivered at an acceptable
pressure drop
C. Appliance color
D. Building height
Correct Answer: B. The amount of gas that can be delivered at
an acceptable pressure drop
Rationale: Proper sizing ensures appliances receive the
required gas supply without excessive pressure loss.
11. What is pressure drop?
A. Increase in gas pressure along a pipe
B. Loss of pressure as gas moves through the piping system
C. Change in pipe color
D. Increase in pipe diameter
AND CORRECT NSWERS (VERIFIED ANSWERS) Q&A
2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of a gas piping system?
A. To transport potable water
B. To distribute fuel gas safely to appliances
C. To remove combustion products
D. To supply electrical power
Correct Answer: B. To distribute fuel gas safely to appliances
Rationale: Gas piping systems are designed to safely convey
fuel gas from the supply source to approved appliances.
2. Which property of natural gas is intentionally added to
make leaks detectable?
A. Color
B. Odor
C. Moisture
D. Pressure
Correct Answer: B. Odor
Rationale: An odorant is added to natural gas so leaks can be
detected by smell.
3. What should be done first when a strong gas odor is
detected inside a building?
A. Turn on electrical lights
,B. Operate a telephone inside the building
C. Avoid ignition sources and leave the area
D. Start a ventilation fan
Correct Answer: C. Avoid ignition sources and leave the area
Rationale: Ignition sources can ignite accumulated gas.
Occupants should move to a safe location and follow
emergency procedures.
4. Which gas is commonly used in residential and commercial
fuel-gas systems?
A. Oxygen
B. Natural gas
C. Nitrogen
D. Carbon dioxide
Correct Answer: B. Natural gas
Rationale: Natural gas is widely used as a fuel for heating,
cooking, and other appliances.
5. What is the purpose of a gas shutoff valve?
A. Increase gas pressure
B. Stop gas flow
C. Filter combustion air
D. Reduce pipe diameter
Correct Answer: B. Stop gas flow
Rationale: A shutoff valve allows gas flow to an appliance or
piping section to be stopped.
,6. Which organization publishes the National Fuel Gas Code?
A. NFPA
B. OSHA
C. EPA
D. ANSI alone
Correct Answer: A. NFPA
Rationale: NFPA 54 is the National Fuel Gas Code, developed
and published through NFPA's standards process.
7. What is the purpose of a gas pressure regulator?
A. Increase pipe size
B. Control gas pressure
C. Remove water from combustion air
D. Measure gas temperature
Correct Answer: B. Control gas pressure
Rationale: Regulators control gas pressure to keep it within the
range required by the downstream system or appliance.
8. Why must gas piping be properly supported?
A. To increase gas temperature
B. To prevent excessive movement and stress
C. To increase gas pressure
D. To eliminate the need for valves
Correct Answer: B. To prevent excessive movement and stress
Rationale: Proper supports keep piping stable and reduce
mechanical stress on pipe, joints, and appliances.
, 9. What is the primary concern when selecting a material for
gas piping?
A. Its decorative appearance
B. Its compatibility and approval for fuel-gas service
C. Its ability to conduct electricity
D. Its weight only
Correct Answer: B. Its compatibility and approval for fuel-gas
service
Rationale: Piping materials must be approved and suitable for
the gas, pressure, environment, and installation method.
10. What does pipe sizing primarily determine?
A. Paint color
B. The amount of gas that can be delivered at an acceptable
pressure drop
C. Appliance color
D. Building height
Correct Answer: B. The amount of gas that can be delivered at
an acceptable pressure drop
Rationale: Proper sizing ensures appliances receive the
required gas supply without excessive pressure loss.
11. What is pressure drop?
A. Increase in gas pressure along a pipe
B. Loss of pressure as gas moves through the piping system
C. Change in pipe color
D. Increase in pipe diameter
