NEW MEXICO (LP-9) – LP-GAS DISPENSING STATION NEW EXAM QUESTIONS AND CORRECT ANSWERS FOR TOP PERFORMANCE

1. LP-gas is primarily composed of which hydrocarbons?
A. Methane and ethane
B. Propane and butane
C. Ethylene and acetylene
D. Hydrogen and nitrogen
ANSWER : B
Explanation: LP-gas (liquefied petroleum gas) mainly consists of propane and
butane, stored as liquids under pressure.


2. Which NFPA standard governs LP-Gas storage, handling, and
dispensing?
A. NFPA 54
B. NFPA 70
C. NFPA 58
D. NFPA 10
ANSWER : C
Explanation: NFPA 58 (Liquefied Petroleum Gas Code) regulates LP-gas
systems, including dispensing stations.


3. What is the primary odorant added to LP-gas for leak detection?
A. Chlorine
B. Mercaptan
C. Sulfur dioxide
D. Ammonia
ANSWER : B
Explanation: Ethyl mercaptan is added so leaks can be detected by smell.

,4. LP-gas vapor is heavier or lighter than air?
A. Lighter
B. Equal weight
C. Heavier
D. Weight varies
ANSWER : C
Explanation: LP-gas vapor is heavier than air and can collect near the ground,
increasing explosion risk.


5. What is the normal vapor pressure of propane at 70°F?
A. 14.7 psi
B. 50 psi
C. 110 psi
D. 250 psi
ANSWER : C
Explanation: Propane has a vapor pressure of approximately 110 psi at 70°F.


6. What is the maximum allowable filling level for LP-gas containers?
A. 90%
B. 85%
C. 80%
D. 75%
ANSWER : C
Explanation: LP-gas containers are limited to 80% capacity to allow for liquid
expansion.


7. Why must LP-gas containers not be filled completely full?
A. To reduce corrosion
B. To allow vapor circulation
C. To allow thermal expansion
D. To reduce odor

, ANSWER : C
Explanation: Liquid propane expands when heated; extra space prevents
dangerous over-pressurization.


8. What device prevents overfilling of LP-gas containers?
A. Pressure relief valve
B. Excess flow valve
C. Overfill prevention device (OPD)
D. Regulator
ANSWER : C
Explanation: OPDs stop filling once the container reaches 80%.


9. Which valve automatically closes during excessive gas flow?
A. Pressure relief valve
B. Manual shutoff
C. Excess flow valve
D. Backflow preventer
ANSWER : C
Explanation: An excess flow valve shuts when abnormal flow occurs (e.g., line
rupture).


10. Pressure relief valves on LP-gas containers are designed to:
A. Prevent backflow
B. Release gas if pressure becomes excessive
C. Control fuel flow
D. Regulate appliance pressure
ANSWER : B
Explanation: Relief valves protect containers from rupture by venting excess
pressure.


11. What color is typically used for LP-gas emergency shutoff valves?

, A. Blue
B. Yellow
C. Red
D. Green
ANSWER : B
Explanation: Yellow is commonly used to identify gas shutoff components.


12. Smoking is permitted at an LP-gas dispensing station when:
A. Wind is calm
B. Containers are empty
C. At least 25 feet away
D. Never
ANSWER : D
Explanation: Smoking is strictly prohibited anywhere near LP-gas dispensing
operations.


13. Minimum distance between LP-gas dispensers and ignition sources is
typically:
A. 5 feet
B. 10 feet
C. 15 feet
D. 25 feet
ANSWER : B
Explanation: NFPA 58 requires at least 10 feet from ignition sources.


14. What is the function of a regulator in an LP-gas system?
A. Increase pressure
B. Store gas
C. Reduce and control pressure
D. Detect leaks
ANSWER : C
Explanation: Regulators reduce high container pressure to usable appliance
pressure.