TPC 307 Basic Hydraulics

Question 1

What characterstic of a fluid does the term “specific gravity” describe?

Answer 1

Density

Question 2

Pressure is measured in ______ in the English system.

Answer 2

Pounds per square inch

Question 3

Which of the following is NOT needed in order to calculate the work a hydraulic cylinder can do?

Answer 3

Power (ft-lb/min)

Question 4

Pascals Law states that pressure exerted on a confined liquid:

Answer 4

Is distributed equally throughout the liquid

Question 5

According to Bernoulli’s Principle, when fluid flow increases in a system the pressure…

Answer 5

Decreases

Question 6

A hydraulic fluid must be able to do all of the following EXCEPT

Answer 6

Compress easily

Question 7

A hydraulic fluid that exhibits little change in viscosity when heated is said to have a high….

Answer 7

Viscosity index

Question 8

The ability of a fluid to penetrate into small clearances between closely fitted parts is determined by the fluid’s….

Answer 8

Viscosity

Question 9

Which of the following, when added to hydraulic fluid will limit oxidation?

Answer 9

A chemical inhibitor

Question 10

The best method of controlling hydraulic fluid contamination is the use of

Answer 10

Good maintenance procedure

Question 11

The ability of a filter or strainer to remove 100% of the contaminant particles of a particular size from a hydraulic fluid is called it’s:

Answer 11

Absolute rating

Question 12

When the maximum allowable pressure drop of a filter is reached, the filter will…

Answer 12

Allow particles to pass through the medium

Question 13

The purpose of a filter in a hydraulic system is to…

Answer 13

remove small contaminates

Question 14

Depth filters do NOT

Answer 14

have a long service life

Question 15

Surface filter media made of sintered metal powders are used in high pressure systems because of their:

Answer 15

Thick mass

Question 16

The separation of contaminants from hydraulic fluid in a reservoir is aided by:

Answer 16

Slow fluid movement

Question 17

What is used in a hydraulic reservoir to aid fluid cooling?

Answer 17

A baffle

Question 18

To mantain the temperature of a hydraulic fluid effectively, the reservoir should have

Answer 18

Thin walls

Question 19

An air breather is installed on a fluid reservoir to:

Answer 19

Vent the reservoir

Question 20

Peak hydraulic system demands are usually met by the use of a(n)

Answer 20

Accumulator

Question 21

The resistance of a hydraulic system to fluid flow causes

Answer 21

Pressure

Question 22

Pump capacity is rated in all of the following terms EXCEPT

Answer 22

Pounders per square inch

Question 23

The ratio of in actual delivery rate of a pump to its displacement is its….

Answer 23

Volumetric efficiency

Question 24

Which of the following is NOT a type of gear pump?

Answer 24

Vane

Question 25

Internal gear pumps normally are used in applications that have

Answer 25

Pressures of less than 1000 psi

Question 26

The flow rate of hydraulic fluid through piping or tubing is measured in

Answer 26

GPM

Question 27

Pressure loss in a hydraulic line depends on the

Answer 27

Flow velocity

Question 28

Hydraulic lines should NEVER be constructed of

Answer 28

Galvanized pipe

Question 29

In noncritical applications having no severe stress, safe working pressures of hydraulic piping are based of providing a safety factor of:

Answer 29

6

Question 30

A disadvantage of using hose in hydraulic systems instead of piping or tubing is that the hose:

Answer 30

Is less permanent

Question 31

Which of the following kinds of valves should be used in a hydraulic system to change the direction of motion of the cylinder?

Answer 31

Directional control valve

Question 32

A three-way valve is identified by its three…

Answer 32

Paths

Question 33

The closing force of a direct-acting solenoid valve is approximately

Answer 33

15lbs

Question 34

The construction of a spool valve causes to:

Answer 34

Be partially balanced

Question 35

A four-way valve that can operate in three postions is called a:

Answer 35

Closed crossover valve

Question 36

The operating differential pressure of a relief valve is the diference between its maximum pressure and the…

Answer 36

Cracking pressure

Question 37

The flow from the outlet of a sequence valve is at

Answer 37

Line pressure

Question 38

FLuid pressure in one section of a hydraulic system is limited by a

Answer 38

Reducing valve

Question 39

A shock suppressor is used in a hydraulic system as

Answer 39

Protection against pressure surges

Question 40

A meter-out flow-control valve is used to regulate fluid flow from a(n)

Answer 40

Actuator

Question 41

Straight-line mechanical force is created by a

Answer 41

Hydraulic cylinder

Question 42

The force exerted by a double-acting piston is

Answer 42

Less on the rod side

Question 43

A cylinder in which the retracting stroke is the power stroke is called a

Answer 43

Pull-type cylinder

Question 44

When a hydraulic cylinder is added to an existing system, be sure that the

Answer 44

Pump capacity is adequate

Question 45

Mechanical shock is controlled in a hydraulic cylinder by means of a

Answer 45

Cushioning device

Question 46

Which of the following statements about hydraulic motors is true?

Answer 46

They are all positive-displacement types

Question 47

The pressure range of a hydraulic motor may vary from

Answer 47

100 to 5000 psi

Question 48

The overall efficiency of a hydraulic motors is defned as the

Answer 48

Output horsepower divided by the input horsepower

Question 49

A crescent-shaped separator is used on some _______ gear motors

Answer 49

Internal

Question 50

Internal leakage in hydraulic gear motor is held to a minmum by the use of

Answer 50

Wear plates