DC BOILER EXAM ACTUAL EXAM COMPLETE 240
QUESTIONS AND CORRECT DETAILED ANSWERS
Because of the large volume of water, the boiler type most likely to cause a boiler
explosion is a ___ boiler. - ANSWER: firetube
The part of a boiler with the heat and gases of combustion on one side and water on
the other side is known as the ___ surface. - ANSWER: heating
___ is the pressure at which the density of water and steam are the same. -
ANSWER: Critical pressure
An electric boiler produces heat using electrodes or ___. - ANSWER: resistance coils
Boiler horsepower (BHP) is the amount of energy equal to the evaporation of ___
lb/hr of water from and at a feedwater temperature of 212°F. - ANSWER: 34.5
A high pressure steam boiler operates at a steam pressure of more than ___ psi. -
ANSWER: 15
A ___ results in a higher boiling point for water in a boiler. - ANSWER: higher steam
pressure
A(n) ___ is a boiler that uses heat recovered from a hot gas stream, such as hot
exhaust gases from a kiln or from a gas turbine. - ANSWER: heat recovery steam
generator (HRSG)
A ___ is the lowest part of the water side of a watertube boiler. - ANSWER: mud
drum
By increasing the number of passes and the number of fire tubes, water can absorb
more heat and ___ increases. - ANSWER: thermal efficiency
The steam drum of watertube boilers is dished (concave) to eliminate the need for
___. - ANSWER: stays
___ stress occurs when two forces of equal intensity act from opposite directions
and push toward the center of an object. - ANSWER: Compressive
___ are used to direct the gases of combustion so that they come in close contact
with the boiler heating surface. - ANSWER: Baffles
A ___ is a set of tubes that is placed in the furnace area of watertube boilers and
used to increase the heating surface of boilers and the service life of refractory. -
ANSWER: waterwall
,A ___ boiler comes completely assembled, with its own pressure vessel, burner,
draft fans, and fuel train. - ANSWER: package
Boiler plates and stays are subjected to ___ stress. - ANSWER: tensile
___ are used to prevent bulging in boilers. - ANSWER: Through stays
A ___ converts the energy from the expansion of high-pressure steam into the
mechanical energy of rotation. - ANSWER: turbine
A ___ is a device that converts mechanical energy into electrical energy. - ANSWER:
generator
Cogeneration is the process of ___ and then using the waste heat for heating
buildings, providing process heat, or further electrical generation. - ANSWER:
generating electricity
Food processing plants use steam for ___, pasteurization, and sterilization. -
ANSWER: cooking
___ is the production of electricity as a result of a conductor passing through a
magnetic field. - ANSWER: Electromagnetic induction
___ generators are the most common generators used to produce electrical power. -
ANSWER: AC
___ is often used as a prime mover that is used to rotate turbines to generate
electricity. - ANSWER: High-pressure steam
Exhaust gases from engines and turbines pass through a heat exchanger to produce
hot water or steam for use in plant heating or processes in ___ plants. - ANSWER:
combined heat and power (CHP)
CHAPTER 2 - ANSWER:
___ are used for steam loads that require dry steam. - ANSWER: Superheaters
A ___ can be installed at the point of use to reduce the steam pressure to the
pressure needed for the load. - ANSWER: pressure-reducing station
A ___ is used to send condensate back to the condensate return. - ANSWER: steam
trap
Feedwater flows into a boiler to be heated by ___. - ANSWER: gases of combustion
, Each steam load device has one or more ___ valves that allow the load device to be
taken out of service for repairs. - ANSWER: isolation
It takes ___ lb of water to produce 1 lb of steam. - ANSWER: 1.0
A deaerator tank is located above the feedwater pumps so that the water is supplied
to the pumps ___. - ANSWER: at a positive pressure
In the deaerator tank, noncondensable gases are separated and directed to the
atmosphere through a ___. - ANSWER: vent
Feedwater can be pumped through a ___ where it is heated to a relatively high
temperature by the gases of combustion. - ANSWER: closed feedwater heater
In the deaerator tank, a ___ to add makeup water to the deaerator tank to
compensate for the condensate lost. - ANSWER: float opens a feed valve
A shutoff valve is used when ___. - ANSWER: making repairs
On larger watertube boilers, a(n) ___ can heat the feedwater by using gases of
combustion before the feedwater enters the boiler. - ANSWER: economizer
Once fuel oil reaches the burner, it is the function of the burner to ___ the oil so it
can mix with air and burn. - ANSWER: atomize
In a low-pressure gas system, the zero gas governor reduces the pressure of the gas
to ___ psi. - ANSWER: 0
In a low-pressure gas system, the air and gas mixture in the furnace is ignited by the
___. - ANSWER: pilot
Modern coal plants use ___ coal that is blown into the combustion chamber where it
burns in suspension. - ANSWER: pulverized
___ valves are typically slow-opening, fast-closing, hydraulic-electric valves and
should have an internal proof-of-closure switch. - ANSWER: Safety shutoff
A(n) ___ is used to clean fuel oil before it goes to a burner. - ANSWER: strainer
Stop valves isolate a tank when ___. - ANSWER: it is not in use
Most steam plants that use No. ___ fuel oil have two tanks. - ANSWER: 6
In a basic pulverized coal system, the coal ___ stores the coal before it flows onto
