DC Third Class Stationary Boiler Exam
2025 COMPLETE EXAM QUESTIONS
AND VERIFIED ANSWERS |RECENTLY
TESTING ACTUAL EXAM QUESTIONS|
100% SOLVED!!
What is the thermal efficiency percentage of boiler with a stack temperature of 600 F
and furnace temperature of 2800 F ? - ANSWER-78.5
What is the proper order of zeolite rejuvenation water softener . - ANSWER-Back Wash,
Brine, Rinse , and Service
given the three phase 480-volt motor has a current draw of 42amps and a power factor
rating of 90% - ANSWER-181
a four-wire wye-connected system with a phase-to-phase voltage of 208 volt has a volta
has a phase to neutral voltage of 120 volts - ANSWER-120 volts
steam (High Velocity) what kind of energy ? - ANSWER-Mechanical
Which of the following statement is not ture concerning a superheat ? - ANSWER-Super
Heater (BTU)
The ______ pump supplies the water to the condenser to condense the steam. -
ANSWER-Condensate
What is the first thing that happen for a three-element regulator to change the output of
the controller? - ANSWER-Condensate Flow Increases
The primary reason for using wet scrubbers is to ? - ANSWER-Remove flue gas
particulates
What is used on the outer rim of the blades or nozzles to stiffen the blade against
vibration and confine the steam to the ________ ? - ANSWER-Shroud Ring
The refrigerant in a condenser to usually sub cooled between _________ degree F
below the condensing temperature? - ANSWER-.7 to 9 degrees
,if you are operation a boiler with a three-element feed water regulator, when is being
measured and recorded by mechanically operated water ? - ANSWER-Steam Flow,
Feedwater and drum level
given thermocouples have both a hot junction and a cold junction. the cold junction
measured the ____________ point ? - ANSWER-Reference
A water heating system that uses the same pipe for supply and return is called a
__________ system - ANSWER-One pipe
a malfunction in the deaerate feed water tank is indicated by ? - ANSWER-Boiler
requiring excessive amount of oxygen scavenge chemicals.
what uses the theory of centirifical force that applies to the roating element of turbine
and controls the speed of the turbine? - ANSWER-Speed Governor
which of the following is not purpose of an air cock on a steam drum ? - ANSWER-to let
the air escape while filing the drum
which of the following types of boiler is more suited for pressure exceeding 350 psi? -
ANSWER-Scotch Marine
An automatic control valve commonly used to maintain feed water level in a boiler
whose internal design is constructed with 2 valve and ? - ANSWER-balancing valve
what are the 2 chief heat producing elements? - ANSWER-carbon and hydrogen
copper testing is used to detect ? - ANSWER-heat exchanger and pump water
and on and off type control system is usually found on what type of boiler? - ANSWER-
package fire tube boiler
the chemical used to perform water treatment test are called? - ANSWER-reagents
on turbine, what is between every set to rotating blades - ANSWER-stationary blades
the color of R-404A refrigerant is ? - ANSWER-Orange
what is used when a large load must be carried to maintain the proper exit position of
turbine shaft? - ANSWER-thrust bearing
given a pressure drop calculates flow measurement across an orifice two widely used
secondary element which connects differential pressure to a usable output signal? -
ANSWER-transmitter and receiver
in what year was the first clen air act regulation passes ? - ANSWER-1963
,what should the water temperature be when leaving DA TANK ? - ANSWER-Within 3 to
5 degrees of entering temperature
which type of stoker feed system use a ram feed ? - ANSWER-Underfeed?
boiler figure - ANSWER-d. internal fire boiler
how are non-condensable gas and air removed from the condenser? - ANSWER-
Ejectors
The stop and start of a boiler? - ANSWER-Aquastat
a direct drop-in replacement for R-22, that is compatible with all refrigerant oil is ? -
ANSWER-R-417A
Turbine drain are supplies with traps that are ___________ when the turbine is in
operation and ______________ when it is being started up? - ANSWER-close, open
given the following reading make up water conductivity is 750 micro feed water
conductivity is 200 micro and the condensate return is 55 micro what is the percentage
of the condensate return? - ANSWER-.79
how much water does it take to create one pound of steam? - ANSWER-1.0 lb.
