Boiler Operator Licensing Exam Study Guide – Practice Questions with Answers. GRADED A+. Latest 2026/2027 Update.

Boiler Operator Licensing
Exam Study Guide – Practice
Questions with Answers.
GRADED A+. Latest 2026/2027
Update.



1 or more safety valves - Ans✔✔-all steam boilers must have



Locked closed - Ans✔✔-before anyone enters the boiler drum, the main steam
stop valve, bottom blowdown valves, & feedwater valves should be



212 degrees F - Ans✔✔-at atmospheric pressure, water begins to boil at
approximately



Fuel oil, gas, & coal - Ans✔✔-fuels most commonly used in boilers



Steam pressure gauge - Ans✔✔-must be connected to the highest part of the
steam side of the boiler



Half full - Ans✔✔-with an NOWL in a boiler, the gauge glass is approximately

, Foaming - Ans✔✔-a high surface tension on top of the boiler water can lead to



Mud drum - Ans✔✔-Bottom blowdown on a boiler removes sludge & sediment
from the



Tin - Ans✔✔-a boiler fusible plug is brass or bronze with a core of



Pounds per square inch - Ans✔✔-a steam pressure gauge is calibrated in



Try cocks - Ans✔✔-a secondary means of determining boiler water level



Oily waste rag storage - Ans✔✔-fires caused by spontaneous combustion are
most likely to occur in the



Steam - Ans✔✔-a siphon installed between the boiler & the pressure gauge
protects the Bourdon tube from



Prevent formation of scale - Ans✔✔-boiler feedwater is chemically treated to



Inside tube surface - Ans✔✔-in a firetube boiler, soot accumulates on the



1.5 times the MAWP - Ans✔✔-the pressure applied on the boiler during a
hydrostatic test should be