Red Seal Interprovincial Examination Gasfitter
Class B Questions And Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. The purpose of a gas pressure regulator is to
a) Increase the pressure of gas in a line
b) Maintain a constant downstream pressure
c) Shut off gas in case of a leak
d) Filter impurities from the gas
Regulators ensure appliances receive gas at the correct pressure
regardless of fluctuations in supply.
2. Which of the following is a primary safety device in a gas
appliance?
a) Thermocouple
b) Burner
c) Gas valve
d) Pilot tube
The gas valve controls the flow of gas to the appliance, stopping
flow if unsafe conditions occur.
3. When connecting a gas line to a water heater, the minimum
distance from the floor must comply with
a) 50 mm
b) 100 mm
c) 150 mm
, d) 200 mm
Code requirements specify a minimum clearance to reduce fire and
safety hazards.
4. A gas leak is suspected. The safest first step is to
a) Light a match to locate the leak
b) Shut off the gas supply and ventilate the area
c) Spray water on the leak
d) Ignore it and monitor
Gas leaks are highly flammable and can be explosive; proper
ventilation and shutdown are critical.
5. The function of a venting system in a gas appliance is to
a) Provide oxygen for combustion
b) Remove combustion by-products
c) Both a and b
d) Cool the appliance
Venting ensures safe removal of combustion gases while supplying
adequate air for combustion.
6. When testing a gas line for leaks using a soap solution, bubbles
indicate
a) No leak
b) A blockage
c) A leak
d) Proper pressure
Soap solution creates bubbles where gas escapes, indicating a
leak.
7. The term “Class B Gasfitter” refers to someone qualified to
a) Work on natural gas only
, b) Work on propane only
c) Install and service low-pressure gas systems for residential
applications
d) Work on industrial high-pressure gas systems
Class B certification covers residential and light commercial low-
pressure systems.
8. What is the maximum allowable working pressure for a Class B gas
system in residential applications?
a) 7 kPa
b) 14 kPa
c) 20 kPa
d) 50 kPa
Class B systems operate at low pressures to ensure safety in
homes.
9. A gas appliance has a yellow flame. This indicates
a) Complete combustion
b) Incomplete combustion
c) Proper gas flow
d) Low pressure
A yellow flame produces carbon monoxide and indicates improper
combustion.
10. When installing a gas appliance, the gas line must be tested
a) After completing the installation
b) Before the appliance is put into service
c) Only if a leak is suspected
d) After one month of operation
Testing before use ensures the system is safe and leak-free.
Class B Questions And Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. The purpose of a gas pressure regulator is to
a) Increase the pressure of gas in a line
b) Maintain a constant downstream pressure
c) Shut off gas in case of a leak
d) Filter impurities from the gas
Regulators ensure appliances receive gas at the correct pressure
regardless of fluctuations in supply.
2. Which of the following is a primary safety device in a gas
appliance?
a) Thermocouple
b) Burner
c) Gas valve
d) Pilot tube
The gas valve controls the flow of gas to the appliance, stopping
flow if unsafe conditions occur.
3. When connecting a gas line to a water heater, the minimum
distance from the floor must comply with
a) 50 mm
b) 100 mm
c) 150 mm
, d) 200 mm
Code requirements specify a minimum clearance to reduce fire and
safety hazards.
4. A gas leak is suspected. The safest first step is to
a) Light a match to locate the leak
b) Shut off the gas supply and ventilate the area
c) Spray water on the leak
d) Ignore it and monitor
Gas leaks are highly flammable and can be explosive; proper
ventilation and shutdown are critical.
5. The function of a venting system in a gas appliance is to
a) Provide oxygen for combustion
b) Remove combustion by-products
c) Both a and b
d) Cool the appliance
Venting ensures safe removal of combustion gases while supplying
adequate air for combustion.
6. When testing a gas line for leaks using a soap solution, bubbles
indicate
a) No leak
b) A blockage
c) A leak
d) Proper pressure
Soap solution creates bubbles where gas escapes, indicating a
leak.
7. The term “Class B Gasfitter” refers to someone qualified to
a) Work on natural gas only
, b) Work on propane only
c) Install and service low-pressure gas systems for residential
applications
d) Work on industrial high-pressure gas systems
Class B certification covers residential and light commercial low-
pressure systems.
8. What is the maximum allowable working pressure for a Class B gas
system in residential applications?
a) 7 kPa
b) 14 kPa
c) 20 kPa
d) 50 kPa
Class B systems operate at low pressures to ensure safety in
homes.
9. A gas appliance has a yellow flame. This indicates
a) Complete combustion
b) Incomplete combustion
c) Proper gas flow
d) Low pressure
A yellow flame produces carbon monoxide and indicates improper
combustion.
10. When installing a gas appliance, the gas line must be tested
a) After completing the installation
b) Before the appliance is put into service
c) Only if a leak is suspected
d) After one month of operation
Testing before use ensures the system is safe and leak-free.
