License Practice Exam Questions, Special
Boiler License Practice Exam Minnesota,
Safe Boiler Operation Fundamentals—
Special Engineer's Guide for the State of
Minnesota, Practice Test #1, Special
Boiler License Study... with correct
answers 2025/2026
For the purpose of rating boiler horsepower for an Engineers License only, how many square
feet of boiler surface shall be equivalent to one boiler horsepower on a boiler? - Correct
answer10 Sq. Ft. Heating Surface
,What is meant by the term "Low Pressure Boiler"? - Correct answerBoilers operating at a steam
or other vapor pressure of 15psig or less, or a hot water or other liquid boiler in which the
pressure does not exceed 160 psig or a temperature of 250 degrees F.
A person holding a current State of Minnesota Special Engineers License could be in charge of,
or a shift engineer in what size plant(s)? - Correct answerHigh and Low pressure boilers not to
exceed a total of 50 boiler horsepower, or a shift engineer in a 100 horsepower plant.
Special Engineer may serve as an apprentice of what size water/liquid or steam/vapor boiler? -
Correct answerIn any plant regardless of size under the direct supervision of a properly licensed
engineer.
The purpose of low water cut out on a steam or hot water boiler is to what? - Correct
answerShut off the burner when a low water condition exists.
The valve or valves that must relieve all excess pressure on a steam or hot water boiler are
what? - Correct answerSafety valve and/or an ASME approved safety relief valve.
A Tri indicator could be found on a: - Correct answerHot water boiler
A tri indicator would inform the boiler operator of what? - Correct answerThe TEMPERATURE of
the water, the PRESSURE of the water in PSIG, and the ALTITUDE of water in feet.
What is the destructive force in a steam or hot water boiler explosion? - Correct answerThe
instant release of energy stored in the water as heat.
An ASME approved safety relieve calve used on a hot water boiler is tested at the factory on
what? - Correct answerSteam first then hot water.
Some of the things you could find on a steam boiler (or hot water boiler) are what? - Correct
answerLow water cut off, safety valve or safety relief valve, pressure gauge.
,What devices would only be found on a steam boiler? - Correct answerSteam pressure gauge,
tricocks, Pressuretrols
An expansion tank or compression tank would be used in what? - Correct answerHot water
boiler
What is the purpose of the expansion tank? - Correct answerTo provide for expansion and
contraction of the water volume as its temperature varies.
On a hot water boiler, what is the purpose of the vent valve? - Correct answerTo make sure
there is water inside the boiler and to vent any trapped air.
If the safety valve or ASME safety relief valve leaks you would do what? - Correct answerHave
the valve repaired or replaced.
Tri cocks or gauge cocks are sued on a steam boiler to indicate? - Correct answerThe true water
level inside the boiler.
On a steam or hot water boiler, the safety valve or safety relief valve could be tested by? -
Correct answerWhen the boiler is running lifting the lever on the valve or raising the pressure
until they operate.
Before starting a steam or hot water boiler you should check for what? - Correct answerWater
in the boiler.
True or False: Bottom blow down valves are used for both steam and hot water. - Correct
answerTrue
Safety valves or safety relief valves should be manually tested at least...? - Correct
answerMonthly
, The low water cut out is one of the most important electrical/mechanical devices on your boiler.
How often should you test it? - Correct answerDaily
What device must be located between a hot water boiler and the expansion tank? - Correct
answerA shut off valve so the expansion can be isolated and drained during operation of the
boiler.
On a hot water boiler, every time the burner operates the safety relief valve opens. Why? -
Correct answerThe expansion tank is water logged, or the isolating valve for the expansion tank
is closed.
An Aquastat is used on a...? - Correct answerHot water boiler
To reduce thermal shock on hot water boilers, what devices are used? - Correct answerLow limit
or low fire hold control, three way valve, run around pump.
On a steam boiler the control named operator will... - Correct answerOn pressure decrease:
Start. On pressure increase: Stop.
On a hot water boiler the control called the operator will... - Correct answerOn temperature
decrease: Start. On temperature increase: Stop.
On a steam boiler what is a siphon or pigtail used for? - Correct answerTo protect the steam
gauge from too high of temperature.
What is one reason causing the expansion tank to fill with water? - Correct answerAir leaks from
the gauge glass fitting.
What would you do if you cam into a boiler room and found no water in the boiler? - Correct
answerShut off the burner and allow boiler to cool.