Boiler Exam Practice Tests 2026 | Study Guide & Sample Questions

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Boiler Operator Licensing Exam (NEW UPDATED VERSION) LATEST ACTUAL
EXAM QUESTIONS AND CORRECT ANSWERS (VERIFIED QUESTIONS AND
ANSWERS)- GUARANTEED PASS A+ UPDATED 2026




1 or more safety valves - CORRECT ANSWER all steam boilers must
have


QUESTION : Locked closed - CORRECT ANSWER before anyone enters
the boiler drum, the main steam stop valve, bottom blowdown valves, &
feedwater valves should be


QUESTION : 212 degrees F - CORRECT ANSWER at atmospheric
pressure, water begins to boil at approximately


QUESTION : Fuel oil, gas, & coal - CORRECT ANSWER fuels most
commonly used in boilers


QUESTION : Steam pressure gauge - CORRECT ANSWER must be
connected to the highest part of the steam side of the boiler


QUESTION : Half full - CORRECT ANSWER with an NOWL in a boiler,
the gauge glass is approximately


QUESTION : Foaming - CORRECT ANSWER a high surface tension on
top of the boiler water can lead to

2026 2027 GRADED A+

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QUESTION : Mud drum - CORRECT ANSWER Bottom blowdown on a
boiler removes sludge & sediment from the


QUESTION : Tin - CORRECT ANSWER a boiler fusible plug is brass or
bronze with a core of


QUESTION : Pounds per square inch - CORRECT ANSWER a steam
pressure gauge is calibrated in


QUESTION : Try cocks - CORRECT ANSWER a secondary means of
determining boiler water level


QUESTION : Oily waste rag storage - CORRECT ANSWER fires caused
by spontaneous combustion are most likely to occur in the


QUESTION : Steam - CORRECT ANSWER a siphon installed between
the boiler & the pressure gauge protects the Bourdon tube from


QUESTION : Prevent formation of scale - CORRECT ANSWER boiler
feedwater is chemically treated to


QUESTION : Inside tube surface - CORRECT ANSWER in a firetube
boiler, soot accumulates on the




2026 2027 GRADED A+

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QUESTION : 1.5 times the MAWP - CORRECT ANSWER the pressure
applied on the boiler during a hydrostatic test should be


QUESTION : Decreased - CORRECT ANSWER as fuel oil is heated, its
viscosity is


QUESTION : Chimney - CORRECT ANSWER the induced draft fan is
located between the boiler & the


QUESTION : Flash when exposed to an open flame - CORRECT ANSWER
the flash point of fuel oil is the minimum temperature at which the fuel will


QUESTION : Burn continually - CORRECT ANSWER the fire point of
fuel oil is the minimum temperature at which the fuel will


QUESTION : Lowest; flow - CORRECT ANSWER the pour point of fuel
oil is the ____ temperature at which fuel oil will ____


QUESTION : Dangerous to handle - CORRECT ANSWER fuel oil with a
low flash point is


QUESTION : Pressure control - CORRECT ANSWER the operating range
of a steam boiler is controlled by a


QUESTION : Condensate in the line - CORRECT ANSWER water
hammer in steam lines is caused by


2026 2027 GRADED A+