Navedtra 14105 Fluid Power Chapter 3-5

Front 1

Trouble develops in a hydraulic system when the fluid becomes contaminated as the result of?

Back 1

any action that places foreign matter in the fluid

Front 2

By what ways may air enter into a hydraulic system?

Back 2

through improper maintenance, past leaky seals in gas-pressurized accumulators, past actuator piston rod seals

Front 3

True or False. Water contamination of a hydraulic system is NOT a major concern since its presence aids in reducing the flammability of the fluid.

Back 3

False

Front 4

Chemical contamination of hydraulic liquid by oxidation is indicated when the liquid contains what materials?

Back 4

sludge, asphaitine particles, or organic acids

Front 5

Compatibility of hydraulic liquid with the seals and hoses in a system prevents what problems from occuring?

Back 5

chemical reaction between the liquid acid the seal or hose material and consequent breakdown of these parts

Front 6

Lint, rust, sludge, sand particles. All of these contaminants are abrasive EXCEPT?

Back 6

sludge

Front 7

True or False. Whenever drained or used hydraulic fluid is returned to a system, straining is necessary only if the cleanliness of the storage container is questionable.

Back 7

False

Front 8

What agents should parts of a hydraulic component be cleaned with prior to being assembled?

Back 8

an approved dry-cleaning solvent

Front 9

What agents, if combined with minute amounts of water found in operating hydraulic systems, does NOT change into hydrochloric acid?

Back 9

an approved dry-cleaning solvent

Front 10

When you analyze operating hydraulic fluids, changes in what areas may be of particular interest to you?

Back 10

chemical properties, physical properties, and particulate contamination

Front 11

From what locations can fluid samples be taken?

Back 11

pipe drains after sufficient fluid has drained

Front 12

What is the function of a hydraulic pump?

Back 12

to provide flow to the hydraulic system

Front 13

If a hydraulic pump is located below the reservoir, fluid is supplied to its inlet port by what force?

Back 13

gravity

Front 14

the ratings of most hydraulic pumps are determined by their?

Back 14

volumetric output at a given pressure

Front 15

Pump performance can be expressed in what terms?

Back 15

gallons per minute, or cubic inches per revolution

Front 16

True or False. In contrast to a nonpositive-displacement pump that can operate with its discharge outlet completely restricted, a positive-displacement pump cannot do so and must be used with a pressure regulator.

Back 16

true

Front 17

True or False. Slippage is the term given to the amount of fluid that can return from the discharge side to the suction side af a rotary pump through the space or clearances between the stationary and moving parts.

Back 17

True

Front 18

What is generally the basis for rotary pump classification?

Back 18

type of rotating element

Front 19

What type of gears is illustrated in figure 4-1 of your textbook?

Back 19

spur

Front 20

What type of gear-type rotary pumps discharges the smoothest fluid flow?

Back 20

helical

Front 21

Why are helical gear pumps classified as external gear pumps?

Back 21

Both sets of teeth project outward from the center of the gears

Front 22

True or False. Screw pump performance is based on the fluid's viscosity.

Back 22

True

Front 23

Hydraulic hand pumps are used in some aircraft hydraulic systems to provide a source of hydraulic power for what purposes?

Back 23

emergencies, testing certain subsystems during preventive maintenance, and determining the causes of malfunctions in certain subsystems

Front 24

On a hydraulic hand pump why is liquid discharged through the outlet port when the piston is moved to the right?

Back 24

check valve opens, causing the liquid confined in the inlet chamber to flow to the smaller outlet chamber and out the outlet port

Front 25

True or False. Pulsations fo fluid flow from a radial-piston pump are much greater if the pump has an even number of pistons than if it has an odd number.

Back 25

True

Front 26

What component of a radial-piston pump is connected to the cylinder block?

Back 26

Drive shaft

Front 27

The output of the axial-piston pump is determined by what factors?

Back 27

Angle given to the tilting plane

Front 28

What component of a Stratopower pump holds the pistons in constant contact with the mechanical drive mechanism

Back 28

wobble plate

Front 29

Automatic variation of the volume output of a variable-displacement Stratopower pump is controlled by what factors?

Back 29

The pressure in the hydraulic system

Front 30

During nonflow operation of a variable-displacement Stratopower pump, what provides its lubrication?

Back 30

bypass system

Front 31

You must consider what factors when selecting the types of fluied lines for a particular fluid power system?

Back 31

the required pressure of the system, the type of fluid medium, and the location of the system

Front 32

You must give primary consideration to all but what factor in selecting the lines for a particular fluid power system?

Back 32

the material's outside diameter

Front 33

Replacement of a piece of tubing with one having a smaller inside diameter will result in what condition?

Back 33

fluid heating, turbulent fluid flow, and system power loss

Front 34

True or False. As the pipe schedule size increases, the ID decreases, the wall thickness increases, and the OD remains the same

Back 34

True

Front 35

The nominal size of pipe whose outside diameter is 1.900 inches is?

Back 35

1 1/2

Front 36

What is the schedule 40 wall thickness of pipe with a nominal pipe size of 2 inches?

Back 36

0.154 in

Front 37

What is the size of No. 4 rigid tubing, and where is the measurement taken?

Back 37

1/4 inch, outside diameter

Front 38

True or False. The relative bursting pressure for various sies of tubing made of the same meterial is higher for small tubing than for larger tubing of the same wall thickness.

Back 38

True

Front 39

What metals may be used to provide a strong, inexpensive pipe or tubing capabe of withstanding high pressures and temperatures?

Back 39

steel

Front 40

What basic requirements must be considered in designing the lines and connectors of a fluid power system?

Back 40

inside surfaces that do not create turbulent fluid flow, sizes sufficient to deliver adequate quantities of fluid to all components, and strength to withstand pressure surges that exceed the system's working pressure

Front 41

True or false. Bends in piping serve to absorb vibration and to compensate for thermal expansion and contraction.

Back 41

True

Front 42

The determining factor for the radius of the bend to be made in a pipe is the pipe's?

Back 42

inside diameter

Front 43

True or False. Coarse-toothed hacksaw blades are preffered for cutting tubing because they cut faster and are less liable to choke up with the chips.

Back 43

False

Front 44

What procedures should you follow when cutting a tube with a tube cutter?

Back 44

apply continual light pressure to the cutting wheel, remove all burrs on the inside and outside of the tube, and remove all roreign particles from the tube.

Front 45

What statement is NOT correct for cutting tubing with a hacksaw

Back 45

when you clamp the tubing in a vice, tighten the vice until the tubing is just starting to hold without collapsing

Front 46

What parts of the hand tube bender are used to obtain the correct bend radius and the desired bend angle on tubing?

Back 46

the radius block and the slide bar

Front 47

True or False. When flaring a tube the flare must be large enough to seat properly against the fitting.

Back 47

True

Front 48

True or False. When flaring a tube the correct diameter of the flare is obtained by ensuring that the tube is flush with the top face of the die block.

Back 48

False

Front 49

True or False. When flaring a tube the flare must be small enought to allow the threads of the flare nut to slide over it.

Back 49

True

Front 50

Flexible hose should be used in locations where it will be subjected to?

Back 50

severe vibration

Front 51

What information is found along the layline of synthetic rubber hoses having a rubber cover?

Back 51

hose size, cure date, and federal supply code

Front 52

The size of flexible hose is designated in what increments measured at what place?

Back 52

sixteenths-inch, inside diameter

Front 53

The flexible hose that is inert to all fluids presently used and that does not absorb water is composed of what material?

Back 53

PTFE

Front 54

You have completed fabrication of a flexible hose assembly. What, if any, steps must you perform?

Back 54

Proof test the assembly and flush and dry the hose and cap its ends

Front 55

True or False. Sharp bends may reduce the bursting pressure of the hose.

Back 55

True

Front 56

True or False. Supports are never required when the hose is used.

Back 56

False

Front 57

True or False. The hose should be stretched tightly between connections.

Back 57

False

Front 58

True or False. The hose should be wrapped where necessary for protection against chafing.

Back 58

True

Front 59

A characteristic of flexible hose is that under pressure it will?

Back 59

expand in diameter and contract in length