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
For proper operation, auxiliary boiler feed water must have which of the following characteristics?（）
A
High oxygen concentration
B
Low pH
C
Proper alkalinity
D
All of the above
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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 water in an auxiliary boiler should be tested for chloride content to determine ( ).A.total dissolved solidsB.salt contaminationC.water harcnessD.chlorine contamination
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
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The purpose of the safety relief valves installed on an auxiliary boiler is to （）.Arelieve excess fuel oil pressure during the “off” fire cycleBadmit water to the dry pipeCthrottle the forced draft fan output for proper combustionDreduce excess steam pressure in the boiler
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Bottom blow valves are installed on auxiliary water-tube boilers to （）Aremove suspended and precipitated solids from the boiler waterBcompletely drain the boiler in an emergency situationCprevent hardened scale deposits in the water drumDremove floating impurities from the oily water surface
单选题A distorted furnace in a fire-tube auxiliary boiler may be the result of （）Afiring for extended periods in the low fire modeBoverheating, due to waterside depositsCvarying the water level above the crown sheetDcarrying excessive alkalinity in the boiler water
单选题The water in an auxiliary boiler should be tested daily for （）.Adissolved oxygenBchloridesCsludgeDdissolved nitrogen
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All of the followings are the detainable deficiencies under the SOLAS Convention expert（）.AFailure of proper operation of propulsion and other essential machinery, as well as electrical installationBFailure of the proper operation of the main and auxiliary steering gearCFailure of engineering watch arrangements to confirm to the requirements specified for the ship by AdministrationDFailure of the proper operation of emergency generator, lighting, batteries and switches
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
单选题Before an auxiliary boiler is shutdown for an extended period of time, the water in the boiler should have a pH value of （）.A10B7C4D1
单选题The water in an operating auxiliary boiler should be tested for alkalinity and chloride content each（）.AhourBdayCweekDmonth
单选题If an operating auxiliary boiler has a water pH reading of 7, you should （）.Abottom blow the boilerBtreat the water with caustic sodaCtreat the water with chemical scavengersDreduce the water alkalinity to recommended readings
单选题Which action should be taken when an auxiliary boiler in is operation?（）AClean all electrical connectionsBLift the relief valves by handCInspect and clean all solenoid valvesDInspect for oil and water leaks