CFESA Gas Equipment and Safety 1 — Questions and Answers
Question 1: What is the minimum required gas pressure for most commercial natural gas cooking equipment at the manifold?
- 2 inches W.C.
- 3.5 inches W.C. (Correct answer)
- 7 inches W.C.
- 11 inches W.C.
Correct answer: 3.5 inches W.C.
Most commercial natural gas equipment requires a manifold pressure of 3.5 inches W.C. (water column) for proper burner operation.
Question 2: What is the correct manifold pressure for commercial LP (propane) gas equipment?
- 3.5 inches W.C.
- 7 inches W.C.
- 11 inches W.C. (Correct answer)
- 14 inches W.C.
Correct answer: 11 inches W.C.
LP gas commercial equipment typically operates at 11 inches W.C. manifold pressure, which is higher than natural gas due to propane's different combustion properties.
Question 3: A commercial range burner produces a yellow, lazy flame. The most likely cause is:
- Excess primary air
- Insufficient primary air or gas pressure too high (Correct answer)
- Too much secondary air
- Clogged pilot orifice
Correct answer: Insufficient primary air or gas pressure too high
A yellow, lazy flame indicates incomplete combustion caused by insufficient primary air or an excessively rich air-gas mixture.
Question 4: What device automatically shuts off the gas supply if the pilot flame is extinguished on commercial gas equipment?
- Gas pressure regulator
- Thermocouple or thermopile safety system (Correct answer)
- Manual reset valve
- Gas solenoid valve
Correct answer: Thermocouple or thermopile safety system
A thermocouple or thermopile generates a small electrical current when heated by the pilot flame, which holds open the safety gas valve.
Question 5: When checking for gas leaks on commercial equipment, technicians should use:
- An open flame
- Electronic combustible gas detector or listed leak detection solution (Correct answer)
- Compressed air
- Nitrogen pressure test only
Correct answer: Electronic combustible gas detector or listed leak detection solution
An electronic combustible gas detector or listed leak detection solution (never an open flame) is safe and effective for locating gas leaks.
Question 6: What is the purpose of an atmospheric burner's primary air shutter on commercial gas cooking equipment?
- Control gas flow to the burner
- Adjust the ratio of air mixed with gas before combustion (Correct answer)
- Regulate pilot flame size
- Control secondary air above the burner
Correct answer: Adjust the ratio of air mixed with gas before combustion
The primary air shutter adjusts the amount of air mixed with gas at the venturi before the burner, controlling the air-gas mixture for proper combustion.
CFESA Gas Equipment and Safety 1
What is the minimum required gas pressure for most commercial natural gas cooking equipment at the manifold?