module 2: air generation and...

Basic Pneumatics

Module 2: Air generation and

Distribution

PREPARED BY

Academic Services

August 2011

© Applied Technology High Schools, 2011

ATM 1132 – Basic Pneumatics

Module 2: Air generation and distribution


Module Objectives

After the completion of this module, the student will be able to:

Identify the main parts of a pneumatic system.

Identify the main components of the pneumatic work station TP 101.

List the main parts in the compressed air preparation stage.

Identify the symbol of air compressor and its function.

Identify the symbol of air tank and its function.

Explain the purpose of using the cooling and drying unit.

Identify the main parts of the air service unit.

Identify the symbol of air filter and its function.

Identify the symbol of air pressure regulator and its function.

Identify the symbol of lubricator and its function.

Identify some important pneumatic accessories.

Module Contents Topic Page No.

1 Introduction 3

2 Main parts in the compressed air preparation 3

3 Air compressor 4

4 Air tank 5

5 Cooling and drying unit 6

6 Shut off valve 7

7 Piping 7

8 Air service unit 9

9 Pressure regulator 10

10 Air lubricator 10

11 Manifold 11

12 Tubes and fittings 11

13 Pressure gauge 12

14 Safety precautions 13



1 Introduction

Air generation and distribution

The main function of the air generation and distribution is to provide the

system with compressed air which is dry, clean, and at the required

pressure.

The compressed air supply for a pneumatic system should be adequately

calculated and made available in the appropriate quality.

Air is compressed by the air compressor and delivered to an air distribution

system in the factory. To ensure that the quality of the air is acceptable,

air service unit is utilized to prepare the air before being supplied to the

control system.

Malfunctions can be considerably reduced in the system if the compressed

air is correctly prepared.

2 Main parts in the compressed air preparation

1- Air compressor

2- Air tank (Reservoir)

3- Air filter

4- Cooling and drying unit

5- Shut off valve

6- Piping

7- Air Service unit

8- Pressure regulator

9- Air lubricator

10- Manifold

11- Tubes and fittings

12- Pressure Gauge



(a) Air compressor

(b) Air compressor

(c) ISO symbol of air compressor

Fig. 2.1: (a) and (b) are examples of some practical air compressors. (c) ISO symbol of air compressor

2.1 Air compressor

Air compressor is used to produce

the compressed air for the system

by the required volume and

pressure.

As a rule, pneumatic components

are designed for a maximum

operating pressure of 800-1000 kPa

(8 - 10 bar) but in practice it is

recommended to operate at

between 500-600 kPa (5 and 6 bar)

for economic and safe use.

Due to the pressure losses in the

distribution system, the compressor

should provide pressure between

650-700 kPa (6.5 and 7) bar.

Fig. 2.1.a and Fig. 2.1.b are

examples of air compressors while

Fig. 2.1.c shows the ISO symbol of

the air compressor.



2.2 Air Tank (reservoir)

An air reservoir should be fitted to:

Store and stabilize

the compressed air.

Compensate the pressure

fluctuation.

Cool the air.

Fig. 2.2 (a) shows a real air tank while

Fig. 2.2 (b) shows the ISO symbol of an

air reservoir.

(a) Air reservoir

(b) ISO symbol of air reservoir

Fig. 2.2: (a) air reservoir. (b)

ISO symbol of an air reservoir.

2.3 Air Filter

Compressed air filter (Fig. 2.3a) has the

job of removing all contaminants from

the compressed air flowing through it as

well as water which has already

condensed. The compressed air enters

the filter bowl through guide slots.

Liquid particles and larger particles of

dirt are separated centrifugally

collecting in the lower part of the filter

bowl. The collected condensate must be

drained before the level exceeds the

maximum condensate mark, as it will

otherwise be re-entrained in the air

stream.

(a)A picture of a real air filter

(b) ISO symbol of the air filter

Fig. 2.3: (a) air filter.(b) The

ISO symbol of an air filter



2.4 Cooling and drying unit

As the air comes out from the

compressor very hot and humid;

The cooling and drying unit is

used to:

Condensate the water vapor

(humidity) from the

compressed air.

Reduce the compressed air

temperature. (cooling)

The accumulation of condensate

depends largely on the relative

air humidity. The relative air

humidity is dependent on the air

temperature and the weather

situation.

To remove the humidity, we use

many types of air dryers, the

very common and practical one

is by using a cooling unit which

cool the air and at the same

time remove the water vapor.

Fig. 2.4 (a) and (b) show some

examples of real air dryers,

while Fig. 2.4.c represents an

ISO symbol of air dryer.

(a)

(b)

(c)

Fig. 2.4: (a): and (b) are some

examples of real air dryers.

(c) ISO symbol of air dryer.



2.5 Shut off valve

It is used to open and close the

compressed air supply

manually.Fig. 2.5.a shows a sample

of shut-off valve. Fig. 2.5.b

represents the ISO symbol of the

shut-off valve.

(a) Sample of a shut-off valve

(b) ISO symbol of the shut-off valve

Fig. 2.5: (a) picture of shut off

valve.

