更多"An additive used to improve the abi"的相关试题:
[单项选择]If the analysis of used lube oil indicates a high content of iron particles, this could indicate()
A. corrosive deterioration of a bearing
B. inadequate air filtration
C. excessive ring and liner wear
D. excessive cooling of lubricating oil
[单项选择]If a used lube oil analysis indicates excessive fuel dilution, the lube oil should be ()
A. changed
B. centrifuged
C. filtered
D. settled
[单项选择]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 worn
[单项选择]Which lubricating oil additive is used in diesel engines to reduce the tendency for sludge and varnish to form on the engine parts?()
A. Flash point improvers
B. Pour point improvers
C. Inhibitors
D. Foam suppressors
[单项选择]When separating the lube oil without additive, it is usually cleaned with hot water; the aim is to remove () from it.
A. acid
B. sludge
C. mechanical impurity
D. salinity
[单项选择]Although lube oils used in the main lubricating service systems should have a relatively high flash point to avoid ignition, they can create smoke and fire hazards when they()
A. are exposed to a vacuum
B. come in contact with extremely hot surfaces
C. are reduced in temperature to just above the pour point
D. become extremely agitated or aerated
[单项选择]A lube oil filter can be used to remove most contaminants from lube oilA contaminant which will remain in the lube oil after filtering is ().
A. acid
B. fuel oil
C. sediment
D. water
[单项选择]The following measures can be used to improve oily water separator’s separating effect except ()
A. overhauling every two year
B. working at intervals
C. renewing filtration material
D. pumping bilge water from different layers respectively
[单项选择]The lube oil pump used in a diesel engine is a ().
A. volute pump
B. centrifugal pump
C. diaphragm pump
D. gear pump
[单项选择]The lube oil cooler is located after the lube oil filter in order for ()
A. the filter to operate more efficiently
B. the lube oil cooler to be bypassed
C. positive lube oil pump suction to be assured
D. galvanic action in the cooler to be minimized
[单项选择]A lube oil sample taken from the main engine lube oil system has dark yellow opaque color.This is the result of ()
A. water contamination
B. mixing oils of two widely different viscosities
C. overheating
D. aeration
[单项选择]Lube oil filters remove contaminants more efficiently if the oil being filtered is ().
A. under high pressure
B. under low pressure
C. heated to reduce viscosity
D. cooled to increase viscosity
[单项选择]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
[单项选择]Diesel engine lube oil can become contaminated as a result()
A. the water produced during combustion
B. the sulfur in the fuel
C. unburned fuel oil
D. all of the above
[单项选择]Which of the following characteristic of lube oil helps to reduce the amount of deposits in the piston ring belt during the combustion process in a diesel engine?()
A. Low viscosity index
B. Low carbon forming tendencies
C. High film strength
D. High non-corrosive qualities
[单项选择]The pressure difference before and after the lube oil filter indicates ()the filter should be cleaned.
A. when
B. how
C. where
D. whether
[单项选择]Lube oil accumulating in the cooling water system of a diesel engine will result in ()
A. lube cooler failure
B. poor heat transfer
C. mechanical lubricator failure
D. camshaft seizure
[单项选择]Excessive lube oil consumption can result from worn or broken()
A. piston rings
B. valve guides
C. valve seals
D. all of the above