Lubricants And Lubrication Flashcards
A thin layer of lubricant between two surfaces enables one surface to _______ the other.
Slide over
By separating two surfaces slightly, lubricant helps reduce…
Wear
A lubricant can equalize pressures in various places along two contacting surfaces, thereby reducing…
Mechanical shock
An oil cooler radiates heat into the air, usually through its…
Metal fins
By forming a slight “scab” where it is exposed to the air. grease can….
Seal out dirt and other contaminants
The compounds in crude oil are classified as…
Hydrocarbons
The most important property of a lubricating oil is its
Viscosity
The viscosity of an industrial lubricating oil is measured in…
Saybolt Universal Seconds
Grease is used in applications where liquid lubricant would leak out or where frequent lubrication is not…
Possible
The “dropping point” of a grease is the same as its…
Melting point
Antifoam agents are necessary additives for oils used in
Hydraulic systems
Oil additives that react with metal surfaces to form a sulfide or chloride coating are called..
Extreme Pressure Additives
Demulsifiers are useful oil additives when you need to
Remove water from the oil in the system
Lubrication by means of a film consisting of impurities, oxides, and air molecules is called _______ lubrication
Boundary
In full-film lubrication, the moving surfaces are…
Completely separated from each other
Of the following oil blends, the one that undergoes the least change in viscosity as the temperature changes consists of ____% naphthene- base oil and _____% paraffin- base oil
10; 90
The highest quality circulating oil is _____ oil.
Turbine
One of the most important additives in hydraulic oil is a(n) _______ additive
Antifoam
Spindle oils are premium-grade lubricants with a(n)….
Low viscosity
Animal fat is sometimes included in ______ oil to help it stick to the surfaces being lubricated
Steam cylinder
The function of the soap in a grease Is to…
Hold the oil
Calcium-soap greases begin to______ of the temperature rises above 180° F
Dry out
Sodium-soap greases are good_______ purpose greases for use in the ______ of water
General; Absence
Lithium-soap greases work well over a ______ range of temperatures in the ______ of water
Wide; presence
Nonsoap bases for greases include clay minerals, gels, and
Organic complexes
Additives can protect a grease from changes in
Chemical makeup
The ability of an EP grease to overcome short-cycle, high-load conditions depends on the_______ of the _______ in the grease
Film strength; oil
The primary characteristic of calcium soap greases is their resistance to
Water
The particles of a “lamellar” additive are _____ in shape
Thin and flat
In a silicone grease, the lubricant is a ________ and the thickener is a ______ material
Synthetic polymer; soap or non soap
One of the operating requirements of a lubricating device is its ability to
Regulate lubricant flow
Drip-feed oiling depends on _____ for its operation
Gravity
The sump for a splash- or ring type natural lubrication system is (a)
Part of the machine housing
Most pressure lubrication systems have ____ pumps
Gear
Mist lubrication systems are similar operation to air line lubricators, but they handle ______ lubricant at a ______ pressure
More; lower
In some positive feed oil lubrication systems, the pump must both increase the oil pressure and _____ the oil
Meter
A reciprocating force-feed lubricator can be adjusted to______ the flow of lubricant
Control
In metered lubrication, lubricant is dispensed to the individual lubrication points by (a)
Separate metering devices
In a two-line header lubrication system, the control valve
Reverses the lubricant flow
A centralized lubrication system is also called _____ metering
Progressive
In addition to weather and dirt, a plant’s _______ should be considered in protecting stored outside
Environment
New grease being added to a grease distribution system should be
At room temperature
Used lubrication oils can be made suitable for reuse by purification or
Reclamation
The gravity settling method of purifying oil is
Effective
Final filtering of fluids can be accomplished by using
Sintered metal
The greatest single cause of lubricant failure is
Contamination of the lubricant
The main purpose of using route sheets for all lubricators is to
Make sure all lubrication is performed
One of the best ways to prevent lubricators from using the wrong lubricant is to provide
Color-coded fittings on the equipment
The first step in computerizing a plants lubrication program is to
Survey all lubrication requirements
Which number means “monthly” In a 5-day workweek coding system
20
