Red Seal Gasfitter Class B Certification Exam
Questions WITH CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A |INSTANT
DOWNLOAD PDF
1. Which type of gas is typically used for residential heating
and cooking in Canada?
A. Propane
B. Natural gas
C. Butane
D. Hydrogen
Correct Answer: B. Natural gas
Rationale: Natural gas is the most common fuel for residential
heating and cooking due to its availability and efficiency.
2. What is the purpose of a gas pressure regulator?
A. To increase gas pressure
B. To maintain consistent gas pressure
C. To measure gas flow
D. To ignite the gas
Correct Answer: B. To maintain consistent gas pressure
Rationale: A gas pressure regulator ensures appliances receive
gas at a safe and consistent pressure.
3. Which of the following fittings is commonly used for joining
steel gas pipes?
A. Copper compression
B. Threaded
,C. PVC
D. Soldered
Correct Answer: B. Threaded
Rationale: Steel gas pipes are joined using threaded fittings to
create a secure, leak-proof connection.
4. What is the maximum allowable working pressure for a
Class B gas installation?
A. 2 psi
B. 5 psi
C. 10 psi
D. 14 psi
Correct Answer: B. 5 psi
Rationale: Class B gas installations are limited to a maximum of
5 psi to ensure safe residential and commercial operations.
5. What is the recommended test method to check for gas
leaks in piping systems?
A. Use of an open flame
B. Soap solution
C. Electrical multimeter
D. Thermometer
Correct Answer: B. Soap solution
Rationale: Soap solution bubbles at leak points, providing a safe
and effective way to detect gas leaks.
6. What is the main reason for venting gas appliances to the
outside?
A. Reduce energy costs
,B. Prevent indoor gas accumulation
C. Increase appliance efficiency
D. Avoid noise
Correct Answer: B. Prevent indoor gas accumulation
Rationale: Proper venting prevents the build-up of dangerous
gases like carbon monoxide inside the building.
7. Which of the following is a common hazard when working
with gas piping?
A. Electric shock
B. Gas explosion
C. Water contamination
D. Asbestos exposure
Correct Answer: B. Gas explosion
Rationale: Gas leaks can lead to fire or explosions, making
safety precautions critical.
8. What is the primary purpose of a drip leg (sediment trap) in
a gas line?
A. To filter debris and moisture
B. To regulate gas pressure
C. To reduce noise
D. To measure gas flow
Correct Answer: A. To filter debris and moisture
Rationale: A drip leg collects debris and moisture before the gas
reaches the appliance, preventing damage.
9. Which material is typically not permitted for underground
gas piping?
, A. Copper
B. PE (Polyethylene)
C. CSST
D. PVC
Correct Answer: D. PVC
Rationale: PVC is not rated for combustible gas service;
approved materials include polyethylene or coated steel.
10. Before purging a gas system, what must a gasfitter do?
A. Open all appliances
B. Shut off the main gas supply and ensure proper ventilation
C. Ignite the gas immediately
D. Measure gas pressure only
Correct Answer: B. Shut off the main gas supply and ensure
proper ventilation
Rationale: Safety requires the system to be depressurized and
ventilated before purging to prevent accidents.
11. What is the correct orientation for a gas appliance manual
shut-off valve?
A. Parallel to pipe = open; perpendicular = closed
B. Perpendicular to pipe = open; parallel = closed
C. Any orientation works
D. Only horizontal installation
Correct Answer: A. Parallel to pipe = open; perpendicular =
closed
Rationale: This is standard practice to quickly identify the
valve’s status.
Questions WITH CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A |INSTANT
DOWNLOAD PDF
1. Which type of gas is typically used for residential heating
and cooking in Canada?
A. Propane
B. Natural gas
C. Butane
D. Hydrogen
Correct Answer: B. Natural gas
Rationale: Natural gas is the most common fuel for residential
heating and cooking due to its availability and efficiency.
2. What is the purpose of a gas pressure regulator?
A. To increase gas pressure
B. To maintain consistent gas pressure
C. To measure gas flow
D. To ignite the gas
Correct Answer: B. To maintain consistent gas pressure
Rationale: A gas pressure regulator ensures appliances receive
gas at a safe and consistent pressure.
3. Which of the following fittings is commonly used for joining
steel gas pipes?
A. Copper compression
B. Threaded
,C. PVC
D. Soldered
Correct Answer: B. Threaded
Rationale: Steel gas pipes are joined using threaded fittings to
create a secure, leak-proof connection.
4. What is the maximum allowable working pressure for a
Class B gas installation?
A. 2 psi
B. 5 psi
C. 10 psi
D. 14 psi
Correct Answer: B. 5 psi
Rationale: Class B gas installations are limited to a maximum of
5 psi to ensure safe residential and commercial operations.
5. What is the recommended test method to check for gas
leaks in piping systems?
A. Use of an open flame
B. Soap solution
C. Electrical multimeter
D. Thermometer
Correct Answer: B. Soap solution
Rationale: Soap solution bubbles at leak points, providing a safe
and effective way to detect gas leaks.
6. What is the main reason for venting gas appliances to the
outside?
A. Reduce energy costs
,B. Prevent indoor gas accumulation
C. Increase appliance efficiency
D. Avoid noise
Correct Answer: B. Prevent indoor gas accumulation
Rationale: Proper venting prevents the build-up of dangerous
gases like carbon monoxide inside the building.
7. Which of the following is a common hazard when working
with gas piping?
A. Electric shock
B. Gas explosion
C. Water contamination
D. Asbestos exposure
Correct Answer: B. Gas explosion
Rationale: Gas leaks can lead to fire or explosions, making
safety precautions critical.
8. What is the primary purpose of a drip leg (sediment trap) in
a gas line?
A. To filter debris and moisture
B. To regulate gas pressure
C. To reduce noise
D. To measure gas flow
Correct Answer: A. To filter debris and moisture
Rationale: A drip leg collects debris and moisture before the gas
reaches the appliance, preventing damage.
9. Which material is typically not permitted for underground
gas piping?
, A. Copper
B. PE (Polyethylene)
C. CSST
D. PVC
Correct Answer: D. PVC
Rationale: PVC is not rated for combustible gas service;
approved materials include polyethylene or coated steel.
10. Before purging a gas system, what must a gasfitter do?
A. Open all appliances
B. Shut off the main gas supply and ensure proper ventilation
C. Ignite the gas immediately
D. Measure gas pressure only
Correct Answer: B. Shut off the main gas supply and ensure
proper ventilation
Rationale: Safety requires the system to be depressurized and
ventilated before purging to prevent accidents.
11. What is the correct orientation for a gas appliance manual
shut-off valve?
A. Parallel to pipe = open; perpendicular = closed
B. Perpendicular to pipe = open; parallel = closed
C. Any orientation works
D. Only horizontal installation
Correct Answer: A. Parallel to pipe = open; perpendicular =
closed
Rationale: This is standard practice to quickly identify the
valve’s status.
