FLORIDA LP GAS & RULES EXAM QUESTIONS WITH VERIFIED
SOLUTIONS - UPDATED VERSION 2026/2027
1. Q: What are the primary gases that make up LP Gas? ANSWER
Propane, butane, or a mixture of both.
2. Q: What is the boiling point of propane at atmospheric pressure?
ANSWER -44 degrees Fahrenheit (-42 degrees Celsius).
3. Q: Is LP gas lighter or heavier than air? ANSWER Heavier. Propane has
a specific gravity of 1.5, meaning it will settle in low-lying areas.
4. Q: What is the flammable range (LEL to UEL) of propane in air?
ANSWER 2.15% (Lower Explosive Limit) to 9.6% (Upper Explosive Limit).
5. Q: What is the ignition temperature of propane? ANSWER Between
920°F and 1020°F.
6. Q: LP gas in its liquid state is approximately how much heavier than
water? ANSWER About half as heavy (specific gravity of roughly 0.50),
meaning liquid propane will float on top of water.
7. Q: What happens to propane when it changes from a liquid to a vapor?
ANSWER It expands approximately 270 times its liquid volume.
8. Q: What color is a propane flame when burning efficiently? ANSWER
Blue with a slightly yellow tip.
9. Q: What does a yellow, sooty flame indicate? ANSWER Incomplete
combustion, which produces dangerous Carbon Monoxide (CO).
10. Q: How much does a gallon of liquid propane weigh? ANSWER
Approximately 4.24 pounds.
Section 2: Odorization & Leak Detection
11. Q: Is LP gas naturally odorless? ANSWER Yes, in its natural state, LP
gas is both colorless and odorless.
12. Q: What chemical is most commonly added to LP gas for odorization?
ANSWER Ethyl Mercaptan.
,13. Q: What is the minimum odorization requirement for LP gas?
ANSWER It must be detectable by smell at one-fifth (1/5th) of the lower
limit of flammability.
14. Q: What is the "Scratch and Sniff" test? ANSWER A method used to
train individuals to recognize the odor of mercaptan, often using a
scratch-and-sniff card.
15. Q: What conditions can cause LP gas to lose its odor (odor fade)?
ANSWER Oxidation, rust inside the tank, or absorption by certain
materials (like new masonry, drywall, or soil).
16. Q: What should NEVER be used to test for LP gas leaks? ANSWER
Matches, lighters, or any open flame.
17. Q: What are the approved methods for leak testing? ANSWER A
commercial leak detection solution (soap bubble test) or an approved
electronic gas detector.
18. Q: If a leak is detected on a cylinder or tank valve, what is the first
action? ANSWER Move the cylinder to a safe, outdoor location away from
ignition sources and call a qualified technician.
19. Q: What does the "rotten egg" smell indicate? ANSWER The presence
of odorized LP gas in the air, indicating a potential leak.
20. Q: Why is passive odor fade particularly dangerous in underground
tanks? ANSWER Because the soil and moisture can strip the odorant from
the gas before it reaches the surface, meaning a leak might not be smelled.
Section 3: DOT Cylinders (20 lb to 100 lb)
21. Q: What does OPD stand for? ANSWER Overfilling Prevention Device.
22. Q: Are OPD valves required on all propane cylinders? ANSWER No,
they are required on cylinders with a water capacity between 4 lbs and
40 lbs (typically up to 20 lb grilling cylinders).
23. Q: How does an OPD valve work? ANSWER It contains a float that
shuts off the flow of propane into the cylinder when it reaches 80% liquid
capacity.
24. Q: What is the maximum filling capacity for any LP gas container?
ANSWER 80% of the container's total water capacity, to allow for liquid
expansion.
,25. Q: What does a QCC valve stand for? ANSWER Quick Closing Coupling.
26. Q: Can a 20-lb propane cylinder (like those used for grills) be stored
indoors in a residential home? ANSWER No, they must be stored
outdoors in a well-ventilated area.
27. Q: How far must a 100-lb cylinder be placed from an ignition source?
ANSWER At least 10 feet (if not connected to an appliance). If connected
to an appliance, it can be closer per appliance manufacturer instructions.
28. Q: What is required on a cylinder valve to connect it to an appliance?
ANSWER A Type 1 (ACME) nut or a POL fitting (for older models).
29. Q: What is the requalification interval for DOT cylinders? ANSWER
Generally, every 10 or 12 years depending on the requalification method
(e.g., hydrostatic test, visual inspection).
30. Q: What does the "E" stamp on a cylinder collar signify? ANSWER The
cylinder has been exempted from external visual inspection during
requalification because of its specific construction (usually DOT-4B).
31. Q: Can a cylinder be filled if the requalification date has expired?
ANSWER No, it is illegal to fill an out-of-date cylinder.
32. Q: Where must the relief valve on a vertical cylinder point? ANSWER
It must be in the vapor space and point directly upward.
33. Q: What color is propane vapor when it escapes? ANSWER It is
colorless, but the moisture in the air may freeze, causing a white fog or
frost at the leak point.
