FDNY Z51 2025 EXAM TEST BANK
QUESTIONS AND CORRECT ANSWERS
ACCURATELY VERIFIED GRADED A+ JUST
RELEASED.
◉ The only refrigerant /temperature chart available to a refrigerant
engineer list the temperature is degrees Celsius if the chart indicates a
Celsius temperature of 4 degrees to equivalent to F. Answer: 39.2 degrees
◉ A refrigerant engineers was instructed to charge of 60 ton plant with
R134A Refrigerant. The refrigerant engineer will most likely find the
charging valve on the. Answer: Low pressure side of the system
◉ A refrigerant engineer verifies that a chilled water pump is cavitating. Of
the following the most likely cause for this condition. Answer: Water leaks
through the mechanical seals
◉ There is a decrease in the efficiency of a reciprocating compressor. This
mostly likely caused by. Answer: Leaking suction valve
◉ The suction and discharge valve of the reciprocating compressor are
mounted as follows. Answer: Discharge valve on top of the valve plate and
suction valve below.
◉ You are the engineer running a 2000 ton (steam-driven turbine)
centrifugal refrigeration system, a refrigeration system supplies chilled
water to a college campus with multiple buildings. While making your
rounds you notice that the discharge pressure of your condenser water
pumps is significantly lower than the normal. Which following action would
,you avoid taking. Answer: Put on an additional surface condenser pump
and lower the chilled water set point.
◉ Which one of the following will connect to the middle port on a gauge
manifold? Answer: Vacuum pump
◉ The most important reason for installing a muffler in reciprocating
refrigerant machine is. Answer: To contain the compressor pulsation noise
◉ What type of refrigerant is found inside the machines gauges? Answer:
Same type of refrigerant inside the machine
◉ If resistance is cut in half, what happens to the power factor? Answer:
Increases by a factor of two
◉ What are pre hot works procedures performed prior to hot works?
Answer: Check area once a day leading up to hot works
◉ A chilled water system has an air cooled condensing unit on a roof
during cold weather has what type of protection? Answer: Air limiting
device
◉ What is a compressor safety head? Answer: A spring on the valve plate
◉ Standpipe certificate should be available for? Answer: FDNY and building
inspector
◉ The charge in a TEV sensing bulb is? Answer: Similar to refrigerant in
system
, ◉ When you are finished leak testing with R 22 and nitrogen the next step
would be? Answer: Vent refrigerant and nitrogen to open air
◉ There is 7.48 gallons per cubic foot. How many gallons of water are in a
pipe 8 feet in diameter and 10 feet long? Answer: 3758
◉ A technician has been asked to estimate the cost of operating a 5 horse
power mator. Because the plant is build by energy consumed as kilowatt-
hours, the technician will have to calculate the conversion. The equivalent
in energy of a 5 horse power motor operating for 9 hours in kilowatt-hours
is closest to. Answer: 33.6
◉ Cross connections and standpipe risers must be painted. Answer: red
◉ What device automatically controls the speed of a steam turbine?
Answer: Governor valve
◉ What happens when a steam turbine reaches critical speed? Answer:
Turbine will vibrate violently
◉ Superheat has been increasing gradually for over a week. What could be
the cause? Answer: Leak in the system
◉ A rooftop water cooling tower is connected to a water pump in the building
basement with a 12 inches diameter pipe, with the pump turn off, a pressure
gauge at the pumps inlet show a pressure of 140 PSIG the height of the water
column, in feet, would be closet to.. Answer: 323
◉ What device protects the steam turbine from excessive speed? Answer:
Governor assembly
QUESTIONS AND CORRECT ANSWERS
ACCURATELY VERIFIED GRADED A+ JUST
RELEASED.
◉ The only refrigerant /temperature chart available to a refrigerant
engineer list the temperature is degrees Celsius if the chart indicates a
Celsius temperature of 4 degrees to equivalent to F. Answer: 39.2 degrees
◉ A refrigerant engineers was instructed to charge of 60 ton plant with
R134A Refrigerant. The refrigerant engineer will most likely find the
charging valve on the. Answer: Low pressure side of the system
◉ A refrigerant engineer verifies that a chilled water pump is cavitating. Of
the following the most likely cause for this condition. Answer: Water leaks
through the mechanical seals
◉ There is a decrease in the efficiency of a reciprocating compressor. This
mostly likely caused by. Answer: Leaking suction valve
◉ The suction and discharge valve of the reciprocating compressor are
mounted as follows. Answer: Discharge valve on top of the valve plate and
suction valve below.
◉ You are the engineer running a 2000 ton (steam-driven turbine)
centrifugal refrigeration system, a refrigeration system supplies chilled
water to a college campus with multiple buildings. While making your
rounds you notice that the discharge pressure of your condenser water
pumps is significantly lower than the normal. Which following action would
,you avoid taking. Answer: Put on an additional surface condenser pump
and lower the chilled water set point.
◉ Which one of the following will connect to the middle port on a gauge
manifold? Answer: Vacuum pump
◉ The most important reason for installing a muffler in reciprocating
refrigerant machine is. Answer: To contain the compressor pulsation noise
◉ What type of refrigerant is found inside the machines gauges? Answer:
Same type of refrigerant inside the machine
◉ If resistance is cut in half, what happens to the power factor? Answer:
Increases by a factor of two
◉ What are pre hot works procedures performed prior to hot works?
Answer: Check area once a day leading up to hot works
◉ A chilled water system has an air cooled condensing unit on a roof
during cold weather has what type of protection? Answer: Air limiting
device
◉ What is a compressor safety head? Answer: A spring on the valve plate
◉ Standpipe certificate should be available for? Answer: FDNY and building
inspector
◉ The charge in a TEV sensing bulb is? Answer: Similar to refrigerant in
system
, ◉ When you are finished leak testing with R 22 and nitrogen the next step
would be? Answer: Vent refrigerant and nitrogen to open air
◉ There is 7.48 gallons per cubic foot. How many gallons of water are in a
pipe 8 feet in diameter and 10 feet long? Answer: 3758
◉ A technician has been asked to estimate the cost of operating a 5 horse
power mator. Because the plant is build by energy consumed as kilowatt-
hours, the technician will have to calculate the conversion. The equivalent
in energy of a 5 horse power motor operating for 9 hours in kilowatt-hours
is closest to. Answer: 33.6
◉ Cross connections and standpipe risers must be painted. Answer: red
◉ What device automatically controls the speed of a steam turbine?
Answer: Governor valve
◉ What happens when a steam turbine reaches critical speed? Answer:
Turbine will vibrate violently
◉ Superheat has been increasing gradually for over a week. What could be
the cause? Answer: Leak in the system
◉ A rooftop water cooling tower is connected to a water pump in the building
basement with a 12 inches diameter pipe, with the pump turn off, a pressure
gauge at the pumps inlet show a pressure of 140 PSIG the height of the water
column, in feet, would be closet to.. Answer: 323
◉ What device protects the steam turbine from excessive speed? Answer:
Governor assembly