the coal conveyor. - ANSWER: bunker
QUESTIONS AND CORRECT DETAILED ANSWERS
Because of the large volume of water, the boiler type most likely to cause a boiler
explosion is a ___ boiler. - ANSWER: firetube
The part of a boiler with the heat and gases of combustion on one side and water on
the other side is known as the ___ surface. - ANSWER: heating
___ is the pressure at which the density of water and steam are the same. -
ANSWER: Critical pressure
An electric boiler produces heat using electrodes or ___. - ANSWER: resistance coils
Boiler horsepower (BHP) is the amount of energy equal to the evaporation of ___
lb/hr of water from and at a feedwater temperature of 212°F. - ANSWER: 34.5
A high pressure steam boiler operates at a steam pressure of more than ___ psi. -
ANSWER: 15
A ___ results in a higher boiling point for water in a boiler. - ANSWER: higher steam
pressure
A(n) ___ is a boiler that uses heat recovered from a hot gas stream, such as hot
exhaust gases from a kiln or from a gas turbine. - ANSWER: heat recovery steam
generator (HRSG)
A ___ is the lowest part of the water side of a watertube boiler. - ANSWER: mud
drum
By increasing the number of passes and the number of fire tubes, water can absorb
more heat and ___ increases. - ANSWER: thermal efficiency
The steam drum of watertube boilers is dished (concave) to eliminate the need for
___. - ANSWER: stays
___ stress occurs when two forces of equal intensity act from opposite directions
and push toward the center of an object. - ANSWER: Compressive
___ are used to direct the gases of combustion so that they come in close contact
with the boiler heating surface. - ANSWER: Baffles
A ___ is a set of tubes that is placed in the furnace area of watertube boilers and
used to increase the heating surface of boilers and the service life of refractory. -
ANSWER: waterwall
,A ___ boiler comes completely assembled, with its own pressure vessel, burner,
draft fans, and fuel train. - ANSWER: package
Boiler plates and stays are subjected to ___ stress. - ANSWER: tensile
___ are used to prevent bulging in boilers. - ANSWER: Through stays
A ___ converts the energy from the expansion of high-pressure steam into the
mechanical energy of rotation. - ANSWER: turbine
A ___ is a device that converts mechanical energy into electrical energy. - ANSWER:
generator
Cogeneration is the process of ___ and then using the waste heat for heating
buildings, providing process heat, or further electrical generation. - ANSWER:
generating electricity
Food processing plants use steam for ___, pasteurization, and sterilization. -
ANSWER: cooking
___ is the production of electricity as a result of a conductor passing through a
magnetic field. - ANSWER: Electromagnetic induction
___ generators are the most common generators used to produce electrical power. -
ANSWER: AC
___ is often used as a prime mover that is used to rotate turbines to generate
electricity. - ANSWER: High-pressure steam
Exhaust gases from engines and turbines pass through a heat exchanger to produce
hot water or steam for use in plant heating or processes in ___ plants. - ANSWER:
combined heat and power (CHP)
CHAPTER 2 - ANSWER:
___ are used for steam loads that require dry steam. - ANSWER: Superheaters
A ___ can be installed at the point of use to reduce the steam pressure to the
pressure needed for the load. - ANSWER: pressure-reducing station
A ___ is used to send condensate back to the condensate return. - ANSWER: steam
trap
Feedwater flows into a boiler to be heated by ___. - ANSWER: gases of combustion
, Each steam load device has one or more ___ valves that allow the load device to be
taken out of service for repairs. - ANSWER: isolation
It takes ___ lb of water to produce 1 lb of steam. - ANSWER: 1.0
A deaerator tank is located above the feedwater pumps so that the water is supplied
to the pumps ___. - ANSWER: at a positive pressure
In the deaerator tank, noncondensable gases are separated and directed to the
atmosphere through a ___. - ANSWER: vent
Feedwater can be pumped through a ___ where it is heated to a relatively high
temperature by the gases of combustion. - ANSWER: closed feedwater heater
In the deaerator tank, a ___ to add makeup water to the deaerator tank to
compensate for the condensate lost. - ANSWER: float opens a feed valve
A shutoff valve is used when ___. - ANSWER: making repairs
On larger watertube boilers, a(n) ___ can heat the feedwater by using gases of
combustion before the feedwater enters the boiler. - ANSWER: economizer
Once fuel oil reaches the burner, it is the function of the burner to ___ the oil so it
can mix with air and burn. - ANSWER: atomize
In a low-pressure gas system, the zero gas governor reduces the pressure of the gas
to ___ psi. - ANSWER: 0
In a low-pressure gas system, the air and gas mixture in the furnace is ignited by the
___. - ANSWER: pilot
Modern coal plants use ___ coal that is blown into the combustion chamber where it
burns in suspension. - ANSWER: pulverized
___ valves are typically slow-opening, fast-closing, hydraulic-electric valves and
should have an internal proof-of-closure switch. - ANSWER: Safety shutoff
A(n) ___ is used to clean fuel oil before it goes to a burner. - ANSWER: strainer
Stop valves isolate a tank when ___. - ANSWER: it is not in use
Most steam plants that use No. ___ fuel oil have two tanks. - ANSWER: 6
In a basic pulverized coal system, the coal ___ stores the coal before it flows onto
the coal conveyor. - ANSWER: bunker
