FDNY P-99 Certificate of Fitness Exam – Fire Department
of New York | 2025/2026 Questions and Answers Study
Guide
INTRODUCTION:
This comprehensive practice examination is designed to prepare building superintendents, maintenance
personnel, and boiler operators for the FDNY P-99 Certificate of Fitness examination based on
2025/2026 FDNY standards, NYC Fire Code, and ASME Boiler and Pressure Vessel Code requirements.
The exam covers low-pressure boiler operation (maximum 15 psi steam, 250°F hot water), fuel oil
systems including No. 2, 4, and 6 oil characteristics, safety devices and controls, inspection
requirements, and emergency procedures essential for safe operation of heating systems in New York
City residential and commercial buildings.
DOMAIN 1: BOILER DEFINITIONS & CLASSIFICATIONS (Questions 1-15)
Q1: Low pressure steam boilers are defined as having a maximum operating pressure of:
A. 30 psi
B. 15 psi
C. 100 psi
D. 25 psi
Answer: B
Rationale: Per FDNY and ASME codes, low pressure steam boilers are defined as operating at
pressures not exceeding 15 psi. This is a foundational classification for P-99 certification that
distinguishes low-pressure from high-pressure systems requiring different operator certifications.
Q2: Low pressure hot water boilers are defined as operating at a maximum temperature of:
A. 212°F
B. 250°F
C. 275°F
D. 300°F
Answer: B
,Rationale: Low pressure hot water boilers operate at maximum temperatures of 250°F with
maximum working pressure of 160 psi per ASME Section IV and FDNY regulations, beyond which
high-pressure certification and additional safety requirements apply.
Q3: What is the maximum allowable working pressure (MAWP) for low pressure hot water boilers?
A. 100 psi
B. 125 psi
C. 160 psi
D. 200 psi
Answer: C
Rationale: The maximum allowable working pressure for low pressure hot water boilers is 160 psi
per ASME Section IV, which combined with the 250°F temperature limit defines the operational
boundaries for P-99 certified operators.
Q4: At what pressure does water boil at sea level in a steam boiler system?
A. 15 psi
B. 0 psi (atmospheric pressure)
C. 30 psi
D. 5 psi
Answer: B
Rationale: Water boils at 212°F at 0 psi gauge pressure (atmospheric pressure). In steam boilers,
maintaining 15 psi maximum pressure keeps the boiling point at approximately 250°F while
remaining within low-pressure classification limits.
Q5: What distinguishes a steam boiler from a hot water boiler?
A. Steam boilers operate at lower temperatures
B. Steam boilers produce steam vapor while hot water boilers circulate liquid water
C. Steam boilers cannot use fuel oil
D. Hot water boilers operate at higher pressures only
Answer: B
,Rationale: The fundamental distinction is that steam boilers heat water to produce steam vapor for
heating or process use, while hot water boilers heat water without vaporization, circulating liquid
water through the heating system at temperatures below boiling at system pressure.
Q6: What is the minimum size boiler that requires a P-99 Certificate of Fitness holder to be on
premises in NYC?
A. Any size boiler
B. Boilers over 100,000 BTU input
C. Low pressure boilers exceeding 350,000 BTU/hr input or 100 horsepower
D. Only high pressure boilers
Answer: C
Rationale: Per FDNY regulations, a P-99 Certificate of Fitness holder must be on premises when
operating low pressure boilers exceeding 350,000 BTU/hr input or 100 HP, ensuring qualified
supervision of larger systems with greater potential hazard.
Q7: What is the definition of boiler horsepower?
A. The physical size of the boiler
B. The ability to evaporate 34.5 pounds of water per hour at 212°F
C. The weight of the boiler
D. The pressure rating only
Answer: B
Rationale: One boiler horsepower is defined as the ability to evaporate 34.5 pounds of water per
hour at 212°F, or approximately 33,475 BTU/hr, providing a standardized measure of boiler capacity
for regulatory and operational purposes.
Q8: What type of boiler generates steam at 15 psi for building heating?
A. High pressure steam boiler
B. Low pressure steam boiler
C. Power boiler
D. Unfired pressure vessel
Answer: B
, Rationale: A boiler generating steam at 15 psi maximum operating pressure is classified as a low
pressure steam boiler per FDNY and ASME codes, requiring P-99 certification rather than the more
stringent requirements for high pressure (over 15 psi) boilers.
Q9: What is an unfired pressure vessel?
A. A vessel that generates its own heat
B. A vessel that operates at atmospheric pressure only
C. A vessel that operates under pressure but does not generate heat internally
D. A vessel used only for cooling
Answer: C
Rationale: An unfired pressure vessel operates under pressure but does not generate heat internally
(examples: steam accumulators, expansion tanks, compressed air tanks), distinguishing it from fired
boilers and requiring different safety considerations.
Q10: What distinguishes No. 2 fuel oil from No. 6 fuel oil?
A. No. 2 requires heating; No. 6 flows at room temperature
B. No. 2 flows at room temperature; No. 6 requires heating to 100-130°F
C. Both require the same temperature
D. No. 6 is lighter than No. 2
Answer: B
Rationale: No. 2 fuel oil (light oil) flows at room temperature and requires no preheating, while No. 6
fuel oil (residual/bunker oil) is highly viscous and must be heated to 100-130°F for proper pumping
and atomization, requiring additional heating equipment and monitoring.
Q11: What is the primary purpose of a boiler's heating surface?
