TPC 309 Basic Pneumatics

Question 1

In a pneumatic system, what provides the force that performs work?

Answer 1

Compressed air

Question 2

How much work is done by a piston that exerts a force of 15lb through a distance of 10in?

Answer 2

150 in-lb

Question 3

Heating a gas in a sealed, rigid container will ______ the ________ of the gas

Answer 3

Increase; pressure

Question 4

Two cylinders having different diameters are connected by an air line. A force applied to the smaller piston makes it move. In response, the larger piston exerts a force on a load and makes it move. The force on the load is ______ the force applied to the smaller piston, and the distance the load moves is ______ the distance the smaller piston moves.

Answer 4

Greater than; less than

Question 5

When air flowing in a pipe reaches a section where the diameter is reduced, the speed of the air _____ and its pressure _____.

Answer 5

Increases; decreases

Question 6

A reciprocating compressor is one kind of _______ compressor.

Answer 6

Positive-displacement

Question 7

In a typical reciprocating compressor, the intake valves are forced open by the….

Answer 7

Atmospheric pressure

Question 8

The purpose of an intercooler between the stages of a two-stage compresor is to reduce the:

Answer 8

Power needed to run the compressor

Question 9

The purposes of lubricating oil in a compressor are to reduce friction between the moving parts and to…

Answer 9

Improve the cooling of the compressor

Question 10

The advantage of unloading a compressor is to allow it to

Answer 10

Run without delivering air

Question 11

Single-stage sliding-vane compressors can produce pressures up to ______ psi

Answer 11

50

Question 12

Rotary screw compressors run at speeds ranging from ______ to ________ rpm.

Answer 12

3000; 12000

Question 13

Impeller compressors deliver air at _____ volume and ______ pressure.

Answer 13

High; low

Question 14

Compared to other kinds of compressors, centrifugal compressors…

Answer 14

Require more power

Question 15

The most effective method of reducing the output of centrifugal compressors is ______ but may not work well if the reduction is too _____

Answer 15

Speed variation; large

Question 16

Water often collects in a pneumatic system, because when air is compressed it’s _______ decreases.

Answer 16

Moisture capacity

Question 17

The most common way to remove water vapor from the air leaving a compressor is to

Answer 17

Cool the air

Question 18

Water cooled after coolers are typically used with _______-capacity compressors that run ______ hours a day.

Answer 18

Large; ten or more

Question 19

A dessicant removes water from air by ______ it.

Answer 19

Absorbing

Question 20

The main purpose of the receiver in a pneumatic system is to…

Answer 20

Maintain pressure during peak demand

Question 21

The operation of an inertial separator depends on a(n)

Answer 21

rapid change in the direction of air flow

Question 22

Of the particles listed below, the smallest are the _____ particles.

Answer 22

Aerosol

Question 23

A filter can stop 100 percent of the particles down to a specifed minimum size. This size is called the filter’s ______ rating.

Answer 23

Absolute

Question 24

An advantage of wetted filters over dry filters is that wetted filters :

Answer 24

Can be cleaned many times

Question 25

A fine mist lubricator should be use in a pneumatic system if the air flow is ______ and/or the distance to the equipment is ______.

Answer 25

Intermittent; long

Question 26

Laminar air flow in a piping system is made turbulent by

Answer 26

Constructions in the pipe

Question 27

Greater pressure losses occur in a pneumatics system if there air is at ______ pressure, because of greater ______.

Answer 27

Low; friction

Question 28

When used as a compressor discharge line, a pipe run should slope _______ in the direction of the airflow by 1in for every _____ ft of pipe.

Answer 28

Downward; 10

Question 29

When should you use pipe joint compound in connecting NPT-threaded pipe?

Answer 29

Always

Question 30

If an air hose is not completely depressurized when you disconnect it, the greatest danger to you is a sudden…

Answer 30

Blowing of dust or chips

Question 31

A four-way valve has four:

Answer 31

Connections ports

Question 32

The_______ valve is a good throttling device and is suitable for high-pressure service. It causes _____ pressure loss in the line.

Answer 32

Needle; high

Question 33

The spool in a valve controls the flow of air by ______ from one position to another. In a high-pressure system, the spool is ____ to move.

Answer 33

Sliding; easy

Question 34

An advantage of four-way valves over two and three way valves is that they

Answer 34

Simplify the controls

Question 35

A valve has five connecting ports, two of which are exhaust ports. This valve is a _____ valve.

Answer 35

Four-way

Question 36

The cracking pressure or a poppet-type relief valve is determined by the

Answer 36

Spring adjustment

Question 37

A diaphragm-type relief valve responds very quickly to a pressure change because of is

Answer 37

Large pressure-sensitive area

Question 38

The only purpose of a pressure relief valve is to:

Answer 38

Protect the system from damage

Question 39

An increase in pressure on the secondary side of a pressure regulating valve _______ the valve.

Answer 39

Slightly closes

Question 40

The best way to guard against excessive pressure on the secondary side of a pressure regulator is to

Answer 40

Use a regulator with a built-in relief valve

Question 41

The thrust that can be allied when the rod of a single-rod, double-acting pneumatic cylinder is moving out of the cylinder is_____ the thrust that can be applied when the rod is moving into the cylinder.

Answer 41

Greater than

Question 42

An internal spring is sometimes used in return the piston in a ______-acting ______- rod pneumatic cylinder.

Answer 42

Single; single

Question 43

The main purpose of an exhaust-flow control metering valve on a pneumatic cylinder is to….

Answer 43

limit the return-stroke speed

Question 44

A cylinder that must be free to pivot requires a(n) _____ mounting.

Answer 44

Trunnion or clevis

Question 45

You can determine whether a control valve can deliver air rapidly enough for a cylinder by calculating the ______ required by the valve.

Answer 45

Capacity coefficient

Question 46

The highest torque a pneumatic motor can exert on a load is it’s ______ torque.

Answer 46

Stalling

Question 47

The horsepower of a pneumatic motor varies with the _____ and the _____ of the motor shaft.

Answer 47

Speed; torque

Question 48

The highest power ouput of a pneumatic motor occurs when its speed is

Answer 48

Medium

Question 49

An axial-piston pneumatic motor transmits force from the piston to the output shaft by means of a:

Answer 49

Cam plate and gears

Question 50

Air pressure of 100 psi can create hydraulic pressure of 1000 psi if an air piston drives a ______hydraulic piston(s)

Answer 50

Smaller-diameter