Hydraulic System Components: Reservoir, Filters, Hoses and Coolers 190103h Flashcards
1. List four (4) functions of hydraulic oil: a) b) c) d)
a) transmit power
b) lubricate moving parts
c) seal close fitting parts
d) cool the system
- The term viscosity refers to an oil’s:
a) ability to prevent rust.
b) ability to prevent oxidation.
c) internal resistance to flow.
d) change in thickness with temperature.
c) internal resistance to flow.
- List three (3) results of using a hydraulic oil with a viscosity that is too high:
a)
b)
c)
Any three (3) of the following are correct.
a) increased power required to drive the system
b) increased temperature due to higher friction
c) greater pressure drops throughout the system
d) possible sluggish operation
e) de-aeration will be more difficult
- The two (2) most common oil viscosity grading systems are:
a)
b)
a) Society of Automotive Engineers (SAE)
b) International Standards Organization (ISO)
- Viscosity index (VI) refers to:
a) the amount that the oil’s viscosity changes with temperature.
b) the amount that the oil’s viscosity changes with pressure.
c) a method of grading oils by their viscosity.
d) the lowest temperature at which the oil will flow.
a) the amount that the oil’s viscosity changes with temperature.
- Boundary lubrication refers to a condition where:
a) moving parts are completely separated by a film of oil.
b) minute imperfections on the surfaces of moving parts are in contact.
c) anti-wear additives are not required.
d) oxidation of the oil will occur.
b) minute imperfections on the surfaces of moving parts are in contact.
- Define the term oxidation as it relates to hydraulic oil.
Oxidation refers to the reaction of the hydraulic oil with oxygen in the air.
- Three (3) factors that will determine how quickly a hydraulic oil will oxidize are:
a)
b)
c)
a) the amount of air that the oil is exposed to
b) the oil temperature
c) the chemical makeup of the oil
- The most important consideration when selecting a hydraulic oil is:
a) viscosity.
b) viscosity index.
c) pour point.
d) manufacturer’s specifications.
d) manufacturer’s specifications.
- State three (3) functions of the hydraulic reservoir.
a)
b)
c)
a) hold the system oil supply
b) cool the oil
c) allow air and contamination to settle out of the oil
- The ideal capacity for a hydraulic tank is ______________ __
Most mobile heavy equipment hydraulic reservoirs are much smaller than that
because of:
between 2 to 3 times the pump flow rate.
Most mobile heavy equipment hydraulic reservoirs are much smaller than that
because of space limitations.
- Pressurized reservoirs are used in applications where:
a) air must be prevented from entering the oil.
b) the pump inlet line may not otherwise be filled with oil.
c) additional oil cooling is required.
d) very high pressures are encountered.
b) the pump inlet line may not otherwise be filled with oil.
- What procedure must be done before you service a hydraulic system equipped with a
pressurized reservoir?
. depressurize the reservoir
- List three (3) functions of the baffle plate in a hydraulic reservoir.
a)
b)
c)
. a) prevent return oil from flowing directly into the pump inlet line
b) provide time for air and contamination to settle out of the oil
c) prevent slosh
- Contamination in a hydraulic system comes from the following three (3) sources:
a)
b)
c)
a) built-in contamination
b) ingressed contamination
c) internally generated contamination
- The greatest amount of component wear is caused by contamination that is:
a) the same size or smaller than component internal clearances.
b) larger than component internal clearances.
c) 20 µm or larger.
d) ingressed.
a) the same size or smaller than component internal clearances.
- Contamination that restricts the flow of lubricating oil to components is:
a) the same size or smaller than component internal clearances.
b) larger than component internal clearances.
c) 20 µm or larger.
d) ingressed.
b) larger than component internal clearances.
- Coarse filters are called
Coarse filters are called strainers.
- Mesh or sieve number refers to
Mesh or sieve number refers to the number of openings per linear inch.
- A filter having a Beta Rating of P10 = 1 indicates that the filter removes:
a) all contamination that is 10 µm and larger.
b) all contamination that is 10 µm and smaller.
c) 10% of all 1 µm contamination.
d) none of the 10 µm contamination.
d) none of the 10 µm contamination.
- The filtering device most commonly used in the pump inlet line is a:
a) l0 µm filter.
b) 20 µm filter.
c) 100 mesh strainer.
d) 200 mesh strainer.
c) 100 mesh strainer
- The most common filter location on mobile heavy equipment hydraulic systems is
The most common filter location on mobile heavy equipment hydraulic systems is in
series in the return line.
- The pressure drop created by filter media is a result of:
a)
b)
a) oil viscosity
b) filter media permeability
- The function of the filter bypass valve is to:
- The function of the filter bypass valve is to prevent damage to the filter caused by
excess pressure.
- Steel pipe is sized by
nominal inside diameter and wall thickness.
- The term that refers to the wall thickness of steel pipe is:
a) schedule number.
b) dash number.
c) nominal ID.
d) nominal OD.
a) schedule number.
- One disadvantage of using steel pipe as a hydraulic conductor is that it:
a) does not dissipate heat well.
b) is not compatible with all hydraulic oils.
c) can only be used where vibration or movement is present.
d) cannot be bent.
d) cannot be bent.
- Steel tubing is sized by
Steel tubing is sized by outside diameter and wall thickness.
- The main advantage that tubing connectors offer over pipe connectors is that:
they do not use connector threads to seal the connection.
- State the flare angle of the following connectors:
a) Joint Industrial Council (JIC)
b) Society of Automotive Engineers (SAE)
. a) JIC 37°
.
b) SAE 45°
.
- Split-flange connectors seal the connection by using:
a) tapered threads.
b) a 37° flare.
c) a 45° flare.
d) an O-ring.
D) Oring
- Hydraulic hose is used in areas where _________________
is encountered.
vibration or movement is encountered.
- A hydraulic hose that is designated by a “-12”(dash 12) has an:
a) outside diameter of¾ in.
b) inside diameter of¾ in.
c) outside diameter of 1.2 cm.
d) inside diameter of 12 cm.
b) inside diameter of¾ in.
- Two (2) common types of reusable hose connectors are:
a)
b)
a) screw-on socket type
b) press-on sleeve type
- Hydraulic oil coolers are usually connected in __________ in the
system ____ _______ line.
Hydraulic oil coolers are usually connected in series in the system return line.
