To what level may a recovery cylinder be filled when refrigerant is taken out of a low-pressure appliance?
Correct Answer
B) Eighty percent of its rated capacity by weight
Recovery cylinders must be DOT approved and may never be filled past eighty percent of their rated capacity by weight. The remaining space lets the liquid expand if the cylinder warms up in a hot truck or on a sunny roof. Overfilling a cylinder is how they rupture, because liquid refrigerant is nearly incompressible and builds enormous pressure with only a small rise in temperature. The technician weighs the cylinder on a scale during recovery rather than guessing from the sound or the feel of the tank.
Why This Is the Correct Answer
The eighty percent limit leaves a vapor space so warming liquid has somewhere to expand. Because a low-pressure chiller may hold several hundred pounds of refrigerant, the technician will fill and swap several cylinders during one recovery, weighing each one on a scale so none of them passes the limit.
Why the Other Options Are Wrong
Option A: One hundred percent of its rated water capacity
Filling a cylinder completely leaves no vapor space at all. A modest rise in temperature would then create hydrostatic pressure high enough to rupture the cylinder, which is exactly what the fill limit exists to prevent.
Option C: Fifty percent of its rated capacity by weight
Half full is far more conservative than any rule requires and would waste cylinders and truck space on a large chiller job. It is not the limit written for recovery cylinders.
Option D: Ninety percent of its rated capacity by volume
The limit is set on weight, not on volume, because liquid density changes with temperature and refrigerant type. Judging fill by volume gives no reliable protection against liquid expansion.
Memory Technique
Leave room for the boom: one fifth of the drum stays empty so the liquid has somewhere to grow.
Reference Hint
Recovery cylinders must be DOT approved and filled to no more than 80 percent by weight; see 40 CFR 82.154 and DOT cylinder rules.
More epa-608-type-3 Questions
Some jobs on a chiller count as a major repair under the refrigerant rules, which changes what a technician is allowed to do with a badly leaking machine. Which job falls into that category?
An owner asks how many pounds of refrigerant the rules allow to be left inside a chiller once the recovery has been signed off. What is the correct answer to give him?
The motor of a hermetic centrifugal chiller sits inside the pressure boundary rather than outside it on a shaft. What follows from that construction?
An oxygen monitor is used to decide whether a chiller machine room is safe to enter after a refrigerant release. Below what oxygen reading is the atmosphere treated as oxygen deficient?
A low-pressure chiller's rupture disc has a discharge line running from it. Where does that line have to terminate?
A refrigerant vapor detector in a chiller machine room reaches its alarm level. Besides sounding, what is that alarm expected to do?
Which piece of equipment requires a technician to hold Type III certification before it may be serviced?
What property of the refrigerant is what actually places an appliance into the low-pressure category?
During normal operation, what condition exists inside the evaporator of a running low-pressure centrifugal chiller?
In what unit is the required final recovery vacuum for a low-pressure appliance normally expressed?
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