Stationary Engineer Boiler Exam UPDATED ACTUAL Questions and
CORRECT Answers
Question: Pressure gauges should never have a range less than A. half the safety valve set pressure. B.
double the safety valve set pressure. C. times the safety valve set pressure. D. 1 times the safety valve set
pressure.
Correct Answer: D. 1 times the safety valve set pressure.
Question: After water is blown out of a siphon, why should live steam never be allowed to enter a Bourdon
tube? A. The steam will rupture the siphon tube. B. Combustion gases will mix with the steam. C. Live
steam will damage the pressure gauge. D. The water level gauge will be damaged or destroyed.
Correct Answer: C. Live steam will damage the pressure gauge.
Question: All of the following are essential to maintain the proper fuel oil pressure with fuel oil accessories
EXCEPT A. achieving the right flow of fuel. B. proper atomization of the fuel oil. C. heating fuel oil to the
correct temperature. D. obtaining the correct difference in pressure inside and outside the boiler.
Correct Answer: D. obtaining the correct difference in pressure inside and outside the boiler.
Question: Which of the following could be dangerous to safe operation of a low pressure boiler? A. Adding
water to an operating boiler when the water level cannot be seen in the gauge glass tube. B. Opening the
blowdown valve at the bottom of the water gauge glass before making a water level reading. C. Checking
the water level using the try cocks valves when the line to the glass gauge tube is clogged. D. Opening the
water column blowdown valve every day.
Correct Answer: A. Adding water to an operating boiler when the water level cannot be seen in the gauge
glass tube.
Question: Which of the following is best if a low-pressure boiler does not have an air vent? A. Vent the
boiler with the try cocks. B. Vent the boiler with the safety valve. C. Vent the boiler with the fusible plug.
D. Vent the boiler with the blowdown line.
Correct Answer: A. Vent the boiler with the try cocks.
Question: What is the purpose of an evaporation test on a low pressure boiler? A. To test the water column
B. To test the bottom blowdown valve C. To test the steam pressure safety valve D. To test the low water
cutoff control.
Correct Answer: D. To test the low water cutoff control.
Question: Following flame failure, controls must de-energize fuel and ignition circuits A. within 4 seconds.
B. within 6 seconds. C. within 10 seconds. D. within 15 seconds.
Correct Answer: A. within 4 seconds.
Question: How can an operator prevent damage to the tubes while using a cleaner to remove scale from
boiler tubes? A. Never use a chemical cleaning procedure. B. Never use cleaning water under pressure. C.
Never allow the cleaner to stay in one place. D. Never clean the tubes more often than every six months.
Correct Answer: C. Never allow the cleaner to stay in one place.
Question: In a steam boiler, which of the following should never be placed between the safety relief valve
and the boiler? A. A steam trap B. A shut-off valve C. An air eliminator D. A discharge pipe
, Correct Answer: B. A shut-off valve
Question: Which of these should be used on live electrical fires? A. Class D extinguishers B. Class C
extinguishers C. Class B extinguishers D. Class A extinguishers
Correct Answer: B. Class C extinguishers
Question: If certain grades of fuel oil are not preheated properly, they may cause A. higher temperatures in
the furnace. B. back pressure and leaks in the fuel lines. C. poor combustion and high fuel consumption. D.
increased pressure and dangerous levels of steam.
Correct Answer: C. poor combustion and high fuel consumption.
Question: The furnace is almost always in a ___________ pressure. Negative Positive
Correct Answer: Negative
Question: In an open feedwater heater or de-aerating feedwater tank, a clogged vent line will _______
air/non-condensables in feedwater. Increase Decrease
Correct Answer: Increase
Question: Reciprocating pump- rated by diameter of piston. 4x2x4 pump. The first number is the diameter
of the ___________. The second number is the diameter of the ______. The third number is the length of
________.
Correct Answer: steam piston, water piston, stroke
Question: Suction valve on reciprocating pump allows water into the ______ and keeps it from backing up
into the ______ line. If suction water is too hot the pump will become steam bound.
Correct Answer: cylinder, suction
Question: Horizontal split case centrifugal pump- center eye of impeller is ________ suction pressure.
_________ is the formation and collapse of vapor bubbles which will cause vibration and noise. Caused by
__________ water temp or low pressure. Vibration causes damage.
Correct Answer: Lowest, Cavitation, high
Question: Condensate system has ________ vent on top. Condensate is treated to get rid of ____________.
Correct Answer: atmospheric, carbonic acid
Question: The feedwater regulating valve has a _________ line to get rid of sludge/sediment
Correct Answer: blowdown
Question: Thermostatic type steam traps are used on ____________
Correct Answer: radiators
Question: Steam traps increase efficiency by removing ___________ and __________ from the system
Correct Answer: air and condensate
Question: If multiple safeties are on a boiler- the range of their settings should be _____
Correct Answer: 10
Question: %If a boiler has 500 square feet or more of heating surface, ___ feedwater pumps are needed
Correct Answer: 2
CORRECT Answers
Question: Pressure gauges should never have a range less than A. half the safety valve set pressure. B.
double the safety valve set pressure. C. times the safety valve set pressure. D. 1 times the safety valve set
pressure.
