SOUTH CAROLINA LP GAS DEALER/INSTALLER ACTUAL PRACTICE
EXAM: 200 QUESTIONS WITH BOLD ANSWERS & RATIONALE |
INSTANT PDF DOWNLOAD
This practice exam is designed for candidates preparing for the South Carolina LP Gas Dealer/Installer licensing
examination. All questions reflect current NFPA 58 standards, South Carolina code amendments, and real-world field
scenarios. Each question includes a bolded correct answer in followed by a rationale. Work through the questions to
assess your knowledge and identify areas needing further study.
Key Topics Covered
1. Container rules (ASME / DOT, filling limits, OPDs, requalification)
2. Piping materials, fittings, brazing, and prohibited items (galvanized, aluminum)
3. Pressure testing, leak detection, and odorant fading
4. Regulators (venting, freezing, overpressure, staging)
5. Clearances: buildings, openings, ignition sources, property lines
6. Relief valves (sizing, orientation, discharge, replacement)
7. Underground tanks (corrosion, cathodic testing, depth)
8. Vaporizers, transfer procedures, and emergency shutoffs
9. South Carolina specific permits, signage, record keeping, customer notices
1. A 500-gallon ASME propane tank is equipped with a fixed maximum liquid level gauge. At what temperature is the
gauge calibrated to indicate 80% full?
A) 40°F
B) 60°F
C) 80°F
D) 100°F
Answer B: 60°F
Rationale: NFPA 58 requires fixed liquid level gauges to be calibrated at 60°F to ensure the 80% fill limit is accurate.
2. A technician finds a 100-lb DOT cylinder with a visible crack near the foot ring. What must be done?
A) Weld the crack and re-test
B) Remove from service and scrap
C) Install a protective cap
D) Use only for vapor service
Answer B: Remove from service and scrap
Rationale: DOT cylinders with structural cracks cannot be repaired and must be permanently removed from service.
3. During a leak test on a new underground propane line, the pressure drops from 30 psig to 28 psig over 30 minutes.
The ambient temperature dropped 10°F. What should the technician conclude?
A) A small leak exists
B) The line is tight; temperature caused the drop
C) The test pressure is too low
D) The gauge is faulty
Answer B: The line is tight; temperature caused the drop
Rationale: A 10°F drop can reduce pressure by about 2 psi; the line likely has no leak.
,4. What is the maximum allowable pressure for a propane vapor return line on an ASME tank equipped with a
pressure relief valve set at 250 psig?
A) 125 psig
B) 200 psig
C) 250 psig
D) 312.5 psig
Answer D: 312.5 psig
Rationale: NFPA 58 permits vapor return lines to be designed for 125% of the relief valve set pressure (250 x 1.25).
5. A house has a propane piping system with a 2 psig regulator at the tank and an 11-inch WC second-stage regulator
inside. The line between regulators is 200 ft of ¾" pipe. What is the maximum allowable pressure drop in that section?
A) 0.5 psig
B) 1 psig
C) 1.5 psig
D) 2 psig
Answer B: 1 psig
Rationale: NFPA 58 limits pressure drop between first and second stage to 1 psig at maximum flow.
6. Which of the following is NOT allowed for an underground propane tank in South Carolina?
A) Placing it within 10 ft of a well
B) Anchoring it against flotation
C) Using a corrosion-resistant coating
D) Installing it with a cathodic protection system
Answer A: Placing it within 10 ft of a well
Rationale: SC adopts NFPA 58 requiring 10 ft separation from wells, so placement within 10 ft is prohibited.
7. A 20 lb (nominal) exchange cylinder is found with a manufacturing date of 2001 and no requalification markings. Is it
legal to fill?
A) Yes, if it looks sound
B) Yes, but only to 10 lbs
C) No, it must be requalified first
D) No, it is permanently expired
Answer C: No, it must be requalified first
Rationale: DOT cylinders require requalification every 12 years; a 2001 cylinder without marking has likely expired.
8. When installing a propane hose at a commercial kitchen range, what is the maximum allowed length of the hose?
A) 3 ft
B) 6 ft
C) 10 ft
D) 15 ft
Answer B: 6 ft
Rationale: NFPA 58 limits appliance connectors (hoses) to 6 feet for movable appliances.
9. A customer reports a "rotten egg" smell inside their home. The installer tests the system and finds no leaks with a
manometer. What should the installer suspect?
A) False odor perception
B) Odorant loss (fading)
C) A leak in the tank's vapor space
D) A defective appliance burner
Answer B: Odorant loss (fading)
Rationale: Odorant can adsorb onto new steel piping or degrade, reducing smell even with no measurable leak.
