EPA Section 608 Universal Certification ExamType II (High-Pressure Appliances)Medium
A technician is preparing to recover refrigerant from a high-pressure appliance containing R-410A. What is the MOST critical safety precaution to observe when handling the recovery cylinders?
- AEnsure the recovery cylinder is painted gray with a yellow top.
- BAlways store recovery cylinders in a horizontal position.
- CCharge the recovery cylinder with nitrogen before connecting it to the recovery unit.
- DNever fill the recovery cylinder beyond 80% of its capacity by weight.
Show answer & explanationAnswer & explanation
Correct answer: D. Never fill the recovery cylinder beyond 80% of its capacity by weight.
Overfilling a recovery cylinder is extremely dangerous. Refrigerant expands significantly when heated, and an overfilled cylinder can rupture violently due to hydrostatic pressure, causing severe injury or death. The 80% fill limit by weight provides a safety margin for thermal expansion.
Why the other options are wrong
- A. While color coding (gray body, yellow top) is standard for recovery cylinders, it's a labeling convention, not the most critical safety precaution for handling.
- B. Recovery cylinders are typically stored upright (vertical) to allow for proper liquid/vapor withdrawal and stability, not horizontally.
- C. Recovery cylinders should be evacuated to a deep vacuum before use, not charged with nitrogen, to prevent contamination and aid recovery efficiency.
Recovery Cylinder Fill Limit
Recovery cylinders must never be filled beyond 80% of their capacity by weight to prevent dangerous overpressurization from thermal expansion.
- Overfilling can lead to cylinder rupture, causing severe injury or death.
- Use a scale to monitor cylinder weight during recovery.
- The 80% limit accounts for volume expansion with temperature increases.
Memory trick: Eighty percent is plenty, don't fill to ninety, or you'll be empty!