STATIONARY ENGINEER EXAM
STUDY GUIDE | 2026 | 630
QUESTIONS WITH 100% CORRECT
ANSWERS GRADED A+ | UPDATED
& VERIFIED | 74 PAGES
High pressure steam boilers generally operate at pressures
A. above 15 psi and over 6 boiler horsepower.
B. below 15 psi and over 8 boiler horsepower.
C. above 250 psi and over 6 boiler horsepower.
D. at 212 psi and over 8 boiler horsepower. - answer-A. above 15 psi and over 6 boiler
horsepower.
Pressure gauges should never have a range less than
A. half the safety valve set pressure.
B. double the safety valve set pressure.
C. 3/4 times the safety valve set pressure.
D. 1 1/2 times the safety valve set pressure. - answer-D. 1 1/2 times the safety valve set
pressure.
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. - answer-C. Live steam will
damage the pressure gauge.
,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. - answer-D.
obtaining the correct difference in pressure inside and outside the boiler.
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. - answer-A. Adding water to an
operating boiler when the water level cannot be seen in the gauge glass tube.
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. - answer-A. Vent the boiler with the try cocks.
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. - answer-D. To test the low water cutoff control.
, 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. - answer-A. within 4 seconds.
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. - answer-C. Never allow the
cleaner to stay in one place.
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 - answer-B. A shut-off valve
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 - answer-B. Class C extinguishers
If certain grades of fuel oil are not preheated properly, they may cause
A. higher temperatures in the furnace.
STUDY GUIDE | 2026 | 630
QUESTIONS WITH 100% CORRECT
ANSWERS GRADED A+ | UPDATED
& VERIFIED | 74 PAGES
High pressure steam boilers generally operate at pressures
A. above 15 psi and over 6 boiler horsepower.
B. below 15 psi and over 8 boiler horsepower.
C. above 250 psi and over 6 boiler horsepower.
D. at 212 psi and over 8 boiler horsepower. - answer-A. above 15 psi and over 6 boiler
horsepower.
Pressure gauges should never have a range less than
A. half the safety valve set pressure.
B. double the safety valve set pressure.
C. 3/4 times the safety valve set pressure.
D. 1 1/2 times the safety valve set pressure. - answer-D. 1 1/2 times the safety valve set
pressure.
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. - answer-C. Live steam will
damage the pressure gauge.
,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. - answer-D.
obtaining the correct difference in pressure inside and outside the boiler.
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. - answer-A. Adding water to an
operating boiler when the water level cannot be seen in the gauge glass tube.
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. - answer-A. Vent the boiler with the try cocks.
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. - answer-D. To test the low water cutoff control.
, 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. - answer-A. within 4 seconds.
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. - answer-C. Never allow the
cleaner to stay in one place.
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 - answer-B. A shut-off valve
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 - answer-B. Class C extinguishers
If certain grades of fuel oil are not preheated properly, they may cause
A. higher temperatures in the furnace.
