A technician recovers R-134a into a cylinder that still holds recovered R-12 from an earlier job. What is the consequence for that refrigerant?
Correct Answer
A) The mixture is contaminated and can only be sent out for reclamation or for destruction
Mixed refrigerants cannot be sorted out in the field and cannot be reused. Reclaimers charge extra to process mixtures and often will only accept them for destruction, so the cylinder becomes a liability rather than an asset. Beyond the cost, charging a mixed refrigerant into a system produces unpredictable pressures and can damage it. The practical rule is one refrigerant per cylinder, with the cylinder clearly labeled and the recovery machine cleared between different refrigerants.
Why This Is the Correct Answer
Once two refrigerants are combined in a recovery cylinder the contents are contaminated. Field equipment cannot separate them, no appliance is designed for the resulting mixture, and the only lawful destinations are a reclaimer equipped to process mixed refrigerant or a destruction facility.
Why the Other Options Are Wrong
Option B: The mixture may still be charged into any appliance designed for either of the two refrigerants
A mixture is not the same as either of its components. Charging it into equipment designed for one of them produces wrong pressures and poor performance, and the refrigerant no longer meets any purity specification.
Option C: The mixture separates by weight in the cylinder, so the heavier component can be drawn off later
Refrigerants in a cylinder do not settle into separable layers that a technician can draw off. They behave as a mixture, and separating them requires reclamation equipment.
Option D: The mixture is acceptable because both refrigerants are compatible with the same compressor oil
R-12 systems use mineral oil while R-134a systems use polyol ester oil, so the premise is wrong. Oil compatibility would not make a mixed refrigerant usable in any case.
Memory Technique
Mixing is a one-way door. You can stir the paint together but you cannot stir it apart.
Reference Hint
40 CFR 82.152 definition of reclaim to AHRI 700 purity; mixed refrigerant cannot be recycled or reused in the field.
More epa-608-type-1 Questions
A technician certified under Section 608 is asked to service the air conditioning system in a customer's pickup truck. What credential does that particular job actually require?
Facing an unfamiliar packaged refrigeration unit on the bench, how should a technician decide whether the small appliance rules apply to it?
What feature defines a self-contained recovery unit and sets it apart from the system-dependent kind?
When system-dependent recovery equipment is used on a small appliance whose compressor still runs, how can that working compressor be put to use?
Recovery from a small appliance has slowed down and the pressure is barely moving. What accepted technique helps drive the remaining refrigerant out?
After the recovery unit stops pulling on a small appliance, how does a technician confirm that the recovery is actually complete?
A sealed small appliance offers no service port at all. What has to happen before recovery equipment can be connected to it?
As refrigerant from a string of small appliances collects in a recovery cylinder, what fill limit applies to that cylinder?
Refrigerant recovered from a small appliance is going back into service once the repair is finished. When may it be reused without first being sent to a reclaimer?
Why does system-dependent recovery generally take longer to finish than recovery performed with a self-contained machine?
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