If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause may be ______.A.high steam pressure in the boilerB.abnormally high feed-water temperatureC.abnormally high boiler water temperatureD.steam demand exceeding feed pump capacity
If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause may be ______.
A.high steam pressure in the boiler
B.abnormally high feed-water temperature
C.abnormally high boiler water temperature
D.steam demand exceeding feed pump capacity
相关考题：
The fuel supply system to an automatic auxiliary boiler, will be automatically shutdown if the boiler() A.salinity is abnormallyB.high steam demand is tooC.feed-water flow is lowD.water level is abnormally low
The boiler water alkalinity in a coil-type auxiliary boiler should be maintained at the pH recommended by the boiler manufacturer to______.A.precipitate(使沉淀) silica （硅石）from solutionB.reduce corrosion in the heating coilC.prevent clogging and erosion in the coilD.maintain zero water hardness
单选题Which of the following items is necessary for all waste heat boiler installations, regardless of design or manufacturer? （）AControl of evaporationBA separate means to prevent feed-water contaminationCPower circulating pumpDSuper-heater
单选题The most common cause of scale formation in an auxiliary boiler is （）Aconcentrations of calcium sulfate in the boiler waterBfuel oil in the feed waterCimproper treatment of the feed water with calcium sulfateDexcessive feed water alkalinity
单选题The purpose of a temperature sensing device installed in the stack of a small automatically fired auxiliary steam boiler is to secure the oil burner（）Ain the event of a flame failureBin the event of a stack fireCwhen the water level reach the crown sheetDwhen the feed pump discharge pressure drops to a preset minimum
单选题What is NOT a function of the steam drum of a marine water-tube boiler（）.AReceives saturated steam from the generating tubesBServes as a reservoir of boiler feed waterCHolds internal fittings for separation of moisture from steamDCollects steam exhausted from the turbines
单选题In the event of a flame failure in an auxiliary water-tube boiler, you must（）Arelight the boiler immediately to prevent loss of steam pressureBrelight the fire off the brickwork as the bricks are cherry redCpurge the furnace of any combustible gases before attempting to relight the fireDspeed up the feed pump to prevent dry firing when the burner flame is reestablished
单选题The rate of heat transfer in a water-tube auxiliary boiler can be increased by （）.Aoperating the boiler at less than normal water levelBinstalling fins on the firesides of water-tubesCincreasing the amount of excess air to the burnersDtreating the boiler water with chemical oxygen scavengers
单选题Improper maintenance of an automatic auxiliary boiler oil burner could result in （）.Afuel pump failureBfan motor failureCincreased feedwater consumptionDdecreased boiler efficiency
单选题The boiler feed water check valves are located on the （）Afeed pump suction lineBhot wellCshell of the feed heaterDfeed lines to the boiler
单选题Oxygen corrosion in auxiliary boilers is prevented by treating the boiler feed tank with either sodium （）Asulfite or hydrazineBsulfite or hygroscopic sulfiteCbromide or hydrazineDbromide or hygroscopic sulfite
单选题The water in an auxiliary boiler should be tested daily for （）.Adissolved oxygenBchloridesCsludgeDdissolved nitrogen
单选题The valve that prevents water from backing out of the boiler into the feed line is the（）.Abottom-blow valveBskin valveCfeed-check valveDfeed-stop valve
单选题Excessive vibration of an automatically fired auxiliary boiler can be caused by （）Aair or water in the furnaceBcombustion pulsesCfuel oil pump failureDflame failure
单选题A feed pump for an auxiliary boiler might lose suction if the （）.Aboiler water level is lowBfeedwater is too hotCboiler steam demand is lowDfeedwater is too cold
单选题For proper operation, auxiliary boiler feed water must have which of the following characteristics?（）AHigh oxygen concentrationBLow pHCProper alkalinityDAll of the above
单选题The boiler feed pump discharge pressure is higher than the steam drum pressure to （）.Aensure feed water flow into the boilerBkeep the steam drum pressure highCprevent water hammer in the feed lineDhelp the feed water flash to steam
单选题The water level in a steaming auxiliary boiler will always （）Arise when the steam pressure is increasedBremain constant as long as the feed pump operatesCfall when the steam pressure is decreasedDvary as the steam demand changes
单选题The boiler water alkalinity in a coil-type auxiliary boiler should be maintained at the pH recommended by the boiler manufacturer to（）Aprecipitate silica from solutionBreduce corrosion in the heating coilCprevent clogging and erosion in the coilDmaintain zero water hardness
单选题Improper maintenance of the fuel oil burners in an automatically fired auxiliary boiler, could result in （）Aincreased fuel consumptionBincreased feed water consumptionCfuel pump failureDcombustion control system failure
单选题Which of the following conditions could cause the feed pump for an auxiliary boiler to lose suction?（）AIncreased suction head pressureBDecreased feedwater temperatureCPump recirculating line being open too muchDExcessive feedwater temperature
单选题Excessive alkalinity of the water in an auxiliary boiler can cause （）.Acaustic embrittlement of the boiler metalBacidic corrosion of the boiler metalChard scale deposits on the boiler tubesDetching of the heat exchange surfaces
单选题Bottom blow valves are installed on auxiliary water-tube boilers to （）Acompletely drain the boiler in an emergencyBprevent sludge from forming in the drumCremove floating impurities from the boiler water surfaceDremove settled solids from the water drum
单选题The feed water to the boiler will comprise （）.AcondensateBa small amount of make-up feedCA and BDNone of the above
单选题As for an oil-fired boiler if at a normal steaming condition and water goes out of sight in gauge glasses the action you should take is: （） (1) secure oil to fires (2) increase feed pump pressureA（1）B（1）and（2）C（2）Dneither（1）nor（2）
单选题If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause maybe （）.Ahigh steam pressure in the boilerBabnormally high feed water temperatureCabnormally high boiler water temperatureDsteam demand exceeding feed pump capacity