MD STATIONARY ENGINEER EOC 2025/2026 QUESTIONS
WITH ANSWERS GRADED A+
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. - ✔✔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. - ✔✔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. - ✔✔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. - ✔✔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. - ✔✔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 - ✔✔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 - ✔✔B. Class C extinguishers
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. - ✔✔C. poor combustion and
high fuel consumption.
The furnace is almost always in a ___________ pressure.
Negative
Positive - ✔✔Negative
In an open feedwater heater or de-aerating feedwater tank, a clogged vent line will
_______ air/non-condensables in feedwater.
Increase
Decrease - ✔✔Increase
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 ________. - ✔✔steam piston, water piston, stroke
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. - ✔✔cylinder, suction
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. - ✔✔Lowest, Cavitation, high
Condensate system has ________ vent on top. Condensate is treated to get rid of
____________. - ✔✔atmospheric. carbonic acid.
The feedwater regulating valve has a _________ line to get rid of sludge/sediment -
✔✔blowdown
Thermostatic type steam traps are used on ____________ - ✔✔radiators
WITH ANSWERS GRADED A+
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. - ✔✔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. - ✔✔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. - ✔✔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. - ✔✔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. - ✔✔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 - ✔✔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 - ✔✔B. Class C extinguishers
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. - ✔✔C. poor combustion and
high fuel consumption.
The furnace is almost always in a ___________ pressure.
Negative
Positive - ✔✔Negative
In an open feedwater heater or de-aerating feedwater tank, a clogged vent line will
_______ air/non-condensables in feedwater.
Increase
Decrease - ✔✔Increase
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 ________. - ✔✔steam piston, water piston, stroke
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. - ✔✔cylinder, suction
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. - ✔✔Lowest, Cavitation, high
Condensate system has ________ vent on top. Condensate is treated to get rid of
____________. - ✔✔atmospheric. carbonic acid.
The feedwater regulating valve has a _________ line to get rid of sludge/sediment -
✔✔blowdown
Thermostatic type steam traps are used on ____________ - ✔✔radiators
