-
What type of refrigerant is chlorine free?
HFC's
-
Refrigerant migrates to the compressor crankcase because of a difference in ________ between the refrigerant and the oil
vapor pressure
-
Which refrigerant is an HCFC? R-22, R-134a, R-410a, R-12
R- 22
-
Which Refrigerant is an HCFC? R-124, R-134A, R410a, R-12
R-124
-
What factor(s) affects the speed of evacuation?
- A) the size of the equipment being evacuated
- B) the ambient temperature
- C) the amt of moisture in the system
-
Systems charged with R-134a should be leak checked with:
pressurized dry nitrogen
-
HCFC refrigerants contain:
hydrogen, chlorine, fluorine, carbon
-
Manifold gauge sets are often color coded, when this is done, the low pressure gauge is color coded:
blue
-
After refrigerant liquid transfer between recovery unit and the system being emptied, you need to avoid trapping:
liquid refrigerant between service valves
-
When can you use a disposable cylinder to recover refrigerant?
never
-
CFC refrigerants are so named because they contain the elements:
chlorine, fluorine, carbon
-
Recovery equipment that relies upon the compressor in the system would be considered:
system-dependant
-
The EPA requires the installation of a service aperture stub on all appliances using a class I or class II sustance as a refrigerant. The main purpose of this requirement is to make it easier to:
recover refrigerant
-
When dealing with small systems, how many different refrigerants may be recovered in the same cylinder?
only one
-
It is important not to mix different refrigerants in the same container because:
the mixture may be impossible to reclaim
-
Chlorofluorocarbons (CFC's) and hydrochlorofluorocarbons (HCFC's) have which of the following in common?
they must be recovered before opening or disposing of appliances
-
Refrigerant that is recovered can be returned to:
the same system or other systems owned by the same person without restrictions
-
An example of a HFC refrigerant is:
R-134a
-
When transporting cylinders containing used refrigerant, the DOT requires that you:
attach DOT classification tags
-
Blended refrigerants leak from a system:
in uneven amounts due to different vapor pressures
-
Which type of refrigerant is the most harmful to stratospheric ozone?
CFC
-
Long hoses between the unit and the recovery machine should not be used because they cause:
- A) excessive pressure drop
- B) increased recovery time
- C) Increased emissions
-
If corrosion is found within the body of a relief valve, the valve must be:
replaced
-
Disposable refrigerant containers are used for ______ refrigerant.
C) virgin
-
Never use an open flame to heat a refrigerant tank because
- A) it can result in venting refrigerant to the atmosphere
- B) the tank may explode, causing serious injury to people nearby
- C) refrigerant in the tank may decompose, forming a toxic material
-
If an oil is hygroscopic it means that it:
readily absorbs moisture
-
The type of oil that is most commonly used in stationary refrigeration applications w/ HFC-134a refrigerant is:
ester oil
-
Which type of refrigerant is the most harmful to stratospheric ozone?
refrigerants containing bromine
-
Ozone depletion in the Stratosphere is what type of problem?
global
-
Under EPA's regulations, what standard must reclaimed refrigerant meet before it can be resold?
ARI 700
-
Under the EPA's " safe disposal requirements ", who is responsible of making sure that the refrigerant is removed from household refrigerators before they are disposed of:
final person in the disposal chain
-
Ozone depletion potential, or "ODP," is
a measure of the ability of CFCs' and HCFCs' to destroy ozone
-
_______ is the process of removing refrigerant in any condition from a system and storing it in a container without necessarily testing or processing it in any way.
recovering
-
The EPA can require a technician to demonstrate their ability to perform proper procedures for recovering and/or recycling refrigerant. Failure to demonstrate competency can result in:
revocation of the technician's certification
-
Never use oxygen or compressed air to pressurize a system because:
when mixed with compressor oil or some refrigerants, it could explode
-
Which of the following is an approved "drop-in" service replacement for R-12? HFC-134a, HFC-410a, R-407c, according to the EPA there are no "drop-in" replacements
according to the EPA there are no "drop-in" replacements
-
The synthetic lubricant presently used with ternary blends containing HCFCs is
alkybenzene
-
On a typical three port ( three hose) manifold gauge, the center port is used for:
recovery, evacuation and charging
-
What refrigerant type has the highest ozone depletion potential? HCFCs, HFCs, CFCs
CFCs
-
What refrigerant has the lowest ozone depletion potential? R-22, R-11, R-12, or R-113
R-22
-
Which refrigerants must be recovered before opening a system or disposing of a system?
