Power Engineering - 4B3 Practice Questions With Complete
Solutions
A blowdown ring is used on a safety valve to:
a. Adjust the operating pressure of the valve
b. Prevent the safety valve from popping while blowing down
the boiler
c. Increase the blowdown frequency of the safety valve
d. Adjust the differential between opening and closing pressures
Correct Answers d. Adjust the differential between opening and
closing pressures
A boiler feedwater isolation valve:
a. Is used to isolate the deaerator
b. Must be a globe valve
c. Should be located close to the feedwater pump
d. May be a globe valve, provided water enters below the disc
Correct Answers d. May be a globe valve, provided water
enters below the disc
A boiler with a single safety valve has a maximum allowable
working pressure of 1000 kPa. What is the maximum boiler
pressure permissible when the safety valve is blowing?
a. 1060 kPa
b. 1000 kPa
c. 1030 kPa
d. 1100 kPa Correct Answers a. 1060 kPa
,A feedwater pipe, where connected to a power boiler, must
have:
a. A check valve, with a stop valve between the check valve and
the boiler
b. A check valve between the stop valve and the boiler
c. A stop valve only
d. A quick and slow opening stop valve Correct Answers a. A
check valve, with a stop valve between the check valve and the
boiler
A flame failure device is unresponsive to:
a. Ultraviolet light
b. Infra-red light
c. Visible light
d. Fuel flow Correct Answers d. Fuel flow
A flame rod:
a. Is used in combination with a photocell
b. Is used only for oil fired burners
c. Forms an electric circuit with the rod, flame and burner
d. Develops a high resistance in the presence of a flame. Correct
Answers c. Forms an electric circuit with the rod, flame and
burner
A float operated low water fuel cutoff has its switch separated
from boiler pressure by:
a. A float cage
, b. A seal cage
c. A bellows
d. Packing Correct Answers c. A bellows
A gauge glass shows the level of a clear, colourless liquid as
very dark, is the ______________ gauge glass.
a. Bi-colour
b. Tubular
c. Reflex
d. Flat Correct Answers c. Reflex
A high gas pressure fuel cut-off switch:
a. Closes when gas pressure is too high
b. Automatically resets itself when the gas pressure is restored
c. Is located upstream of the automatic fuel valve
d. Prevents excessive fuel pressure from creating an unstable
flame condition Correct Answers d. Prevents excessive fuel
pressure from creating an unstable flame condition
A high pressure boiler with a heating surface not exceeding
_________ in area can have only a single safety valve.
a. 47 m2
b. 36 m2
c. 28 m2
d. 19 m2 Correct Answers a. 47 m2
A low fire start switch:
Solutions
A blowdown ring is used on a safety valve to:
a. Adjust the operating pressure of the valve
b. Prevent the safety valve from popping while blowing down
the boiler
c. Increase the blowdown frequency of the safety valve
d. Adjust the differential between opening and closing pressures
Correct Answers d. Adjust the differential between opening and
closing pressures
A boiler feedwater isolation valve:
a. Is used to isolate the deaerator
b. Must be a globe valve
c. Should be located close to the feedwater pump
d. May be a globe valve, provided water enters below the disc
Correct Answers d. May be a globe valve, provided water
enters below the disc
A boiler with a single safety valve has a maximum allowable
working pressure of 1000 kPa. What is the maximum boiler
pressure permissible when the safety valve is blowing?
a. 1060 kPa
b. 1000 kPa
c. 1030 kPa
d. 1100 kPa Correct Answers a. 1060 kPa
,A feedwater pipe, where connected to a power boiler, must
have:
a. A check valve, with a stop valve between the check valve and
the boiler
b. A check valve between the stop valve and the boiler
c. A stop valve only
d. A quick and slow opening stop valve Correct Answers a. A
check valve, with a stop valve between the check valve and the
boiler
A flame failure device is unresponsive to:
a. Ultraviolet light
b. Infra-red light
c. Visible light
d. Fuel flow Correct Answers d. Fuel flow
A flame rod:
a. Is used in combination with a photocell
b. Is used only for oil fired burners
c. Forms an electric circuit with the rod, flame and burner
d. Develops a high resistance in the presence of a flame. Correct
Answers c. Forms an electric circuit with the rod, flame and
burner
A float operated low water fuel cutoff has its switch separated
from boiler pressure by:
a. A float cage
, b. A seal cage
c. A bellows
d. Packing Correct Answers c. A bellows
A gauge glass shows the level of a clear, colourless liquid as
very dark, is the ______________ gauge glass.
a. Bi-colour
b. Tubular
c. Reflex
d. Flat Correct Answers c. Reflex
A high gas pressure fuel cut-off switch:
a. Closes when gas pressure is too high
b. Automatically resets itself when the gas pressure is restored
c. Is located upstream of the automatic fuel valve
d. Prevents excessive fuel pressure from creating an unstable
flame condition Correct Answers d. Prevents excessive fuel
pressure from creating an unstable flame condition
A high pressure boiler with a heating surface not exceeding
_________ in area can have only a single safety valve.
a. 47 m2
b. 36 m2
c. 28 m2
d. 19 m2 Correct Answers a. 47 m2
A low fire start switch:
