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New York City High-Pressure Boiler Operating Engineer
Written (DOB) Examination | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION
This Comprehensive set of multiple choice questions is designed for the New York City
High-Pressure Boiler Operating Engineer written examination, a closed-book test
administered by the Department of Buildings (DOB). The exam assesses a candidate's
knowledge of high-pressure boiler fundamentals, safe operation and maintenance
procedures, and compliance with applicable NYC construction codes and ASME safety
standards.
QUESTION 1
According to ASME Section I, what is the minimum pressure setting for the lowest safety
valve on a high-pressure steam boiler with a MAWP greater than 100 psi?
A) MAWP
B) 10% above MAWP
C) Not less than 10 psi below MAWP
D) The set pressure cannot exceed MAWP
CORRECT ANSWER: D
EXPERT RATIONALE: Safety valves must be set to open at or below the boiler's
maximum allowable working pressure, never above it.
QUESTION 2
In a high-pressure boiler, what is the primary function of a siphon (pigtail) on a steam
pressure gauge?
A) To dampen gauge fluctuation
B) To protect the gauge from live steam temperature
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C) To increase accuracy of the reading
D) To allow for easier gauge replacement
CORRECT ANSWER: B
EXPERT RATIONALE: The siphon fills with condensate, preventing direct high-
temperature steam from damaging the gauge's internal mechanism.
QUESTION 3
Per NYC code, how often must a high-pressure boiler be inspected internally and
externally by an authorized insurance inspector or the DOB?
A) Every 6 months
B) Annually
C) Every 2 years
D) Only when the boiler is opened for repair
CORRECT ANSWER: B
EXPERT RATIONALE: NYC annual boiler inspections are mandatory for all high-pressure
boilers to ensure compliance with construction codes and safety standards.
QUESTION 4
When performing a bottom blowdown on a steam boiler, what is the correct sequence
of opening valves?
A) Quick-opening valve first, then slow-opening valve
B) Slow-opening valve first, then quick-opening valve
C) Both valves opened simultaneously
D) Slow-opening valve fully open, then crack the quick-opening valve
CORRECT ANSWER: B
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EXPERT RATIONALE: Opening the slow-opening valve first and then the quick-opening
valve reduces water hammer and allows control of the blowdown rate.
QUESTION 5
A boiler operating engineer discovers the water level is not visible in the gauge glass.
The first action must be to:
A) Immediately add feedwater
B) Shut off the fuel and air supply, then investigate
C) Blow down the gauge glass to restore visibility
D) Increase the firing rate to raise the water level
CORRECT ANSWER: B
EXPERT RATIONALE: A hidden water level can mean a low-water condition, risking tube
burnout; the safe procedure is to cut heat input immediately before further steps.
QUESTION 6
What is the purpose of the low-water fuel cutoff on a high-pressure boiler?
A) To shut off the feedwater if the level gets too high
B) To stop fuel flow when the water level drops below a safe point
C) To start the standby feed pump automatically
D) To alarm only, without interrupting combustion
CORRECT ANSWER: B
EXPERT RATIONALE: This safety device prevents boiler damage by immediately cutting
off the fuel supply if the water level falls below the minimum safe operating level.
QUESTION 7
On a boiler equipped with a modulating feedwater control, what happens when the
steam load decreases?
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A) The feedwater valve opens fully
B) The fuel valve closes and the boiler shuts down
C) The feedwater valve modulates toward the closed position
D) The water level will drop sharply
CORRECT ANSWER: C
EXPERT RATIONALE: The modulating control reduces feedwater flow in response to a
lower evaporation rate, maintaining a stable water level without overfilling.
QUESTION 8
According to the NYC Mechanical Code, what is the minimum clearance from
combustible materials for a single-wall metal chimney connector serving a boiler?
A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
CORRECT ANSWER: C
EXPERT RATIONALE: An 18-inch clearance is standard for single-wall connectors to
prevent ignition of nearby combustibles; double-wall connectors permit reduced
clearances.