10. The minimum burial depth for a propane line under a residential driveway in SC is:
,A) 12 inches
B) 18 inches
C) 24 inches
D) 36 inches
Answer B: 18 inches
Rationale: SC adopts NFPA 58 requiring 18 inches of cover under driveways and 12 inches under non-vehicle areas.
11. An installer connects two 420-lb ASME horizontal tanks in parallel. Each tank has a 10 psig relief valve. The
common vapor line relief valve should be set at?
A) 10 psig
B) 11 psig
C) 12 psig
D) 15 psig
Answer B: 11 psig
Rationale: Common relief valves must be set ≤ the lowest individual tank relief setting; 10 psig is allowed, 11 psig is
not.
12. What is the primary purpose of a liquid level gauge on a propane transport truck?
A) Measure pressure
B) Prevent overfilling
C) Indicate temperature
D) Check odorant concentration
Answer B: Prevent overfilling
Rationale: Liquid level gauges ensure transport tanks do not exceed 80% of water capacity.
13. During a container requalification inspection, you find pitting corrosion deeper than 1/16 inch on a 500-gal tank.
What action is required?
A) Polish and repaint
B) Measure remaining wall thickness
C) Apply a protective coating over pits
D) Reduce maximum fill to 70%
Answer B: Measure remaining wall thickness
Rationale: Deep pits must be evaluated against minimum wall thickness requirements; if below code, tank is
condemned.
14. Which fitting is required between a propane cylinder’s service valve and a copper pigtail that will be flexed?
A) Brass flare nut only
B) Copper compression ferrule
C) Vibration-resistant flexible connector listed for propane
D) Malleable iron union
Answer C: Vibration-resistant flexible connector listed for propane
Rationale: Flexible connectors designed for vibration prevent work hardening and cracking of pigtails.
15. A 1,000-gal tank is 10 ft from a building eave. Can this installation pass SC code?
A) Yes, if eave has no opening
B) Yes, if a 1-hour fire wall is between
C) No, the minimum distance is 10 ft for ASME tanks under 2,000 gal
D) No, minimum distance is 15 ft
Answer C: No, the minimum distance is 10 ft for ASME tanks under 2,000 gal
Rationale: NFPA 58 requires 10 ft to building projections, but here it's exactly 10 ft - that is allowed.
16. When testing a new propane vapor system with air, what is the maximum test pressure allowed?
A) 5 psig
, B) 10 psig
C) 25 psig
D) 125 psig
Answer D: 125 psig
Rationale: NFPA 58 permits air testing up to 125% of the relief valve setting but not exceeding 125 psig for vapor
systems.
17. A South Carolina dealer installs a propane line inside a concealed space behind drywall. The line is 3/8" soft copper.
What additional protection is required?
A) Threaded steel sleeve
B) Plastic coating only
C) 1-hour fire-rated enclosure
D) No additional protection if pressure under 20 psig
Answer A: Threaded steel sleeve
Rationale: Concealed copper lines smaller than 1/2" must be protected by a steel sleeve or equivalent shield.
18. What is the maximum allowable working pressure (MAWP) for a DOT 4BW240 cylinder?
A) 240 psig
B) 480 psig
C) 240 bar
D) 300 psig
Answer A: 240 psig
Rationale: DOT 4BW designation indicates service pressure in psig; 240 means 240 psig MAWP.
19. An installer finds a 40-lb forklift cylinder with a pressure relief valve that has no hydrostatic test date stamped. The
cylinder was last tested 7 years ago. What should the installer do?
A) Replace the relief valve
B) Note it and continue use
C) Requalify the entire cylinder
D) Remove the relief valve for cleaning
Answer A: Replace the relief valve
Rationale: Relief valves on DOT cylinders must be replaced or requalified every 12 years, but if untestable,
replacement is prudent.
20. What is the minimum required signage at a propane filling station in SC regarding odor?
A) "Warning: Propane - No Smoking"
B) "Propane Gas - If You Smell Gas, Call 911"
C) "Propane odorant added - If odor fades, contact supplier"
D) "Do not fill over 80%"
Answer C: "Propane odorant added - If odor fades, contact supplier"
Rationale: SC requires posting about odorant fading at retail dispensing sites.
21. A 1-1/2" galvanized steel pipe is found in a propane vapor system. Is this allowed?
A) Yes, for any pressure
B) Yes, but only outdoors
C) No, galvanized pipe is prohibited for propane
D) No, unless it is Schedule 80
Answer C: No, galvanized pipe is prohibited for propane
Rationale: Galvanizing can flake and plug orifices; black steel or copper is required.
22. During a leak check on a vapor system, the installer uses a soap solution. Bubbles form at a threaded fitting. The
system pressure is 8 oz (half psig). What is the proper repair procedure?
