Hydraulics

Question 1

Which pump can be variable displacement?

Answer 1

Piston

Question 2

Which cylinder component prevents slamming against the cap or rod end?

Answer 2

Cushion

Question 3

What two types of pressure systems do we use?

Answer 3

Psia (atmosphere) and psig (gauge)

Question 4

What does a counterbalance valve do?

Answer 4

Keeps a cylinder from dropping a heavy load

Question 5

What type of seals do cylinder pistons have?

Answer 5

Single bidirectional sealing element

Question 6

Which component is designed to store hydraulic fluid at system pressure and release it when demand exceeds pump delivery?

Answer 6

Accumulator

Question 7

Which type of hydraulic pump uses an angled swash plate?

Answer 7

Axial piston

Question 8

A flow path through a normally closed pressure relief valve is opened when fluid pressure is enough to overcome spring pressure. True or False?

Answer 8

True

Question 9

What are the functions of hydraulic fluid?

Answer 9

Transfer of power, lubrication

Question 10

At sea level, a column of air 1 inch tall will weigh?

Answer 10

14.7 pounds

Question 11

Accumulators are filled with inert gas such as nitrogen, can air be used instead?

Answer 11

No

Question 12

Generation of heat by working energy being delivered to components is considered…

Answer 12

System Inefficiency

Question 13

The major cause of entrainment is leakage past cylinder seals. True or False?

Answer 13

False

Question 14

What component dissipates heat, settles contaminants?

Answer 14

Reservoir

Question 15

Manmade oil is called

Answer 15

Synthetic

Question 16

With air-over-oil accumulators, a pinhole size leak can cause the oil spray to become

Answer 16

Combustible

Question 17

High temperature oxidation causes

Answer 17

Lacquer, varnish, sludge

Question 18

A hydraulic actuator converts…

Answer 18

hydraulic energy to mechanical energy

Question 19

A volume that flows in a given amount of time is called

Answer 19

Flow rate

Question 20

SUS stands for

Answer 20

Saybolt Universal Seconds

Question 21

How does a flow control valve work?

Answer 21

Operates by resistance

Question 22

ASTM stands for

Answer 22

American Society for Testing Materials

Question 23

A resistance of a fluid to flow

Answer 23

Viscosity

Question 24

A common fluid used for hydraulic fluid is either…

Answer 24

Paraffinic or naphthenic

Question 25

According to the law of conservation of energy,

Answer 25

Energy can neither be created nor destroyed, but it can change forms

Question 26

Application of a force through a distance

Answer 26

Work

Question 27

Reduction of friction between moving objects

Answer 27

Lubrication

Question 28

One consideration when dealing with energy is…

Answer 28

The STATE in which it is found

Question 29

Define resistance

Answer 29

Any force which can stop or slow the movement of a body

Question 30

2 types of actuators

Answer 30

Rotary or linear

Question 31

A pressure compensated flow control valve delivers a constant flow regardless of fluctuations before and after the valve. True or false?

Answer 31

True

Question 32

Vane pumps containing a pressure compensator produces a constant delivery. True or false?

Answer 32

True

Question 33

A sump strainer should be placed…

Answer 33

on the return side

Question 34

In most cases, flow control valves are installed after the directional control valve and before the actuator. True or false?

Answer 34

False

Question 35

How can dirt get into a hydraulic system?

Answer 35

Built-in, generated, added

Question 36

Most popular piston pump

Answer 36

Axial

Question 37

In the unbalanced design, fluid pressure on one side

Answer 37

Puts stress on the driveshaft and bearings

Question 38

Variable displacement pumps can vary output by…

Answer 38

Varying the position of the cam ring, adjusting the swash plate angle, or changing the size of the chambers

Question 39

The torque required to get a load turning?

Answer 39

Breakaway torque

Question 40

What can block fluid flow and starve a pump?

Answer 40

An oversized or improperly maintained sump strainer

Question 41

What type of flow control valve is designed to change pressure beyond the valve?

Answer 41

Pressure reducing, normally open

Question 42

What does a sequence valve do?

Answer 42

Causes one operation to occur before another by sensing upstream pressure, it is normally closed.

Question 43

Two major classifications of positive displacement pumps

Answer 43

Variable or fixed

Question 44

What Directional Control Valve should be used for a single acting cylinder?

Answer 44

2 position, 3 way

Question 45

Reservoir designs can be:

Answer 45

L-shape, overhead, conventional

Question 46

To start or stop a unidirectional hydraulic motor, what kind of directional control valve should be used?

Answer 46

2 position, 2 way