CHAPTER 30 Flashcards
A common arrangement for temperature control is to _____ the lubricant to the bearing where it picks up heat.
Select one:
A.
Air cool
B.
Use higher viscosity
C.
Circulate minimal quantities of
D.
Circulate generous quantities of
E.
Water cool
D.
Circulate generous quantities of
Lubricants are frequently used to provide sealing between:
Select one:
A.
Lobes and cylinder walls
B.
Impellers and casing walls
C.
Stationary and moving blades
D.
Pistons and cylinder walls
E.
Screws and cylinder walls
D.
Pistons and cylinder walls
Materials that are used as solid lubricants include all of the following except:
Select one:
A.
Soapstone
B.
Molybdenum disulphide
C.
Graphite
D.
Petroleum oil
E.
Mica
D.
Petroleum oil
As well as separating the bearing surfaces, the lubricant forms a film on the surfaces, thus protecting them from:
Select one:
A.
Air
B.
Corrosion
C.
Temperature
D.
Pressure
E.
Moisture
B.
Corrosion
One of the general classes of lubricants is the:
Select one:
A.
Gas
B.
Oil
C.
Semi-solid
D.
Grease
E.
Semi-liquid
C.
Semi-solid
Often chemical compounds (additives) are added to the lubricant to prevent the formation of _____ due to oxidation of the oil.
Select one:
A.
Hydrocarbons
B.
Mercaptans
C.
Alkalines
D.
Acids
E.
Alkaloids
D.
Acids
Fixed oils also called fatty oils produced from all of the following except:
Select one:
A.
Cottonseed oil
B.
Whale oil
C.
Lard
D.
Petroleum oil
E.
Castor oil
D.
Petroleum oil
In cases where surfaces come together with some impact, as with _____, the lubricant serves to absorb shock.
Select one:
A.
Pump impellers
B.
Gear teeth intermeshing
C.
Pump pistons
D.
Pump lobes
E.
Gas turbine blades
B.
Gear teeth intermeshing
Lubricants in general may provide all of the following services except:
Select one:
A.
Physical stability under variations of temperature and pressure
B.
Minimum adhesion to the surfaces to be lubricated
C.
Resistance to emulsion
D.
Resistance to oxidation
E.
Minimum coefficient of friction
B.
Minimum adhesion to the surfaces to be lubricated
If oil has a high viscosity index (VI), this indicates that its viscosity:
Select one:
A.
Changes greatly with pressure change
B.
Changes little with pressure change
C.
Does not changes with temperature change
D.
Changes little with temperature change
E.
Changes greatly with temperature change
D.
Changes little with temperature change
Solid lubricants are suitable for use under conditions of:
Select one:
A.
Dust
B.
High load
C.
Corrosive atmospheres
D.
Dampness
E.
Low load
B.
High load
Synthetic Oils include:
Select one:
A.
Castor oil
B.
Whale oil
C.
Polyglycols and silicones
D.
Lard
E.
Petroleum oil
C.
Polyglycols and silicones
The neutralization number indicates the _____ of oil.
Select one:
A.
Carbonization
B.
Neutralization
C.
Acidity
D.
Volatility
E.
Alkalinity
C.
Acidity
The pour point of oil is the _____ at which the oil will flow.
Select one:
A.
Lowest temperature
B.
Highest pressure
C.
Lowest pressure
D.
Lowest viscosity
E.
Highest temperature
A.
Lowest temperature
Frequently, it is possible to improve the desirable characteristics of lubricating oil by the use of all of the following additives except:
Select one:
A.
Emulsion breakers
B.
Corrosion inhibitors
C.
Anti-oxidants
D.
Detergent-dispersants
E.
Pour point depressants
A.
Emulsion breakers
As the temperature increases the oil will:
Select one:
A.
Thicken and become more viscous (viscosity will be reduced)
B.
Thin out and become less viscous (viscosity will be reduced)
C.
Thin out and become less viscous (viscosity will be increased)
D.
Thin out and become more viscous (viscosity will be reduced)
E.
Thicken and become less viscous (viscosity will be reduced)
B.
Thin out and become less viscous (viscosity will be reduced)
The flash point of oil is the temperature at which the oil gives off sufficient vapour to _____ when mixed with air and exposed to a source of ignition.
Select one:
A.
Burst into flames
B.
Ignite
C.
Burn continuously
D.
Give off smoke
E.
Ignite momentarily
E.
Ignite momentarily
As the temperature decreases the oil will become:
Select one:
A.
Thicker and less viscous (viscosity will be increased)
B.
Thicker and more viscous (viscosity will be increased)
C.
Thinner and less viscous (viscosity will be increased)
D.
Thicker and more viscous (viscosity will be decreased)
E.
Thinner and more viscous (viscosity will be increased)
B.
Thicker and more viscous (viscosity will be increased)
The reasons for using lubricants include all of the following except:
Select one:
A.
To provide sealing
B.
To reduce corrosion
C.
To reduce wear
D.
For temperature control
E.
To increase friction
E.
To increase friction
One of the general classes of lubricants is the:
Select one:
A.
Gas
B.
Grease
C.
Semi-liquid
D.
Solid
E.
Oil
D.
Solid
The viscosity of oil is greatly affected by the _____ of the oil.
Select one:
A.
Specific gravity
B.
Pressure
C.
Density
D.
Mass
E.
Temperature
E.
Temperature
While providing lubrication, semi-solid lubricants (grease) are not able to:
Select one:
A.
Seal out dirt from bearings
B.
Prevent rusting during idle periods
C.
Remove large amounts of heat from the bearing
D.
Give bearing surfaces a protective coating
E.
Seal out water from bearings
C.
Remove large amounts of heat from the bearing
One of the general classes of lubricants is the:
Select one:
A.
Grease
B.
Semi-liquid
C.
Liquid
D.
Oil
E.
Gas
C.
Liquid
Mineral oils are produced from _____ and are the most commonly used class
Select one:
A.
Crude petroleum
B.
Lard
C.
Vegetable origin
D.
Animal origin
E.
Castor oil
A.
Crude petroleum
