EPA Section 608 Universal Certification ExamCoreMedium
A technician is storing recovered R-22 refrigerant in a refillable cylinder. According to DOT regulations, what is the maximum amount of refrigerant that can be safely filled into a 30 lb capacity cylinder for R-22, considering its fill ratio of 0.82 lbs/lb?
- A30.0 lbs
- B24.6 lbs
- C36.6 lbs
- D27.5 lbs
Show answer & explanationAnswer & explanation
Correct answer: B. 24.6 lbs
DOT regulations specify a maximum allowable fill level for refrigerant cylinders to prevent overfilling and potential rupture. The maximum fill is calculated by multiplying the cylinder's water capacity (in pounds) by the refrigerant's specific fill ratio. For R-22, a 30 lb capacity cylinder (which refers to the water weight capacity) and a fill ratio of 0.82 lbs/lb means 30 lbs * 0.82 = 24.6 lbs.
Why the other options are wrong
- A. Incorrect. Filling to the cylinder's stated 'capacity' (referring to water weight) with refrigerant would result in overfilling due to refrigerant density.
- C. Incorrect. This would be an extreme overfill, leading to dangerous pressures.
- D. Incorrect calculation. This might be a common overfill estimate.
DOT Cylinder Fill Limit (R-22)
Department of Transportation (DOT) regulations limit the maximum amount of refrigerant that can be filled into a recovery cylinder, calculated by multiplying the cylinder's water capacity (in pounds) by the refrigerant's specific fill ratio.
- Prevents overfilling and high pressure.
- Calculated: Water Capacity (lbs) x Fill Ratio (lbs/lb).
- R-22 fill ratio is 0.82 lbs/lb.
- Cylinder capacity is typically water weight.
Memory trick: Fill 'Ratio' times 'Capacity' keeps cylinders from 'bursting'.