34. Q: What is the proper way to transport a 20-lb cylinder in a car?
ANSWER Upright, secured to prevent tipping, with the windows rolled
down for ventilation, and the trunk slightly ajar if placed in the trunk.
35. Q: Can you use a wrench on the handwheel of a DOT cylinder valve?
ANSWER No, handwheels are designed to be opened and closed by hand
only. Using a wrench can damage the valve.
Section 4: ASME Tanks (120 gal to 1000+ gal)
36. Q: What does ASME stand for? ANSWER American Society of
Mechanical Engineers.
37. Q: What is the primary difference between a DOT cylinder and an
ASME tank? ANSWER DOT cylinders are portable and built to DOT specs;
, ASME tanks are stationary, built to boiler/pressure vessel codes, and are
installed horizontally.
38. Q: How far must a 120-gallon ASME tank be placed from a building or
property line that can be built upon? ANSWER 5 feet (if 120 gallons) or
10 feet (if 121 to 500 gallons).
39. Q: How far must a 500-gallon ASME tank be placed from an ignition
source? ANSWER 10 feet.
40. Q: How far must a 1,000-gallon ASME tank be placed from a building?
ANSWER 25 feet.
41. Q: Can an ASME tank be placed inside a building? ANSWER Generally
no, unless it is a special industrial application meeting very strict NFPA 58
ventilation and construction requirements.
42. Q: Can an ASME tank be placed under a building? ANSWER Absolutely
not.
43. Q: What is the purpose of the dome/lid on an above-ground ASME
tank? ANSWER To protect the valves, fittings, and regulator from the
elements and physical damage.
44. Q: What must be placed between the tank and the ground for an
above-ground installation? ANSWER A continuous, firm, non-combustible
foundation (concrete pads or solid blocks).
45. Q: What protects the exposed piping between an underground ASME
tank and the building? ANSWER It must be enclosed in a protective
sleeve or conduit.
46. Q: What is required to prevent corrosion on an underground ASME
tank? ANSWER A protective coating (tar/asphalt) and a cathodic
protection system (sacrificial anodes).
47. Q: What is the minimum burial depth for an underground propane
tank? ANSWER Usually below the frost line, but no less than 12 inches
from the top of the tank to the final grade.
48. Q: Can you bury an ASME tank under a driveway? ANSWER No, it
cannot be placed under any paved surface or where vehicles will drive
over it.
49. Q: What type of fill valve do ASME tanks use? ANSWER A bleed valve
(also called a 10% or 80% valve) to indicate maximum fill level.
SOLUTIONS - UPDATED VERSION 2026/2027
1. Q: What are the primary gases that make up LP Gas? ANSWER
Propane, butane, or a mixture of both.
2. Q: What is the boiling point of propane at atmospheric pressure?
ANSWER -44 degrees Fahrenheit (-42 degrees Celsius).
3. Q: Is LP gas lighter or heavier than air? ANSWER Heavier. Propane has
a specific gravity of 1.5, meaning it will settle in low-lying areas.
4. Q: What is the flammable range (LEL to UEL) of propane in air?
ANSWER 2.15% (Lower Explosive Limit) to 9.6% (Upper Explosive Limit).
5. Q: What is the ignition temperature of propane? ANSWER Between
920°F and 1020°F.
6. Q: LP gas in its liquid state is approximately how much heavier than
water? ANSWER About half as heavy (specific gravity of roughly 0.50),
meaning liquid propane will float on top of water.
7. Q: What happens to propane when it changes from a liquid to a vapor?
ANSWER It expands approximately 270 times its liquid volume.
8. Q: What color is a propane flame when burning efficiently? ANSWER
Blue with a slightly yellow tip.
9. Q: What does a yellow, sooty flame indicate? ANSWER Incomplete
combustion, which produces dangerous Carbon Monoxide (CO).
10. Q: How much does a gallon of liquid propane weigh? ANSWER
Approximately 4.24 pounds.
Section 2: Odorization & Leak Detection
11. Q: Is LP gas naturally odorless? ANSWER Yes, in its natural state, LP
gas is both colorless and odorless.
12. Q: What chemical is most commonly added to LP gas for odorization?
ANSWER Ethyl Mercaptan.
,13. Q: What is the minimum odorization requirement for LP gas?
ANSWER It must be detectable by smell at one-fifth (1/5th) of the lower
limit of flammability.
14. Q: What is the "Scratch and Sniff" test? ANSWER A method used to
train individuals to recognize the odor of mercaptan, often using a
scratch-and-sniff card.
15. Q: What conditions can cause LP gas to lose its odor (odor fade)?
ANSWER Oxidation, rust inside the tank, or absorption by certain
materials (like new masonry, drywall, or soil).
16. Q: What should NEVER be used to test for LP gas leaks? ANSWER
Matches, lighters, or any open flame.
17. Q: What are the approved methods for leak testing? ANSWER A
commercial leak detection solution (soap bubble test) or an approved
electronic gas detector.
