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WorksheetsFluid Power Final Exam
Total questions: 182
Worksheet time: 2hrs 24mins
Air supplied to a pneumatic system is supplied through the ____ line.
Intake
Supply
Actuator
Exhaust port
This determines the oil level of the oil reservoir.
Dipstick
Sight glass
Refill indicator
Viscosity
The pressure created by any force is calculated by multiplying the total force by the total area.
What pneumatic component provides straight line motion?
Motor
DCV
Cylinder
Muffler
What fluid is most commonly used in pneumatics?
Air
Oxygen
Water
Oil
What is the reading on the pressure gauge?
300psi
320psi
330psi
350psi
Piston movement compresses air in this type of air compressor.
Medium size compressors
Industrial compressors
Small compressors
Horizontal compressors
Increasing force in a Hydraulic system causes ____.
Pressure to increase
Area to increase
Fluid volume to decrease
Pressure to decrease
A pneumatic system uses a(n) ____ to provide power.
Solid
Gas
Liquid
Electric current
What is pressure?
The weight of an object
Force acting on a given area
The area of a pair of snowshoes
Gravity
A(n) ____ provides power to a hydraulic system by pumping oil from a reservoir into the supply lines.
Air
Relief valve
Pump
Directional control valve
Force can be measured in ____.
Pressure
Gravity
Pounds
Meters
(a) is fluid under pressure that flows to create and transmit power.
Differentiate between hydraulics and pneumatics.
(a) uses liquids, like oil
Describe the difference between fluid transfer and fluid power applications.
Fluid transfer systems usually have a (a) load with low resistance
What are the three principal application areas for fluid power
The three principal application areas for fluid power are (a) , industrial pneumatics, and mobile hydraulics.
In a pneumatic system, the force that does the work is supplied in what form?
Compressed air
Pistons in cylinders
Compressed oil
Inertia
What determines the amount of force required to move an object?
The object's inertia
The slope the object is on
The object's mass
The object's shape
How does gauge pressure (psig) compare to atmospheric pressure (psia)?
Gauge pressure indicates air pressure above atmospheric pressure
Gage pressure indicates air pressure below atmospheric pressure
Atmospheric pressure indicates air pressure above gauge pressure
None of these are correct
How is the amount of work done by a pneumatic cylinder determined?
Volume multiplied by temperature
Pressure multiplied by the temperature
Force divided by the distance of travel
Force multiplied to the piston's distance of travel
Calculate the amount of work done by a cylinder having a 10-in2 piston area and a 12-in. stroke when operated at 50 psi.
(a) foot-lbs
How is Power calculated?
Work done ÷ Distance traveled
Force x Mass
Force x Volume
Work done ÷ time it took to do the work
What component in a compressed air system produces the pneumatic energy?
Pneumatic valves
Pneumatic cylinders
Reservoir
Air compressor
_________ describes the rapid intermingling of the molecules of one gas with another.
Diffusion
Confusion
Dispersion
Conversion
In what direction does the pressure of a confined gas act on the container walls?
The pressure is greater at the bottom of the container
Gas does not exert pressure on its container's walls
The pressure is equal in all directions
Pressure is greater at the top of the container
Using the equation P1 x V1 = P2 x V2 , find P2 if P1 = 100 (psig), V1 = 100, and V2 = 10. (Remember to do all calculations in psia.)
(a) psig
What happens when heat is applied to gas contained in a cylinder?
The pressure increases
The volume of the gas shrinks
The pressure decreases
None of these are correct
Pneumatic (a) is defined as the force that permits a small amount of pressure to move a larger object.
What would the output force be if a 50-lb force is applied to a piston having an area of 10 in2 and transferred to a piston having an area of 75 in2?
(a) lbs of force.
If the small piston in a pneumatic system having a 2.5-to-1 leverage increase travels 5 in, how far will the large piston travel?
(a) inches
What kind of airflow is ideal in a pneumatic system?