(b) The ISO symbol of shut off

valve

2.6 Piping

The pipe diameter of the air distribution system should be selected in

such a way that the pressure loss from the pressurized reservoir to the

consuming device ideally does not exceed approx. 10 kPa (0.1 bar).

2.6.1 Selection factors of the pipe diameter:

1. Flow rate

2. Line length

3. Permissible pressure loss

4. Operating pressure

5. Number of flow control points in the line



2.6.2 Piping layout

Ring circuits (Fig. 2.6.a) are most

frequently used as main lines. This

method of installing pressure lines

also achieves a constant supply in

the case of high air consumption.

In pipe-run layout, the pipe lines

must be installed in the direction

of flow with a gradient of 1 to 2%

as shown in Fig. 2.6.b. This is

particularly important in the case

of branch lines.

Condensate can be removed from

the lines at the lowest point.

Any branching of air consumption

points where lines run horizontally

should always be installed on the

upper side of the main line.

Shut-off valves can be used to

block sections of compressed air

lines if these are not required or

need to be closed down for repair

or maintenance purposes.

(a) Ring (loop) pneumatic

distribution system

(b) pipe-run pneumatic distribution

system

Fig. 2.6 : (a) shows the ring or loop

distribution system. (b) shows the

pipe-run distribution system



2.7 Air service unit

The air service unit shown in Fig.

2.7.a is a combination of the

following:

1. Compressed air filter (with

water separator)

2. Compressed air regulator

3. Compressed air lubricator

Fig. 2.7.b is the air service unit

without lubricator in our labs.

The main function of the service unit

is to provide the pneumatic system

with a well cleaned, lubricated and

regulated compressed air.

(Condition the compressed air).

Fig. 2.7.a and Fig. 2.7.b Show some

real air service unit. And Fig. 2.7.c

shows the detailed ISO symbol of

the service unit. While Fig 2.7.d

shows the Simplified ISO symbol of

the service unit.

(a) A picture of an air

service unit

(b) A picture of an air

service unit

(c) Detailed ISO symbol of the

service unit

(d) Simplified ISO symbol of the

service unit

Fig. 2.7



2.8 Pressure regulator

(Reduce/regulate the pressure).

The purpose of the regulator (Fig. 2.8.a)

is to keep the operating pressure of the

system (secondary pressure) virtually

constant regardless of fluctuations in

the line pressure (primary pressure) and

the air consumption. Fig. 2.8.b

represents the ISO symbol of the air

regulator.

(a) Pressure regulator

(b) ISO symbol of the pressure

regulator.

Fig. 2.8: (a) pressure

regulator.(b) ISO symbol of the

pressure regulator.

2.9 Air lubricator

(Lubricate the moving parts)

Most moving parts require some type of

lubrication. The efficiency of cylinders, valves

and air motors can be greatly improved if they

are supplied with adequate lubrication.

Pneumatic components can be lubricated by

using an air line lubricator (Fig. 2.9.a), a

device for adding lubricating oil in aerosol

form into a compressed air line. The air

passing through the lubricator transports the

lubricant to air tools, cylinders or other air

operated equipment. Fig. 2.9.b represents the

ISO symbol of the air lubricator.

(a) air lubricator

(b) ISO symbol of the air

lubricator.

Fig. 2.9

(a) Air lubricator. (b)ISO

symbol of the air

lubricator.



2.10 Manifold (distributor)

It is used to provide multi equal

pressure outlets. Fig. 2.10.a shows

a pneumatic manifold (distributor).

Fig. 2.10.b represents the ISO

symbol of the pneumatic pressure

source.

Fig. 2.10.c represents the ISO

symbol of T junction.

Each output port has check valve

(Non return valve).

(a) pneumatic manifold (distributor)

(b) ISO symbol of the pressure

source

(c) ISO symbol of T junction

Fig. 2.10

2.11 Tubes and fittings

Fig. 2.11.a shows some types of tubes

that are used in connecting pneumatic

circuits.

Fig. 2.11.b shows some important

fittings such as T connections and

cross connections.

(a) some types of tubes

(b) some types of fittings

Fig. 2.11



2.12 Pressure gauge

It used to display the actual amount

of the pressure in two main units PSI

and bar.

1 bar= 14.7 PSI

Fig. 2.12.a shows a real pressure

gauge. Fig. 2.12.b represents the ISO

symbol of the pressure gauge.

(a) pneumatic pressure gauge

(b) ISO symbol of a pressure

gauge

Fig. 2.12



5. For further reading, you can use the following links:

1- www.Fest-didactic.com 2- http://www.eng2all.com/vb/t28932.html 3- http://www.logiclab.hu/lesson.php?fe=2

6. Supplementary recourses

1- Pneumatics video from Festo.

2- FluidSIM software.

7. References

1- Festo manuals and workbook TP101 2- Festo manuals and textbook TP101



Student’s notes

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Worksheet 1 QI) Draw the ISO Symbols for the following components:

1- Air compressor …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

2- Air filter

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

3- Shut off valve

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

4- Pressure gauge

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… Q2) what is the function of the following components:

1- Air tank …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

2- Manifold

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

3- Pressure regulator

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

4- Air service unit

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

module 2: air generation and...

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