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Excessive piston ring wear in a diesel engine will cause()
A . high lube oil viscosity
B . increased lube oil consumption
C . low lube oil temperatures
D . high firing pressure
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Excessive lube oil consumption by a reciprocating air compressor can be caused by ().
A、using a slightly dirty air filter
B、using oil having an excessive viscosity
C、intercooler or after-cooler leaks
D、carrying the oil level higher than normal
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Production of mechanical foam by a portable in-line foam proportioner().
A . increases the size of foam bubbles formed
B . increases the rate of foam production
C . improves the extinguishing properties of foam
D . gives the nozzleman more freedom of movement,since it can be placed anywhere in the hose line
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Foaming of the oil in a refrigeration compressor crankcase is caused by ().
A . refrigerant boiling out of solution from the lube oil
B . liquid refrigerant flooding the compressor and system
C . lube oil viscosity being reduced by refrigerant dilution
D . compressor suction pressure suddenly increasing
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What is an advantage of using foam in fire fighting?()
A . It is effective in controlling fire in flowing oil such as coming from a broken fuel line
B . It absorbs heat from materials that could cause reignition
C . Most foams can be used jointly with dry chemical extinguishing agents to attack a fire by two methods of extinguishment
D . Once the surface is blanketed with foam and the fire is extinguished,no further foam is required
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How does foam extinguish an oil fire?()
A . By cooling the oil below the ignition temperature
B . By removing the fuel source from the fire
C . By excluding the oxygen from the fire
D . By increasing the weight of the oil
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If a used lube oil analysis indicates excessive fuel dilution, the lube oil should be ()
A . changed
B . centrifuged
C . filtered
D . settled
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In a refrigeration system, foaming of the crankcase oil may cause the ().
A . expansion valve to overfeed
B . compressor to knock
C . water regulating valve to fail
D . crankcase drains to plug
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In the common rail system, excessive pressure in the header may be caused by ()
A . improper adjustment of the bypass valve
B . a dribble in the fuel injection nozzle
C . insufficient leak-off through injection nozzle packing
D . a malfunctioning injection nozzle
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Excessive scale formation in a distilling plant may result from ().
A . poor distillate quality
B . reduced evaporator capacity
C . low brine concentration
D . improper vacuum regulatio
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Excessive lube oil consumption can result from worn or broken()
A . piston rings
B . valve guides
C . valve seals
D . all of the above
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A portable foam fire extinguisher is placed in operation by()
A . turning it upside down
B . pressing the foam lever
C . squeezing the grip handle
D . opening the hose valve
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A four-stroke cycle, turbocharged, 1000 horsepower diesel engine has been operating under loadThe load suddenly increases, causing excessive black exhaust smoke, and a rapid rise in the lube oil temperatureIn response to this condition, you should:()
A . reduce load
B . check your exhaust
C . adjust cooling water temperature
D . increase lube oil flow
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A foam-type portable fire extinguisher would be most useful in combating a fire in().
A . soild materials such as wood or bales of fiber
B . flammable liquids
C . a piece of electrical equipment
D . combustible metallic solid
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When an oil fire has been extinguished, the surface of the oil should be kept covered with foam to prevent ().
A . air from contacting the oil vapors
B . permitting re-ignition boiling of the heated oil
C . spontaneous combustion below the oil surface
D . toxic fumes from escaping to the surface
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To avoid excessive pressures in the fuel oil filling system during bunkering, you should ().
A . close the tank filling valves quickly
B . top off all tanks at the same time
C . rill completely all tanks to less than 95% full
D . reduce the loading rate when topping off
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Excessive oil foaming in the crankcase of a refrigeration compressor at start up can cause().
A . compressor damage from improper lubrication
B . refrigerant absorption by the lubricant
C . increased viscosity in the lubricant
D . carbon deposit on the compressor suction valve
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A foam-type portable fire extinguisher is most useful in fighting a fire in().
A . generators
B . oil drums
C . the bridge controls
D . combustible metal
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A condition that can increase the foaming tendency of lube oil is ()
A . excessively high oil temperatures
B . water or moisture contamination
C . fuel dilution
D . life its cylinder relief vale
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If a used lube oil analysis indicates an excessive chromate content, this means ()
A . air filtration is inadequate
B . engine coolant leaking into the lube oil
C . fuel oil is leaking into the lube oil
D . the piston rings are excessively wor
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Which of the following conditions could be a cause of excessive fuel dilution of diesel engine lube oil?()
A . Leaking fuel injectors
B . Lower than normal compression
C . Delayed fuel injection
D . All of the above are correct
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Excessive circulation of the lubricating oil with the refrigerant in a refrigeration system will cause______.
A.carbon deposits on the compressor suction valves
B.the evaporator temperature to increase
C.rapid corrosion of the thermal expansion valve
D.no operating problems