Hydraulics

Question 1

The amount of power put out by the actuator depends on the flow and pressure

Answer 1

The amount of power put out by the actuator depends on the flow and pressure

Question 2

The operation of a hydraulic jack is based on which of the following laws?

Answer 2

Pascals law

Question 3

Hydraulic pumps create flow only

Answer 3

Hydraulic pumps create flow only

Question 4

What is the metric unit of pressure?

Answer 4

Pascals

Question 5

The resistance to flow in a hydraulic system is increased with a heavier load. T or F

Answer 5

True

Question 6

What is the resulting fore when 2000 psi acts upon a cylinder with a piston diameter of 4 inches

Answer 6

25,120 lbs

Question 7

Why do manufacturers design equipment using a double acting cylinder which will extend when lifting lifting the heaviest load?

Answer 7

The Poston are is greater when the cylinder extends

Question 8

Fact

Answer 8

Series hydraulic systems allow pressure to be compounded

Question 9

What is the term for when pressure created due to gravity acting on a fluid

Answer 9

Head

Question 10

Fact

Answer 10

Both atmospheric and head pressure force oil into the pump inlet

Question 11

Differential cylinders extend slower than they retract

Answer 11

Differential cylinders extend slower than they retract

Question 12

Gauge pressure includes atmospheric pressure. T or F

Answer 12

False

Question 13

Pressure can be measured in inches of mercury. T or F

Answer 13

True

Question 14

Why does liquid flow?

Answer 14

Liquids flow due to differential pressure

Question 15

Flow rate is measured in gallons per minute

Answer 15

Flow rate is measured in gallons per minute

Question 16

The speed of a liquid increases as it is forced through a restrictor

Answer 16

The speed of a liquid increases as it is forced through a restrictor

Question 17

What is a hydraulic actuator

Answer 17

Motor

Question 18

Hydrostatics is about liquids with low flows and high pressure

Answer 18

Hydrostatics is about liquids with low flows and high pressure

Question 19

Pressure is responsible for creating force. T or F

Answer 19

True

Question 20

The units of torque can be expressed as “lb-in” T or F

Answer 20

True

Question 21

The units of volume can be expressed as “sq-inches”.

Answer 21

False

Question 22

Torque is a force which acts in a rotational motion only

Answer 22

Torque is a force which acts in a rotational motion only

Question 23

Steel pipe is more rugged than steel tubing. T or F

Answer 23

True

Question 24

What is a result of using hydraulic fluid which is too viscous?

Answer 24

Increased power to the drive system

Question 25

What hydraulic components allows contaminants to settle?

Answer 25

Reservoir

Question 26

Internal baffle plates allow contaminates to settle in the reservoir

Answer 26

Internal baffle plates allow contaminates to settle in the reservoir

Question 27

It is advisable not to mix oils. T or F

Answer 27

True

Question 28

What describes the pour point of hydraulic oil?

Answer 28

The lowest temperature at which the oil will flow

Question 29

What best describes boundary lubrication

Answer 29

Asperities contact because of close tolerances

Question 30

Why is revealing a joint using pipe thread a problem

Answer 30

The overall length of the joint decreases

Question 31

What type of fittings are used in hydraulic applications?

Answer 31

JIC 37 degrees

Question 32

What best describes a hose which has a size of -8"

Answer 32

The hose has an inside diameter of 1/2"

Question 33

What filter rating compares the amount of particles entering the filter to the number of particles leaving the filter?

Answer 33

Beta rating

Question 34

What does the term "skiving" refer to?

Answer 34

Removing some external rubber

Question 35

What hydraulic components help prevent premature oxidization of hydraulic oil?

Answer 35

Oil cooler

Question 36

Where are most hydraulic oil coolers located?

Answer 36

Most coolers are placed in series in the return line

Question 37

What best describes the type of cooler used when the cooler is located in front of the engine radiator?

Answer 37

Oil to air

Question 38

What us not a component of a double acting hydraulic cylinder

Answer 38

Glad hand

Question 39

The effects of aeration are visible by watching the actuators

Answer 39

The effects of aeration are visible by watching the actuators

Question 40

Which of the following best describes a direct acting relief valve

Answer 40

Normally closed pressure control valve

Question 41

Relief valves can be readjusted by adding or subtracting shims. T or F

Answer 41

True

Question 42

Cracking pressure is the pressure required to allow the relief valve ball to unseat

Answer 42

Cracking pressure is the pressure required to allow the relief valve ball to unseat

Question 43

Why are rotary directional control valves typically used in systems with low flow and low pressure

Answer 43

Rotary control valves have high internal leakage

Question 44

What type of cylinders retract and extend hydraulically

Answer 44

Double acting cylinders

Question 45

What feature of a spool valve prevents oil leakage around the spool

Answer 45

Grooves

Question 46

What frature of a spool valve allows the operator a small amount of flow control?

Answer 46

Metering notches

Question 47

What feature provides reduced operator effort to activate a spool valve?

Answer 47

Pilot operation

Question 48

Closed center valves block oil from the pump when in the neutral position

Answer 48

Closed center valves block oil from the pump when in the neutral position

Question 49

What type of hydraulic actuator requires an external force to return to its home position?

Answer 49

Single acting cylinder

Question 50

Positive displacement pumps trap fluid to create flow

Answer 50

Positive displacement pumps trap fluid to create flow

Question 51

What is Pump displacement?

Answer 51

Pump displacement is the amount of fluid delivered when the pump turns one revolution

Question 52

What is pump flow rate?

Answer 52

The amount of fluid delivered after the pump runs for 1 minute at rated RPM

Question 53

Which component of a un-balanced external gear pump wears the most?

Answer 53

The inlet side of the pump body

Question 54

What feature of an external gear pump increases its volumetric efficiency?

Answer 54

Pressure plates