QUESTION 9
The ASME Code stamp on a boiler pressure vessel indicates:
A) The insurance company that insured the boiler
B) That the boiler meets the code requirements for construction
C) The maximum operating time before inspection
D) The manufacturer's recommended firing rate
CORRECT ANSWER: B
New York City High-Pressure Boiler Operating Engineer
Written (DOB) Examination | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION
This Comprehensive set of multiple choice questions is designed for the New York City
High-Pressure Boiler Operating Engineer written examination, a closed-book test
administered by the Department of Buildings (DOB). The exam assesses a candidate's
knowledge of high-pressure boiler fundamentals, safe operation and maintenance
procedures, and compliance with applicable NYC construction codes and ASME safety
standards.
QUESTION 1
According to ASME Section I, what is the minimum pressure setting for the lowest safety
valve on a high-pressure steam boiler with a MAWP greater than 100 psi?
A) MAWP
B) 10% above MAWP
C) Not less than 10 psi below MAWP
D) The set pressure cannot exceed MAWP
CORRECT ANSWER: D
EXPERT RATIONALE: Safety valves must be set to open at or below the boiler's
maximum allowable working pressure, never above it.
QUESTION 2
In a high-pressure boiler, what is the primary function of a siphon (pigtail) on a steam
pressure gauge?
A) To dampen gauge fluctuation
B) To protect the gauge from live steam temperature
,2|Page
C) To increase accuracy of the reading
D) To allow for easier gauge replacement
CORRECT ANSWER: B
EXPERT RATIONALE: The siphon fills with condensate, preventing direct high-
temperature steam from damaging the gauge's internal mechanism.
QUESTION 3
Per NYC code, how often must a high-pressure boiler be inspected internally and
externally by an authorized insurance inspector or the DOB?
A) Every 6 months
B) Annually
C) Every 2 years
D) Only when the boiler is opened for repair
CORRECT ANSWER: B
EXPERT RATIONALE: NYC annual boiler inspections are mandatory for all high-pressure
boilers to ensure compliance with construction codes and safety standards.
QUESTION 4
When performing a bottom blowdown on a steam boiler, what is the correct sequence
of opening valves?
A) Quick-opening valve first, then slow-opening valve
B) Slow-opening valve first, then quick-opening valve
C) Both valves opened simultaneously
D) Slow-opening valve fully open, then crack the quick-opening valve
CORRECT ANSWER: B
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EXPERT RATIONALE: Opening the slow-opening valve first and then the quick-opening
valve reduces water hammer and allows control of the blowdown rate.
QUESTION 5
A boiler operating engineer discovers the water level is not visible in the gauge glass.
The first action must be to:
A) Immediately add feedwater
B) Shut off the fuel and air supply, then investigate
C) Blow down the gauge glass to restore visibility
D) Increase the firing rate to raise the water level
CORRECT ANSWER: B
EXPERT RATIONALE: A hidden water level can mean a low-water condition, risking tube
burnout; the safe procedure is to cut heat input immediately before further steps.
QUESTION 6
What is the purpose of the low-water fuel cutoff on a high-pressure boiler?
A) To shut off the feedwater if the level gets too high
B) To stop fuel flow when the water level drops below a safe point
C) To start the standby feed pump automatically
D) To alarm only, without interrupting combustion
CORRECT ANSWER: B
EXPERT RATIONALE: This safety device prevents boiler damage by immediately cutting
off the fuel supply if the water level falls below the minimum safe operating level.
QUESTION 7
On a boiler equipped with a modulating feedwater control, what happens when the
steam load decreases?
, 4|Page
A) The feedwater valve opens fully
B) The fuel valve closes and the boiler shuts down
C) The feedwater valve modulates toward the closed position
D) The water level will drop sharply
CORRECT ANSWER: C
EXPERT RATIONALE: The modulating control reduces feedwater flow in response to a
lower evaporation rate, maintaining a stable water level without overfilling.
QUESTION 8
According to the NYC Mechanical Code, what is the minimum clearance from
combustible materials for a single-wall metal chimney connector serving a boiler?
A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
CORRECT ANSWER: C
EXPERT RATIONALE: An 18-inch clearance is standard for single-wall connectors to
prevent ignition of nearby combustibles; double-wall connectors permit reduced
clearances.
QUESTION 9
The ASME Code stamp on a boiler pressure vessel indicates:
A) The insurance company that insured the boiler
B) That the boiler meets the code requirements for construction
C) The maximum operating time before inspection
D) The manufacturer's recommended firing rate
CORRECT ANSWER: B
