NJ Black Seal Exam
NJ BLACK SEAL EXAM NEWEST 2025/2026 COMPLETE ALL
QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||BRAND NEW VERSION!
After an adjustment of the packing gland on a valve that had a minor packing leak,
the operator attempts to operate the valve but finds it stuck. What is the most
probable cause? - ANSWER-The operator overtightened the packing, causing the
stem to bind.
What pressure must be exceeded in order for a high pressure valve to have the
arrangement of the small valve shown below? - ANSWER-100 PSI
In a cooling water system when comparing a 3 inch gate valve to a 3 inch globe
valve used for the same application in the process. - ANSWER-The globe valve
produces the larger head loss and the smaller flow rate.
The purpose of back seating a manual valve in an operating system us to? -
ANSWER-Isolate system pressure from the packing stuffing box to minimize
packing leakage.
When a discharge valve is opened to the atmosphere, the pressure on the up
stream side of the valve will - ANSWER-Decrease, and the pressure on the
downstream side will stay the same.
When comparing globe valve and gate valve in the same application, the gate
valve has a _______ pressure drop when fully open and the is the ______ choice
for throttling - ANSWER-Lower: Poorer
1|Page
, NJ Black Seal Exam
Which of the following is generally accepted method for locally verifying that a
manual valve is fully close in a depressurized static piping system? - ANSWER-
Attempt to turn the valve hand wheel in the fully closed direction and verify no
movement.
Which of the following is not a function of a non return valve? - ANSWER-Opens
automatically if the boiler operating pressure drops below the header pressure.
Which of the following types of similarly sized valves in an operating water system
produces that least frictional head loss when fully open? - ANSWER-Ball valves
Which of the following types of similarly sized valves require most manual valve
stem rotation to move the valve. - ANSWER-Gate Valve
Which one of the following statements is the generally an accepted method to
verify at the local level that a manual valve is fully closed on a statin piping system
that is in the depressurized condition? - ANSWER-As an operator you would
attempt to turn the hand wheel in the closed direction to verify no movement.
The voltage of an ignition transformer is created and travels to electrodes. Wheat
holds and protects the electrodes in place? - ANSWER-The electrodes are held in
place by a bracket.
Identify the typical origin of the line at point A - ANSWER-This line is the main gas
line from the utility supplier.
2|Page
, NJ Black Seal Exam
What is the BTU content of natural gas? - ANSWER-100,000 btu/therm
What would high pressure differential across a fuel oil strainer set indicate? -
ANSWER-A dirty fuel oil strainer
What are two elements in a fuel oil that produce most of its heat? - ANSWER-
Carbon and hydrogen
The term viscosity can be best defined as? - ANSWER-The point at which oil starts
to flow
Which formula would you use to calculate BTU/LB heat content of fuel oil? -
ANSWER-17,687+57.7XAPI@60 degrees F
Which of the following best defines the ratio of total heat supplied by the fuel to
the total heat absorbed by a boiler? - ANSWER-Thermal efficiency
You are installing a boiler according to the boiler rules and regulations. Where
must the filter and strainer oil fires boilers be installed. - ANSWER-Upstream from
the safety shut off valve
From the image what type of fuel system is indicated? - ANSWER-Fuel oil burner
arrangement
What must take place in order for combustion air to flow open automatically
during equipment operation? - ANSWER-There must be and adequate opening for
3|Page
, NJ Black Seal Exam
the flow of fuel gas into the confines of the boiler room to ensure proper
combustion.
What type of burner provides atomization without the use of steam or air? -
ANSWER-The pressure type burner
In a steam generated plant, what purpose does the economizer serve? - ANSWER-
To heat feed water using stack gasses.
In a boiler operation what is necessary for complete combustion? - ANSWER-
(MATT) mixture, atomization, time, temp
In modern stationary engineering, a flue gas analysis is done to: - ANSWER-
Determine combustion efficiency
In the ignition system on an oil burner, what causes the spark to jump the gap and
ignite the fuel? - ANSWER-A high voltage spark of 10,000 VDC produced from the
transformer. Jumps gap between electrode tips.
A gradual increase in the stack temp could indicate what condition? - ANSWER-
Heating surface fouling.
