CLASS 5 BOILER PRACTICE EXAM 2025/2026 QUESTIONS
WITH ANSWERS GRADED A+
✔✔Pulverized coal is burned in? - ✔✔Suspension
✔✔Best way to get rid of TDS (Total dissolved solids) is what? - ✔✔Continuous
Blowdown
✔✔What does the usable plug do for the boiler? - ✔✔It is the last low water alarm
✔✔What is the difference between PSIA and PSIG - ✔✔14.7 psi
✔✔How much pressure is a low pressure boiler? - ✔✔Under 15 psi
✔✔What is the ASME? - ✔✔American Society of Mechanical Engineering
✔✔What is NOWL? - ✔✔Normal Operating Water Level
✔✔What is NOP? - ✔✔Normal operating pressure
✔✔what is the percentage of oxygen and nitrogen in a boiler? - ✔✔21% oxygen and
79% nitrogen
✔✔what is the purpose of a blow down valve? - ✔✔to remove sediment and sludge
from the mud drum of the boiler
✔✔What is MAWP? - ✔✔Max allowable working pressure. Should not exceed 6%
✔✔if there is a problem in the boiler room who do you call? - ✔✔Chief Engineer
✔✔if there is a gas leak or a gas smell in the boiler room who do you call? - ✔✔The
Gas Company
✔✔What does it mean to drop the fusible plug? - ✔✔It means you melted the fusible
plug
✔✔Name three types of stress? - ✔✔compression, Tensile, shear
✔✔Name three ways to transfer heat? - ✔✔Convection, Conduction, and Radiant
✔✔what type of fittings are used on high and low pressure boilers? - ✔✔Low pressure:
Screwed
High pressure: flanged and welded
, ✔✔what is the purpose of pouring water down a floor drain? - ✔✔prevent gas or odor
from building up
✔✔how often should you blow down the boiler? - ✔✔Every 24hrs or once a day
✔✔What are three types of Refrigerants used on boilers? - ✔✔Ammonia, Lithium
Bromide, Lithium Chloride
✔✔What is sensible heat? - ✔✔Change in Temperature
✔✔What is latent heat? - ✔✔A change in state of phase
✔✔What is a BTU? - ✔✔The amount heat it takes to raise 1 pound of water 1 degree F
✔✔What does MATT mean? - ✔✔Mixture, Atomization, Time, Temp
✔✔A high pressure boiler is greater than what psig and what bhp? - ✔✔15 psi and 6
bhp
✔✔what will happen if there is a sudden dropping pressure and not a drop in the
temperature? - ✔✔A boiler explosion
✔✔When you double the temperature of a gas what happens to the volume? - ✔✔It
doubles
✔✔How often do you blowdown the gauge glass and water column? - ✔✔at least once
a shift and its at the beginning of the shift
✔✔what is located on the water column keep sludge from building inside? - ✔✔A blow
down valve
✔✔In a water tube boiler water is inside the tube, where is the gasses of combustion? -
✔✔Around the tubes
✔✔A microprocessor burner control system will secure the flame on all problems
EXCEPT - ✔✔Changing fuel ratio depending on steam load change
✔✔If I have oxygen fuel and release in heat, what other factor is missing? -
✔✔Temperature
✔✔Positioning control system need what to operate? - ✔✔Clean, dry air
WITH ANSWERS GRADED A+
✔✔Pulverized coal is burned in? - ✔✔Suspension
✔✔Best way to get rid of TDS (Total dissolved solids) is what? - ✔✔Continuous
Blowdown
✔✔What does the usable plug do for the boiler? - ✔✔It is the last low water alarm
✔✔What is the difference between PSIA and PSIG - ✔✔14.7 psi
✔✔How much pressure is a low pressure boiler? - ✔✔Under 15 psi
✔✔What is the ASME? - ✔✔American Society of Mechanical Engineering
✔✔What is NOWL? - ✔✔Normal Operating Water Level
✔✔What is NOP? - ✔✔Normal operating pressure
✔✔what is the percentage of oxygen and nitrogen in a boiler? - ✔✔21% oxygen and
79% nitrogen
✔✔what is the purpose of a blow down valve? - ✔✔to remove sediment and sludge
from the mud drum of the boiler
✔✔What is MAWP? - ✔✔Max allowable working pressure. Should not exceed 6%
✔✔if there is a problem in the boiler room who do you call? - ✔✔Chief Engineer
✔✔if there is a gas leak or a gas smell in the boiler room who do you call? - ✔✔The
Gas Company
✔✔What does it mean to drop the fusible plug? - ✔✔It means you melted the fusible
plug
✔✔Name three types of stress? - ✔✔compression, Tensile, shear
✔✔Name three ways to transfer heat? - ✔✔Convection, Conduction, and Radiant
✔✔what type of fittings are used on high and low pressure boilers? - ✔✔Low pressure:
Screwed
High pressure: flanged and welded
, ✔✔what is the purpose of pouring water down a floor drain? - ✔✔prevent gas or odor
from building up
✔✔how often should you blow down the boiler? - ✔✔Every 24hrs or once a day
✔✔What are three types of Refrigerants used on boilers? - ✔✔Ammonia, Lithium
Bromide, Lithium Chloride
✔✔What is sensible heat? - ✔✔Change in Temperature
✔✔What is latent heat? - ✔✔A change in state of phase
✔✔What is a BTU? - ✔✔The amount heat it takes to raise 1 pound of water 1 degree F
✔✔What does MATT mean? - ✔✔Mixture, Atomization, Time, Temp
✔✔A high pressure boiler is greater than what psig and what bhp? - ✔✔15 psi and 6
bhp
✔✔what will happen if there is a sudden dropping pressure and not a drop in the
temperature? - ✔✔A boiler explosion
✔✔When you double the temperature of a gas what happens to the volume? - ✔✔It
doubles
✔✔How often do you blowdown the gauge glass and water column? - ✔✔at least once
a shift and its at the beginning of the shift
✔✔what is located on the water column keep sludge from building inside? - ✔✔A blow
down valve
✔✔In a water tube boiler water is inside the tube, where is the gasses of combustion? -
✔✔Around the tubes
✔✔A microprocessor burner control system will secure the flame on all problems
EXCEPT - ✔✔Changing fuel ratio depending on steam load change
✔✔If I have oxygen fuel and release in heat, what other factor is missing? -
✔✔Temperature
✔✔Positioning control system need what to operate? - ✔✔Clean, dry air