the color for H-407c refrigerant cyclinder? - ANSWER-chocolate
in a water tube boiler over heating of the tubes might be caused by? - ANSWER-scale
formation on the insdie of the water tube
super critical boiler operate above the critical ________ of the water steam loop of the
_________ and operating temperature above ___________degrees? - ANSWER-
pressure 3206.2 ; 705.6
the electrostatic precipitation collects fly ash in the flue gas by placing a? - ANSWER-
high voltage AC current to the collection plates, which causes the dust
which of the following is technique to control particulates from boilers? - ANSWER-
fabric filter
a unit of force imposed on a unit of area is called? - ANSWER-pressure
which of the following statement concerning a superheater is true? - ANSWER-the
superheater safety valve is set at a lower pressure than the drum safety valve
, to be accurate when it is installed a mercury tube pressure control must be mounted. -
ANSWER-in a veritical position
the ______ pump is a type of pump where high pressure steam enters the venture inlet
and enter into the mixing tube with a lower pressure but higher temp - ANSWER-injector
which of the following is a technique is control nitrous oxide emissions? - ANSWER-
S.C.R Selective Catalytic
a boiler is steaming at 50% of the load, and suddenly the fire goes out, in this case what
happens to the water level? - ANSWER-water shrinks and trips the LWCO
The function of the diffuser of the diffuser on a turbine type centrifugal pump is to? -
ANSWER-convert high velocity to pressure
for what is the turbine extraction steam used? - ANSWER-heating boiler feed water
all of the following are types of synthetic refrigerant oil except? - ANSWER-Naphthenic
how do you ensure
that complete combustion will take place in the combustion chamber? - ANSWER-
increase excess air
to protect a circuit from over current fuses are connected in? - ANSWER-series
which coal has the highest volume of carbon ? - ANSWER-anthracite
which of the following are the correct definition of "Critical Pressure" and critical
temperature - ANSWER-critical pressure is pressure at which water and steam have the
same density ect....
which of the following type of pumps can be started with the discharge valve closed ? -
ANSWER-centrifugal
a chiller water coil is an example of _________ dehumidification? - ANSWER-
mechanical
condensate pump remove water from the ________? - ANSWER-condenser
the erosion which occurs when steam or high velocity fluid flows through a throttled
valve is called - ANSWER-wire drawing
air is bypassed around the air heater when? - ANSWER-the boiler steam load is at a
minimum
2025 COMPLETE EXAM QUESTIONS
AND VERIFIED ANSWERS |RECENTLY
TESTING ACTUAL EXAM QUESTIONS|
100% SOLVED!!
What is the thermal efficiency percentage of boiler with a stack temperature of 600 F
and furnace temperature of 2800 F ? - ANSWER-78.5
What is the proper order of zeolite rejuvenation water softener . - ANSWER-Back Wash,
Brine, Rinse , and Service
given the three phase 480-volt motor has a current draw of 42amps and a power factor
rating of 90% - ANSWER-181
a four-wire wye-connected system with a phase-to-phase voltage of 208 volt has a volta
has a phase to neutral voltage of 120 volts - ANSWER-120 volts
steam (High Velocity) what kind of energy ? - ANSWER-Mechanical
Which of the following statement is not ture concerning a superheat ? - ANSWER-Super
Heater (BTU)
The ______ pump supplies the water to the condenser to condense the steam. -
ANSWER-Condensate
What is the first thing that happen for a three-element regulator to change the output of
the controller? - ANSWER-Condensate Flow Increases
The primary reason for using wet scrubbers is to ? - ANSWER-Remove flue gas
particulates
What is used on the outer rim of the blades or nozzles to stiffen the blade against
vibration and confine the steam to the ________ ? - ANSWER-Shroud Ring
The refrigerant in a condenser to usually sub cooled between _________ degree F
below the condensing temperature? - ANSWER-.7 to 9 degrees
,if you are operation a boiler with a three-element feed water regulator, when is being
measured and recorded by mechanically operated water ? - ANSWER-Steam Flow,
Feedwater and drum level
given thermocouples have both a hot junction and a cold junction. the cold junction
measured the ____________ point ? - ANSWER-Reference
A water heating system that uses the same pipe for supply and return is called a
__________ system - ANSWER-One pipe
a malfunction in the deaerate feed water tank is indicated by ? - ANSWER-Boiler
requiring excessive amount of oxygen scavenge chemicals.