Correct Answer: D. 1 times the safety valve set pressure.
Question: After water is blown out of a siphon, why should live steam never be allowed to enter a Bourdon
tube? A. The steam will rupture the siphon tube. B. Combustion gases will mix with the steam. C. Live
steam will damage the pressure gauge. D. The water level gauge will be damaged or destroyed.
Correct Answer: C. Live steam will damage the pressure gauge.
Question: All of the following are essential to maintain the proper fuel oil pressure with fuel oil accessories
EXCEPT A. achieving the right flow of fuel. B. proper atomization of the fuel oil. C. heating fuel oil to the
correct temperature. D. obtaining the correct difference in pressure inside and outside the boiler.
Correct Answer: D. obtaining the correct difference in pressure inside and outside the boiler.
Question: Which of the following could be dangerous to safe operation of a low pressure boiler? A. Adding
water to an operating boiler when the water level cannot be seen in the gauge glass tube. B. Opening the
blowdown valve at the bottom of the water gauge glass before making a water level reading. C. Checking
the water level using the try cocks valves when the line to the glass gauge tube is clogged. D. Opening the
water column blowdown valve every day.
Correct Answer: A. Adding water to an operating boiler when the water level cannot be seen in the gauge
glass tube.
Question: Which of the following is best if a low-pressure boiler does not have an air vent? A. Vent the
boiler with the try cocks. B. Vent the boiler with the safety valve. C. Vent the boiler with the fusible plug.
D. Vent the boiler with the blowdown line.
Correct Answer: A. Vent the boiler with the try cocks.
Question: What is the purpose of an evaporation test on a low pressure boiler? A. To test the water column
B. To test the bottom blowdown valve C. To test the steam pressure safety valve D. To test the low water
cutoff control.
Correct Answer: D. To test the low water cutoff control.
Question: Following flame failure, controls must de-energize fuel and ignition circuits A. within 4 seconds.
B. within 6 seconds. C. within 10 seconds. D. within 15 seconds.
Correct Answer: A. within 4 seconds.
Question: How can an operator prevent damage to the tubes while using a cleaner to remove scale from
boiler tubes? A. Never use a chemical cleaning procedure. B. Never use cleaning water under pressure. C.
Never allow the cleaner to stay in one place. D. Never clean the tubes more often than every six months.
Correct Answer: C. Never allow the cleaner to stay in one place.
Question: In a steam boiler, which of the following should never be placed between the safety relief valve
and the boiler? A. A steam trap B. A shut-off valve C. An air eliminator D. A discharge pipe
, Correct Answer: B. A shut-off valve
Question: Which of these should be used on live electrical fires? A. Class D extinguishers B. Class C
extinguishers C. Class B extinguishers D. Class A extinguishers
Correct Answer: B. Class C extinguishers
Question: If certain grades of fuel oil are not preheated properly, they may cause A. higher temperatures in
the furnace. B. back pressure and leaks in the fuel lines. C. poor combustion and high fuel consumption. D.
increased pressure and dangerous levels of steam.
Correct Answer: C. poor combustion and high fuel consumption.
Question: The furnace is almost always in a ___________ pressure. Negative Positive
Correct Answer: Negative
Question: In an open feedwater heater or de-aerating feedwater tank, a clogged vent line will _______
air/non-condensables in feedwater. Increase Decrease
Correct Answer: Increase
Question: Reciprocating pump- rated by diameter of piston. 4x2x4 pump. The first number is the diameter
of the ___________. The second number is the diameter of the ______. The third number is the length of
________.
Correct Answer: steam piston, water piston, stroke
Question: Suction valve on reciprocating pump allows water into the ______ and keeps it from backing up
into the ______ line. If suction water is too hot the pump will become steam bound.
Correct Answer: cylinder, suction
Question: Horizontal split case centrifugal pump- center eye of impeller is ________ suction pressure.
_________ is the formation and collapse of vapor bubbles which will cause vibration and noise. Caused by
__________ water temp or low pressure. Vibration causes damage.
Correct Answer: Lowest, Cavitation, high
Question: Condensate system has ________ vent on top. Condensate is treated to get rid of ____________.
Correct Answer: atmospheric, carbonic acid
Question: The feedwater regulating valve has a _________ line to get rid of sludge/sediment
Correct Answer: blowdown
Question: Thermostatic type steam traps are used on ____________
Correct Answer: radiators
Question: Steam traps increase efficiency by removing ___________ and __________ from the system
Correct Answer: air and condensate
Question: If multiple safeties are on a boiler- the range of their settings should be _____
Correct Answer: 10
Question: %If a boiler has 500 square feet or more of heating surface, ___ feedwater pumps are needed
Correct Answer: 2
