Lubezz 2 Flashcards
A thin layer of lubricant between 2 surfaces enables one surface to [BLANK] the other
Slide over
By separating 2 surfaces slightly, a lubricant helps reduce
Wear
A lubricant can equalize pressures in various places along 2 contacting surfaces, thereby reducing
Mechanical shock
An air 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 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 a system
Lubrication by means of a film consisting of impurities, oxides, and air molecules is called [BLANK] 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 [BLANK] % naphthene-base oil and [BLANK] % paraffin-base oil
10; 90
The highest quality of circulating oil is [BLANK] oil
Turbine
One of the most important additive in hydraulic oil is an [BLANK] additive
Antifoam
Spindle oils are premium-grade lubricants with a
Low viscosity
Animal fat is sometimes included in [BLANK] oil to help it stick to the surfaces being lubricated
Steam cylinder
The function of a soap in a grease is to
Hold the oil
Calcium-soap greases begin to [BLANK] if the temperature rises above 180 degrees F
Dry out
Sodium-soap greases are good [BLANK]-purpose greases for use in the [BLANK] of water
General; absence
Lithium-soap greases work well over a [BLANK] range of temperatures in the [BLANK] of water
Wide; presence
Nonsoap bases for greases include clay minerals, gels, and
Organic complexes
Additives can help protect a grease from changes in
Chemical makeup
The ability of an EP grease to overcome short-cycle, high-load conditions depends on the [BLANK] of the [BLANK] 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 [BLANK] in shape
Thin and flat
In a silicone grease, the lubricant is a [BLANK] and the thickener is a [BLANK] material
Synthetic polymer; soap or nonsoap
One of the operating requirements of a lubricating device is its ability to
Regulate lubricant flow
Drip-feed oiling depends on [BLANK] for its operation
Gravity
The sump for a splash- or ring-type natural lubricating system is
Part of the machine housing
Most pressure lubrication systems have [BLANK] pumps
Gear
Mist lubrication systems are similar in operation to air line lubricators, but they handle [BLANK] lubricant at a [BLANK] pressure
More; lower
In some positive feed oil lubrication systems, the pump must both increase the oil pressure and [BLANK] the oil
Meter
A reciprocating force-feed lubricator can be adjusted to [BLANK] the flow of the lubricant
Control
In metered lubrication, lubricant is dispensed to the individual lubrication points by
Separate metering devices
In a two-line headed lubrication system, the control valve
Reverses the lubricant flow
A centralized lubricating system is also called [BLANK] metering
Progressive
In addition to weather and dirt, a plant’s [BLANK] should be considered in protecting lubricants stored outside
Environment
New grease being added to a grease distribution system should be
At room temperature
Used lubricating oils and be made suitable for use 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 single greatest 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 plant’s lubrication program is to
Survey all lubrication requirements
Which number means “monthly” in a 5-day workweek coding system?
20