all refrigerants must be recovered
-
When dehydrating a system, the system can be heated to
decrease the dehydration time
-
Use _______ to remove ice from the sight glass.
an alcohol spray
-
What atom of the CFC molecule causes ozone depletion?
chlorine
-
Refrigerant vapors or mist should not be inhaled because:
they may cause heart irregularities and/or unconsiousness
-
The high pressure gauge on service manifold sets has a continuous scale, usually calibrated to read from:
0-500psi
-
P.P.E.'s (gloves, safety glasses, safety shoes, etc.) should always be worn is when:
handling and filling cylinders
-
"Self-contained" recovery devices:
can capture liquid and/or vapor refrigerant without the assistance of components in the air-conditioning or refrigeration equipment
-
It is necessary to place a refrigerant label on:
a refrigerant cylinder which is being returned for reclaiming
-
Before you dispose of any system containing a refrigerant, you must:
recover the refrigerant
-
Refrigerant leaves the condenser of an operating system as a:
high pressure liquid
-
Non-Azeotropic refrigerants leak from a system:
in uneven amounts due to different vapor pressures
-
Whe using nitrogen to pressurize a system, you should always:
charge through a pressure regulator
-
All recovery equipment currently being made is required to have
an EPA approved certification label
-
The color code for approved refrigerant recovery cylinders is
yellow tops and gray bodies
-
All devices used for refrigerant recovery must:
meet EPA standards
-
Which of the following gases help form the earth's protective shield? chlorine, chlorides, carbon monoxide, stratosphere ozone
stratosphere ozone
-
Refrigerant cylinders should always be:
- A) free of rust and damage
- B) color coded to indicate the contents
- C) secure
-
It is illegal to:
knowingly release any refrigerant during the service, maintenance, repair or disposal of appliances, with the exception of de minimis releases
-
When using nitrogen in a system, when is it a violation of the EPA prohibition on venting?
release of mixtures of nitrogen and refrigerant that result from adding nitrogen to a fully charged appliance to "leak-check" the appliance
-
An award of up to what amount may be paid to a person supplying information that leads to a penalty against the technician who is intentionally venting?
$10,000
-
Ester based oils can be mixed with:
no other oils
-
Recycling and recovery equipment intended for use with air-conditioning and refrigeration equipment (except for small appliances) must be tested under:
ARI 740
-
A compound pressure gauge, typically used on the low side of the system, measures pressure in:
psig and inches of mercury
-
Which of the following human health effects could result from an increase in ultraviolet radiation?
an increase in cataracts cases
-
When a system will not hold a vacuum after it has been evacuated, then:
the system may be leaking
-
You can determine safe pressure for leak testing a system from the:
low-side test-pressure data-plate value
-
Systems charged with R-410a should be leak checked with:
pressurized nitrogen
-
Which chemicals are controlled by the Montreal Protocol? chlorofluorocarbons, hydrochlorofluorocarbons, halons
chlorofluorocarbons, hydrochlorofluorocarbons, halon
-
After 1995, any supplies of CFC refrigerant to service existing units in the USA can only come from:
recovery and recycling
-
A ternary refrigerant blend is a ____ part mixture. two, three, four or five
three
-
Reusable refrigerant containers that are normally under any pressure above 15 psig, must be hydrostatically tested and date stamped every: 1yr, 2yr, 3yr or 5yr
5 years
-
Refrigerant recovery during low ambient temperatures will:
slow the recovery process
-
What characteristic(s) of CFCs make them more likely to reach the stratosphere than most other compounds containing chlorine?
refrigerants that contain chlorine but not hydrogen are so stable that they do not break down in the lower atmosphere after being released. the chlorine or bromine reacts with ozone, causing it to change back to oxygen, thus destroying the ozone layer.
