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