Power Engineering 4B Book 3 Boiler Safety
Devices Latest Update 2025-2026 Actual Exam
110 Questions with 100% Verified Correct
Answers Guaranteed A+ Verified by Professor
a - CORRECT ANSWER: A blowdown ring is used on a safety valve to:
a. Adjust the differential between opening and closing pressures
b. Increase the blowdown frequency of the safety valve
c. Prevent the safety valve from popping while blowing down the boiler
d. Adjust the operating pressure of the valve
a - CORRECT ANSWER: a high pressure boiler with a heating surface not exceeding
__________ in area can have only a single safety valve
a) 47m2
b) 36m2
c) 28m2
d) 19m2
a - CORRECT ANSWER: a low water fuel cutoff on an unattended steam boiler shall be
installed so that
a) it cannot be rendered inoperative
b) it starts the feed water pump
c) it can be isolated if its not required
,d) it shuts down the burner when the water level falls below the lowest visible part of the
gauge glass
a - CORRECT ANSWER: A variable resistance modulating control
a. Works in conjunction with a modulating motor
b. Utilizes a mercury switch
c. Senses steam temperature
d. Operates only in the vertical position
a - CORRECT ANSWER: all boiler fittings not properly or clearly identified
a) must not be used
b) may be used for low pressure services
c) are acceptable for some powerhouse piping applications
d) must be sent back to the manufacturer for proper identification
a - CORRECT ANSWER: an automatic boiler on-off firing rate control has one
adjustment for pressure set-point and another for
a) differential adjustment
b) manual or automatic control
c) water level adjustment
d) high steam pressure limit set point adjustment
a - CORRECT ANSWER: If a high pressure boiler is on high fire with the main steam
stop valve closed, the safety valves must ensure that the
, a) Boiler pressure does not exceed the maximum allowable working pressure of the
boiler by more than 6%
b) Boiler pressure does not exceed the set point of the safety valve
c) Steam pressure does not exceed the maximum allowable working pressure of the
boiler
d) Boiler pressure does not exceed the hydrostatic test pressure
a - CORRECT ANSWER: Testing a safety valve on a boiler by pulling the try-lever
Select one:
a. Ensures the valve is free to operate
b. Takes approximately two seconds
c. Ensures the closing pressure is correct
d. Ensures the popping pressure is correct
a - CORRECT ANSWER: The lowest visible point of the gauge glass for a horizontal
firetube power boiler with diameter greater than 400 mm must be
a. 75 mm above the lowest permissible water level
b. 25 mm below the highest fire tube
c. Level with the normal water level
d. Level with the highest fire tube
a - CORRECT ANSWER: the main controlling device used with an On-Off combustion
fuel control is a ___________ sensing element
a) pressure
b) level
c) flow
Devices Latest Update 2025-2026 Actual Exam
110 Questions with 100% Verified Correct
Answers Guaranteed A+ Verified by Professor
a - CORRECT ANSWER: A blowdown ring is used on a safety valve to:
a. Adjust the differential between opening and closing pressures
b. Increase the blowdown frequency of the safety valve
c. Prevent the safety valve from popping while blowing down the boiler
d. Adjust the operating pressure of the valve
a - CORRECT ANSWER: a high pressure boiler with a heating surface not exceeding
__________ in area can have only a single safety valve
a) 47m2
b) 36m2
c) 28m2
d) 19m2
a - CORRECT ANSWER: a low water fuel cutoff on an unattended steam boiler shall be
installed so that
a) it cannot be rendered inoperative
b) it starts the feed water pump
c) it can be isolated if its not required
,d) it shuts down the burner when the water level falls below the lowest visible part of the
gauge glass
a - CORRECT ANSWER: A variable resistance modulating control
a. Works in conjunction with a modulating motor
b. Utilizes a mercury switch
c. Senses steam temperature
d. Operates only in the vertical position
a - CORRECT ANSWER: all boiler fittings not properly or clearly identified
a) must not be used
b) may be used for low pressure services
c) are acceptable for some powerhouse piping applications
d) must be sent back to the manufacturer for proper identification
a - CORRECT ANSWER: an automatic boiler on-off firing rate control has one
adjustment for pressure set-point and another for
a) differential adjustment
b) manual or automatic control
c) water level adjustment
d) high steam pressure limit set point adjustment
a - CORRECT ANSWER: If a high pressure boiler is on high fire with the main steam
stop valve closed, the safety valves must ensure that the
, a) Boiler pressure does not exceed the maximum allowable working pressure of the
boiler by more than 6%
b) Boiler pressure does not exceed the set point of the safety valve
c) Steam pressure does not exceed the maximum allowable working pressure of the
boiler
d) Boiler pressure does not exceed the hydrostatic test pressure
a - CORRECT ANSWER: Testing a safety valve on a boiler by pulling the try-lever
Select one:
a. Ensures the valve is free to operate
b. Takes approximately two seconds
c. Ensures the closing pressure is correct
d. Ensures the popping pressure is correct
a - CORRECT ANSWER: The lowest visible point of the gauge glass for a horizontal
firetube power boiler with diameter greater than 400 mm must be
a. 75 mm above the lowest permissible water level
b. 25 mm below the highest fire tube
c. Level with the normal water level
d. Level with the highest fire tube
a - CORRECT ANSWER: the main controlling device used with an On-Off combustion
fuel control is a ___________ sensing element
a) pressure
b) level
c) flow