A. To store fuel oil
B. To transfer heat from combustion gases to water
C. To support the boiler structure
D. To filter combustion air
Answer: B
of New York | 2025/2026 Questions and Answers Study
Guide
INTRODUCTION:
This comprehensive practice examination is designed to prepare building superintendents, maintenance
personnel, and boiler operators for the FDNY P-99 Certificate of Fitness examination based on
2025/2026 FDNY standards, NYC Fire Code, and ASME Boiler and Pressure Vessel Code requirements.
The exam covers low-pressure boiler operation (maximum 15 psi steam, 250°F hot water), fuel oil
systems including No. 2, 4, and 6 oil characteristics, safety devices and controls, inspection
requirements, and emergency procedures essential for safe operation of heating systems in New York
City residential and commercial buildings.
DOMAIN 1: BOILER DEFINITIONS & CLASSIFICATIONS (Questions 1-15)
Q1: Low pressure steam boilers are defined as having a maximum operating pressure of:
A. 30 psi
B. 15 psi
C. 100 psi
D. 25 psi
Answer: B
Rationale: Per FDNY and ASME codes, low pressure steam boilers are defined as operating at
pressures not exceeding 15 psi. This is a foundational classification for P-99 certification that
distinguishes low-pressure from high-pressure systems requiring different operator certifications.
Q2: Low pressure hot water boilers are defined as operating at a maximum temperature of:
A. 212°F
B. 250°F
C. 275°F
D. 300°F
Answer: B
,Rationale: Low pressure hot water boilers operate at maximum temperatures of 250°F with
maximum working pressure of 160 psi per ASME Section IV and FDNY regulations, beyond which
high-pressure certification and additional safety requirements apply.
Q3: What is the maximum allowable working pressure (MAWP) for low pressure hot water boilers?
A. 100 psi
B. 125 psi
C. 160 psi
D. 200 psi
Answer: C
Rationale: The maximum allowable working pressure for low pressure hot water boilers is 160 psi
per ASME Section IV, which combined with the 250°F temperature limit defines the operational
boundaries for P-99 certified operators.
Q4: At what pressure does water boil at sea level in a steam boiler system?
A. 15 psi
B. 0 psi (atmospheric pressure)
C. 30 psi
D. 5 psi
Answer: B
Rationale: Water boils at 212°F at 0 psi gauge pressure (atmospheric pressure). In steam boilers,
maintaining 15 psi maximum pressure keeps the boiling point at approximately 250°F while
remaining within low-pressure classification limits.
Q5: What distinguishes a steam boiler from a hot water boiler?
A. Steam boilers operate at lower temperatures
B. Steam boilers produce steam vapor while hot water boilers circulate liquid water
C. Steam boilers cannot use fuel oil
D. Hot water boilers operate at higher pressures only
Answer: B
,Rationale: The fundamental distinction is that steam boilers heat water to produce steam vapor for
heating or process use, while hot water boilers heat water without vaporization, circulating liquid
water through the heating system at temperatures below boiling at system pressure.
Q6: What is the minimum size boiler that requires a P-99 Certificate of Fitness holder to be on
premises in NYC?
A. Any size boiler
B. Boilers over 100,000 BTU input
C. Low pressure boilers exceeding 350,000 BTU/hr input or 100 horsepower
D. Only high pressure boilers
Answer: C
Rationale: Per FDNY regulations, a P-99 Certificate of Fitness holder must be on premises when
operating low pressure boilers exceeding 350,000 BTU/hr input or 100 HP, ensuring qualified
supervision of larger systems with greater potential hazard.
Q7: What is the definition of boiler horsepower?
A. The physical size of the boiler
B. The ability to evaporate 34.5 pounds of water per hour at 212°F
C. The weight of the boiler
D. The pressure rating only
Answer: B
Rationale: One boiler horsepower is defined as the ability to evaporate 34.5 pounds of water per
hour at 212°F, or approximately 33,475 BTU/hr, providing a standardized measure of boiler capacity
for regulatory and operational purposes.
Q8: What type of boiler generates steam at 15 psi for building heating?
A. High pressure steam boiler
B. Low pressure steam boiler
C. Power boiler
D. Unfired pressure vessel
Answer: B
, Rationale: A boiler generating steam at 15 psi maximum operating pressure is classified as a low
pressure steam boiler per FDNY and ASME codes, requiring P-99 certification rather than the more
stringent requirements for high pressure (over 15 psi) boilers.
Q9: What is an unfired pressure vessel?
A. A vessel that generates its own heat
B. A vessel that operates at atmospheric pressure only
C. A vessel that operates under pressure but does not generate heat internally
D. A vessel used only for cooling
Answer: C
Rationale: An unfired pressure vessel operates under pressure but does not generate heat internally
(examples: steam accumulators, expansion tanks, compressed air tanks), distinguishing it from fired
boilers and requiring different safety considerations.
Q10: What distinguishes No. 2 fuel oil from No. 6 fuel oil?
A. No. 2 requires heating; No. 6 flows at room temperature
B. No. 2 flows at room temperature; No. 6 requires heating to 100-130°F
C. Both require the same temperature
D. No. 6 is lighter than No. 2
Answer: B
Rationale: No. 2 fuel oil (light oil) flows at room temperature and requires no preheating, while No. 6
fuel oil (residual/bunker oil) is highly viscous and must be heated to 100-130°F for proper pumping
and atomization, requiring additional heating equipment and monitoring.
Q11: What is the primary purpose of a boiler's heating surface?
A. To store fuel oil
B. To transfer heat from combustion gases to water
C. To support the boiler structure
D. To filter combustion air
Answer: B
