Basic Hydraulics And Pneumatics - Maysaa Nazar


Basic Hydraulics andPneumaticsModule 1: Introduction to PneumaticsPREPARED BYIAT Curriculum UnitMarch 2011 Institute of Applied Technology, 2011

ATM 1122 – Basic Hydraulics and PneumaticsModule 1: Introduction to PneumaticsModule ObjectivesAfter the completion of this module, the student will be able to: Identify the common uses of pneumatic systems. Identify the main parts of a pneumatic system. Identify the main components of the pneumatic work station TP 101. Understand how to to construct a pneumatic circuit Explain the structure and signal flow of a pneumatic system. 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.

ATM 1112 – Basic Hydraulics and PneumaticsModule Contents1Introduction . . of pneumatics . 8Disadvantages. 8Structure and signal flow of pneumatic systems . 94.15industrial applications . 5Industrial processes . 5Some of the pneumatic applications in our life . 6Advantages and disadvantages of pneumatics . 83.13.24What does pneumatic mean . 3Defentition of pneumatics . 3What is the fluid power . 3Primary levels of the pneumatic system . 9Air generation and distribution . 115.1 Preparation the compressed air. . 115.2 Main parts in the compressed air preparation. . 125.2.1 Air compressor . 125.2.2 Air Tank (reservoir) . 135.2.3 Cooling and drying unit . 145.2.4 Piping . 155.2.5 Air service unit . 176Pneumatic accessories . (distributor) . 20Shut-off valves . 20Tubes and fittings . 20Pressure gauges . 21References . 222Module 1: Introduction to pneumatics

ATM 1122 – Basic Hydraulics and Pneumatics1 Introduction1.1 What Does Pneumatic Mean?Pneumatics comes from the Greek word pneuma, which means 'breath orwind'. It is basically the use of under pressure gas that helps in performing acertain work in science and technology.1.2 Definition of pneumaticsPneumatics is the transmission and control of forces and movements by meansof compressed air. (The use of compressed air as a medium to do work).1.3 What is the fluid power?Fluid power is the energy transmitted and controlled by means of apressurized fluid, either liquid or gas. The term fluid power applies to bothhydraulics and pneumatics. Hydraulics (oil or water) use liquids under pressurewhile pneumatics use compressed air or other neutral gases.Pneumatics technology has for some considerable time been used in carryingout the simplest mechanical tasks, but nowadays has played a vital andimportant role in automation and development of sophisticated technologies.Module 1: Introduction to pneumatics3

ATM 1112 – Basic Hydraulics and Pneumatics2Applications of pneumatics:2.1industrial applicationsPneumatic systems are used in many industrial applications such as: Material handling Clamping Shifting Positioning Branching of material flow Packaging Filling Transfer of materials Sorting of parts Stamping and embossing of components2.2Industrial processesPneumatic systems are used in carrying out machining and some industrialprocesses such as: Drilling Turning Milling Sawing Finishing Forming4Module 1: Introduction to pneumatics

ATM 1122 – Basic Hydraulics and Pneumatics2.3Some of the pneumatic applications in our life:A Pneumatic machine is used todismantle an automobile tireA pneumatic machine is used in anautomobile paintingA heavy duty pneumatic jackhammerA pneumatic filling machineModule 1: Introduction to pneumatics5

ATM 1112 – Basic Hydraulics and PneumaticsA dental drill is one of the uses of thepneumatic technologyA pneumatic device is used to fill thetire with compressed air to adjust thetire pressure.6Module 1: Introduction to pneumatics

ATM 1122 – Basic Hydraulics and Pneumatics3Advantages and disadvantages of pneumatics:3.1 Advantages:1- Availability: Air is available everywhere in unlimited quantities.2- Transport: Air can be easily transported in pipelines, even over largedistances.3- Storage: Compressed air can be stored in a reservoir/tank and removedas required.4- Temperature: Compressed air is relatively insensitive to temperaturefluctuations.5- Cleanliness: Unubricated exhaust air is clean.6- The running cost is relatively inexpensive7- Speed: Compressed air is a very fast working medium. This enables highworking speeds to be attained.8- Overload safe: Pneumatic tools and operating components can be loadedto the point of stopping and are therefore overload safe.3.2 Disadvantages:1- Preparation: Compressed air requires good preparation. Dirt andcondensates should be removed.2- Speed: As air is compressible; it is difficult to achieve uniform andconstant piston speed.3- Force requirement: Compressed air is economical only up to a certainforce requirement. Under the normal working pressure of 600 to 700 kPa(6 to 7 bar).4- Noise level: The exhaust air is loud (noise). This problem has now,however been largely solved due to the development of soundabsorption material and silencers.Module 1: Introduction to pneumatics7

