MN SPECIAL BOILER LICENSE EXAM GUIDE FOR MHS CUSTODIANS
Q & A #10
High Pressure Boiler - correct answer Above 15psi steam & 160psi water pressure
After blowing down column and glass the water should return how? - correct answer
Quickly
When entering a steam boiler room what is the first thing an operator should do? -
correct answer Check water level
What type of safety valve is required - correct answer A.S.M.E. approved direct spring
loaded
When operating a boiler what is most important? - correct answer Safety
When draining a boiler how should you cool it? - correct answer Slowly
How does a low water cut off protect a boiler? - correct answer Shuts off fuel in case of
low water
If you cannot determine water level what should you do? - correct answer Shut off
burner or extinguish fire
Why is a lifting lever on a safety valve? - correct answer Test operation of the valve
Which is the most important valve on a boiler? - correct answer Safety valve
Who is responsible for a boiler inspection? - correct answer Owner or properly licensed
engineer
If water glass is shut off or plugged what do you do? - correct answer Continue in
operation using tri cocks with continuous attendance
What is the process of removing unburned gas from the combustion chamber called? -
correct answer Purging
A safety valve is attached to a steam boiler for what purpose? - correct answer To
prevent over pressure
If a boiler became low on water who must be notified? - correct answer The boiler
inspector
If a low water cut off does not work when tested what do you do? - correct answer Shut
down and repair immediately
,What is the purpose of an expansion tank? - correct answer Allows for expansion and
contraction as water volume varies
State of MN requires boilers to be inspected how often? - correct answer Depends if it is
steam or hot water.
How long do you vent a boiler before starting fires? - correct answer 4 air exchanges
What is the rapid burning of fuel and oxygen resulting in heat? - correct answer
Combustion
What is the purpose of bottom blowdowns besides removing sludge? - correct answer
To drain the boiler
What turns a hot water boiler on based on water temperature? - correct answer An
aquastat
Steam boilers under 200 horsepower must have low water cutoff tested how often? -
correct answer When in operation and on low fire
What is an indication of a gauge glass not working properly? - correct answer No
movement in the water glass
When comparing a hot water boiler to a steam boiler, what does a hot water boiler have
that a steam boiler does not? - correct answer Circulating pump, expansion tank, and
an aquastat
What is the device that will shut the boiler down in case of low water? - correct answer
Low water cutoff
What must be displayed in a boiler room? - correct answer Current license and log book
According to national board code, safety valves are to be tested how often? - correct
answer 90 days
What device removes air and condensate? - correct answer Steam trap
What must be done after a hot water boiler has been drained, cleaned and refilled? -
correct answer Remove air
What can a special engineer operate? - correct answer In charge of 50 horsepower.
Shift operator 100 horsepower high or low pressure
What are the three main types of boilers? - correct answer Fire tube, water tube, cast
iron sectional
, How much experience is required for a special license? - correct answer No experience
At a minimum, what is required in a log book? - correct answer Who, what and when
When in operation a 40 horsepower boiler may be left unattended for how long? -
correct answer 24 hours
What method of testing low water cut off most accurately simulates low water? - correct
answer Shutting off the feed pump and feeder valve supply and blowing down low water
cutoff
Low water cutoff on a hot water boiler must be able to be tested how? - correct answer
Without draining the entire system
Dial of a steam gauge must be graduated to not less than what? - correct answer 1 and
1/2 times the safety valve setting
Cast iron boilers are held together how? - correct answer With bolts
Tubes in a fire tube boiler serve what function? - correct answer Support tube sheets
and increase heating surface
When in operation, a high pressure boiler of 25 horsepower must be checked how
often? - correct answer Every 24 hours
A feed water line must have what two valves? - correct answer Check & stop
After a new boiler is installed, what must be performed? - correct answer Hydrostatic
test
All stationary boilers of what pressure must have 2 valves on the blow off line? - correct
answer 100psi
How is boiler efficiency calculated? - correct answer Output divided by input
Boiler efficiency can be increased how? - correct answer Minimize soot and scale
Boilers operate most efficiently at what type of fire? - correct answer High fire
What are three ways to transfer heat? - correct answer Radiation, conduction,
convection
For licensing purposes, how many square feet heating space equals a boiler
