NYC STATIONARY ENGINEER LICENSE PART 3 EXAM STUDY SET WITH COMPLETE
SOLUTIONS 100% VERIFIED!!! ALREADY GRADED A+ LATEST UPDATE
SECTION ONE: BOILER OPERATION AND COMBUSTION
1. What is the primary function of a boiler in a heating system?
A. To cool water for distribution
B. To transfer heat to water or steam
C. To generate electrical power
D. To filter air for ventilation
B. To transfer heat to water or steam
Rationale: Boilers transfer heat energy to water or steam for building heating and process
applications. This is the fundamental purpose of any boiler system.
2. What is the normal color of a properly adjusted gas flame?
A. Red
B. Blue
C. Orange
D. Yellow
B. Blue
Rationale: A blue flame indicates proper combustion with sufficient oxygen and correct
fuel-air mixture. Yellow or orange flames indicate incomplete combustion and soot
formation.
3. Which safety device shuts down the burner if the pilot flame is lost?
,A. Pressure switch
B. Flame safeguard control
C. Check valve
D. Thermostat
B. Flame safeguard control
Rationale: Flame safeguard controls monitor the pilot or main flame and immediately shut
off fuel if flame is lost, preventing unburned fuel accumulation and potential explosion.
4. What is a sign of incomplete combustion in a gas-fired boiler?
A. Blue flame
B. Yellow flame
C. No flame
D. Steady flame
B. Yellow flame
Rationale: A yellow flame indicates incomplete combustion, which produces soot and
carbon monoxide. Proper burner adjustment should produce a blue flame.
5. What does a sudden drop in boiler water level indicate?
A. Normal operation
B. Serious problem requiring immediate shutdown
C. Feedwater is too cold
D. Steam demand is low
B. Serious problem requiring immediate shutdown
Rationale: A sudden drop in water level indicates a serious problem such as a tube leak or
steam leak. The boiler must be shut down immediately to prevent catastrophic failure.
6. What is the purpose of a safety relief valve on a boiler?
A. To increase pressure
B. To regulate temperature
C. To prevent overpressure
D. To control water level
C. To prevent overpressure
Rationale: Safety relief valves automatically release excess pressure when it exceeds the
maximum allowable working pressure, preventing boiler failure and explosion.
, 7. What is the function of a low-water cutoff?
A. Automatically add water to the boiler
B. Control water temperature
C. Shut down the burner if water level drops below safe level
D. Drain sediment from the boiler
C. Shut down the burner if water level drops below safe level
Rationale: The low-water cutoff is a critical safety device that shuts down the burner
automatically when water level drops to an unsafe level, preventing boiler overheating and
damage.
8. When should a boiler be shut down immediately?
A. When steam pressure is stable
B. When a cracked tube is discovered
C. When water level is normal
D. When feedwater is warm
B. When a cracked tube is discovered
Rationale: A cracked boiler tube is a serious safety hazard. The boiler must be shut down
immediately and the tube properly repaired or replaced before resuming operation.
9. What does a high carbon monoxide reading in flue gas indicate?
A. High combustion efficiency
B. Incomplete combustion and poor fuel efficiency
C. Excessive excess air
D. Clean combustion
B. Incomplete combustion and poor fuel efficiency
Rationale: High CO levels indicate incomplete combustion due to insufficient oxygen or
poor fuel-air mixing, resulting in wasted fuel and a safety hazard.
10. What is the minimum blowdown percentage for a spring-loaded safety valve per
NYC code?
A. 2%
B. 5%
C. 10%
D. 15%
SOLUTIONS 100% VERIFIED!!! ALREADY GRADED A+ LATEST UPDATE
SECTION ONE: BOILER OPERATION AND COMBUSTION
1. What is the primary function of a boiler in a heating system?
A. To cool water for distribution
B. To transfer heat to water or steam
C. To generate electrical power
D. To filter air for ventilation
B. To transfer heat to water or steam
Rationale: Boilers transfer heat energy to water or steam for building heating and process
applications. This is the fundamental purpose of any boiler system.
2. What is the normal color of a properly adjusted gas flame?
A. Red
B. Blue
C. Orange
D. Yellow
B. Blue
Rationale: A blue flame indicates proper combustion with sufficient oxygen and correct
fuel-air mixture. Yellow or orange flames indicate incomplete combustion and soot
formation.
3. Which safety device shuts down the burner if the pilot flame is lost?
,A. Pressure switch
B. Flame safeguard control
C. Check valve
D. Thermostat
B. Flame safeguard control
Rationale: Flame safeguard controls monitor the pilot or main flame and immediately shut
off fuel if flame is lost, preventing unburned fuel accumulation and potential explosion.
4. What is a sign of incomplete combustion in a gas-fired boiler?
A. Blue flame
B. Yellow flame
C. No flame
D. Steady flame
B. Yellow flame
Rationale: A yellow flame indicates incomplete combustion, which produces soot and
carbon monoxide. Proper burner adjustment should produce a blue flame.
5. What does a sudden drop in boiler water level indicate?
A. Normal operation
B. Serious problem requiring immediate shutdown
C. Feedwater is too cold
D. Steam demand is low
B. Serious problem requiring immediate shutdown
Rationale: A sudden drop in water level indicates a serious problem such as a tube leak or
steam leak. The boiler must be shut down immediately to prevent catastrophic failure.
6. What is the purpose of a safety relief valve on a boiler?
A. To increase pressure
B. To regulate temperature
C. To prevent overpressure
D. To control water level
C. To prevent overpressure
Rationale: Safety relief valves automatically release excess pressure when it exceeds the
maximum allowable working pressure, preventing boiler failure and explosion.
, 7. What is the function of a low-water cutoff?
A. Automatically add water to the boiler
B. Control water temperature
C. Shut down the burner if water level drops below safe level
D. Drain sediment from the boiler
C. Shut down the burner if water level drops below safe level
Rationale: The low-water cutoff is a critical safety device that shuts down the burner
automatically when water level drops to an unsafe level, preventing boiler overheating and
damage.
8. When should a boiler be shut down immediately?
A. When steam pressure is stable
B. When a cracked tube is discovered
C. When water level is normal
D. When feedwater is warm
B. When a cracked tube is discovered
Rationale: A cracked boiler tube is a serious safety hazard. The boiler must be shut down
immediately and the tube properly repaired or replaced before resuming operation.
9. What does a high carbon monoxide reading in flue gas indicate?
A. High combustion efficiency
B. Incomplete combustion and poor fuel efficiency
C. Excessive excess air
D. Clean combustion
B. Incomplete combustion and poor fuel efficiency
Rationale: High CO levels indicate incomplete combustion due to insufficient oxygen or
poor fuel-air mixing, resulting in wasted fuel and a safety hazard.
10. What is the minimum blowdown percentage for a spring-loaded safety valve per
NYC code?
A. 2%
B. 5%
C. 10%
D. 15%