ATM 1112 – Basic Hydraulics and Pneumatics4 Structure and signal flow of pneumatic systemsPneumatic systems consist of an interconnection of different groups ofelements. This group of elements forms a control path for signal flow,starting from the signal section (input) through to the actuating section(output). Control elements control the actuating elements in accordancewith the signals received from the processing elements.4.1Primary levels of the pneumatic system:Figure 1.1: Pneumatic signal flow and the coreesponding control elements8Module 1: Introduction to pneumatics

ATM 1122 – Basic Hydraulics and Pneumatics0ZFigure 1.2 : Examples of pneumatic control elements shoen in a practicalcircuitModule 1: Introduction to pneumatics9

ATM 1112 – Basic Hydraulics and Pneumatics5Air generation and distributionThe main function of the air generation and distribution is to provide thesystem with compressed air which is dry, clean, and at the required pressureThe compressed air supply for a pneumatic system should be adequatelycalculated and made available in the appropriate quality.Air is compressed by the air compressor and delivered to an air distributionsystem in the factory. To ensure that the quality of the air is acceptable, airservice unit is utilized to prepare the air before being supplied to the controlsystem.Malfunctions can be considerably reduced in the system if the compressed airis correctly prepared. A number of aspects must be considered5.1Preparation of the compressed air:The following points should be considered in preparing compressed air plants:1. Quantity of air required to meet the demand of the system2. Type of compressor to be used to produce the quantity required3. Pressure requirements4. Storage requirements5. Requirements for air cleanliness6. Acceptable humidity levels to reduce corrosion and sticky operation7. Lubrication requirements, if necessary8. Temperature of the air and effects on the system9. Line sizes and valve sizes to meet demand10. Material selection to meet environmental and system requirements11. Drainage points and exhaust outlets in the distribution system12. Layout of the distribution system to meet demand.10Module 1: Introduction to pneumatics

ATM 1122 – Basic Hydraulics and Pneumatics5.2Main parts in the compressed air preparation5.2.1 Air compressor:Air compressor is used to produce thecompressed air for the system by therequired volume and pressure.As a rule, pneumatic components aredesigned for a maximum operatingpressure of 800-1000 kPa (8 - 10 bar)but in practice it is recommended tooperate at between 500-600 kPa (5and 6 bar) for economic and safe use.Due to the pressure losses in the(a) Air compressordistribution system, the compressorshould be delivered between 650-700kPa (6.5 and 7) bar to attain thesefigures. Figure 1.3.a and figure 1.3.bare examples of air compressors whilefigure 1.3.c shows the ISO symbol ofthe air compressor.(b) Air compressor(c) ISO symbol of air compressorFigure 1.3: (a) and (b) are examplesof some practical air compressors.(c) ISO symbol of air compressor.Module 1: Introduction to pneumatics11

ATM 1112 – Basic Hydraulics and Pneumatics5.2.2Air Tank (reservoir)An air reservoir should be fitted to: Storeandstabilizesthecompressed air. Compensatethepressurefluctuation. Cool the air.(a) Air reservoirFigure 1.4 (a) shows a real air tankwhile the figure 1.4 (b) shows theISO symbol of an air reservoir.(b) ISO symbol of air reservoirFigure 1.4: (a) air reservoir. (b) ISOsymbol of an air reservoir.12Module 1: Introduction to pneumatics

ATM 1122 – Basic Hydraulics and Pneumatics5.2.3Cooling and drying unitAs the air comes out from thecompressor very hot and humid;The cooling and drying unit is usedto: Condensatethewatervapor(humidity) from the compressedair. Reducethecompressedairtemperature.The accumulation of condensate(a)depends largely on the relative airhumidity. The relative air rsituation. To remove the humidity,we use many types of air dryers,the very common and practical oneis by using a cooling unit whichcool the air and at the same timeremove the water vapor. Figure 1.5(a) and (b) show some examples of(b)real air dryers, while figure 1.5.crepresents an ISO symbol of airdryer.(c)Figure 1.5: (a): and (b) are someexamples of real air dryers.(c) ISO symbol of air dryer.Module 1: Introduction to pneumatics13

ATM 1112 – Basic Hydraulics and Pneumatics5.2.4PipingThe pipe diameter of the air distribution system should be selected in such away that the pressure loss from the pressurized reservoir to the consumingdevice ideally does not exceed approx. 10 kPa (0.1 bar). of the pipe diameter:1. Flow rate2. Line length3. Permissible pressure loss4. Operating pressure5. Number of flow control points in the line5.2.4.2Piping layoutRing circuits (figure 1.6.a) are most frequently used as main lines. Thismethod of installing pressure lines also achieves a constant supply in the caseof high air consumption. In pipe-run layout, the pipe lines must be installed inthe direction of flow with a gradient of 1 to 2% as shown in figure 1.6 b. Thisis particularly important in the case of branch lines. Condensate can beremoved from the lines at the lowest point. Any branching of air consumptionpoints where lines run horizontally should always be installed on the upperside of the main line. Branching for condensate removal is installed on theunderside of the main line. Shut-off valves can be used to block sections ofcompressed air lines if these are not required or need to be closed down forrepair or maintenance purposes.14Module 1: Introduction to pneumatics

