Pneumatics

Question 1

In a pneumatic system what must be present at all times for the system to function

Answer 1

Force

Question 2

When you add gauge pressure to atmospheric pressure you get

Answer 2

Absolute pressure

Question 3

Force x distance in feet or inches equals

Answer 3

Foot pounds or inch pounds

Question 4

A physical law dealing with heat is Charles law, it says if the volume of a confined quantity of gas remains the same,

Answer 4

The change in the pressure of the gas varies directly with a change in the absolute temperature of the gas

Question 5

A principal of leverage states that for every force increase there is a corresponding movement what

Answer 5

Decrease

Question 6

As temperatures increase the molecules bump into each other more frequently while they are moving, which gives them a greater resistance to flow this is called

Answer 6

Dynamic viscosity

Question 7

Positive displacement compressors do what

Answer 7

Confine the air and compress it by decreasing the volume of the space

Question 8

Dynamic compressors do what

Answer 8

Accelerate the air with rapidly turning rotor blades

Question 9

Less power is needed to compress air because what is used between stages

Answer 9

Inter cooler, cooling between stages reduces the volume of air that is compressed

Question 10

What does lube oil do

Answer 10

Reduce friction and improve heat transfer

Question 11

What is unloading a compressor

Answer 11

Relieving all internal pressure, so it starts easier

Question 12

Single stage vane compressors can develop up to how much psi

Answer 12

50 psi

Question 13

Wet type rotary screw compressors do not use

Answer 13

Timing gears

Question 14

The impeller compressor is designed for what

Answer 14

High volume rather than high pressure

Question 15

Two disadvantages of centrifugal compressors are that they

Answer 15

Require more horsepower and that they operate at very high speeds

Question 16

Four control methods of a centrifugal compressor is what

Answer 16

Speed variation, suction throttling, discharge throttling, and recirculation, the most efficient tho is speed variation

Question 17

The recommended method of cleaning dry filters are

Answer 17

To use recommended solvent to clean

Question 18

The amount of moisture or water vapor that exists in free air depends on the temp and weather conditions. The amount of moisture in the air at anytime compared to the amount of water vapor the air could hold if it were completely saturated is referred to as

Answer 18

Relative humidity

Question 19

Water cooled compressors are used with

Answer 19

Large compressors or medium sized compressors that run for more than eight hours a day

Question 20

After coolers are built strong because why

Answer 20

They operate at high pressures

Question 21

Most systems or aftercoolers have what to remove moister

Answer 21

Mechanical separators

Question 22

Deliquescent is what

Answer 22

Desiccant used to absorb moisture

Question 23

Air receivers do what

Answer 23

There most important purpose is their ability to store compressed air

Question 24

What is used as a pre filter to pick up large dirt particles

Answer 24

Inertial separators

Question 25

Absolute rating in reference to a filter is

Answer 25

It's ability to stop 100% dirt particles

Question 26

Closely packed fine metallic wire is used in what type of filter

Answer 26

Depth filter

Question 27

Wetted filters cost more than dry filters but

Answer 27

They can be cleaned and reused many times

Question 28

Fine lubricators mist oil and are used for

Answer 28

Long distances complicated piping and systems with intermittent equipment operation

Question 29

Lubricators should be mounted blank the pressure regulator

Answer 29

After

Question 30

Turbulent flow creates

Answer 30

Heat

Question 31

How to avoid turbulence

Answer 31

Inner walls of air line should be smooth and with the least amount of bends possible

Question 32

Pressure loss in a pipe is affected by

Answer 32

Airflow volume, pipe diameter, and the air pressure

Question 33

Airflow at lower pressures is affected blank by friction

Answer 33

More

Question 34

Npt threads seal how

Answer 34

Flank to flank (side to side) contact with the air of pipe dope

Question 35

Compressor discharge and distribution lines should slope 1 inch for every

Answer 35

10 feet, the slope should be downward in the direction of air flow

Question 36

Control valves are identified how

Answer 36

Number of connecting ports, type of control element, method of operation, number of control positions

Question 37

A needle valve is made is excellent at

Answer 37

High pressure service but has high pressure losses

Question 38

A plunger controls the entire air flow through a valve in what kind of valve

Answer 38

Direct acting normally closed two way solenoid valve

Question 39

Spoil valves are great, why

Answer 39

Easy to operate even at high pressures, they can be made to shift to more than one position

Question 40

Three way valves may be used how

Answer 40

Diverter or selector valves, holding valves, and directional valves. The only difference is how they are hooked up

Question 41

Four way valves are used to

Answer 41

Simplify pneumatic circuits

Question 42

A five way valve is

Answer 42

A special four way valve with an extra exhaust port

Question 43

A pressure control valve is done how

Answer 43

Unloading, holding back or blocking open the valve ports

Question 44

Relief valves are located where

Answer 44

Between the pressure reg and the individual piece of equipment, it protects from full outlet line pressure if the regulator fails

Question 45

Cracking pressure is adjusted how

Answer 45

By adjusting the spring

Question 46

Diaphragm valves respond much faster than poppet valves because

Answer 46

The compressed air works on a much larger pressure sensitive area (a diaphragm)

Question 47

Pressure relief valves do what

Answer 47

Only job is to protect the system and its components from damage

Question 48

Pressure regulators sometimes have what built in

Answer 48

A relief valve

Question 49

Pneumatic cylinders do not require what

Answer 49

Air lines to return air to the receiver

Question 50

Which side of the piston has less pressure on it

Answer 50

The rod side

Question 51

A single acting cylinder is equipped with

Answer 51

An internal spring

Question 52

An exhaust flow control metering valve prevents the cylinder from experience what

Answer 52

Shock

Question 53

Pivoted cylinder mountings are classed as being

Answer 53

Trunnions or clevis and have no rigid support

Question 54

Capacity coefficient is what

Answer 54

A control valves ability to handle the air of a cylinder

Question 55

The valve port size should be what than the cylinder port size

Answer 55

No smaller, equal

Question 56

Pneumatic motors need a starting or break a way force called

Answer 56

Torque

Question 57

Positive displacement motors are usually the

Answer 57

Fixed displacement type

Question 58

Maximum power output is obtained at what speed

Answer 58

Medium speed and medium torque output

Question 59

The horsepower output of pneumatic motors is the product of the shaft...

Answer 59

Speed and torque

Question 60

Starting torque is what

Answer 60

Is the turning force the motor exerts from a dead stop typically 75% of the stalling torque, this means it's really hard to stall the motor

Question 61

The thrust of the piston causes the wobble (cam) plate to

Answer 61

Rotate, this motion is transferred through gears to the output shaft

Question 62

The force applied to the hydraulic fluid is spread over a smaller area so it creates what

Answer 62

Greater pressure ( pressure multiplier )