問題一覧
1
Characteristics of hydrofluoroolefins (HFOs) include being _____ global warming petentials.
non-ozone-depleting and having high
2
HFO refrigerants are less flammable than hydrocarbon refrigerants because they contain ____
fluorine
3
____ have ozone-depletion potentials of more than zero.
R-123 and R-22
4
Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydro-fluorocarbons (HFCs) _____.
must be recovered before opening or disposing of appliances
5
A violation of the Clean Air Act, such as the knowing release of refrigerant during the maintenance, service, repair, or disposal of appliances, can result in fines up to $_____ per day per violation.
44,539
6
______ typically have the lowest global warming potential.
HFOs
7
During the servicing of a refrigeration system containing R-12, the refrigerant must be _____.
recovered
8
It is true that _____.
propane cylinders used for grilling contain impurities that can damage refrigeration equipment
9
HFO refrigerants are miscible in _____.
POE lubricants
10
An oil sample is not needed when _____.
increased temperature glide is suspected
11
_____ is not a violation of CAA or EPA regulations.
Knowingly recovering an exempt refrigerant
12
Some HFO refrigerants are classified as A2L because they _
are less flammable than hydrocarbon refrigerants but still flammable
13
_____ is not classified as an A3 (higher flammability) refrigerant.
HFO-1234yf
14
_____ an appliance that contains HCFCs or HFCs does not require a person to be a Section 608 certified technician.
Rewiring an external electric circuit for
15
It is illegal to _____.
knowingly release CFC, HCFC, or HFC refrigerants during the service, maintenance, repair, or disposal of appliances
16
Blended refrigerants leak from a system ____.
in uneven amounts due to different vapor pressures
17
For blends or refrigerant replacements, the _____ must be considered for two refrigerants even though their saturation pressure-temperature behaviors are similar.
potential to oxidize copper tubing
18
It is lawful to use HCFC-22 when _____.
servicing existing R-22 systems
19
_____ should be used to leak check a system designed for use with R-410A that has been opened for a major system repair.
Pressurized Nitrogen
20
The GWPs of isobutene (R-600a), propane (R-290), and R-441A are _____ the GWPs of HFC-134a, R-404A, and R-410A.
significantly lower than
21
A system is dehydrated when _____.
the vacuum indicator shows that the required finished vacuum has been reached and held
22
A characteristic of HFC refrigerants that makes them damaging to the environment includes _____.
having a very high GWP
23
Although it is never safe to heat a refrigerant storage or recovery tank with an open flame, _____ is not a reason to avoid doing so.
reclaimers not accepting visibly burnt recovery tanks
24
_____ elastomers used in seals and gaskets are generally not compatible with HFO refrigerants.
Silicone
25
The high-pressure gauge on a service manifold set has a continuous scale, typically calibrated to read from ____ to _____.
0 psi; 800 psi