Q-01 FDNY CORRECT ANSWERS 2025
Rupture members, when used in parallel with a relief valve, are not to exceed _____% above
designed working pressure - CORRECT-ANSWERS-20%
Butterfly valve: where can it be used? - CORRECT-ANSWERS-Can be used on the inlet
and outlet of a water pump
What electrical motor protection device automatically resets itself? - CORRECT-ANSWERS-
The thermal protector
746 watts equals how many kilowatt hours? - CORRECT-ANSWERS-.746 kilowatt hours
What position is the liquid line service valve normally in? - CORRECT-ANSWERS-Back-
seated
In an operating evaporator, oil stays on top of which refrigerant? - CORRECT-ANSWERS-
Carbon dioxide, R-744
At what pressure does the relief valve blow on a high pressure machine? - CORRECT-
ANSWERS-300 psi
What would indicate a restriction (such as dirt or scale) in the liquid line? - CORRECT-
ANSWERS-Frost immediately after the restriction
What does solubility mean? - CORRECT-ANSWERS-The ability of a refrigerant to
mix with other substances
Charging Vapor —In a compression system, where do you charge the vapor? - CORRECT-
ANSWERS-Suction side of the compressor at the Suction Service Valve
,When comparing a brine with s PH of 8 to one with a PH of 10, its alkalinity is: - CORRECT-
ANSWERS-100 times greater (ex. PH 8 to PH 9 is 10 times greater)
In an efficiently operating induced draft cooling tower, the leaving water is between: -
CORRECT-ANSWERS-Dry bulb and wet bulb temperature
To produce the desired evaporator temperature, the power input is reduced by keeping head
pressure... - CORRECT-ANSWERS-Head pressure as low as possible & suction
pressure as high as needed
The accumulator is usually between the... - CORRECT-ANSWERS-Compressor and
evaporator
An oiling system in a large centrifugal system should consist of at least... - CORRECT-
ANSWERS-Reservoir, pump and distribution lines
In an evaporator that chills brine, the greatest cooling effect on the brine results from the... -
CORRECT-ANSWERS-Boiling of low pressure liquid
The flow of weak liquor to the absorber is controlled by
A) gas pressure
B) throttling device
C) float valve
D) pressure of the strong liquor pump - CORRECT-ANSWERS-B) throttling device
The best way of detecting ammonia brine is by using
A) CO2 gas
B) potassium of lime
C) Nessler reagent
D) carbonate of soda - CORRECT-ANSWERS-C) Nessler reagent
, The best time to purge an ammonia plant with 250 lbs. of ammonia is
A) during shut-down, because you will lose ammonia
B) while charging the plant
C) during operation
D) none of the above - CORRECT-ANSWERS-C) during operation
What will make the strong liquor in the absorber decrease?
A) expansion valve open too much
B) A decrease in evaporator load
C) An increase in evaporator load
D) Too much steam on the generator - CORRECT-ANSWERS-B) A decrease in
evaporator load
Which of the following statements is incorrect?
A) A service valve is a key-operated shut-off valve used during shipment, installation and repairs
B) Brine is a liquid cooled by refrigeration and used for the transmission of heat
C) A fusible plug has a set-temperature fusible member to relieve pressure
D) A rupture member automatically ruptures at a predetermined temperature - CORRECT-
ANSWERS-D) A rupture member automatically ruptures at a predetermined
temperature
Oil in a refrigerant should
A) have a high pour point
B) have a low flash point
C) have a high viscosity
D) not contain moisture - CORRECT-ANSWERS-D) not contain moisture
In an NH3 dry expansion evaporator with TXV and bulb clamped properly on the outlet of the
evaporator, the superheat is
A) 7 to 10° F
B) 5 to 9° F
C) 20 to 30° F
D) 1 to 2° F - CORRECT-ANSWERS-A) 7 to 10° F
The setting of a fusible plug is
A) 280° F
Rupture members, when used in parallel with a relief valve, are not to exceed _____% above
designed working pressure - CORRECT-ANSWERS-20%
Butterfly valve: where can it be used? - CORRECT-ANSWERS-Can be used on the inlet
and outlet of a water pump
What electrical motor protection device automatically resets itself? - CORRECT-ANSWERS-
The thermal protector
746 watts equals how many kilowatt hours? - CORRECT-ANSWERS-.746 kilowatt hours
What position is the liquid line service valve normally in? - CORRECT-ANSWERS-Back-
seated
In an operating evaporator, oil stays on top of which refrigerant? - CORRECT-ANSWERS-
Carbon dioxide, R-744
At what pressure does the relief valve blow on a high pressure machine? - CORRECT-
ANSWERS-300 psi
What would indicate a restriction (such as dirt or scale) in the liquid line? - CORRECT-
ANSWERS-Frost immediately after the restriction
What does solubility mean? - CORRECT-ANSWERS-The ability of a refrigerant to
mix with other substances
Charging Vapor —In a compression system, where do you charge the vapor? - CORRECT-
ANSWERS-Suction side of the compressor at the Suction Service Valve
,When comparing a brine with s PH of 8 to one with a PH of 10, its alkalinity is: - CORRECT-
ANSWERS-100 times greater (ex. PH 8 to PH 9 is 10 times greater)
In an efficiently operating induced draft cooling tower, the leaving water is between: -
CORRECT-ANSWERS-Dry bulb and wet bulb temperature
To produce the desired evaporator temperature, the power input is reduced by keeping head
pressure... - CORRECT-ANSWERS-Head pressure as low as possible & suction
pressure as high as needed
The accumulator is usually between the... - CORRECT-ANSWERS-Compressor and
evaporator
An oiling system in a large centrifugal system should consist of at least... - CORRECT-
ANSWERS-Reservoir, pump and distribution lines
In an evaporator that chills brine, the greatest cooling effect on the brine results from the... -
CORRECT-ANSWERS-Boiling of low pressure liquid
The flow of weak liquor to the absorber is controlled by
A) gas pressure
B) throttling device
C) float valve
D) pressure of the strong liquor pump - CORRECT-ANSWERS-B) throttling device
The best way of detecting ammonia brine is by using
A) CO2 gas
B) potassium of lime
C) Nessler reagent
D) carbonate of soda - CORRECT-ANSWERS-C) Nessler reagent
, The best time to purge an ammonia plant with 250 lbs. of ammonia is
A) during shut-down, because you will lose ammonia
B) while charging the plant
C) during operation
D) none of the above - CORRECT-ANSWERS-C) during operation
What will make the strong liquor in the absorber decrease?
A) expansion valve open too much
B) A decrease in evaporator load
C) An increase in evaporator load
D) Too much steam on the generator - CORRECT-ANSWERS-B) A decrease in
evaporator load
Which of the following statements is incorrect?
A) A service valve is a key-operated shut-off valve used during shipment, installation and repairs
B) Brine is a liquid cooled by refrigeration and used for the transmission of heat
C) A fusible plug has a set-temperature fusible member to relieve pressure
D) A rupture member automatically ruptures at a predetermined temperature - CORRECT-
ANSWERS-D) A rupture member automatically ruptures at a predetermined
temperature
Oil in a refrigerant should
A) have a high pour point
B) have a low flash point
C) have a high viscosity
D) not contain moisture - CORRECT-ANSWERS-D) not contain moisture
In an NH3 dry expansion evaporator with TXV and bulb clamped properly on the outlet of the
evaporator, the superheat is
A) 7 to 10° F
B) 5 to 9° F
C) 20 to 30° F
D) 1 to 2° F - CORRECT-ANSWERS-A) 7 to 10° F
The setting of a fusible plug is
A) 280° F
