Power Engineering 4B Book 3 Boiler Safety
Devices Exam With Complete Solutions
c - ANSWER Primary controls, as used in a burner management system
a) should be cleaned of carbon deposits monthly
b) generate a voltage, which is used to monitor flames
c) must shut off the fuel within 4 seconds of flame failure
d) are unreliable and unsafe
b - ANSWER An outside screw and yolk valve
a) must be a gate valve
b) shows its operating position
c) is difficult to lubricate
d) requires no packing
c - ANSWER a manual high-low should be switched to high or auto
a) prior to ignition of the main flame
b) when pressure is too low
c) when the boiler has been properly warmed up
d) during boiler prepurge
c - ANSWER In steam boiler firing rate control systems, the measured variable is
a) fuel pressure
b) combustion air damper position
c) the steam pressure
d) firing rate control valve positon
b - ANSWER combustion air safety switches are found
a) on natural draft boilers
b) on boilers that use mechanical draft
c) on light-oil fired boilers
d) on gas fired boilers
b - ANSWER when a boiler steam outlet stop valve is required by code , the
preferred style of valve is
,a) a non-rising stem globe valve
b)an outside screw and yolk, rising stem
c) a non-rising stem gate valve
d) a ball valve
c - ANSWER Every steam boiler must have a safety valve that is
a) placed in the piping system leading from the steam stop valve
b) fitted securely to a shut off valve, which is directly connected to the top of the
boiler
c) fitted in a vertical position, directly connected to the top of the boiler
d) connected to the steam or water space of the boiler, without any intervening
fitting
d - ANSWER the purpose of the spring in the safety valve is to
a) help open the testing lever
b) adjust the pressure setting of the valve
c) adjust the blowdown of the valve
d) hold down the disk on the seat
d - ANSWER if the boiler produces steam at a higher rate than the rate of steam
consumption, and its condition goes unchecked
a) soot will develop on the fireside
b) the boiler efficiency will drop
c) the boiler will overheat
d) the boiler will over-pressurize
b - ANSWER an important fitting, which is installed before steam boiler pressure
gauge and the boiler itself and is designed to prevent damage to the gauge, is a
a) tee with a plug
b) Syphon
c) Blowdown valve
d) test connection for an inspector
a - ANSWER the main controlling device used with an On-Off combustion fuel
control is a ___________ sensing element
a) pressure
b) level
c) flow
d) electronic
, c - ANSWER One purpose of the small valve on top of the shell of most boilers,
which is not required by code , is to
a) allow water into the boiler when the boiler is being drained or cooled
preventing the formation of a vacuum
b) allow water to escape before steam stop valve is opened during the warm-up
period
c) allow air to escape the boiler when the boiler is being filled with water
d) allow air into the boiler when the boiler is being filled with water
a - 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
c - ANSWER When is a stop valve allowed between a heating boilers safety valve
and the boiler drum?
a) only if the stop valve is locked open
b) if there is more than one safety valve
c) never
d) if the stop valve is quick opening design
c - ANSWER the discharge pipe from a boiler safety valve is supported
independently of the safety valve
a) because the steam drum can not support the extra mass of the discharge pipe
b) so the discharge pipe can drain more easily
c) so the discharge pipe can expand without putting force on the safety valve
d) to prevent leakage at the pipe joint
b - ANSWER an operator should check that the boiler safety valve will open at its
set pressure by
a) asking the inspector to bring a master pressure gauge
b) increasing the boiler pressure and noting the pressure at which the valve
opens
c) putting a piece of pipe over the lifting lever and lifting the valve off its seat
when the set pressure is reached
d) using air pressure during a shutdown to raise the pressure in the boiler until
the set pressure is reached
Devices Exam With Complete Solutions
c - ANSWER Primary controls, as used in a burner management system
a) should be cleaned of carbon deposits monthly
b) generate a voltage, which is used to monitor flames
c) must shut off the fuel within 4 seconds of flame failure
d) are unreliable and unsafe
b - ANSWER An outside screw and yolk valve
a) must be a gate valve
b) shows its operating position
c) is difficult to lubricate
d) requires no packing
c - ANSWER a manual high-low should be switched to high or auto
a) prior to ignition of the main flame
b) when pressure is too low
c) when the boiler has been properly warmed up
d) during boiler prepurge
c - ANSWER In steam boiler firing rate control systems, the measured variable is
a) fuel pressure
b) combustion air damper position
c) the steam pressure
d) firing rate control valve positon
b - ANSWER combustion air safety switches are found
a) on natural draft boilers
b) on boilers that use mechanical draft
c) on light-oil fired boilers
d) on gas fired boilers
b - ANSWER when a boiler steam outlet stop valve is required by code , the
preferred style of valve is
,a) a non-rising stem globe valve
b)an outside screw and yolk, rising stem
c) a non-rising stem gate valve
d) a ball valve
c - ANSWER Every steam boiler must have a safety valve that is
a) placed in the piping system leading from the steam stop valve
b) fitted securely to a shut off valve, which is directly connected to the top of the
boiler
c) fitted in a vertical position, directly connected to the top of the boiler
d) connected to the steam or water space of the boiler, without any intervening
fitting
d - ANSWER the purpose of the spring in the safety valve is to
a) help open the testing lever
b) adjust the pressure setting of the valve
c) adjust the blowdown of the valve
d) hold down the disk on the seat
d - ANSWER if the boiler produces steam at a higher rate than the rate of steam
consumption, and its condition goes unchecked
a) soot will develop on the fireside
b) the boiler efficiency will drop
c) the boiler will overheat
d) the boiler will over-pressurize
b - ANSWER an important fitting, which is installed before steam boiler pressure
gauge and the boiler itself and is designed to prevent damage to the gauge, is a
a) tee with a plug
b) Syphon
c) Blowdown valve
d) test connection for an inspector
a - ANSWER the main controlling device used with an On-Off combustion fuel
control is a ___________ sensing element
a) pressure
b) level
c) flow
d) electronic
, c - ANSWER One purpose of the small valve on top of the shell of most boilers,
which is not required by code , is to
a) allow water into the boiler when the boiler is being drained or cooled
preventing the formation of a vacuum
b) allow water to escape before steam stop valve is opened during the warm-up
period
c) allow air to escape the boiler when the boiler is being filled with water
d) allow air into the boiler when the boiler is being filled with water
a - 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
c - ANSWER When is a stop valve allowed between a heating boilers safety valve
and the boiler drum?
a) only if the stop valve is locked open
b) if there is more than one safety valve
c) never
d) if the stop valve is quick opening design
c - ANSWER the discharge pipe from a boiler safety valve is supported
independently of the safety valve
a) because the steam drum can not support the extra mass of the discharge pipe
b) so the discharge pipe can drain more easily
c) so the discharge pipe can expand without putting force on the safety valve
d) to prevent leakage at the pipe joint
b - ANSWER an operator should check that the boiler safety valve will open at its
set pressure by
a) asking the inspector to bring a master pressure gauge
b) increasing the boiler pressure and noting the pressure at which the valve
opens
c) putting a piece of pipe over the lifting lever and lifting the valve off its seat
when the set pressure is reached
d) using air pressure during a shutdown to raise the pressure in the boiler until
the set pressure is reached