(a)
________ is a measure of air's internal friction that describes its resistance to flow.
Volume
Density
Pressure
Viscosity
Bernoulli's principle states that the total energy of a gas in a pneumatic system remains (a)
What is component 1?
(a)
What is component 2?
(a)
What is component 3?
(a)
What is component 4?
(a)
What is component 5?
(a)
What is component 6?
(a)
What is component 7?
(a)
What is component 9?
(a)
What is component 10?
(a)
The most efficient and commonly found flow arrangement in a water-cooled intercooler is (a) .
The movable part of a discharge valve is held in place with a (a) until it is displaced with compressed air.
When when a compressor is relieved of all internal pressure it is said to be " (a) ".
When distinguished by their operating principles, what are the two classifications of air compressors?
(a) and dynamic
A (a) air compressor increases air pressure by accelerating the air.
What are the two methods used to connect the compressor drive to the compressor?
the motors can be connected to the compressor directly or by (a) or speed reducers
What are the two functions of cylinder-wall lubrication?
cylinder-wall lubrication prevents the piston rings from (a) and removes heat
How can the cooling efficiency of an air-cooled compressor with finned tubes be improved?
to aid in transferring the heat from the tubes, most air-cooled compressors have a (a) mounted on the compressor crankshaft
The (a) lubrication method is used for heavy-duty compressors.
A compressor that compresses air at only one end of a cylinder is called a (a) compressor.
A compressor that compresses air in more than one stage is called a (a) compressor.
What is a benefit of an intercooler in a multistage compressor?
less power is needed to compress the air because cooling between stages reduces the volume of air that is compressed in the second stage.
Decreased heat transfer in the system allow for a more linear flow of the fluid in the compressor
Lower pressure drop across the compressor which allows for more heat distribution and reversing any turbulent flow
To be efficient, a positive displacement compressor must (a) air volume.
What are the five kinds of positive displacement rotary compressors?
sliding-vane, dry-screw, wet-screw, liquid-ring, and impellor or lobe types
Centrifugal, Axial, Turbojet, Scroll, and Vane-Lobe compressors
Vacuum-Jet, Spiral-Torque, Helical Flux, Rotor-Pad, and Gear-Ring compressors
The maximum discharge pressure a single-stage vane compressor can produce is (a) psi.
Dry rotary-screw positive displacement compressors have how many rotors?
Four
One
Three
Two
Which kind of compressor can deliver large amounts of oil-free air at pressures up to 120 psi?
Multistage dynamic compressor
Liquid-ring compressor
Centrifugal compressor
Dry rotary-screw compressor
A wet rotary-screw compressor uses timing gears.
Because of its low discharge pressure, an impeller compressor is often called a (a) .
The (a) forms the space in which the air is compressed in a liquid-ring compressor.
What prevents contact between the impellers of an impeller compressor?
The timing gears prevent the lobes from coming in contact
A positive displacement compressor that is best suited for light-duty applications is a (a) compressor.
Where are the compressing impellers of a three-stage centrifugal compressor mounted?
On the diffuser
n the intercooler housing
On the speed increaser
On the inlet housing
What prevents excessive air temperatures on most centrifugal compressors?
most centrifugal compressors are equipped with (a) and aftercoolers to prevent the air temperature from increasing excessively
What two factors determine the discharge pressure of a multistage dynamic compressor?
The speed of the (a) and the number of stages
The most efficient method of controlling the output of centrifugal compressors is _____ _____.
(a)
Actual cubic feet per minute (acfm) is also called ____ ____ ____.
(a)
If you are converting FROM psia TO psig, do you add or subtract 14.7?
add
subtract
If you are converting FROM psig TO psia, do you add or subtract 14.7?
add
subtract
(a) is the total push or pull on an object
(a) is the amount of force exerted over the area it's pushing/pulling
(a) is an object's resistance to changing its current state of motion
(a) represents two things:
1. the amount of matter in an object
2. a measure of an object's inertia
the (a) of a substance is its mass-per-unit-volume
(a) law states that a confined fluid transmits pressure equally in all directions
(a) law states that the product of the absolute pressure and volume of a gas is the same at any volume and pressure
what are the three different types of power?
