REFRIGERATION EXAM QUESTIONS
WITH VERIFIED ANSWERS
Which of the devices listed will indicate whether or not a refrigeration system's
dehydrator continues to be capable of removing moisture from the circulating
refrigerant? - Answer- Liquid line moisture indicating sight glass.
The primary purpose of the liquid line strainer used in a refrigeration system is to
prevent dirt and scale from entering what system component(s)? - Answer- thermal
expansion valves.
Why are dehydrators usually located in the liquid line of refrigeration systems? -
Answer- prevent icing of the expansion valve.
At ambient temperature and atmospheric pressure, what is the status of R-134a? -
Answer- odorless gas
What is the physical state and pressure condition of refrigerant as it leaves a receiver in
a typical refrigeration system? - Answer- high-pressure liquid.
Refrigerant entering the compressor of a refrigeration system should be in which of the
following conditions? - Answer- Low-pressure vapor
Regarding heat transfer principles, which of the following are true? - Answer- Heat
transfer always flows from hot regions to cold regions.
In a low-pressure refrigeration system, excessive running of the purge recovery unit
generally indicates which probable condition? - Answer- system leaks on the low side.
In a low-pressure centrifugal chiller, what is meant by the term 'high efficiency purge
unit?' - Answer- Those purge units which discharge very little refrigerant with the air
being removed.
If a condenser coil of an air-cooled container refrigeration system becomes dirty and
requires cleaning, what would be an acceptable method of cleaning? - Answer- high-
pressure water wash.
, excessive moisture being collected in the purge unit of a low-pressure refrigeration
system could indicate which probable condition? - Answer- leaking condenser or chiller
tubes
moisture in a refrigeration system can cause which of the following conditions? -
Answer- freezing the expansion valve closed, hermetic burner blowout, and corrosion of
system piping.
all the above
if the combination moisture indicator and sight glass indicates an accumulation of
moisture within the system, which of the listed procedures would be the most practical
to follow? - Answer- close the king valve, pump down the system, isolate the drier,
remove the desiccant core, and replace the new drier cartridge.
what is a quick method used to test a water-cooled condenser for the presence of a
refrigerant leak without actually pinpointing the actual location? - Answer- check the
drains on the condenser heads with a halide torch.
some chlorinated fluorocarbon refrigerants may decompose into a toxic irritating gas
under what conditions? - Answer- exposed to an open flame or hot surface
what must be done to use standard leak detection methods on a low-pressure
refrigeration system charged with refrigerant? - Answer- raise the pressure in the
system above atmospheric
to test for a suspected large refrigerant leak from an R-22 refrigeration system in an
enclosed area , how should this be done? - Answer- apply a soap solution to fittings
seen to have oil residue
which of the following statements is true concerning the testing of an R-22 refrigeration
system for leaks in an enclosed compartment with a halide torch? - Answer- halide
torches are useful in locating very small R-22 leaks
what is the color of a flame produced by a halide torch when there is no halogenated
refrigerant present at the location of the exploring tube - Answer- blue
moisture is removed from recovered refrigerant using a recycling machine by what
means? - Answer- circulating the refrigerant through a dehydrator
what must be done, at a minimum, before a system can legally be opened up for repairs
while adhering to the prohibition against the venting of halogenated fluorocarbon
refrigerants to the atmosphere? - Answer- recovery of the refrigerant
in a refrigeration system,the push-pull technique can be used for the recovery of the
refrigerant in what state? - Answer- both liquid and vapor
WITH VERIFIED ANSWERS
Which of the devices listed will indicate whether or not a refrigeration system's
dehydrator continues to be capable of removing moisture from the circulating
refrigerant? - Answer- Liquid line moisture indicating sight glass.
The primary purpose of the liquid line strainer used in a refrigeration system is to
prevent dirt and scale from entering what system component(s)? - Answer- thermal
expansion valves.
Why are dehydrators usually located in the liquid line of refrigeration systems? -
Answer- prevent icing of the expansion valve.
At ambient temperature and atmospheric pressure, what is the status of R-134a? -
Answer- odorless gas
What is the physical state and pressure condition of refrigerant as it leaves a receiver in
a typical refrigeration system? - Answer- high-pressure liquid.
Refrigerant entering the compressor of a refrigeration system should be in which of the
following conditions? - Answer- Low-pressure vapor
Regarding heat transfer principles, which of the following are true? - Answer- Heat
transfer always flows from hot regions to cold regions.
In a low-pressure refrigeration system, excessive running of the purge recovery unit
generally indicates which probable condition? - Answer- system leaks on the low side.
In a low-pressure centrifugal chiller, what is meant by the term 'high efficiency purge
unit?' - Answer- Those purge units which discharge very little refrigerant with the air
being removed.
If a condenser coil of an air-cooled container refrigeration system becomes dirty and
requires cleaning, what would be an acceptable method of cleaning? - Answer- high-
pressure water wash.
, excessive moisture being collected in the purge unit of a low-pressure refrigeration
system could indicate which probable condition? - Answer- leaking condenser or chiller
tubes
moisture in a refrigeration system can cause which of the following conditions? -
Answer- freezing the expansion valve closed, hermetic burner blowout, and corrosion of
system piping.
all the above
if the combination moisture indicator and sight glass indicates an accumulation of
moisture within the system, which of the listed procedures would be the most practical
to follow? - Answer- close the king valve, pump down the system, isolate the drier,
remove the desiccant core, and replace the new drier cartridge.
what is a quick method used to test a water-cooled condenser for the presence of a
refrigerant leak without actually pinpointing the actual location? - Answer- check the
drains on the condenser heads with a halide torch.
some chlorinated fluorocarbon refrigerants may decompose into a toxic irritating gas
under what conditions? - Answer- exposed to an open flame or hot surface
what must be done to use standard leak detection methods on a low-pressure
refrigeration system charged with refrigerant? - Answer- raise the pressure in the
system above atmospheric
to test for a suspected large refrigerant leak from an R-22 refrigeration system in an
enclosed area , how should this be done? - Answer- apply a soap solution to fittings
seen to have oil residue
which of the following statements is true concerning the testing of an R-22 refrigeration
system for leaks in an enclosed compartment with a halide torch? - Answer- halide
torches are useful in locating very small R-22 leaks
what is the color of a flame produced by a halide torch when there is no halogenated
refrigerant present at the location of the exploring tube - Answer- blue
moisture is removed from recovered refrigerant using a recycling machine by what
means? - Answer- circulating the refrigerant through a dehydrator
what must be done, at a minimum, before a system can legally be opened up for repairs
while adhering to the prohibition against the venting of halogenated fluorocarbon
refrigerants to the atmosphere? - Answer- recovery of the refrigerant
in a refrigeration system,the push-pull technique can be used for the recovery of the
refrigerant in what state? - Answer- both liquid and vapor
