New York City Fire Department | Low Pressure Oil Burner Operator (P-99)
P-99 Low Pressure Boilers Certification
Examination 2026/2027 | Verified Questions
New York City Fire Department | Low Pressure Oil Burner Operator | Professional Boiler Operator
Candidates
100 Verified Questions | 5 Core Domains | Academic Year 2026/2027
Prepared by
New York City Fire Department | Low Pressure Oil Burner Operator (P-99)
P-99 Certificate of Fitness Examination Actual Exam | Academic Year 2026/2027
P-99 Low Pressure Boilers Certification Examination 2026/2027 | Verified Questions
,INTRODUCTION
This document contains 100 original Verified Questions covering the full P-99 Certificate of Fitness
examination for the academic year 2026/2027. The content addresses every core domain of the New York
City Fire Department Low Pressure Oil Burner Operator curriculum: Domain 1 – Boiler Fundamentals,
Steam & Combustion; Domain 2 – Fuel Oil Systems & Atomization; Domain 3 – Oil Burner Components
& Controls; Domain 4 – Boiler Operation, Blowdown & Safety Devices; and Domain 5 – FDNY Rules,
Codes & Certification Requirements. Each question is designed to reinforce official course objectives,
FDNY P-99 Notice of Exam and Study Materials, NYC Fire Code Chapter 6, and the operational safety
skills required for professional-level low-pressure boiler operator certification readiness.
ACTUAL QUESTIONS
Domain 1: Boiler Fundamentals, Steam & Combustion
Question 1. According to standard definitions used in low-pressure boiler operation, a low-
pressure steam boiler operates at a maximum steam pressure of:
A. 5 psig
B. 30 psig
C. 15 psig
D. 100 psig
Correct Answer: C
Rationale: Low-pressure steam boilers are limited to a maximum of 15 psig; pressures above this
classify the boiler as high-pressure under applicable codes.
Question 2. The primary purpose of combustion air in an oil-fired boiler is to:
A. Cool the combustion chamber walls
B. Supply the oxygen required for complete burning of the fuel
C. Increase the viscosity of the fuel oil
D. Reduce the temperature of the flue gases only
Correct Answer: B
Rationale: Combustion requires oxygen; adequate air supply ensures complete oxidation of the fuel,
minimizing soot and unburned hydrocarbons.
Question 3. Incomplete combustion in an oil burner typically produces:
A. Only carbon dioxide and water vapor
B. Pure oxygen as a byproduct
C. No measurable exhaust gases
D. Carbon monoxide, soot, and other unburned hydrocarbons
Correct Answer: D
Rationale: Insufficient air or poor atomization leads to incomplete oxidation, generating carbon
monoxide, smoke, and soot that indicate inefficient and potentially hazardous operation.
Question 4. Steam is generated in a boiler when water reaches its boiling point and
absorbs:
A. Latent heat of vaporization
B. Sensible heat only
C. Only radiant heat from the burner
D. No additional heat once boiling begins
Correct Answer: A
P-99 Low Pressure Boilers Certification Examination 2026/2027 | Verified Questions
, Rationale: After water reaches saturation temperature, further heat input (latent heat) converts liquid
water into steam without an immediate temperature rise.
Question 5. The three essential elements required for combustion are:
A. Fuel, nitrogen, and pressure
B. Water, oil, and electricity
C. Fuel, oxygen (air), and heat (ignition source)
D. Steam, draft, and atomization only
Correct Answer: C
Rationale: The fire triangle consists of fuel, oxidizer (oxygen from air), and sufficient heat to initiate and
sustain the reaction.
Question 6. In a fire-tube boiler, the hot gases of combustion travel:
A. Through the tubes while water surrounds the tubes
B. Outside the tubes while water is inside the tubes
C. Only in the combustion chamber
D. Through a separate economizer exclusively
Correct Answer: A
Rationale: Fire-tube design routes combustion gases inside the tubes; the surrounding water absorbs
heat from the tube walls.
Question 7. The heating surface of a boiler is defined as the area:
A. Of the exterior casing only
B. Of the burner refractory alone
C. Of the stack and breeching
D. Exposed to the heat of combustion on one side and water or steam on the other
Correct Answer: D
Rationale: Effective heating surface transfers heat from the products of combustion to the water or
steam and is the basis for boiler capacity ratings.
Question 8. Draft in a boiler system is the difference in pressure that causes:
A. Fuel oil to flow from the tank
B. Air and combustion gases to move through the burner, furnace, and flue passages
C. Water to circulate in the gauge glass
D. Steam to condense in the return lines
Correct Answer: B
Rationale: Natural or mechanical draft provides the pressure differential that moves combustion air
into the burner and exhaust gases out through the chimney.
Question 9. Excess air in combustion is supplied primarily to:
A. Ensure complete combustion and compensate for imperfect mixing
B. Increase fuel consumption deliberately
C. Lower the flame temperature below ignition point
D. Eliminate the need for a chimney
Correct Answer: A
Rationale: A controlled amount of excess air guarantees that all fuel molecules find oxygen, reducing
the risk of incomplete combustion while avoiding excessive heat loss up the stack.