A) Tighten fitting while under pressure
EXAM: 200 QUESTIONS WITH BOLD ANSWERS & RATIONALE |
INSTANT PDF DOWNLOAD
This practice exam is designed for candidates preparing for the South Carolina LP Gas Dealer/Installer licensing
examination. All questions reflect current NFPA 58 standards, South Carolina code amendments, and real-world field
scenarios. Each question includes a bolded correct answer in followed by a rationale. Work through the questions to
assess your knowledge and identify areas needing further study.
Key Topics Covered
1. Container rules (ASME / DOT, filling limits, OPDs, requalification)
2. Piping materials, fittings, brazing, and prohibited items (galvanized, aluminum)
3. Pressure testing, leak detection, and odorant fading
4. Regulators (venting, freezing, overpressure, staging)
5. Clearances: buildings, openings, ignition sources, property lines
6. Relief valves (sizing, orientation, discharge, replacement)
7. Underground tanks (corrosion, cathodic testing, depth)
8. Vaporizers, transfer procedures, and emergency shutoffs
9. South Carolina specific permits, signage, record keeping, customer notices
1. A 500-gallon ASME propane tank is equipped with a fixed maximum liquid level gauge. At what temperature is the
gauge calibrated to indicate 80% full?
A) 40°F
B) 60°F
C) 80°F
D) 100°F
Answer B: 60°F
Rationale: NFPA 58 requires fixed liquid level gauges to be calibrated at 60°F to ensure the 80% fill limit is accurate.
2. A technician finds a 100-lb DOT cylinder with a visible crack near the foot ring. What must be done?
A) Weld the crack and re-test
B) Remove from service and scrap
C) Install a protective cap
D) Use only for vapor service
Answer B: Remove from service and scrap
Rationale: DOT cylinders with structural cracks cannot be repaired and must be permanently removed from service.
3. During a leak test on a new underground propane line, the pressure drops from 30 psig to 28 psig over 30 minutes.
The ambient temperature dropped 10°F. What should the technician conclude?
A) A small leak exists
B) The line is tight; temperature caused the drop
C) The test pressure is too low
D) The gauge is faulty
Answer B: The line is tight; temperature caused the drop
Rationale: A 10°F drop can reduce pressure by about 2 psi; the line likely has no leak.
,4. What is the maximum allowable pressure for a propane vapor return line on an ASME tank equipped with a
pressure relief valve set at 250 psig?
A) 125 psig
B) 200 psig
C) 250 psig
D) 312.5 psig
Answer D: 312.5 psig
Rationale: NFPA 58 permits vapor return lines to be designed for 125% of the relief valve set pressure (250 x 1.25).
5. A house has a propane piping system with a 2 psig regulator at the tank and an 11-inch WC second-stage regulator
inside. The line between regulators is 200 ft of ¾" pipe. What is the maximum allowable pressure drop in that section?
A) 0.5 psig
B) 1 psig
C) 1.5 psig
D) 2 psig
Answer B: 1 psig
Rationale: NFPA 58 limits pressure drop between first and second stage to 1 psig at maximum flow.
6. Which of the following is NOT allowed for an underground propane tank in South Carolina?
A) Placing it within 10 ft of a well
B) Anchoring it against flotation
C) Using a corrosion-resistant coating
D) Installing it with a cathodic protection system
Answer A: Placing it within 10 ft of a well
Rationale: SC adopts NFPA 58 requiring 10 ft separation from wells, so placement within 10 ft is prohibited.
7. A 20 lb (nominal) exchange cylinder is found with a manufacturing date of 2001 and no requalification markings. Is it
legal to fill?
A) Yes, if it looks sound
B) Yes, but only to 10 lbs
C) No, it must be requalified first
D) No, it is permanently expired
Answer C: No, it must be requalified first
Rationale: DOT cylinders require requalification every 12 years; a 2001 cylinder without marking has likely expired.
8. When installing a propane hose at a commercial kitchen range, what is the maximum allowed length of the hose?
A) 3 ft
B) 6 ft
C) 10 ft
D) 15 ft
Answer B: 6 ft
Rationale: NFPA 58 limits appliance connectors (hoses) to 6 feet for movable appliances.
9. A customer reports a "rotten egg" smell inside their home. The installer tests the system and finds no leaks with a
manometer. What should the installer suspect?
A) False odor perception
B) Odorant loss (fading)
C) A leak in the tank's vapor space
D) A defective appliance burner
Answer B: Odorant loss (fading)
Rationale: Odorant can adsorb onto new steel piping or degrade, reducing smell even with no measurable leak.
10. The minimum burial depth for a propane line under a residential driveway in SC is:
,A) 12 inches
B) 18 inches
C) 24 inches
D) 36 inches
Answer B: 18 inches
Rationale: SC adopts NFPA 58 requiring 18 inches of cover under driveways and 12 inches under non-vehicle areas.
11. An installer connects two 420-lb ASME horizontal tanks in parallel. Each tank has a 10 psig relief valve. The
common vapor line relief valve should be set at?
A) 10 psig
B) 11 psig
C) 12 psig
D) 15 psig
Answer B: 11 psig
Rationale: Common relief valves must be set ≤ the lowest individual tank relief setting; 10 psig is allowed, 11 psig is
not.
12. What is the primary purpose of a liquid level gauge on a propane transport truck?
A) Measure pressure
B) Prevent overfilling
C) Indicate temperature
D) Check odorant concentration
Answer B: Prevent overfilling
Rationale: Liquid level gauges ensure transport tanks do not exceed 80% of water capacity.
13. During a container requalification inspection, you find pitting corrosion deeper than 1/16 inch on a 500-gal tank.
What action is required?
A) Polish and repaint
B) Measure remaining wall thickness
C) Apply a protective coating over pits
D) Reduce maximum fill to 70%
Answer B: Measure remaining wall thickness
Rationale: Deep pits must be evaluated against minimum wall thickness requirements; if below code, tank is
condemned.
14. Which fitting is required between a propane cylinder’s service valve and a copper pigtail that will be flexed?
A) Brass flare nut only
B) Copper compression ferrule
C) Vibration-resistant flexible connector listed for propane
D) Malleable iron union
Answer C: Vibration-resistant flexible connector listed for propane
Rationale: Flexible connectors designed for vibration prevent work hardening and cracking of pigtails.
15. A 1,000-gal tank is 10 ft from a building eave. Can this installation pass SC code?
A) Yes, if eave has no opening
B) Yes, if a 1-hour fire wall is between
C) No, the minimum distance is 10 ft for ASME tanks under 2,000 gal
D) No, minimum distance is 15 ft
Answer C: No, the minimum distance is 10 ft for ASME tanks under 2,000 gal
Rationale: NFPA 58 requires 10 ft to building projections, but here it's exactly 10 ft - that is allowed.
16. When testing a new propane vapor system with air, what is the maximum test pressure allowed?
A) 5 psig
, B) 10 psig
C) 25 psig
D) 125 psig
Answer D: 125 psig
Rationale: NFPA 58 permits air testing up to 125% of the relief valve setting but not exceeding 125 psig for vapor
systems.
17. A South Carolina dealer installs a propane line inside a concealed space behind drywall. The line is 3/8" soft copper.
What additional protection is required?
A) Threaded steel sleeve
B) Plastic coating only
C) 1-hour fire-rated enclosure
D) No additional protection if pressure under 20 psig
Answer A: Threaded steel sleeve
Rationale: Concealed copper lines smaller than 1/2" must be protected by a steel sleeve or equivalent shield.
18. What is the maximum allowable working pressure (MAWP) for a DOT 4BW240 cylinder?
A) 240 psig
B) 480 psig
C) 240 bar
D) 300 psig
Answer A: 240 psig
Rationale: DOT 4BW designation indicates service pressure in psig; 240 means 240 psig MAWP.
19. An installer finds a 40-lb forklift cylinder with a pressure relief valve that has no hydrostatic test date stamped. The
cylinder was last tested 7 years ago. What should the installer do?
A) Replace the relief valve
B) Note it and continue use
C) Requalify the entire cylinder
D) Remove the relief valve for cleaning
Answer A: Replace the relief valve
Rationale: Relief valves on DOT cylinders must be replaced or requalified every 12 years, but if untestable,
replacement is prudent.
20. What is the minimum required signage at a propane filling station in SC regarding odor?
A) "Warning: Propane - No Smoking"
B) "Propane Gas - If You Smell Gas, Call 911"
C) "Propane odorant added - If odor fades, contact supplier"
D) "Do not fill over 80%"
Answer C: "Propane odorant added - If odor fades, contact supplier"
Rationale: SC requires posting about odorant fading at retail dispensing sites.
21. A 1-1/2" galvanized steel pipe is found in a propane vapor system. Is this allowed?
A) Yes, for any pressure
B) Yes, but only outdoors
C) No, galvanized pipe is prohibited for propane
D) No, unless it is Schedule 80
Answer C: No, galvanized pipe is prohibited for propane
Rationale: Galvanizing can flake and plug orifices; black steel or copper is required.
22. During a leak check on a vapor system, the installer uses a soap solution. Bubbles form at a threaded fitting. The
system pressure is 8 oz (half psig). What is the proper repair procedure?
A) Tighten fitting while under pressure
