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56 Cards in this Set
- Front
- Back
If the boiler is generating 20,000 lb/hr of steam, it must be supplied with ____ lb/hr of feedwater |
20,000 |
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From the deaerator, oxygen and other noncondensable gases are separated from the feedwater and directed to the atmosphere _____ |
Through the vent |
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A(n) _____ is a system of measuring instruments and controllers that work together to control a process |
Control system |
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One pound of water is needed to produce ____ of steam |
1 pound |
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In a low-pressure gas system, the ____ valve is an electric valve that can’t be opened until the gas pilot is lit |
Manual reset |
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_____ are used for loads that require dry steam, such as turbines |
Superheaters |
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In a feedwater system, the ____ valve is located closest to the shell of the boiler on the feedwater line so that the check valve can be repaired without draining (dumping) the boiler |
Stop |
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A steaming boiler can have the water in the gauge glass go from half full to empty in a matter of _____ if water is not added to the boiler |
Minutes |
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In a fuel oil system, the purpose of duplex strainers is to ____ |
Permit one strainer to be cleaned while the other is in service |
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Superheated steam has more ____ than saturated steam at the same pressure |
Heat energy |
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The deaerator tank is located ____ |
Above the feedwater pumps |
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A gas pilot line on a high-pressure gas system supplies gas through a _____ valve to the pilot gas pressure regulator |
Shutoff |
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The purpose of any fuel oil system is to supply fuel oil to the burner at the proper ____ |
Temperature and pressure |
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Number _____ fuel oil needs to be heated before it is pumped so that it can flow |
6 |
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Pulverizing coal allows ____ |
For closer contact between the coal and oxygen for complete combustion |
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Draft is _____ caused by a difference in pressure between two points |
The flow of air or gases of combustion |
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Natural draft is the result of temperature difference between ____ |
Air and gases of combustion |
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In a low-pressure gas system, the air mixes with the gas in the _____ |
Injector |
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A measuring instrument can use a ____ to send a signal to a controller |
Transmitter |
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Pulverized coal is ground into a fine powder and blown into the combustion chamber where it is burned in ____ |
Suspension |
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A control system uses a ____ to execute a control strategy |
Control loop |
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Water weighs approximately ____ lb/gal |
8.3 |
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Induced draft is produced by pulling air through the boiler furnace with a fan located in the ____ |
Breeching |
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A control loop uses a ____ as the control element |
Steam pressure controller |
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Codes may require that a(n) ____ be positioned before the firing-rate valve that controls the volume of gas to the burner |
Manual shutoff valve |
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Feedwater is typically pumped into a(n) ____ where it is heated to a relatively high temperature by the gases of combustion discharged from the boiler. |
Economizer |
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_____ is produced by a fan supplying air to the furnace |
Forced draft |
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Boiler instruments consists of devices used to measure ____, opacity, and other process conditions |
Temperature, pressure, and flow |
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A ____ contains a primary element, a control element, and a final element |
Control loop |
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____ is a clean, minimally polluting fuel that requires no storage and is readily available in most areas. |
Natural gas |
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Which four separate systems must function in order for a steam boiler to operate? _____ |
1: steam system 2: feedwater system 3: fuel system 4: draft system - the instrumentation and control system is important too |
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_____ is the vapor that forms when water is heated to its boiling point. |
steam |
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In a steam system if the pressure controls fail, a _____ is a last resort to control the pressure. |
safety valve |
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A _____ is used when multiple boilers are in battery. |
steam header |
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As steam gives up its heat, it ____ |
condenses back to water |
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Any time there is a reduction in steam pressure through a pressure-reducing station there must be a _____ |
safety valve |
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_____ is water supplied to a boiler. |
feedwater |
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A(n) _____ opens a feed valve located on a water line to a deaerator tank to add makeup water to compensate for the condensate lost. |
float |
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A(n) _____ are needed so the heater can be taken out of service without a shutdown. |
bypass line and outlet valve |
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A control element, or feedwater regulator, is located at the _____ |
boiler normal operating water level |
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A feedwater regulator is equipped with a ____ valve to ensure that the water and steam lines are free of sludge and sediment |
blowdown |
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In a low-pressure gas system, there is a safety switch between the manual reset valve and zero gas governor called a _____ |
vaporstat |
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In a high-pressure gas system, a low-gas-pressure switch with a ____ causes the combustion controller to secure the safety shutoff valves if the gas pressure is too low. |
manual reset |
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No. 2 fuel oil generally _____ |
flows freely |
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_____ isolate a tank when it is not in use. |
stop valves |
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A ____ is used to clean the fuel before it goes to the burner |
strainer |
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Natural draft is produced without a _____ |
fan |
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In a natural draft system, the amount of draft can be increased by _____ |
a taller stack |
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Forced draft systems produce a pressure in a furnace that is ____ atmospheric pressure |
slightly above |
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_____ draft is draft produced by pulling air through the boiler furnace with a fan |
induced |
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From the stack of a combination draft system, the gases of combustion discharge into the _____ |
atmosphere |
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A _____ can be used to convert the movement of the internal parts of a pressure gauge into an electrical or digital signal that can be sent to a control system. |
transducer |
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A(n) _____ is the method a controller uses to manipulate the measured value into something that can be used to make changes to the process to keep it at the desired operating conditions. |
control strategy |
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The ____ are the final elements that control the flow of gas and air to a burner. |
gas valve and damper |
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List all the steps in the feedwater system: |
- I recommend you read page 31 and page 32 for a thorough explanation. - keep in mind, this is a general overview of a complete boiler. Some boilers may not have all of the components listed, such as a feedwater heater. 1: condensate return line 2: surge tank 3: deaerator tank 4: vent 5: float 6: feed valve 7: water line 8: internal overflow line 9: waste 10: suction line 11: feedwater pump 12: second feedwater pump 13: suction valves 14: discharge valves 15: check valves 16: feedwater discharge line 17: closed feedwater heater 18: inlet valve 19: outlet valve 20: bypass line and valve 21: main feedwater stop valve 22: boiler 23: control element (feedwater regulator) 24: steam line 25: shutoff valve 26: control element line 27: shutoff valve 28: feedwater regulating valve 29: shutoff valves 30: bypass valve 31: stop valve 32: check valve 33: blowdown valve 34: economizer |
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List all the steps in a steam system: |
- I recommend you read page 29 and page 30 for a thorough explanation. - keep in mind, this is a general overview of a complete boiler. Some boilers may not have all of the components listed, such as a feedwater heater. 1: steam drum 2: safety valve 3: superheater 4: automatic nonreturn valve 5: main steam stop valve 6: main steam line 7: distribution line 8: pressure-reducing station 9: load 10: steam trap 11: condensate return |