Thermal power, chemical power, and radiant power
fluid power, electrical power, and mechanical power
Nuclear power, magnetic power, and acoustic power
Solar power, gravitational power, and wind power
What are the four methods of identifying control valves?
number of primary system connecting ports, number of control positions, type of control element, and method of operation.
Flow capacity, valve material, actuator size, and installation orientation
Number of ports, pressure rating, temperature rating, and valve size
Type of fluid handled, valve body shape, fail-safe position, and control signal type
is a gate valve better suited for shutoff or throttling service?
shutoff
throttling
What causes the high pressure losses in a needle valve?
the valve seat is (a) than the inlet and outlet connections of the valve.
What is the most common method of controlling automatically operated valves?
Electric solenoid
What are the two classifications of two-position automatically operated valves?
Normally open and Normally closed
How are large quantities of high pressure air best controlled?
pilot operated solenoid valves are almost always used
How is the control element of a two-position, three-way valve normally held in the non-actuated position?
the center position is maintained by (a) when the valve is not actuated.
What usually happens to compressed air when it completes its work?
it can be (a) to the atmosphere.
What is one advantage of using four-way valves in a pneumatic system?
Four-way valves are used to (a) pneumatic circuits. They reduce the total number of controls in a system.
In how many directions can air flow in a non-actuated two-position, four-way valve?
(a)
How is the centering of a three-position, four-way valve accomplished?
The centering is usually accomplished by (a) located at each end of the control element.
What characteristic of a fluid does the term specific gravity describe?
Weight
Viscosity
Density
Volume
Pressure is measured in _____ in the English (Imperial) system.
Pounds per square inch
Feet per second
Newtons
Pounds
Which of the following is not needed in order to calculate the work a hydraulic cylinder can do?
Piston travel (in)
Pressure (psi)
Piston area (in2)
Power (ft-lb/min)
Pascal's law states that pressure exerted on a confined liquid:
Is distributed equally throughout the liquid
Is greater at the edges of the container then at the center
Cannot be transmitted
Is transmitted in a straight line
(a) force is what gives an object weight.
The density of a liquid is expressed in terms of (a) . (Two words)
The specific gravity of a liquid is determined by comparing the weight of the fluid to the weight of an equal volume of (a)
The amount of work done when a force moves an object through a distance is expressed in what units?
Foot-pounds
Newton-meters
Pounds
Pounds per square inch
The amount of work done in a give period of time is called (a)
What's the missing energy of the four types of energy produced in a hydraulic system?
hydraulic, kinetic, potential, and (a)
Can a liquid be compressed?
yes
no
The rapid intermingling of molecules of one gas or liquid with another is called (a)
What factor of a substance determines the pressure it exerts on the bottom of a vessel?
Mass
Weight
Volume
If a force of 200 lbs is exerted against a piston having an area of 5 square inches, what is the resulting pressure?
(a) psi
What word can describe the ideal fluid flow in a hydraulic power system?
(a)
When a pipe handling a fluid is too small for the velocity of that fluid, what happens to the flow?
The fluid flow becomes (a)
The two types of energy a hydraulic fluid has are (a) and potential
The two types of energy a hydraulic fluid has are kinetic and (a)
According to Bernoulli's principle, when flow increases, pressure will _______.
decrease
stay the same
increase
become unpredictable
The surface tension characteristics of petroleum-based hydraulic fluids improves when ____ are added.
Demulsifier additives
Viscosity-index-improver additives
Anti-wear agents
Pour-point depressants
The ASTM D2270 standard is used to determine __.
What is safe for oil additives
Weight classes for oil
Oil moisture content
Oil viscosity index
Oil viscosity decreases when temperature ____.
