CoreDifficulty 1/5
A recovery cylinder must not be filled beyond what proportion of its capacity?
- ASeventy percent, because the cylinder must be weighed before it is transported
- BSixty percent, because the relief valve cannot operate above that fill level
- CEighty percent, because liquid refrigerant expands as its temperature rises
- DNinety percent, because the remaining space allows vapour to be drawn off
Show answer and rationale
Correct: C. Overfilling is a rupture risk: a cylinder filled hydrostatically full has nowhere to expand into when it warms, and the vapour space is what absorbs that expansion.
- D — Ninety percent is the small-appliance recovery threshold for a working compressor, not a fill limit.
- A — Weighing a cylinder is required practice, but seventy percent is not the regulatory fill limit.
- B — Relief valves are not rated by fill percentage, and sixty percent is not the figure in the rule.