18. Q: If a leak is detected on a cylinder or tank valve, what is the first
action? ANSWER Move the cylinder to a safe, outdoor location away from
ignition sources and call a qualified technician.
19. Q: What does the "rotten egg" smell indicate? ANSWER The presence
of odorized LP gas in the air, indicating a potential leak.
20. Q: Why is passive odor fade particularly dangerous in underground
tanks? ANSWER Because the soil and moisture can strip the odorant from
the gas before it reaches the surface, meaning a leak might not be smelled.
Section 3: DOT Cylinders (20 lb to 100 lb)
21. Q: What does OPD stand for? ANSWER Overfilling Prevention Device.
22. Q: Are OPD valves required on all propane cylinders? ANSWER No,
they are required on cylinders with a water capacity between 4 lbs and
40 lbs (typically up to 20 lb grilling cylinders).
23. Q: How does an OPD valve work? ANSWER It contains a float that
shuts off the flow of propane into the cylinder when it reaches 80% liquid
capacity.
24. Q: What is the maximum filling capacity for any LP gas container?
ANSWER 80% of the container's total water capacity, to allow for liquid
expansion.
,25. Q: What does a QCC valve stand for? ANSWER Quick Closing Coupling.
26. Q: Can a 20-lb propane cylinder (like those used for grills) be stored
indoors in a residential home? ANSWER No, they must be stored
outdoors in a well-ventilated area.
27. Q: How far must a 100-lb cylinder be placed from an ignition source?
ANSWER At least 10 feet (if not connected to an appliance). If connected
to an appliance, it can be closer per appliance manufacturer instructions.
28. Q: What is required on a cylinder valve to connect it to an appliance?
ANSWER A Type 1 (ACME) nut or a POL fitting (for older models).
29. Q: What is the requalification interval for DOT cylinders? ANSWER
Generally, every 10 or 12 years depending on the requalification method
(e.g., hydrostatic test, visual inspection).
30. Q: What does the "E" stamp on a cylinder collar signify? ANSWER The
cylinder has been exempted from external visual inspection during
requalification because of its specific construction (usually DOT-4B).
31. Q: Can a cylinder be filled if the requalification date has expired?
ANSWER No, it is illegal to fill an out-of-date cylinder.
32. Q: Where must the relief valve on a vertical cylinder point? ANSWER
It must be in the vapor space and point directly upward.
33. Q: What color is propane vapor when it escapes? ANSWER It is
colorless, but the moisture in the air may freeze, causing a white fog or
frost at the leak point.
34. Q: What is the proper way to transport a 20-lb cylinder in a car?
ANSWER Upright, secured to prevent tipping, with the windows rolled
down for ventilation, and the trunk slightly ajar if placed in the trunk.
35. Q: Can you use a wrench on the handwheel of a DOT cylinder valve?
ANSWER No, handwheels are designed to be opened and closed by hand
only. Using a wrench can damage the valve.
Section 4: ASME Tanks (120 gal to 1000+ gal)
36. Q: What does ASME stand for? ANSWER American Society of
Mechanical Engineers.
37. Q: What is the primary difference between a DOT cylinder and an
ASME tank? ANSWER DOT cylinders are portable and built to DOT specs;
, ASME tanks are stationary, built to boiler/pressure vessel codes, and are
installed horizontally.
38. Q: How far must a 120-gallon ASME tank be placed from a building or
property line that can be built upon? ANSWER 5 feet (if 120 gallons) or
10 feet (if 121 to 500 gallons).
39. Q: How far must a 500-gallon ASME tank be placed from an ignition
source? ANSWER 10 feet.
40. Q: How far must a 1,000-gallon ASME tank be placed from a building?
ANSWER 25 feet.
41. Q: Can an ASME tank be placed inside a building? ANSWER Generally
no, unless it is a special industrial application meeting very strict NFPA 58
ventilation and construction requirements.
42. Q: Can an ASME tank be placed under a building? ANSWER Absolutely
not.
43. Q: What is the purpose of the dome/lid on an above-ground ASME
tank? ANSWER To protect the valves, fittings, and regulator from the
elements and physical damage.
44. Q: What must be placed between the tank and the ground for an
above-ground installation? ANSWER A continuous, firm, non-combustible
foundation (concrete pads or solid blocks).
45. Q: What protects the exposed piping between an underground ASME
tank and the building? ANSWER It must be enclosed in a protective
sleeve or conduit.
46. Q: What is required to prevent corrosion on an underground ASME
tank? ANSWER A protective coating (tar/asphalt) and a cathodic
protection system (sacrificial anodes).
47. Q: What is the minimum burial depth for an underground propane
tank? ANSWER Usually below the frost line, but no less than 12 inches
from the top of the tank to the final grade.
48. Q: Can you bury an ASME tank under a driveway? ANSWER No, it
cannot be placed under any paved surface or where vehicles will drive
over it.
49. Q: What type of fill valve do ASME tanks use? ANSWER A bleed valve
(also called a 10% or 80% valve) to indicate maximum fill level.
