Work in any type of plant Special (License Grade)
Can operate low-pressure steam or hot water (no steam Grade C (License Grade)
engines/turbines)
Can operate high-pressure or low-pressure steam or hot Grade B (License Grade)
water (no steam engines/turbines)
Can operate any plant including plants with steam Grade A (License Grade)
engines/turbines
Take Charge (max 50 hpr) Special (License Class)
Shift Engineer (max 100 hpr)
Take Charge (max 100 hpr) 2nd Class (License Class)
Shift Engineer (max 500 hpr)
Take Charge (max 500 hpr) 1st Class (License Class)
Shift Engineer (unlimited hpr)
Take Charge (unlimited hpr) Chief (License Class)
Shift engineer (unlimited hpr)
Can operate and take responsibility for the plant while on Shift Engineer
duty
You are the main person in charge of the plant. You Take Charge
supervise shift engineers.
= 10 sq. Ft of heating surface 1 boiler horsepower =
1 gallon of water weighs _____ pounds 8.3
_____ kilowatts = 1 horsepower 10 kilowatts (for licensing)
__________ BTU/hr = 1 horsepower 67,000 BTU/hr (for licensing)
Where should a boiler license be displayed? In the boiler room
Stuvia 2026-2027
, MN Special Boilers License Prep Test
What will raise one pound of water by one degree F One BTU
When entering a steam boiler room what is the first thing Check water level
an operator should do?
A high pressure boiler is classified as such when what - ? Above 15 psi, above 160 psi water, and temps above 250°F
What type of safety valve is required? A.S.M.E. Approved
When operating a boiler, what is most important? Efficiency
How does a low water fuel cut off (LWCO) protect a boiler? Shuts off fuel in case of low water
If you cannot determine water level what do you do? shut off the burner when a low water condition exists.
Can you compress a liquid? No
What boilers are low pressure only? Cast Iron Sectional and Firebox
What holds cast iron sections together? Push nipples and Tie Rods
On electric boilers, how large should the ground wire be? At least as big as the largest incoming wire
Directs flow of combustion gasses, water, and/or steam Baffle
Amount of times the heat moves through the tubes in a fire Passes
tube boiler
Hard surface insulation (brick, concrete,...) Refractory
Helps keep shape and position of boiler Stays
Stuvia 2026-2027