Decreases
Increases
Remains the same for long periods
Becomes erratic
____ shown on the sight gauge indicate the high and low level of the oil.
One mark
Two marks
LEDs
Indicator lights
In order to move fluid through a filter, a hydraulic pump and ____ is necessary.
Strainer
Filter
Motor
Tubing
To prevent wear and provide long life, the moving parts in the hydraulic system must be ____.
Certified
Tested
Lubricated
Anodized
What type of smell does oil have when it starts to break down?
Sweet
Strong
Bitter
None
To transfer oil from a container to the oil reservoir, use a portable ____ if one is available.
Bucket
Filter cart
Funnel
Metal can
If bypass indicators on the filters reach a level that shows the filter or filters are ____, stop the filter cart, replace the filter elements and restart the unit.
New
Working
Filtering
Loaded
A spin-on filter is used for ____ applications that include the return line and the suction line.
High pressure
All
No
Low pressure
A(n) ____ filter has a filter element enclosed inside a metal shield.
Spin-on
Cartridge-type
Suction strainer
Pump
Before installing the new filter element, apply a thin film of ____ to the filter seal to lubricate the seal.
Dirty oil
Clean oil
Motor oil
Mineral oil
The replaceable element of a cartridge filter is located in a(n) ____, which is usually bolted onto an installed housing.
Metal shield
Reservoir
Pump
Strainer
The beta system is for rating ____.
Pump efficiency
Hydraulic filters
Oil viscosity
Hose capacity
The ____ Contamination Code uses a code of three numbers to indicate the cleanliness of a fluid, such as 21/18/15.
ISO 6604
ISO 4406
IOS 6604
IOS 4406
More than ____ of all hydraulically powered machine downtime and malfunctions are due to contamination in the fluid.
0.1
0.25
0.5
0.35
The bypass check valve opens on a filter is an indication the ____.
The system pressure is too high
Filter has reached its capacity
System has a decrease in flow
The system is hot
As a filter collects dirt, the ____ difference will grow, indicating that it is time to clean or replace the filter.
Pressure
Volume
Flow
Dissolved solids
The strainer assembly is usually located within the ____, but in some applications an external strainer is located on the inlet line.
Pump
Reservoir
Motor
Filter
The most common location for a filter is in the ____, where the filter cleans all fluid returning to the reservoir.
Main return line
pump
Motor
Reservoir
Hydraulic circuits usually have the strainer mounted ____.
At the inlet of the circuit
The outlet line of the pump
Inside the reservoir
On the outside of the tank
A hydraulic fluid must be able to do all of the following except:
Flow easily
Transmit power
Reduced friction
Compress easily
A hydraulic fluid that exhibits little change in viscosity when heated up is said to have a high:
Viscosity index
Film strength
Friction point
Pour point
The ability of a fluid to penetrate into small clearances between closely fitted parts is determined by the fluid's:
Film strength
Pour point
Viscosity
Friction point
Which of the following, when added to hydraulic fluid, will limit oxidation?
Liquid wrench
Pipe joint compound
A chemical inhibitor
Water
The best method of controlling hydraulic fluid contamination is the use of:
Proper temperatures
Chemical additives
Duplex filters
Good maintenance practices
List the two major functions of hydraulic fluid.
To transmit (a) through the system, and to provide lubrication to reduce friction between mechanical parts
Does a low-viscosity hydraulic fluid flow faster or slower than a high-viscosity fluid?
Slower
Faster
About the same
A measure of the extent to which the viscosity of a fluid changes with changes in temperature is called the (a)
the (a) of a fluid describes the lowest temperature at which it can flow?
A (a) is a fluid that resists the formation of water-fluid emulsion?
The property of a fluid that allows it to maintain a film under a heavy load is called (a)
(a) is the property of a fluid that gives it the clinging slipperiness to lubricate parts.