On boilers equipped with an air preheater, what is the purpose of the bypass
damper? - ANSWER-To control the temperature of the combustion air
4|Page
NJ BLACK SEAL EXAM NEWEST 2025/2026 COMPLETE ALL
QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||BRAND NEW VERSION!
After an adjustment of the packing gland on a valve that had a minor packing leak,
the operator attempts to operate the valve but finds it stuck. What is the most
probable cause? - ANSWER-The operator overtightened the packing, causing the
stem to bind.
What pressure must be exceeded in order for a high pressure valve to have the
arrangement of the small valve shown below? - ANSWER-100 PSI
In a cooling water system when comparing a 3 inch gate valve to a 3 inch globe
valve used for the same application in the process. - ANSWER-The globe valve
produces the larger head loss and the smaller flow rate.
The purpose of back seating a manual valve in an operating system us to? -
ANSWER-Isolate system pressure from the packing stuffing box to minimize
packing leakage.
When a discharge valve is opened to the atmosphere, the pressure on the up
stream side of the valve will - ANSWER-Decrease, and the pressure on the
downstream side will stay the same.
When comparing globe valve and gate valve in the same application, the gate
valve has a _______ pressure drop when fully open and the is the ______ choice
for throttling - ANSWER-Lower: Poorer
1|Page
, NJ Black Seal Exam
Which of the following is generally accepted method for locally verifying that a
manual valve is fully close in a depressurized static piping system? - ANSWER-
Attempt to turn the valve hand wheel in the fully closed direction and verify no
movement.
Which of the following is not a function of a non return valve? - ANSWER-Opens
automatically if the boiler operating pressure drops below the header pressure.
Which of the following types of similarly sized valves in an operating water system
produces that least frictional head loss when fully open? - ANSWER-Ball valves
Which of the following types of similarly sized valves require most manual valve
stem rotation to move the valve. - ANSWER-Gate Valve
Which one of the following statements is the generally an accepted method to
verify at the local level that a manual valve is fully closed on a statin piping system
that is in the depressurized condition? - ANSWER-As an operator you would
attempt to turn the hand wheel in the closed direction to verify no movement.
The voltage of an ignition transformer is created and travels to electrodes. Wheat
holds and protects the electrodes in place? - ANSWER-The electrodes are held in
place by a bracket.
Identify the typical origin of the line at point A - ANSWER-This line is the main gas
line from the utility supplier.
2|Page
, NJ Black Seal Exam
What is the BTU content of natural gas? - ANSWER-100,000 btu/therm
What would high pressure differential across a fuel oil strainer set indicate? -
ANSWER-A dirty fuel oil strainer
What are two elements in a fuel oil that produce most of its heat? - ANSWER-
Carbon and hydrogen
The term viscosity can be best defined as? - ANSWER-The point at which oil starts
to flow
Which formula would you use to calculate BTU/LB heat content of fuel oil? -
ANSWER-17,687+57.7XAPI@60 degrees F
Which of the following best defines the ratio of total heat supplied by the fuel to
the total heat absorbed by a boiler? - ANSWER-Thermal efficiency
You are installing a boiler according to the boiler rules and regulations. Where
must the filter and strainer oil fires boilers be installed. - ANSWER-Upstream from
the safety shut off valve
From the image what type of fuel system is indicated? - ANSWER-Fuel oil burner
arrangement
What must take place in order for combustion air to flow open automatically
during equipment operation? - ANSWER-There must be and adequate opening for
3|Page
, NJ Black Seal Exam
the flow of fuel gas into the confines of the boiler room to ensure proper
combustion.
What type of burner provides atomization without the use of steam or air? -
ANSWER-The pressure type burner
In a steam generated plant, what purpose does the economizer serve? - ANSWER-
To heat feed water using stack gasses.
In a boiler operation what is necessary for complete combustion? - ANSWER-
(MATT) mixture, atomization, time, temp
In modern stationary engineering, a flue gas analysis is done to: - ANSWER-
Determine combustion efficiency
In the ignition system on an oil burner, what causes the spark to jump the gap and
ignite the fuel? - ANSWER-A high voltage spark of 10,000 VDC produced from the
transformer. Jumps gap between electrode tips.
A gradual increase in the stack temp could indicate what condition? - ANSWER-
Heating surface fouling.
On boilers equipped with an air preheater, what is the purpose of the bypass
damper? - ANSWER-To control the temperature of the combustion air
4|Page
