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36 Cards in this Set
- Front
- Back
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An ON-OFF steam boiler a) will maintain a fairly constant steam pressure b) operates most efficiently at continuous firing c) will cycle on and off based on temperature d) must have a low capacity e) cannot operate in a multiboiler system |
b) operates most efficiently at continuous firing |
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A modulating control steam heating boiler a) is always fully automatic b) will have a wide operating pressure range c) has very efficient operation d) will have a constant combustion air flow rate e) cannot operate in a multiboiler system |
c) has a very efficient operation |
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An operating control switch for an ON-OFF boiler a) uses a differential spring to reduce cycling b) can only have its cut-in setting adjusted c) has an unadjustable span between cut-in and cut-out d) utilizes a resistance coil e) operates in conjunction with a modutrol motor |
a) uses a differential spring to reduce cycling |
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A levelling indicator is found on a) the casing of a heating boiler b) a low-water fuel cutoff switch c) a boiler feedwater pump d) a modutrol motor e) an ON-OFF operating control switch |
e) an ON-OFF operating control switch |
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An item found upstream of an operating control switch is a a) modutrol motor b) siphon c) combustion air proving switch d) test connection for an inspector e) feedwater pressure gage |
b) siphon |
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On a multiburner boiler the high fire nozzle will a) be in operation on start-up b) operate continuously when steam demand exceeds boiler capacity c) be ignited by a pilot flame d) respond to electrical resistance e) operate regardless of where the manual over-ride switchis set |
b) operate continuously |
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A manual "high-low" switch should be switched to "high" or"auto" a) as soon as the main flame has stabilized b) prior to ignition of the main flame c) when pressure is too low d) when the boiler has been properly warmed up e) during boiler pre-purge |
d) when the boiler has been properly warmed up |
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A resistance control or "potentiometer" for modulating control a) works in conjunction with a modutrol motor b) utilizes a mercury switch c) senses steam temperature d) can only be used on a fully automatic boiler e) can operate only in the vertical position |
a) works in conjunction with a modutrol motor |
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A potentiometer control a) varies electrical current to a modutrol motor b) will start and stop a boiler c) cannot have its settings adjusted d) eliminates the need for a high limit control e) will not result in simultaneous adjustment of air andfuel |
a) varies electrical current to a modutrol motor |
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A high limit control switch a) is necessary on all boilers b) activates after the safety valve opens c) is a normally open switch d) usually does not require manual resetting e) must be used when a boiler is not under continuoussupervision |
e) must be used when a boiler is not under continuous supervision |
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Prior to a boiler safety valve popping during routine boiler operation a) a try lever test should be performed b) the pressure gage should be checked c) the high limit switch should open d) the feedwater pump should stop e) the high level alarm should sound |
c) the high limit switch should open |
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A hot water boiler operating control can be a pressure switch a) which is normally open b) which is sensitive to the expansion and contraction of boiler water c) utilizing a closed liquid filled system d) sensitive to steam pressure e) sensitive to boiler water pressure |
c) utilizing a closed liquid filled system |
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A thermal element is a) used to measure pressure b) capable of sensing temperature and converting it to apressure signal c) a type of open system d) used to measure heat content e) commonly termed an "aquastat" |
b) capable of sensing temperature and converting it to a pressure signal |
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An aquastat a) senses water level b) is like a thermal element without a capillary tube c) can be located away from its point of measurement d) measures water flow e) is a modulating device |
b) is like a thermal element without a capillary tube |
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A low fire switch a) is a type of manual over-ride b) takes no part in the start-up of an automatic boiler c) is a normally closed switch d) utilizes a thermal element for its operation e) acts as an interlock to ensure minimum damper setting |
e) acts as an interlock to ensure minimum damper setting |
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What is the purpose of the high limit temperature control ona hot water boiler? a) to take over operating the boiler if the water level control fails b) to allow you to take off the operating control formaintenance without shutting down the boiler c) to shut down the burner if the water temperature risestoo high d) to prevent the pressure in the boiler rising above 210kPa gage e) to limit high pressure and temperature from developing inthe boiler |
c) to shut down the burner if the water temperature rises too high |
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Combustion air safety switches are commonly found a) on natural draft boilers b) on hot water boilers only c) on boilers utilizing a forced draft fan d) on gas fired boilers only e) as noninterlocking devices and take no part in a startup |
c) on boilers utilizing a forced draft fan |
