City of Omaha Second Grade Stationary
Engineer Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
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1.A stationary engineer operating a boiler plant must understand that the
primary purpose of a safety valve on a steam boiler is to:
A. Control the normal operating pressure of the boiler
B. Release excess steam pressure to prevent boiler failure
C. Increase steam production during peak demand
D. Remove dissolved solids from boiler water
Answer: B. Release excess steam pressure to prevent boiler failure
A safety valve is a pressure-relief device designed to automatically open
when boiler pressure exceeds a safe limit, preventing catastrophic damage
or explosion.
2. The lowest allowable water level in a steam boiler is established
mainly to prevent:
A. Excessive fuel consumption
B. Low steam temperature
C. Overheating and failure of boiler heating surfaces
D. Condensation in the steam lines
Answer: C. Overheating and failure of boiler heating surfaces
,If the water level drops too low, metal surfaces exposed to intense heat
may overheat, weaken, and fail because water is no longer absorbing heat
from the furnace area.
3. The function of a boiler feedwater pump is to:
A. Circulate combustion air
B. Supply water to the boiler at operating pressure
C. Remove steam from the boiler
D. Reduce boiler pressure
Answer: B. Supply water to the boiler at operating pressure
Feedwater pumps deliver treated water into the boiler against internal
pressure so steam production can continue safely and efficiently.
4. The main purpose of boiler water treatment is to:
A. Increase fuel pressure
B. Prevent scale and corrosion
C. Increase flame temperature
D. Reduce steam pressure
Answer: B. Prevent scale and corrosion
Water treatment removes or controls impurities that can form scale, cause
corrosion, and reduce boiler efficiency or damage equipment.
5. A boiler blowdown operation is performed to:
A. Increase boiler pressure
B. Remove concentrated impurities from boiler water
,C. Increase burner capacity
D. Clean the combustion chamber
Answer: B. Remove concentrated impurities from boiler water
Blowdown removes dissolved solids and sludge that accumulate in boiler
water, helping maintain proper water chemistry.
6. The device that indicates the water level inside a steam boiler is called
a:
A. Pressure gauge
B. Thermostat
C. Water column and gauge glass
D. Safety valve
Answer: C. Water column and gauge glass
The water column connects to the boiler and displays the actual water
level through the gauge glass for safe operation.
7. A boiler pressure gauge should normally be connected to:
A. The combustion chamber
B. The steam space of the boiler
C. The fuel supply line
D. The feedwater tank
Answer: B. The steam space of the boiler
The pressure gauge measures the pressure of steam within the boiler so
the operator can monitor operating conditions.
, 8. The purpose of a low-water cutoff device is to:
A. Increase steam pressure
B. Shut down the burner when water level becomes unsafe
C. Increase feedwater temperature
D. Reduce fuel costs automatically
Answer: B. Shut down the burner when water level becomes unsafe
A low-water cutoff protects the boiler by stopping firing before
overheating occurs due to insufficient water coverage.
9. The three basic requirements for combustion are:
A. Water, steam, and pressure
B. Fuel, oxygen, and heat
C. Air, water, and electricity
D. Fuel, steam, and lubrication
Answer: B. Fuel, oxygen, and heat
Combustion requires a combustible material, oxygen to support burning,
and enough heat to begin and sustain the reaction.
10. Excessive air supplied to a burner generally causes:
A. Increased heat transfer efficiency
B. Reduced stack temperature
C. Heat loss through the chimney
D. Lower oxygen content in exhaust gases
Answer: C. Heat loss through the chimney
Engineer Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1.A stationary engineer operating a boiler plant must understand that the
primary purpose of a safety valve on a steam boiler is to:
A. Control the normal operating pressure of the boiler
B. Release excess steam pressure to prevent boiler failure
C. Increase steam production during peak demand
D. Remove dissolved solids from boiler water
Answer: B. Release excess steam pressure to prevent boiler failure
A safety valve is a pressure-relief device designed to automatically open
when boiler pressure exceeds a safe limit, preventing catastrophic damage
or explosion.
2. The lowest allowable water level in a steam boiler is established
mainly to prevent:
A. Excessive fuel consumption
B. Low steam temperature
C. Overheating and failure of boiler heating surfaces
D. Condensation in the steam lines
Answer: C. Overheating and failure of boiler heating surfaces
,If the water level drops too low, metal surfaces exposed to intense heat
may overheat, weaken, and fail because water is no longer absorbing heat
from the furnace area.
3. The function of a boiler feedwater pump is to:
A. Circulate combustion air
B. Supply water to the boiler at operating pressure
C. Remove steam from the boiler
D. Reduce boiler pressure
Answer: B. Supply water to the boiler at operating pressure
Feedwater pumps deliver treated water into the boiler against internal
pressure so steam production can continue safely and efficiently.
4. The main purpose of boiler water treatment is to:
A. Increase fuel pressure
B. Prevent scale and corrosion
C. Increase flame temperature
D. Reduce steam pressure
Answer: B. Prevent scale and corrosion
Water treatment removes or controls impurities that can form scale, cause
corrosion, and reduce boiler efficiency or damage equipment.
5. A boiler blowdown operation is performed to:
A. Increase boiler pressure
B. Remove concentrated impurities from boiler water
,C. Increase burner capacity
D. Clean the combustion chamber
Answer: B. Remove concentrated impurities from boiler water
Blowdown removes dissolved solids and sludge that accumulate in boiler
water, helping maintain proper water chemistry.
6. The device that indicates the water level inside a steam boiler is called
a:
A. Pressure gauge
B. Thermostat
C. Water column and gauge glass
D. Safety valve
Answer: C. Water column and gauge glass
The water column connects to the boiler and displays the actual water
level through the gauge glass for safe operation.
7. A boiler pressure gauge should normally be connected to:
A. The combustion chamber
B. The steam space of the boiler
C. The fuel supply line
D. The feedwater tank
Answer: B. The steam space of the boiler
The pressure gauge measures the pressure of steam within the boiler so
the operator can monitor operating conditions.
, 8. The purpose of a low-water cutoff device is to:
A. Increase steam pressure
B. Shut down the burner when water level becomes unsafe
C. Increase feedwater temperature
D. Reduce fuel costs automatically
Answer: B. Shut down the burner when water level becomes unsafe
A low-water cutoff protects the boiler by stopping firing before
overheating occurs due to insufficient water coverage.
9. The three basic requirements for combustion are:
A. Water, steam, and pressure
B. Fuel, oxygen, and heat
C. Air, water, and electricity
D. Fuel, steam, and lubrication
Answer: B. Fuel, oxygen, and heat
Combustion requires a combustible material, oxygen to support burning,
and enough heat to begin and sustain the reaction.
10. Excessive air supplied to a burner generally causes:
A. Increased heat transfer efficiency
B. Reduced stack temperature
C. Heat loss through the chimney
D. Lower oxygen content in exhaust gases
Answer: C. Heat loss through the chimney