Question 10. The flash point of a fuel oil is the lowest temperature at which:
A. The oil will support continuous combustion
P-99 Low Pressure Boilers Certification Examination 2026/2027 | Verified Questions
P-99 Low Pressure Boilers Certification
Examination 2026/2027 | Verified Questions
New York City Fire Department | Low Pressure Oil Burner Operator | Professional Boiler Operator
Candidates
100 Verified Questions | 5 Core Domains | Academic Year 2026/2027
Prepared by
New York City Fire Department | Low Pressure Oil Burner Operator (P-99)
P-99 Certificate of Fitness Examination Actual Exam | Academic Year 2026/2027
P-99 Low Pressure Boilers Certification Examination 2026/2027 | Verified Questions
,INTRODUCTION
This document contains 100 original Verified Questions covering the full P-99 Certificate of Fitness
examination for the academic year 2026/2027. The content addresses every core domain of the New York
City Fire Department Low Pressure Oil Burner Operator curriculum: Domain 1 – Boiler Fundamentals,
Steam & Combustion; Domain 2 – Fuel Oil Systems & Atomization; Domain 3 – Oil Burner Components
& Controls; Domain 4 – Boiler Operation, Blowdown & Safety Devices; and Domain 5 – FDNY Rules,
Codes & Certification Requirements. Each question is designed to reinforce official course objectives,
FDNY P-99 Notice of Exam and Study Materials, NYC Fire Code Chapter 6, and the operational safety
skills required for professional-level low-pressure boiler operator certification readiness.
ACTUAL QUESTIONS
Domain 1: Boiler Fundamentals, Steam & Combustion
Question 1. According to standard definitions used in low-pressure boiler operation, a low-
pressure steam boiler operates at a maximum steam pressure of:
A. 5 psig
B. 30 psig
C. 15 psig
D. 100 psig
Correct Answer: C
Rationale: Low-pressure steam boilers are limited to a maximum of 15 psig; pressures above this
classify the boiler as high-pressure under applicable codes.
Question 2. The primary purpose of combustion air in an oil-fired boiler is to:
A. Cool the combustion chamber walls
B. Supply the oxygen required for complete burning of the fuel
C. Increase the viscosity of the fuel oil
D. Reduce the temperature of the flue gases only
Correct Answer: B
Rationale: Combustion requires oxygen; adequate air supply ensures complete oxidation of the fuel,
minimizing soot and unburned hydrocarbons.
Question 3. Incomplete combustion in an oil burner typically produces:
A. Only carbon dioxide and water vapor
B. Pure oxygen as a byproduct
C. No measurable exhaust gases
D. Carbon monoxide, soot, and other unburned hydrocarbons
Correct Answer: D
Rationale: Insufficient air or poor atomization leads to incomplete oxidation, generating carbon
monoxide, smoke, and soot that indicate inefficient and potentially hazardous operation.
Question 4. Steam is generated in a boiler when water reaches its boiling point and
absorbs:
A. Latent heat of vaporization
B. Sensible heat only
C. Only radiant heat from the burner
D. No additional heat once boiling begins
Correct Answer: A
P-99 Low Pressure Boilers Certification Examination 2026/2027 | Verified Questions
, Rationale: After water reaches saturation temperature, further heat input (latent heat) converts liquid
water into steam without an immediate temperature rise.
Question 5. The three essential elements required for combustion are:
A. Fuel, nitrogen, and pressure
B. Water, oil, and electricity
C. Fuel, oxygen (air), and heat (ignition source)
D. Steam, draft, and atomization only
Correct Answer: C
Rationale: The fire triangle consists of fuel, oxidizer (oxygen from air), and sufficient heat to initiate and
sustain the reaction.
Question 6. In a fire-tube boiler, the hot gases of combustion travel:
A. Through the tubes while water surrounds the tubes
B. Outside the tubes while water is inside the tubes
C. Only in the combustion chamber
D. Through a separate economizer exclusively
Correct Answer: A
Rationale: Fire-tube design routes combustion gases inside the tubes; the surrounding water absorbs
heat from the tube walls.
Question 7. The heating surface of a boiler is defined as the area:
A. Of the exterior casing only
B. Of the burner refractory alone
C. Of the stack and breeching
D. Exposed to the heat of combustion on one side and water or steam on the other
Correct Answer: D
Rationale: Effective heating surface transfers heat from the products of combustion to the water or
steam and is the basis for boiler capacity ratings.
Question 8. Draft in a boiler system is the difference in pressure that causes:
A. Fuel oil to flow from the tank
B. Air and combustion gases to move through the burner, furnace, and flue passages
C. Water to circulate in the gauge glass
D. Steam to condense in the return lines
Correct Answer: B
Rationale: Natural or mechanical draft provides the pressure differential that moves combustion air
into the burner and exhaust gases out through the chimney.
Question 9. Excess air in combustion is supplied primarily to:
A. Ensure complete combustion and compensate for imperfect mixing
B. Increase fuel consumption deliberately
C. Lower the flame temperature below ignition point
D. Eliminate the need for a chimney
Correct Answer: A
Rationale: A controlled amount of excess air guarantees that all fuel molecules find oxygen, reducing
the risk of incomplete combustion while avoiding excessive heat loss up the stack.
Question 10. The flash point of a fuel oil is the lowest temperature at which:
A. The oil will support continuous combustion
P-99 Low Pressure Boilers Certification Examination 2026/2027 | Verified Questions
