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55 Cards in this Set

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R-134 a refrigerant charged systems should be leak checked with:
Pressurized nitrogen
The oils that will be employed with most of the HFC-134a refrigeration applications are:
Esters
The ozone layer protects the earth from:
Ultraviolet radiation from the sun
Disposing of disposable cylinders is accomplished by:
Assuring that all refrigerant is recovered and that all the cylinders are rendered useless then recycling the metal.
Recovery equipment that relies upon the compressor in the appliance and/or the pressure of the refrigerant in the appliance would be considered:
System-dependent
What is the strongest evidence that CFC's are in the stratosphere?
Measurement of CFC's in air samples from the stratosphere
Which of the following CFC or HCFC refrigerant releases is considered a violation of the prohibition on venting:
Release of mixtures of nitrogen and refrigerant that results from adding nitrogen to a fully charged appliance to leak-check the appliance
Self-contained recovery devices:
Can capture liquid and/or vapor refrigerant without the assistance of components in the air-conditioning or refrigeration equipment
Systems to be charged with R-134a should be leak checked with:
Pressurized nitrogen
Violation of the Clean Air Act, including the knowing release of refrigerant during the maintenance, service, repair or disposal of appliances, can result in fines up to:
$25,000 per day per violation
EPA may require technicians to demonstrate their ability to perform proper procedures for recovering and/or recycling refrigerant. Failure to demonstrate or failure to properly use the equipment may result in:
Revocation of the technician's certification
EPA regulations require the installation of a service aperture or process stub on all appliances using a class I or class II substance as a refrigerant. The main purpose of this requirement is to make it easier to:
Recover refrigerant
Which of the following is a "high-pressure refrigerant” under EPA's refrigerant recycling regulations:
R-12
Ozone depletion in the stratosphere is what type of problem?
Global
The term used to describe the fact that a refrigerant blend has a range of boiling or condensing points at a constant temperature is:
Temperature glide
Vacuum line (hoses) should be:
Equal to or larger than pump intake connection
Which of the following is a "low-pressure refrigerant” under EPA's refrigerant recycling regulations:
R-123
Ozone depletion potential, or "ODP”, is:
A measurement of CFCs' and HCFCs' ability to destroy ozone
All recovery equipment now manufactured is required to have
An EPA approved certification label
A refrigerant oil that is hygroscopic:
Readily absorbs moisture
An example of an HFC refrigerant is:
R-134a
The smallest container in which refrigerants may be sold to Section 608 certified technicians is:
20 lb.
Recovery equipment that relies upon the compressor in the appliance and/or the pressure of the refrigerant in the appliance would be considered:
System-dependent
Hydrochlorofluorocarbon (HCFC) refrigerants contain:
Hydrogen, chlorine, fluorine and carbon
When pressurizing a refrigeration system with nitrogen, what rule should you always follow?
Charge through a pressure regulator
Blended refrigerants leak from a system:
In uneven amounts due to different vapor pressures
For accurate readings during evacuation the system vacuum gauge should be connected:
As far from the vacuum pump as possible
Which of the following is not an approved technique of system cleanup after a burnout?
Flushing with liquid refrigerant to clean field tubing
Equipment covered by EPA regulations include:
All air-conditioning and refrigeration equipment containing and using CFC and HCFC refrigerants
The synthetic lubricant presently used with ternary blends containing HCFCs is:
Alkylbenzene
An example of a CFC refrigerant is:
R-12
The piping connection to the vacuum pump should be:
As short in length and as large in diameter as possible
When recovering refrigerant, it is important not to mix different refrigerants in the same container because:
The mixture may be impossible to reclaim
Which of the following gases help form the earth's protective shield?
Stratospheric Ozone
It is illegal to:
Knowingly release CFC or HCFC refrigerants and their substitutes during the service,maintenance, repair or disposal of appliances, with the exceptiion of de minimis releases
What characteristic(s) of CFCs make them more likely to reach the stratosphere than most other compounds containing chlorine?
CFCs neither dissolve in water nor break down into compounds that dissolve in water, so they do not rain out of the atmosphere
Under the "safe disposal requirements”, who is responsible for the ensuring that refrigerant has been removed from household refrigerators before they are disposed of?
The final person in the disposal chain
Which of the following human health effects could result from an increase in ultraviolet radiation?
An increase in the number of cataracts
What is a ternary blend refrigerant?
A three-part mixture
Removing refrigerant in any condition from a system and storing it in an external container without necessarily testing or processing it in any way defines:
Recovering
Whenever working with any solvents, chemicals and refrigerants, the technician should review:
Material safety data sheets
Reusable containers for refrigerants that are under high pressure (above 15psig) at normal ambient temperature must be hydrostatically tested and date stamped every:
5 years
Manufactures often color code the exterior of gauges. On a typical gauge manifold set, the high pressure gauge is color-coded:
Red
The component which changes a low pressure vapor to a high pressure vapor is the:
Compressor
Upon completion of refrigerant liquid transfer between recovery unit and the refrigeration system, you should guard against trapping:
Liquid refrigerant between service valves
The reason for dehydrating a refrigeration system is:
To remove water and water vapor
Which type of refrigerant is the most harmful to stratospheric ozone?
CFC
The capacity of a vacuum pump and its suction line size will determine:
The length of dehydration time
Whenever dry nitrogen from a portable cylinder is used in service and installation practice, what Item is of most importance in consideration of safety?
A relief valve is inserted in the downstream line from the pressure regulator
Approved refrigerant recovery cylinders can be identified by which color code?
Yellow tops and gray bodies
Evacuation of a system is a suggested method of:
Dehydration
What is being done in the U.S. to stop damage to the stratospheric ozone layer?
Capturing and ultimately eliminating use of chlorofluorocarbons
Refrigerant will migrate to a compressor's crankcase because of a difference in _________ between the oil and refrigerant:
Vapor pressure
The state of the refrigerant entering the compressor of the refrigeration system is:
Low-pressure vapor
Refrigerant entering the metering or expansion device of a refrigeration system is a:
Liquid