CFC Refrigerant Cylinder & Storage Safety 3 — Questions and Answers
Question 1: What is the primary purpose of the pressure-relief device on a refrigerant recovery cylinder?
- To allow refrigerant to be vented intentionally during service
- To automatically release pressure if it exceeds a safe threshold, preventing rupture (Correct answer)
- To indicate when the cylinder is full
- To maintain a minimum pressure inside the cylinder
Correct answer: To automatically release pressure if it exceeds a safe threshold, preventing rupture
The pressure-relief device (fusible plug or relief valve) protects the cylinder from catastrophic rupture by releasing pressure if it reaches a dangerous level.
Question 2: Under EPA Section 608 regulations, which cylinders are approved for recovering refrigerant in the field?
- Any steel container rated for pressure
- DOT-approved recovery cylinders or system-dependent recovery (Correct answer)
- Standard propane cylinders painted gray
- Original manufacturer shipping cylinders only
Correct answer: DOT-approved recovery cylinders or system-dependent recovery
EPA Section 608 requires refrigerant recovery into DOT-approved recovery cylinders or, in some cases, back into the system being serviced.
Question 3: Which statement about refillable refrigerant cylinders is CORRECT?
- They may be refilled by any certified technician in the field
- They must be retested and recertified by the cylinder owner periodically per DOT requirements (Correct answer)
- They have no retest requirement as long as they are not damaged
- They may be refilled with any refrigerant regardless of original design pressure
Correct answer: They must be retested and recertified by the cylinder owner periodically per DOT requirements
DOT regulations require periodic hydrostatic retest of refillable cylinders (typically every 5 years) to ensure structural integrity.
Question 4: What does the tare weight (TW) stamped on a refrigerant cylinder represent?
- The maximum weight of refrigerant the cylinder can hold
- The weight of the empty cylinder itself (Correct answer)
- The total gross weight when full
- The weight of the cylinder plus its valve assembly only
Correct answer: The weight of the empty cylinder itself
Tare weight is the weight of the empty cylinder, used as a baseline to calculate how much refrigerant has been added by weight.
Question 5: A technician notices frost forming on the outside of a refrigerant cylinder during recovery operations. This indicates:
- The cylinder is over-pressurized and about to rupture
- Liquid refrigerant is flashing inside the cylinder, cooling it — a normal occurrence during rapid filling (Correct answer)
- The cylinder's pressure-relief valve has opened
- The refrigerant is contaminated with water
Correct answer: Liquid refrigerant is flashing inside the cylinder, cooling it — a normal occurrence during rapid filling
Frost on the cylinder exterior during recovery is caused by latent heat absorption as liquid refrigerant evaporates inside — this is normal and not a safety concern.
Question 6: What is the maximum percentage of a recovery cylinder's rated capacity that should be filled with liquid refrigerant (by weight)?
- 60%
- 80% (Correct answer)
- 100%
- 110%
Correct answer: 80%
Recovery cylinders should not be filled above 80% of their rated capacity by weight to allow for thermal expansion of the liquid refrigerant.
Question 7: Which of the following is NOT an acceptable method to move a heavy refrigerant cylinder across a shop floor?
- Using a refrigerant cylinder hand truck
- Tilting and rolling it on its base edge
- Dragging it across the floor on its side (Correct answer)
- Using a two-wheeled dolly designed for gas cylinders
Correct answer: Dragging it across the floor on its side
Dragging a cylinder on its side can damage the valve, rupture the fusible plug, or damage the cylinder itself — always use proper material handling equipment.
CFC Refrigerant Cylinder & Storage Safety 3
What is the primary purpose of the pressure-relief device on a refrigerant recovery cylinder?