Z-51 REFRIGERATION TEST EXAM WITH
CORRECT ACTUAL QUESTIONS AND
CORRECTLY WELL DEFINED ANSWERS
LATEST 2025 ALREADY GRADED A+
Manifold hoses should be equipped with? - ANSWERS-Low loss fittings
Water regulating valves are used for? - ANSWERS-Maintaining condenser
pressure to a pre-determined level
What type of sprinkler system needs inspecting? - ANSWERS-Automatic
You are performing hot works near a sprinkler head. What can you do to
prevent the fire alarm from going off? - ANSWERS-Put a non-combustible
barrier to protect the sprinkler head
How long does it take to warm up a steam turbine? - ANSWERS-10-15 minutes
,Why is a pressure relief valve better than a fusible plug? - ANSWERS-Minimizes
refrigerant loss
What is the state of refrigerant entering the compressor on a reciprocating
machine? - ANSWERS-Superheated vapor
In the absence of water chemical treatment of a cooling tower: - ANSWERS-
Drain the tower every one to two weeks and replace with fresh water
The amount of refrigerant that flows through the orifices of an economizer is
determined by the: - ANSWERS-Differences between the high side and low side
pressure
The installation of an inline refrigerant cleaning system is advisable: - ANSWERS-
To remove impurities from the system
The type of refrigerant system that is least likely to leak refrigerant into the
building space that are being cooled: - ANSWERS-Indirect system
The suction pressure of a reciprocating compressor is 65 PSIG. The discharge
pressure of this compressor is 120 PSIG. The atmospheric is 14.7 PSI. The
compression ratio for the given condition is closest to: - ANSWERS-1.69
,A superheated vapor is: - ANSWERS-Dry vapor above the saturation
temperature
A refrigerant engineer verifies that a condenser water pump is cavitating. Of the
following, the most likely cause for this condition is: - ANSWERS-A faulty cooling
tower water level controller
A centrifugal water pump is known as a lift pump when the: - ANSWERS-The
water supply to the pump suction inlet is below the pump level
A TXV is used to maintain constant: - ANSWERS-Evaporator superheat
The chilled water supply to the building is 55 deg F. If the chiller is being used
for human comfort, should you be concerned about this, and why? - ANSWERS-
Yes, this temp is too high for human comfort purposes
The packing gland of a centrifugal pump serves to: - ANSWERS-The drip part of
the packing gland gives evidence that there is water in the pump
Capacity control of reciprocating hermetic compressor is typically achieved
through: - ANSWERS-Operation of the hot gas bypass valve
The most important reason to sub-cool the refrigerant in the condenser is to
ensure that: - ANSWERS-A pure liquid refrigerant will enter the metering device
, A refrigeration engineer is logging readings from a reciprocating system.
Compressor discharge temperature have dropped significantly and the suction
line pressure is high. Which of the following that may be causing this set of
condition? - ANSWERS-An expansion valve that is open too wide
Efficiency of the refrigerant cycle is affected by the operations of the condenser.
Of the following, a more efficient centrifugal compressor operation results from:
- ANSWERS-Lowering the condensing pressure
The heat removed from the refrigerant in a condenser is: - ANSWERS-Sensible
and latent heat
The refrigerant unit that you have been assigned to is being taken out of service
for a major repair. You have been assigned to withdraw refrigerant for storage
in suitable containers. According to the NYC Fire Code, you must ensure that the
containers: - ANSWERS-Are approved by the US Dept. of Transportation
Which of the following best describes how the cylinder unloader works? -
ANSWERS-Keep in the suction valve opened while the compressor is in the
return stroke
In most semi-hermetic compressors, the suction vapor is used to: - ANSWERS-
Cool the motor
CORRECT ACTUAL QUESTIONS AND
CORRECTLY WELL DEFINED ANSWERS
LATEST 2025 ALREADY GRADED A+
Manifold hoses should be equipped with? - ANSWERS-Low loss fittings
Water regulating valves are used for? - ANSWERS-Maintaining condenser
pressure to a pre-determined level
What type of sprinkler system needs inspecting? - ANSWERS-Automatic
You are performing hot works near a sprinkler head. What can you do to
prevent the fire alarm from going off? - ANSWERS-Put a non-combustible
barrier to protect the sprinkler head
How long does it take to warm up a steam turbine? - ANSWERS-10-15 minutes
,Why is a pressure relief valve better than a fusible plug? - ANSWERS-Minimizes
refrigerant loss
What is the state of refrigerant entering the compressor on a reciprocating
machine? - ANSWERS-Superheated vapor
In the absence of water chemical treatment of a cooling tower: - ANSWERS-
Drain the tower every one to two weeks and replace with fresh water
The amount of refrigerant that flows through the orifices of an economizer is
determined by the: - ANSWERS-Differences between the high side and low side
pressure
The installation of an inline refrigerant cleaning system is advisable: - ANSWERS-
To remove impurities from the system
The type of refrigerant system that is least likely to leak refrigerant into the
building space that are being cooled: - ANSWERS-Indirect system
The suction pressure of a reciprocating compressor is 65 PSIG. The discharge
pressure of this compressor is 120 PSIG. The atmospheric is 14.7 PSI. The
compression ratio for the given condition is closest to: - ANSWERS-1.69
,A superheated vapor is: - ANSWERS-Dry vapor above the saturation
temperature
A refrigerant engineer verifies that a condenser water pump is cavitating. Of the
following, the most likely cause for this condition is: - ANSWERS-A faulty cooling
tower water level controller
A centrifugal water pump is known as a lift pump when the: - ANSWERS-The
water supply to the pump suction inlet is below the pump level
A TXV is used to maintain constant: - ANSWERS-Evaporator superheat
The chilled water supply to the building is 55 deg F. If the chiller is being used
for human comfort, should you be concerned about this, and why? - ANSWERS-
Yes, this temp is too high for human comfort purposes
The packing gland of a centrifugal pump serves to: - ANSWERS-The drip part of
the packing gland gives evidence that there is water in the pump
Capacity control of reciprocating hermetic compressor is typically achieved
through: - ANSWERS-Operation of the hot gas bypass valve
The most important reason to sub-cool the refrigerant in the condenser is to
ensure that: - ANSWERS-A pure liquid refrigerant will enter the metering device
, A refrigeration engineer is logging readings from a reciprocating system.
Compressor discharge temperature have dropped significantly and the suction
line pressure is high. Which of the following that may be causing this set of
condition? - ANSWERS-An expansion valve that is open too wide
Efficiency of the refrigerant cycle is affected by the operations of the condenser.
Of the following, a more efficient centrifugal compressor operation results from:
- ANSWERS-Lowering the condensing pressure
The heat removed from the refrigerant in a condenser is: - ANSWERS-Sensible
and latent heat
The refrigerant unit that you have been assigned to is being taken out of service
for a major repair. You have been assigned to withdraw refrigerant for storage
in suitable containers. According to the NYC Fire Code, you must ensure that the
containers: - ANSWERS-Are approved by the US Dept. of Transportation
Which of the following best describes how the cylinder unloader works? -
ANSWERS-Keep in the suction valve opened while the compressor is in the
return stroke
In most semi-hermetic compressors, the suction vapor is used to: - ANSWERS-
Cool the motor