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A high gas pressure fuel cut-off switch a) closes when gas pressure is too high b) is never a manual reset device c) must be located upstream of an automatic fuel valve d) is a normally open switch e) opens when gas pressure is too high |
e) opens when gas pressure is too high |
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A test lead or "jumper wire" is required when testing a) high steam pressure or water temperature limiting controls b) a high gas pressure fuel cut-off switch c) a safety valve with the test lever d) the low water fuel cut-off switch e) a low gas pressure fuel cut-off |
a) high steam pressure or water temperature limiting controls |
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Quickly closing the main burner manual cock valve duringboiler operation should check the a) flame scanner b) combustion air proving switch c) low gas pressure fuel cut-off d) high gas pressure fuel cut-off e) low fire interlock switch |
d) high pressure fuel cut-off |
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The combustion air proving switch a) should be checked when air flow is minimum b) should not be checked while the boiler is in the purgecycle of start-up c) is a normally closed switch d) must always be a manual reset device e) should be checked when air flow is maximum |
e)should be checked when air flow is maximum |
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A modulating control steam heating boiler: a) is always fully automatic b) will have a wide operating pressure range c) will have a constant fuel flow rate d) will have a constant combustion air flow rate |
b) will have a wide operating pressure range |
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A low fire switch: a) is part of the start-up logic sequence b) takes no part in the start-up of an automatic boiler c) is a normally closed switch d) utilizes a thermal element for its operation |
a) is always fully automatic |
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A high gas pressure fuel cut-off switch: a) utilizes a thermal element for its operation b) is never a manual reset device c) must be located upstream of an automatic fuel device d) opens when gas pressure is too high |
d) opens when gas pressure is too high |
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The types of burners required for high-low fire control are: a) steam atomizing b) air atomizing c) spud jet d) multiple nozzles |
d) multiple nozzles |
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When a boiler is shut down on the high limit control, what must the operator do before starting the boiler up again? a) Restart the forced draft fan b) Reset the lockout on the high limit controller c) Reset the boiler main power supply d) Switch the boiler control to the low-fire model |
b) Reset the lockout on the high limit controller |
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A low gas pressure fuel cut-off switch will shut down the burner due to: a) fan failure b) low air pressure c) low steam pressure d) feedwater pump failure e) low gas pressure |
e) low gas pressure |
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A high fire switch: a) is closed when the damper is in low air position b) is closed when the damper is in high fire position c) is closed when the damper is closed d) is a normally closed switch e) is opened when the damper is in low air position |
b) is closed when the damper is in high position |
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A thermal element is: a) used to measure pressure b) capable of sensing temperature and converting it to a pressure signal c) type of open system d) used to measure heat content e) commonly termed an aquastat |
b) capable of sensing temperature and converting it to a pressure signal |
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An aquastat: a) senses water level b) is like a thermal element without a capillary tube c) can be located away from its point of measurement d) measures water flow e) is a modulating device |
b) is like a thermal element without a capillary tube |
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A test lead or jumper wire is required when testing: a) high steam pressure or water temperature limiting controls b) high gas pressure fuel cut-off switch c) a safety valve with the test lever d) the low water fuel cut-off switch e) a low gas pressure fuel cut-off |
a) high steam pressure or water temperature limiting controls |
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The modulating control should be blown clean at regular intervals with: a) water b) oil c) compressed air d) flue gas e) steam |
c) compressed air |
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On a multiburner boiler the operating limit pressure control: a) starts and stops the burner but only controls the low fire nozzle b) starts and stops the burner but only controls the high fire nozzle c) controls both the high and low fire nozzles d) maintains steam pressure at a constant value e) maintains gas pressure at a constant value |
a) starts and stops the burner but only controls the low fire nozzle |
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Modulating combustion control: a) controls the steam and feed water flow b) controls fuel and air flow c) controls the steam pressure to the oil atomizer d) controls the back draft damper e) controlos the draft and feed water temperature |
b) controls the fuel and air flow |
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The type of combustion fuel control frequently used on a small package boiler is a/an: a) scanner b) modulating control c) high fuel level cut-off d) constant pressure control e) on and off control |
e) on and off control |
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A steam heating boiler is found cycling due to the cut-in and cut-out points on the ON-OFF control being set too close. To correct this problem you must: a) increase water level b) increase boiler pressure c) adjust the pressure adjustment screw d) adjust the differential adjustment screw e) reduce the firing rate |
d) adjust the differential adjustment screw |