-
A system is dehydrated to:
remove water and water vapor
-
What refrigerant listed is a "low-pressure refrigerant" under EPA's refrigerant recycling regulations? R-22, R-123, R-134a or R-500
R-123
-
Which of the following is a "high-pressure refrigerant" under EPA's refrigerant recycling regulations? R-11, R-22, R-113 or R-123
R-22
-
When dealing with small systems, how many different refrigerants may be recovered into the same cylinder?
only one
-
The evacuation of a system is a method of:
dehydration
-
This chemical was found in the upper stratosphere and that indicates that the ozone layer is being destroyed. chlorine monoxide, carbon monoxide, carbon dioxide, or nitrogen dioxide
chlorine monoxide
-
Which refrigerant contains a CFC? R-12, R-22, R-134a, R-410a
R-12
-
According to the EPA, of the refrigerants listed below, which types of refrigerants will not contribute to global warming? CFCs, HCFCs, HFCs, the all contribute to global warming
they all contribute to global warming
-
According to the EPA, an oil sample should be taken for which of the following reasons? a new filter-drier has been installed, the system had a leak or a major component failure, system not cooling properly, recycled refrigerant was added to the system
the system had a leak or a major component failure
-
A refillable refrigerant cylinder must never be filled to more than _______ of its capacity by weight:
80%
-
Which of the following is a "very high-pressure refrigerant" under EPA's refrigerant recycling regulations? R-22, R-134a, R-13, R-500
R-13
-
In a vapor compression refrigeration system, cooling occurs when:
refrigerant liquid turns to a vapor
-
What statement is true about an azeotropic refrigerant mixture? it is always made from just two components., it ha a pressure-temperature curve identical to one of its components., it is a mixture that is always made from at least three component refrigerants., it is a mixture that acts like a single-component refrigerant over its entire range.
It is a mixture that acts like a single-component refrigerant over its entire range
-
What is one of the most serious results of damage to the ozone layer?
increase in human skin cancer
-
When moisture exists in an operating system, which of the following is the most likely to occur? copper tubes and fittings will rust, compressor discharge valves will freeze up, acid will form, compressor head pressures will rise
acid will form
-
Each chlorine atom in the stratosphere ca destroy ______ ozone molecules.
100,000
-
State and local governments can make state laws that:
- follow the clean air act/EPA regulations
- contain stricter regulations than the clean air act/EPA regulations
-
It is important not to mix R-22 and R-410a refrigerants in the same container because
the mixture may be impossible to reclaim
-
The term used to describe the fact that a refrigerant blend has a range of boiling or condensing points at a constant pressure is:
temperature glide
-
To scrap a disposable cylinder, the internal cylinder pressure should be reduced to at least:
0 psig
-
What is the best proof that CFCs are in the stratosphere?
