Q: The push-pull method of recovery is used:

Push-pull uses vapor from the recovery cylinder to push liquid out of the system, speeding up bulk transfer in large systems (>10 lbs).

Question 1

What is the primary reason for recovering refrigerant?

Accepted Answer

The core mandate of Section 608 is environmental protection: preventing the release of harmful ODS (CFCs/HCFCs) and HFCs.

Question 2

Recovery equipment used for the service or repair of small appliances must be certified by an EPA-approved laboratory if manufactured after:

Accepted Answer

November 15, 1993 is the cutoff date. Equipment made after this date must be third-party certified.

Question 3

During refrigerant recovery, which state of refrigerant is removed first to minimize time?

Accepted Answer

Liquid recovery is much faster than vapor recovery because liquid has a higher density. Removing liquid first bulk-transfers the mass.

Question 4

A 'Self-Contained' recovery device:

Accepted Answer

Self-contained (active) equipment has its own means (compressor/pump) to draw refrigerant out, independent of the appliance's operation.

Question 5

When recovering refrigerant into a non-pressurized container from a refrigerator with an inoperative compressor:

Accepted Answer

Heating and tapping the compressor helps release refrigerant trapped in the oil, which is critical when the compressor cannot run to circulate it.

Question 6

Which factor can affect the speed and efficiency of refrigerant recovery?

Accepted Answer

Long/narrow hoses increase friction (pressure drop). High ambient temps raise tank pressure (bad) but help boil system refrigerant (good). All play a role.

Question 7

If a system contains 100 lbs of R-500, what is the required evacuation level before opening the system?

Accepted Answer

R-500 is a high-pressure refrigerant. <200 lbs requires 0 inches Hg vacuum.

Question 8

The push-pull method of recovery is used:

Accepted Answer

Push-pull uses vapor from the recovery cylinder to push liquid out of the system, speeding up bulk transfer in large systems (>10 lbs).

Question 9

Why is it important to monitor the weight of the recovery cylinder?

Accepted Answer

Safety is the primary reason. Overfilling (>80%) leaves no room for expansion, creating an explosion hazard.

Question 10

Mixing different refrigerants in a recovery tank will:

Accepted Answer

Mixed refrigerants cannot be separated easily. Reclaimers will destroy the mix and charge high fees.

Question 11

If a reclamation facility determines that the refrigerant sent to them is too contaminated to be reclaimed, they will:

Accepted Answer

Heavily contaminated or mixed refrigerant that cannot be purified is incinerated (destroyed) in accordance with EPA rules.

Question 12

When recovering from a system with a burnout, what additional step is recommended?

Accepted Answer

Burnouts create acid and sludge. A filter drier protects the recovery machine from these contaminants.

Question 13

Recycling refrigerant involves:

Accepted Answer

Recycling is the onsite cleaning of refrigerant to remove oil and moisture using filters, allowing reuse in the same owner's equipment.

Question 14

When switching a recovery unit from R-22 to R-410A, you must:

Accepted Answer

To prevent cross-contamination (mixing oils and refrigerants), the machine must be purged/evacuated and filters changed.

Question 15

For small appliances, how much refrigerant must be recovered if the compressor is operative?

Accepted Answer

With a working compressor, the standard is 90% of the charge.

Question 16

What feature of a recovery machine helps prevent the tank from overfilling?

Accepted Answer

A float switch connects to the recovery machine and shuts it off when the tank reaches 80% capacity.

Question 17

Passive recovery is fastest when:

Accepted Answer

Heat increases system pressure (pushing refrigerant out), and cold lowers tank pressure (pulling refrigerant in). This differential drives passive recovery.

Question 18

To remove ice from a sight glass or viewing port, use:

Accepted Answer

Alcohol spray melts ice without damaging the glass or creating a fire hazard (unlike a torch).

Question 19

The required recovery level for a very high-pressure appliance (like R-503) is:

Accepted Answer

Very high-pressure appliances require recovery to 0 inches Hg vacuum.

Question 20

Which of the following creates a 'High Pressure' condition that stops recovery?

Accepted Answer

If the tank valve is closed, the recovery machine pumps against a dead head, rapidly raising discharge pressure until the high-pressure switch trips.

Question 21

Why is it necessary to purge the gauge hoses before connecting to a system?

Accepted Answer

Air trapped in hoses will be pushed into the system or recovery tank if not purged, contaminating the refrigerant.

Question 22

During vapor recovery, the compressor of the recovery machine might overheat if:

Accepted Answer

Recovery compressors rely on the flow of refrigerant vapor for cooling. If flow is restricted (deep vacuum or blockage), it can overheat.

Question 23

Recovering refrigerant in the vapor phase reduces:

Accepted Answer

Liquid recovery can sweep oil out of the system. Vapor recovery leaves the oil behind but is slower.

Question 24

What does 'Dehydration' mean in refrigeration?

Accepted Answer

Dehydration is the process of removing moisture from a system, typically via deep evacuation.

Question 25

Ideally, a system should be evacuated to:

Accepted Answer

500 microns is the industry standard for a deep vacuum that ensures moisture removal.

Question 26

Recovery cylinders are designed to be refilled. Disposable cylinders are designed to be:

Accepted Answer

Disposable cylinders (DOT 39) have a check valve that prevents refilling. They must be used once and discarded.

Question 27

Before disposing of an appliance, you must:

Accepted Answer

The key disposal requirement is recovering refrigerant to the EPA-mandated vacuum levels.

Question 28

Which condition allows for evacuating a system to 0 psig instead of a deep vacuum?

Accepted Answer

If leaks prevent holding a vacuum, pulling deep vacuum would just suck in air. The EPA allows stopping at 0 psig in this case.

Question 29

When using a gauge manifold, the 'Low Loss Fitting' refers to:

Accepted Answer

Low-loss fittings (required by EPA) seal the hose end to minimize refrigerant release during disconnection.

Question 30

What effect does low ambient temperature have on recovery?

Accepted Answer

Cold temperatures lower the system pressure, reducing the pressure differential that pushes refrigerant into the recovery machine, slowing the process.

Question 31

Which recovery method is typically used on a system with a receiver?

Accepted Answer

The King Valve (receiver outlet valve) provides direct access to liquid refrigerant, making it the ideal spot for bulk liquid recovery.

Question 32

The scale used to weigh a recovery tank must be:

Accepted Answer

While shut-off features are great, the fundamental requirement is accuracy to prevent overfilling.

Question 33

When recovering R-11 or R-123 (Low Pressure), the recovery tank pressure will likely be:

Accepted Answer

Low-pressure refrigerants boil above room temperature (R-11 ~75°F, R-123 ~82°F). At normal room temp, they are liquids and often in a vacuum or very low pressure.

Question 34

Why is it important to remove the Schrader valve core before recovery on large systems?

Accepted Answer

The valve core is a significant restriction. Removing it allows full-bore flow, drastically speeding up recovery.

Question 35

Refrigerant leaving a recovery machine is typically:

Accepted Answer

Recovery machines condense the vapor they pump so it enters the recovery cylinder as a liquid.

Recovery & Recycling Practice Questions

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