horsepower? - correct answer 10 square feet
Q & A #10
High Pressure Boiler - correct answer Above 15psi steam & 160psi water pressure
After blowing down column and glass the water should return how? - correct answer
Quickly
When entering a steam boiler room what is the first thing an operator should do? -
correct answer Check water level
What type of safety valve is required - correct answer A.S.M.E. approved direct spring
loaded
When operating a boiler what is most important? - correct answer Safety
When draining a boiler how should you cool it? - correct answer Slowly
How does a low water cut off protect a boiler? - correct answer Shuts off fuel in case of
low water
If you cannot determine water level what should you do? - correct answer Shut off
burner or extinguish fire
Why is a lifting lever on a safety valve? - correct answer Test operation of the valve
Which is the most important valve on a boiler? - correct answer Safety valve
Who is responsible for a boiler inspection? - correct answer Owner or properly licensed
engineer
If water glass is shut off or plugged what do you do? - correct answer Continue in
operation using tri cocks with continuous attendance
What is the process of removing unburned gas from the combustion chamber called? -
correct answer Purging
A safety valve is attached to a steam boiler for what purpose? - correct answer To
prevent over pressure
If a boiler became low on water who must be notified? - correct answer The boiler
inspector
If a low water cut off does not work when tested what do you do? - correct answer Shut
down and repair immediately
,What is the purpose of an expansion tank? - correct answer Allows for expansion and
contraction as water volume varies
State of MN requires boilers to be inspected how often? - correct answer Depends if it is
steam or hot water.
How long do you vent a boiler before starting fires? - correct answer 4 air exchanges
What is the rapid burning of fuel and oxygen resulting in heat? - correct answer
Combustion
What is the purpose of bottom blowdowns besides removing sludge? - correct answer
To drain the boiler
What turns a hot water boiler on based on water temperature? - correct answer An
aquastat
Steam boilers under 200 horsepower must have low water cutoff tested how often? -
correct answer When in operation and on low fire
What is an indication of a gauge glass not working properly? - correct answer No
movement in the water glass
When comparing a hot water boiler to a steam boiler, what does a hot water boiler have
that a steam boiler does not? - correct answer Circulating pump, expansion tank, and
an aquastat
What is the device that will shut the boiler down in case of low water? - correct answer
Low water cutoff
What must be displayed in a boiler room? - correct answer Current license and log book
According to national board code, safety valves are to be tested how often? - correct
answer 90 days
What device removes air and condensate? - correct answer Steam trap
What must be done after a hot water boiler has been drained, cleaned and refilled? -
correct answer Remove air
What can a special engineer operate? - correct answer In charge of 50 horsepower.
Shift operator 100 horsepower high or low pressure
What are the three main types of boilers? - correct answer Fire tube, water tube, cast
iron sectional
, How much experience is required for a special license? - correct answer No experience
At a minimum, what is required in a log book? - correct answer Who, what and when
When in operation a 40 horsepower boiler may be left unattended for how long? -
correct answer 24 hours
What method of testing low water cut off most accurately simulates low water? - correct
answer Shutting off the feed pump and feeder valve supply and blowing down low water
cutoff
Low water cutoff on a hot water boiler must be able to be tested how? - correct answer
Without draining the entire system
Dial of a steam gauge must be graduated to not less than what? - correct answer 1 and
1/2 times the safety valve setting
Cast iron boilers are held together how? - correct answer With bolts
Tubes in a fire tube boiler serve what function? - correct answer Support tube sheets
and increase heating surface
When in operation, a high pressure boiler of 25 horsepower must be checked how
often? - correct answer Every 24 hours
A feed water line must have what two valves? - correct answer Check & stop
After a new boiler is installed, what must be performed? - correct answer Hydrostatic
test
All stationary boilers of what pressure must have 2 valves on the blow off line? - correct
answer 100psi
How is boiler efficiency calculated? - correct answer Output divided by input
Boiler efficiency can be increased how? - correct answer Minimize soot and scale
Boilers operate most efficiently at what type of fire? - correct answer High fire
What are three ways to transfer heat? - correct answer Radiation, conduction,
convection
For licensing purposes, how many square feet heating space equals a boiler
horsepower? - correct answer 10 square feet