The chemical reaction of a fluid with oxygen from the air is called (a)
(a) is a general term to describe any deterioration of a metallic surface caused by the chemical reaction of an acid or alkali.
A form of corrosion specific to when steel and iron oxidizes while moisture is also present is called (a)
Is water heavier or lighter than hydraulic fluid?
heavier
lighter
How are fine contaminant particles usually measured?
The (a) is a customary unit for measuring the dimensions of fine particles.
What are the two types of filter media used in hydraulic systems?
(a) media and depth media.
What is the usual cause of abrasions migration?
(a) that causes the filtering medium to loosen from its housing or seal
Most strainers used in hydraulic systems have what kind of surface medium?
Most strainers use a porous (a) .
How are contaminations removed from a stacked-disk strainer?
It has housing that has a manual (a) to remove the accumulated particles from the surface without shutting the system down.
What are two advantages of Filters over strainer?
They are able to accumulate (a) contaminant particles better than strainers, and they can continue to function with a comparatively low pressure drop.
Most filters are furnished with what kind of media?
(a)
What should you do when a depth filter becomes dirty?
(a)
In what application are wound-yarn filters used?
This type of filter is preferred for (a) concentrations of particles.
What is the advantage of pleating a paper medium?
It provides a large (a) .
When replacing a filter, you should always check the condition of what component?
(a)
What problem is indicated by high pressure drops across new filters or strainers?
They are probably not (a) for the application.
A medium that collects particles on a single-layered surface
(a)
A rating of the percentage of contaminants of a particular size that a strainer or filter can stop from entering a system
(a)
When distinguished by their operating principles, what are the two classifications of air compressors?
positive-displacement and (a)
Differentiate between hydraulics and pneumatics.
(a) uses gases, like air
What are two advantages of Filters over strainer?
They are able to accumulate smaller contaminant particles better than strainers, and they can continue to function with a comparatively (a) pressure drop.
What are the two types of filter media used in hydraulic systems?
surface media and (a) media.
How are fine contaminant particles usually measured?
The (a) is a customary unit for measuring the dimensions of fine particles.
List the two major functions of hydraulic fluid.
To transmit power through the system, and to provide (a) to reduce friction between mechanical parts
What's the missing energy of the four types of energy produced in a hydraulic system?
hydraulic, heat, potential, and (a)
What's the missing energy of the four types of energy produced in a hydraulic system?
kinetic, heat, potential, and (a)
What's the missing energy of the four types of energy produced in a hydraulic system?
kinetic, heat, hydraulic, and (a)
What is one advantage of using four-way valves in a pneumatic system?
Four-way valves are used to simplify pneumatic circuits. They reduce the total number of (a) in a system.
What is a disadvantage of two-way spool valves?
They are not always pressure balanced
What two factors determine the discharge pressure of a multistage dynamic compressor?
The speed of the impeller and the number of (a)
What are the two functions of cylinder-wall lubrication?
cylinder-wall lubrication prevents the piston rings from wearing and removes (a)
Describe the difference between fluid transfer and fluid power applications.
Fluid transfer systems usually have a light load with (a) resistance
Describe the difference between fluid transfer and fluid power applications.
fluid power systems tend to have a (a) load with high resistance.
Describe the difference between fluid transfer and fluid power applications.
fluid power systems tend to have a large load with (a) resistance.
What are the three principal application areas for fluid power
The three principal application areas for fluid power are industrial hydraulics , (a) , and mobile hydraulics.
What are the three principal application areas for fluid power
The three principal application areas for fluid power are industrial hydraulics , industrial pneumatics, and (a) .
Machining equipment used in factories falls under industrial hydraulics
automation, assembly, and air tools fall under industrial pneumatics
excavating and farming equipment falls under mobile hydraulics
True
False
What prevents excessive air temperatures on most centrifugal compressors?
most centrifugal compressors are equipped with intercoolers and (a) to prevent the air temperature from increasing excessively
