Stationary Engineer License Exam Prep Questions and answers with explanations

Stationary Engineer
License Exam
1.


Question: What is the primary purpose of a safety valve on a boiler?
Answer: To automatically release excess steam pressure to prevent explosions.


2.


Question: According to ASME Code, what is the maximum allowable accumulation of
pressure above the maximum allowable working pressure (MAWP) when the safety
valve is discharging?

,Answer: 6% above MAWP.


3.


Question: What is the function of a deaerator in a boiler system?
Answer: To remove dissolved oxygen and carbon dioxide from feedwater, preventing
corrosion.


4.


Question: What device measures draft in a boiler furnace?
Answer: A draft gauge or manometer.


5.


Question: What type of pump is most commonly used for boiler feedwater service?
Answer: A centrifugal pump.


6.


Question: When starting a steam turbine, why must it be warmed up slowly?
Answer: To prevent thermal shock and uneven expansion that can damage the
turbine.


7.


Question: What is the purpose of a boiler economizer?
Answer: To recover heat from flue gases to preheat boiler feedwater, improving
efficiency.


8.

, Question: How often must a low-water fuel cut-off on a boiler be tested?
Answer: At least once per shift (per ASME and state regulations).


9.


Question: What is the difference between a fire-tube and water-tube boiler?
Answer:


Fire-tube: Hot gases pass through tubes surrounded by water.


Water-tube: Water circulates inside tubes heated externally by combustion gases.


10.


Question: What is cavitation in a pump?
Answer: The formation and collapse of vapor bubbles in liquid due to low pressure,
which can damage the pump impeller.


11.


Question: Which device prevents backflow of boiler water into the feedwater
supply?
Answer: A check valve or backflow preventer.


12.


Question: What type of current is typically used for large motor-driven equipment in
boiler plants?
Answer: Three-phase alternating current (AC).


13.