what uses the theory of centirifical force that applies to the roating element of turbine
and controls the speed of the turbine? - ANSWER-Speed Governor
which of the following is not purpose of an air cock on a steam drum ? - ANSWER-to let
the air escape while filing the drum
which of the following types of boiler is more suited for pressure exceeding 350 psi? -
ANSWER-Scotch Marine
An automatic control valve commonly used to maintain feed water level in a boiler
whose internal design is constructed with 2 valve and ? - ANSWER-balancing valve
what are the 2 chief heat producing elements? - ANSWER-carbon and hydrogen
copper testing is used to detect ? - ANSWER-heat exchanger and pump water
and on and off type control system is usually found on what type of boiler? - ANSWER-
package fire tube boiler
the chemical used to perform water treatment test are called? - ANSWER-reagents
on turbine, what is between every set to rotating blades - ANSWER-stationary blades
the color of R-404A refrigerant is ? - ANSWER-Orange
what is used when a large load must be carried to maintain the proper exit position of
turbine shaft? - ANSWER-thrust bearing
given a pressure drop calculates flow measurement across an orifice two widely used
secondary element which connects differential pressure to a usable output signal? -
ANSWER-transmitter and receiver
in what year was the first clen air act regulation passes ? - ANSWER-1963
,what should the water temperature be when leaving DA TANK ? - ANSWER-Within 3 to
5 degrees of entering temperature
which type of stoker feed system use a ram feed ? - ANSWER-Underfeed?
boiler figure - ANSWER-d. internal fire boiler
how are non-condensable gas and air removed from the condenser? - ANSWER-
Ejectors
The stop and start of a boiler? - ANSWER-Aquastat
a direct drop-in replacement for R-22, that is compatible with all refrigerant oil is ? -
ANSWER-R-417A
Turbine drain are supplies with traps that are ___________ when the turbine is in
operation and ______________ when it is being started up? - ANSWER-close, open
given the following reading make up water conductivity is 750 micro feed water
conductivity is 200 micro and the condensate return is 55 micro what is the percentage
of the condensate return? - ANSWER-.79
how much water does it take to create one pound of steam? - ANSWER-1.0 lb.
the color for H-407c refrigerant cyclinder? - ANSWER-chocolate
in a water tube boiler over heating of the tubes might be caused by? - ANSWER-scale
formation on the insdie of the water tube
super critical boiler operate above the critical ________ of the water steam loop of the
_________ and operating temperature above ___________degrees? - ANSWER-
pressure 3206.2 ; 705.6
the electrostatic precipitation collects fly ash in the flue gas by placing a? - ANSWER-
high voltage AC current to the collection plates, which causes the dust
which of the following is technique to control particulates from boilers? - ANSWER-
fabric filter
a unit of force imposed on a unit of area is called? - ANSWER-pressure
which of the following statement concerning a superheater is true? - ANSWER-the
superheater safety valve is set at a lower pressure than the drum safety valve
, to be accurate when it is installed a mercury tube pressure control must be mounted. -
ANSWER-in a veritical position
the ______ pump is a type of pump where high pressure steam enters the venture inlet
and enter into the mixing tube with a lower pressure but higher temp - ANSWER-injector
which of the following is a technique is control nitrous oxide emissions? - ANSWER-
S.C.R Selective Catalytic
a boiler is steaming at 50% of the load, and suddenly the fire goes out, in this case what
happens to the water level? - ANSWER-water shrinks and trips the LWCO
The function of the diffuser of the diffuser on a turbine type centrifugal pump is to? -
ANSWER-convert high velocity to pressure
for what is the turbine extraction steam used? - ANSWER-heating boiler feed water
all of the following are types of synthetic refrigerant oil except? - ANSWER-Naphthenic
how do you ensure
that complete combustion will take place in the combustion chamber? - ANSWER-
increase excess air
to protect a circuit from over current fuses are connected in? - ANSWER-series
which coal has the highest volume of carbon ? - ANSWER-anthracite
which of the following are the correct definition of "Critical Pressure" and critical
temperature - ANSWER-critical pressure is pressure at which water and steam have the
same density ect....
which of the following type of pumps can be started with the discharge valve closed ? -
ANSWER-centrifugal
a chiller water coil is an example of _________ dehumidification? - ANSWER-
mechanical
condensate pump remove water from the ________? - ANSWER-condenser
the erosion which occurs when steam or high velocity fluid flows through a throttled
valve is called - ANSWER-wire drawing
air is bypassed around the air heater when? - ANSWER-the boiler steam load is at a
minimum