measurement of CFCs in air samples from stratosphere
-
During servicing of a refrigeration system containing R-22, the refrigerant must be:
recovered
-
Which of the following statements would be considered good service practices for conserving refrigerant? recover or recycle refrigerant, keep systems tight, find and repair leaks
- recover or recycle refrigerant
- keep systems tight
- find and repair leaks
-
Data shows that chlorine in the stratosphere comes mainly from CFCs rather than from natural sources such as volcanoes because:
the rise in the amount of chlorine in the stratosphere matches the rise in the amount of fluorine, which has different natural sources than chlorine., the rise in the amount of chlorine in the stratosphere matches the rise in CFC emissions., air samples taken from the stratosphere over erupting volcanoes shows that the volcanoes contribute a small quantity of chlorine to the stratosphere when compared to CFC's
-
It has been illegal to vent substitutes for CFC and HCFC refrigerants since:
november 1995
-
According to ASHRAE's 1992 refrigerant safety classification, which of the following designations would be the most safe? A-1,
A-3, B-1, B-3
A-1
-
In general, blended refrigerants should be charge:
as a liquid
-
Equipment covered by EPA regulations include
all air-conditioning and refrigeration equipment using CFC, HCFC of HFC refrigerants
-
Which atom of the CFC molecule causes ozone depletion? fluorine, chlorine, sodium, helium
chlorine
-
The proper method of discarding a disposable refrigerant cylinder is to:
assure that all refrigerant is recovered and that the cylinder is rendered useless, then recycle the metal
-
A hermetic compressor must never be operated when:
there is a dehydration vacuum in the system
-
Of the items listed below, which is (are) violation(s) of the clean air act? falsifying or failing to keep required records. failing to reach required evacuation levels before opening or disposing of appliances., knowingly releasing CFC or HCFC refrigerants or their substitutes while preparing appliances
all of the above
-
When evacuating a system, the hoses should be:
as short in length and as large in diameter as possible
-
To obtain an accurate vacuum readings during system evacuation, the system vacuum gauge should be located:
as far from the vacuum pump as possible
-
Refrigerant that enters the expansion or throttling device (also known as the metering device) is a: saturated vapor, superheated vapor, mixture of vapor and liquid, liquid
liquid
-
Even though R-22 is considered non-toxic, it:
is lighter than air, can cause asphyxia, is a class I refrigerant, can be detected by its color
can cause asphyxia
-
R-410A is not a typical blended refrigerant because: it is a near azeotropic refrigerant., it can be charged as either a liquid or vapor., while it has a 400 series refrigerant number it behaves like a 500 series refrigerant
all of the above are true
-
Never overfill refrigerant storage cylinders because:
the internal pressure of the cylinders may rise in heated areas and cause an explosion
-
Of the refrigerants listed below, which has the lowest ozone depletion potential? R-22, R-11, R-12, R-113
R-22
-
Which refrigerant contains a CFC? R-500, R-410A, R-134A, R123
R-500
-
Which refrigerant is an HCFC? R-123, R-134A, R-410A, R-12
R-123
-
Of the refrigerants listed, which has the lowest ozone depletion potential? R-22,
R-123, R-134A, R-502
R-134A
-
"Self-contained" recovery devices:
can capture liquid and/or vapor refrigerant without the assistance of components in the air-conditioning or refrigeration equipment
-
The Montreal Protocol is:
a treaty among nations that controls production of CFCs and HCFCs
-
What gas(es) would cause the least damage to the environment during a leak check? dry nitrogen and R-22, dry nitrogen and R-12, compressed air and R-12, dry nitrogen
dry nitrogen
-
According to the EPA, a _______ leak detection method is considered to be the most effective for locating the general area of a small leak.
electronic or ultrasonic tester
-
Measuring the system's final vacuum is always done with:
the system isolated and the vacuum pump heated
-
Which safety precaution(s) should always be followed: never apply an open flame to a refrigerant cylinder, never cut or weld any refrigerant line when refrigerant is in the line, never use oxygen to purge lines or to pressurize a system
all of the above
-
If a technician has a system where some R-502 was added to an R-22 system. The technician should:
recover all the refrigerant into a separate tank
-
What refrigerant(s) must be recovered before opening a system or disposing of a system?
all refrigerants must be recovered
-
During servicing of a refrigeration system containing R-12, the refrigerant must be:
recovered
-
Refrigerant that enters the compressor, under normal operating conditions, is a:
low pressure vapor
-
According to the EPA, when dealing with customer complaints regarding additional costs due to refrigerant recovery efforts, the technician should:
- explain that refrigerant recovery is necessary to protect human health and the environment
- explain that refrigerant recovery is required by federal(and in some cases state and local) laws
- inform the customer that professional service personnel are duty bound to follow the law and to protect the evvironment
-
Refrigerant entering the compressor of a refrigeration system is a:
superheated vapor
-
According to EPA regulations, which of the following procedures is not an approved technique for system cleanup after a burnout?
Installing a suction-line filter-drier, flushing with liquid refrigerant to clean tubing, triple evacuation, deep vacuum evacuation
flushing with liquid refrigerant to clean tubing
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