Minnesota Liquefied Petroleum Gas
Service Technician Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary component of liquefied petroleum gas (LP gas)
used for residential applications?
A. Methane
B. Propane
C. Hydrogen
D. Oxygen
Answer: B. Propane
Propane is the most common LP gas used in residential systems because it
can be liquefied under moderate pressure and stored efficiently in tanks.
2. LP gas changes from liquid to vapor primarily when:
,A. Pressure increases
B. Temperature decreases
C. Pressure is reduced
D. Water is added
Answer: C. Pressure is reduced
Reducing pressure allows liquid propane to expand and vaporize so it can
be supplied to appliances.
3. The odorant added to LP gas is mainly used to:
A. Increase heating value
B. Detect leaks
C. Reduce pressure
D. Prevent freezing
Answer: B. Detect leaks
LP gas naturally has little odor, so odorants such as mercaptans are added
to help users detect gas leaks.
4. LP gas vapor is:
A. Lighter than air
B. Heavier than air
,C. The same density as air
D. Nonflammable
Answer: B. Heavier than air
Propane vapor is heavier than air and can collect in low areas if a leak
occurs.
5. The purpose of a pressure regulator in an LP gas system is to:
A. Increase tank pressure
B. Convert liquid to solid
C. Reduce and control gas pressure
D. Add odorant
Answer: C. Reduce and control gas pressure
Regulators reduce high tank pressure to a controlled pressure suitable for
appliance operation.
6. A common odorant used in LP gas is:
A. Nitrogen
B. Carbon dioxide
C. Ethyl mercaptan
D. Oxygen
Answer: C. Ethyl mercaptan
, Ethyl mercaptan is added because its strong odor helps identify escaping
gas.
7. The first action when an LP gas leak is suspected inside a building is to:
A. Turn on electrical switches
B. Light a flame to locate the leak
C. Extinguish ignition sources and evacuate if needed
D. Increase appliance operation
Answer: C. Extinguish ignition sources and evacuate if needed
Safety requires avoiding sparks or flames and removing people from
danger before investigating the leak.
8. LP gas tanks are normally filled only to approximately:
A. 50% capacity
B. 80% capacity
C. 95% capacity
D. 100% capacity
Answer: B. 80% capacity
The 80% fill limit provides space for liquid expansion as temperature
changes.
9. The vapor pressure of propane increases when:
Service Technician Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary component of liquefied petroleum gas (LP gas)
used for residential applications?
A. Methane
B. Propane
C. Hydrogen
D. Oxygen
Answer: B. Propane
Propane is the most common LP gas used in residential systems because it
can be liquefied under moderate pressure and stored efficiently in tanks.
2. LP gas changes from liquid to vapor primarily when:
,A. Pressure increases
B. Temperature decreases
C. Pressure is reduced
D. Water is added
Answer: C. Pressure is reduced
Reducing pressure allows liquid propane to expand and vaporize so it can
be supplied to appliances.
3. The odorant added to LP gas is mainly used to:
A. Increase heating value
B. Detect leaks
C. Reduce pressure
D. Prevent freezing
Answer: B. Detect leaks
LP gas naturally has little odor, so odorants such as mercaptans are added
to help users detect gas leaks.
4. LP gas vapor is:
A. Lighter than air
B. Heavier than air
,C. The same density as air
D. Nonflammable
Answer: B. Heavier than air
Propane vapor is heavier than air and can collect in low areas if a leak
occurs.
5. The purpose of a pressure regulator in an LP gas system is to:
A. Increase tank pressure
B. Convert liquid to solid
C. Reduce and control gas pressure
D. Add odorant
Answer: C. Reduce and control gas pressure
Regulators reduce high tank pressure to a controlled pressure suitable for
appliance operation.
6. A common odorant used in LP gas is:
A. Nitrogen
B. Carbon dioxide
C. Ethyl mercaptan
D. Oxygen
Answer: C. Ethyl mercaptan
, Ethyl mercaptan is added because its strong odor helps identify escaping
gas.
7. The first action when an LP gas leak is suspected inside a building is to:
A. Turn on electrical switches
B. Light a flame to locate the leak
C. Extinguish ignition sources and evacuate if needed
D. Increase appliance operation
Answer: C. Extinguish ignition sources and evacuate if needed
Safety requires avoiding sparks or flames and removing people from
danger before investigating the leak.
8. LP gas tanks are normally filled only to approximately:
A. 50% capacity
B. 80% capacity
C. 95% capacity
D. 100% capacity
Answer: B. 80% capacity
The 80% fill limit provides space for liquid expansion as temperature
changes.
9. The vapor pressure of propane increases when:
