Propane Certification Propane Storage and Handling 2 — Questions and Answers
Question 1: What is the primary distinction between a DOT cylinder and an ASME propane container?
- DOT containers are for industrial use only; ASME containers are for residential use only
- DOT cylinders are portable and built to Department of Transportation specs; ASME containers are stationary and built to pressure vessel codes (Correct answer)
- DOT containers are always larger in capacity than ASME containers
- ASME containers must always be buried underground; DOT cylinders are always above ground
Correct answer: DOT cylinders are portable and built to Department of Transportation specs; ASME containers are stationary and built to pressure vessel codes
DOT cylinders are designed for portability and transport under DOT regulations, while ASME containers are stationary storage vessels built to American Society of Mechanical Engineers pressure vessel codes.
Question 2: What does 'FIFO' mean in the context of propane cylinder storage, and why is it practiced?
- Fill In, Fill Out — a procedure requiring empty cylinders to be refilled before new stock is accepted
- First In, First Out — older cylinders are used before newer ones to prevent exceeding requalification dates (Correct answer)
- Fuel Injection, Fuel Operation — a burner management control sequence
- Final Inspection, Final Outflow — a quality control release process
Correct answer: First In, First Out — older cylinders are used before newer ones to prevent exceeding requalification dates
FIFO (First In, First Out) ensures cylinders stored longest are used first, preventing them from remaining in inventory past their requalification dates.
Question 3: What is the standard requalification interval for most DOT propane cylinders after their initial 12-year qualification period?
- 3 years
- 5 years (Correct answer)
- 7 years
- 10 years
Correct answer: 5 years
After the initial 12-year qualification period, most DOT cylinders must be requalified every 5 years to ensure the container remains structurally sound for continued service.
Question 4: In what direction must the discharge outlet of a propane container's pressure relief valve (PRV) be directed?
- Toward the ground to prevent gas from rising toward ignition sources
- Away from the container and toward an open area, not toward personnel or ignition sources (Correct answer)
- Toward the connected appliance to enable controlled venting
- Downward into a collection pipe for gas recovery
Correct answer: Away from the container and toward an open area, not toward personnel or ignition sources
PRV discharge must be directed away from the container and away from personnel or ignition sources so that venting gas disperses safely into the open atmosphere.
Question 5: Per NFPA 58, what minimum separation is required between separate groups of propane cylinders stored outdoors when the aggregate LP-Gas content of any group exceeds 300 pounds?
- 5 feet
- 10 feet
- 20 feet (Correct answer)
- 25 feet
Correct answer: 20 feet
NFPA 58 requires at least 20 feet of separation between separate groups of cylinders to limit the spread of fire or gas release from one group to another.
Question 6: What special consideration applies to forklift propane cylinders compared to standard upright residential cylinders?
- Forklift cylinders operate at significantly higher pressures requiring thicker walls
- Forklift cylinders are mounted horizontally and require a liquid service valve with a dip tube configured for that orientation (Correct answer)
- Forklift cylinders contain a propane-butane mixture different from standard LP-Gas
- Forklift cylinders are exempt from DOT requalification requirements
Correct answer: Forklift cylinders are mounted horizontally and require a liquid service valve with a dip tube configured for that orientation
Forklift cylinders are mounted horizontally, requiring a specifically configured liquid service valve and internal dip tube positioned to deliver liquid propane correctly in that horizontal orientation.
Question 7: When transporting propane cylinders in an enclosed vehicle, which of the following practices is required?
- Cylinders must be emptied before transport in any enclosed vehicle
- Cylinders must be secured upright and the vehicle must be adequately ventilated (Correct answer)
- Cylinders must be refrigerated during transport in warm weather conditions
- Cylinders must be transported with a continuously active propane gas detector
Correct answer: Cylinders must be secured upright and the vehicle must be adequately ventilated
Cylinders in enclosed vehicles must be secured to prevent movement and the vehicle must be ventilated so any minor leakage cannot accumulate to a dangerous concentration.
Propane Certification Propane Storage and Handling 2
What is the primary distinction between a DOT cylinder and an ASME propane container?