NJ BLACK SEAL BOILER OPERATOR EXAM PREPARATION – VERSION 1 QUESTIONS COMPLETE WITH 100% VERIFIED ANSWERS

NJ BLACK SEAL BOILER OPERATOR EXAM
PREPARATION – VERSION 1 QUESTIONS
COMPLETE WITH 100% VERIFIED ANSWERS




1. A boiler operating at 14 psi steam is classified as:
A) High pressure
B) Low pressure
C) Power boiler
D) Supercritical
Correct Answer: B
*Explanation: Low-pressure steam boilers operate at or below 15 psi.*
2. The maximum allowable working pressure for a heating boiler is
found on the:
A) Safety valve tag
B) Boiler nameplate
C) Gauge glass
D) Feedwater line
Correct Answer: B
Explanation: The manufacturer stamps the MAWP on the boiler
nameplate.
3. A boiler’s safety valve should be set at or below:
A) 110% of MAWP

,B) MAWP
C) 90% of MAWP
D) 50% of MAWP
Correct Answer: B
Explanation: Safety valves must be set at or below MAWP to prevent
overpressure.
4. What is the primary function of a boiler’s water column?
A) To store extra water
B) To reduce water turbulence for accurate level reading
C) To increase steam pressure
D) To filter feedwater
Correct Answer: B
Explanation: The water column dampens fluctuations so the gauge glass
shows a stable level.
5. A boiler explosion caused by sudden ignition of accumulated fuel is a:
A) Crown sheet failure
B) Furnace explosion
C) Low water explosion
D) Hydrostatic failure
Correct Answer: B
Explanation: Fuel vapor accumulation and ignition cause furnace
explosions.
6. Which of the following is a watertube boiler characteristic?
A) Water passes through tubes, hot gas outside
B) Hot gas passes through tubes, water outside
C) No water tubes
D) Used only for low pressure

,Correct Answer: A
Explanation: In watertube boilers, water circulates inside tubes
surrounded by hot gases.
7. The try lever on a safety valve is used to:
A) Adjust the set pressure
B) Manually lift the valve for testing
C) Lock the valve closed
D) Remove the valve
Correct Answer: B
Explanation: The try lever manually lifts the valve to verify it is not stuck.
8. A boiler operator notices the water level is not visible in the gauge
glass. The first action is:
A) Immediately add water
B) Shut off the burner and then try to determine water level
C) Open the blowdown valve
D) Increase feedwater pressure
Correct Answer: B
Explanation: Shut off fire first; adding water to an overheated boiler can
cause explosion.
9. The Hartford Loop is installed on:
A) Hot water boilers
B) Steam heating boilers
C) Electric boilers
D) Superheaters
Correct Answer: B
Explanation: The Hartford Loop prevents boiler drainage through return
line leaks.

, 10. A boiler’s feedwater line should have a check valve located:
A) At the feedwater pump discharge, near the boiler
B) On the steam outlet
C) On the blowdown line
D) On the gauge glass
Correct Answer: A
Explanation: The check valve prevents backflow from boiler to
feedwater line.
11. What is the purpose of boiler blowdown?
A) To reduce steam pressure
B) To remove sludge and concentrated solids
C) To add water
D) To increase temperature
Correct Answer: B
Explanation: Blowdown controls total dissolved solids and removes
sediment.
12. A low-pressure hot water boiler has a maximum temperature of:
A) 212°F
B) 250°F
C) 300°F
D) 350°F
Correct Answer: B
*Explanation: ASME Section IV limits low-pressure hot water boilers to
250°F.*
13. A boiler’s stack temperature is excessively high. This could indicate:
A) Soot on fireside or scale on waterside
B) Low excess air