DC 1st Class Boiler Exam Questions
And Answers
Moving blading in which space between blades is the same size at
the blading inlet, and the blading outlet. - - correct answer
✅Impulse Blading
To blowdown a boiler equipped with a quick opening and slow
opening valve on the bottom blowdown line, the_________. - -
correct answer ✅quick opening valve is opened first and closed
last.
Hardness of water is the measurement in ppm of ________ and
________ in the water. - - correct answer ✅calcium and
magnesium
A pump delivers 175 gallons per minute against a pressure of 55
psi; the suction pressure is 15 psi. If a pump is 80% efficient, what is
the horsepower needed? - - correct answer ✅HP=5.1 HP= (Head in
Feet) x (Weight in Lbs.)/ 33,000 x Efficiency
a duplex double-acting reciprocating feed water pump has____ - -
correct answer ✅two steam Pistons 2 to 2 2/2 times larger in area
than the water piston
,DC 1st Class Boiler Exam Questions
And Answers
Name a technique to control the nitrous oxide emissions. - - correct
answer ✅Selective Catalytic Reduction
Spalling in a boiler occurs in the ____? - - correct answer
✅Combustion chamber
A technology in which solid waste is heated in an oxygen starved
atmosphere to break down the solids into a gas is called ______? - -
correct answer ✅Pyrolysis
What is the primary purpose of using wet scrubbers? - - correct
answer ✅To remove sulfur dioxides
The thermal efficiency of a boiler with a stack temperature of 750°F
and and a furnace temperature of 3200°F is_______? - - correct
answer ✅75% ((3200-750)/3200) x 100
________is a water-purification process in which the water to be
treated is pressurized and applied against the surface of a
semipermeable membrane. - - correct answer ✅Reverse osmosis
The airflow switch at the burner fan housing______. - - correct
answer ✅Ensures the primary air fan is functioning
, DC 1st Class Boiler Exam Questions
And Answers
How many inches of steam space in a cylinder of an engine 12"x28"
and the stroke is 5/8 of its full travel? - - correct answer ✅1978.
V=AxL V=3.14(6x6)x28x.625= 1978
What is the horsepower requirement of a pump that moves 2500
gpm of water against a head of 475' if the pump is operating at 58%
efficiency? - - correct answer ✅516.8 HP=Head x Weight/33000 x
efficiency. (Head =475, Weight = 2500gpm x 8.33) (475x
20825)/19140
A ______ is the condition that is being controlled - - correct answer
✅process variable
Although boiler tubes and boiler drums withstand the same
pressure, the walls of the boiler tubes are much thinner because
______. - - correct answer ✅The tubes are much smaller in
diameter
A lead sulfide cell detects_____. - - correct answer ✅Burner pilot
and main flame
And Answers
Moving blading in which space between blades is the same size at
the blading inlet, and the blading outlet. - - correct answer
✅Impulse Blading
To blowdown a boiler equipped with a quick opening and slow
opening valve on the bottom blowdown line, the_________. - -
correct answer ✅quick opening valve is opened first and closed
last.
Hardness of water is the measurement in ppm of ________ and
________ in the water. - - correct answer ✅calcium and
magnesium
A pump delivers 175 gallons per minute against a pressure of 55
psi; the suction pressure is 15 psi. If a pump is 80% efficient, what is
the horsepower needed? - - correct answer ✅HP=5.1 HP= (Head in
Feet) x (Weight in Lbs.)/ 33,000 x Efficiency
a duplex double-acting reciprocating feed water pump has____ - -
correct answer ✅two steam Pistons 2 to 2 2/2 times larger in area
than the water piston
,DC 1st Class Boiler Exam Questions
And Answers
Name a technique to control the nitrous oxide emissions. - - correct
answer ✅Selective Catalytic Reduction
Spalling in a boiler occurs in the ____? - - correct answer
✅Combustion chamber
A technology in which solid waste is heated in an oxygen starved
atmosphere to break down the solids into a gas is called ______? - -
correct answer ✅Pyrolysis
What is the primary purpose of using wet scrubbers? - - correct
answer ✅To remove sulfur dioxides
The thermal efficiency of a boiler with a stack temperature of 750°F
and and a furnace temperature of 3200°F is_______? - - correct
answer ✅75% ((3200-750)/3200) x 100
________is a water-purification process in which the water to be
treated is pressurized and applied against the surface of a
semipermeable membrane. - - correct answer ✅Reverse osmosis
The airflow switch at the burner fan housing______. - - correct
answer ✅Ensures the primary air fan is functioning
, DC 1st Class Boiler Exam Questions
And Answers
How many inches of steam space in a cylinder of an engine 12"x28"
and the stroke is 5/8 of its full travel? - - correct answer ✅1978.
V=AxL V=3.14(6x6)x28x.625= 1978
What is the horsepower requirement of a pump that moves 2500
gpm of water against a head of 475' if the pump is operating at 58%
efficiency? - - correct answer ✅516.8 HP=Head x Weight/33000 x
efficiency. (Head =475, Weight = 2500gpm x 8.33) (475x
20825)/19140
A ______ is the condition that is being controlled - - correct answer
✅process variable
Although boiler tubes and boiler drums withstand the same
pressure, the walls of the boiler tubes are much thinner because
______. - - correct answer ✅The tubes are much smaller in
diameter
A lead sulfide cell detects_____. - - correct answer ✅Burner pilot
and main flame
