A technician is running a push-pull recovery and is watching the sight glass in the liquid hose feeding the recovery cylinder. What does it mean when that sight glass clears and stays clear?
Correct Answer
A) The liquid in the appliance has been transferred, and the job should be finished with a vapor recovery pass
In push-pull the machine pushes vapor into the appliance while liquid flows out the liquid line into the cylinder. As long as liquid is moving, the sight glass runs full. When the appliance runs out of liquid, the glass clears and stays clear, and the transfer stops accomplishing much. That is the signal to break down the push-pull hookup and finish the job with the recovery machine in vapor mode, pulling the remaining vapor down to the level required for that appliance. Fill level is tracked separately on a scale.
Why This Is the Correct Answer
The sight glass is showing what is in the liquid hose. Full means liquid is still transferring; clear and stable means the appliance has no more liquid to give. Push-pull only moves liquid, so that is the point where the method has done its work and vapor recovery takes over.
Why the Other Options Are Wrong
Option B: The recovery cylinder has reached its safe fill limit and has to be swapped for an empty one before continuing
Fill level is judged by weight on a scale, never by the look of the hose. A cylinder can be well short of its limit and still show a clear glass once the appliance liquid is gone.
Option C: Air has entered the hoses and the whole setup has to be evacuated before continuing the pull
Air entering the hoses would not clear a glass that liquid is flowing through, and a properly purged push-pull setup does not admit air mid-job. A clear glass means the liquid ran out.
Option D: The recovery machine has lost its oil charge and should be shut down immediately for service
A recovery machine short of oil announces itself through noise, heat, and lost capacity long before anything shows in the hose. A clear liquid sight glass is not an oil symptom at all.
Memory Technique
Glass full, liquid moving. Glass clear, switch gear - go to vapor.
Reference Hint
40 CFR 82.156 requires recovery to the applicable level before opening; push-pull is a technique for moving the liquid portion quickly.
More epa-608-type-2 Questions
A walk-in cooler condensing unit holds a full charge of twenty-five pounds of R-404A, which is below the fifty pound threshold that brings an appliance under the leak repair provisions. What still applies to this unit?
An office building has thirty water source heat pumps on a common water loop, and each one left the factory assembled, hermetically sealed and charged with four pounds of R-410A. How is one of those units classified?
A data sheet for an unfamiliar refrigerant lists a boiling point of about fifty-five degrees Fahrenheit at atmospheric pressure. What does that tell a technician holding Core and Type II certification?
A technician holds Core, Type I and Type III certification and is sent to recover the charge from a twenty ton rooftop unit charged with R-410A. What does that combination of sections allow on this job?
A fleet garage technician holds only the vehicle air conditioning certification issued under Section 609 and is asked to recover the charge from the shop's own rooftop air conditioner. What does that credential allow?
A split system's outdoor unit, indoor coil and the line set the installer ran and brazed between them are being considered. For the purposes of the refrigerant rules, what makes up the appliance here?
On a new installation the line set is brazed to a factory charged outdoor unit and an indoor coil shipped under a nitrogen holding charge, with the outdoor unit's service valves still closed. What does the recovery requirement call for before that brazing?
A rooftop unit's data plate has weathered until the charge figure cannot be read, and the technician needs the full charge to place the appliance under the evacuation and leak provisions. Where should that figure come from?
A computer room air conditioning unit holds forty pounds of R-407C and connects to a remote air cooled condenser through refrigerant piping run and brazed by the installer. How is that unit classified?
A shop's office manager, who holds no technician certification, is sent to a supply house to pick up a new recovery machine for the commercial crew. What does the sales restriction require at that counter?
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