ATM 1122 – Basic Hydraulics and Pneumatics(a) Ring (loop) pneumatic distribution system(b) pipe-run pneumatic distribution systemFigure 1.6 : (a) shows the ring or loop distribution system. (b) shows the piperun distribution systemModule 1: Introduction to pneumatics15

ATM 1112 – Basic Hydraulics and Pneumatics.5.2.5Air service unitThe air service unit shown in figure1.7.aisacombinationofthefollowing:1. Compressedairfilter(withwater separator)2. Compressed air regulator3. Compressed air lubricatorThe main function of the service unit(a)picture of an air serviceunitis provide the pneumatic system withawellcleaned,lubricatedandregulated compressed air.(Condition the compressed air).Removalofmostcontaminants(water, compressor oil, dirt, rust, pipe(b) Detailed ISO symbol of the serviceunitscale and other foreign materials).Obviously,aninefficientsystemresults in higher costs per unit ofcompressed air, improper or erratic(c) Simplified ISO symbol of thetool operation, shortened componentservice unitlife,reducedcapacityandtheformation of rust and sludge in the Figure 1.7: (a) Shows a real servicemain and branch lines.unit. (b) ISO symbol of the serviceunit. (c) Simplified ISO symbol of theservice unit.16Module 1: Introduction to pneumatics

ATM 1122 – Basic Hydraulics and Pneumatics5.2.5 .1Air filterCompressed air filter (Figure 1.8a)hasthejobofremovingallcontaminants from the compressed airflowing through it as well as waterwhich has already condensed. Thecompressed air enters the filter bowlthrough guide slots. Liquid particlesandlargerparticlesofdirtareseparated centrifugally collecting in(a)a picture of a real air filterthe lower part of the filter bowl. Thecollected condensate must be drainedbeforethelevelexceedsthemaximum condensate mark, as it willotherwise be re-entrained in the air (b) ISO symbol of the air filterstream.Figure 1.8: (a) air filter.(b) The ISOsymbol of an air filterModule 1: Introduction to pneumatics17

ATM 1112 – Basic Hydraulics and Pneumatics5.2.5 .2Pressure regulator(Reduce/regulate the pressure).The purpose of the regulator (figure1.9.a)istokeeptheoperatingpressure of the system (secondarypressure) virtually constant regardless(a) real pressure regulatorof fluctuations in the line pressure(primarypressure)andtheairconsumption. Figure 1.9.b representsthe ISO symbol of the air regulator.5.2.5 .3(b) ISO symbol of the pressureAir lubricatorregulator.(Lubricate the moving parts)Most moving parts require some typeoflubrication.Theefficiencyofcylinders, valves and air motors canbegreatlyimprovediftheyaresupplied with adequate canbeairlinelubricator (figure 1.9.c), a device foradding lubricating oil in aerosol form(c) air lubricatorinto a compressed air line. The airpassingthroughthelubricatortransports the lubricant to air tools,cylindersorotherairoperated(d) ISO symbol of the air Figure 1.9.d represents an Figure 1.9: (a) pressure regulator.(b)ISO symbol of the pressure regulator.ISO symbol of the air lubricator(c) Air lubricator. (d)ISO symbol ofthe air lubricator.18Module 1: Introduction to pneumatics

ATM 1122 – Basic Hydraulics and Pneumatics6pneumatic accessoriesOther important components that are used in the pneumatic lab6.1 Manifold (distributor): it ).represents the ISO symbol of thepneumatic manifold.(a) pneumatic manifold (distributor)Each output port has check valve(Non return valve).(b) ISO symbol of the pneumatic manifold6.2 Shut off valvesIt is used to open and close mple of shut-off valve. Figure1.10d represents the ISO symbolof the shut-off valve(c) Sample of a shut-off valve6.3(d) ISO symbol of the shut-off valveTubes and fittingsFigure 1.10e shows some types oftubes that are used in connectingpneumatic circuits. Figure 1.10fshowssomeimportantfittingssuch as T connections and crossconnections.(e) some types of tubesModule 1: Introduction to pneumatics19

ATM 1112 – Basic Hydraulics and Pneumatics6.4ItPressure gaugeusedto display theactualamount of the pressure in twomain units Pascal and bar1 bar 14.5 p.s.iFigure1.10gpressureshowsgauge.Figureareal(f) different fittings1.10hrepresents the ISO symbol of thepressure gauge.(g) pneumatic pressure gauge(h) ISO symbol of a pressure gaugeFigure 1.10Activity:Compare between hydraulics and pneumatics.20Module 1: Introduction to pneumatics

ATM 1122 – Basic Hydraulics and PneumaticsReferences1. Festo Didactic pneumatic basic level textbook TP 101.2. Introduction to fluid power by James L. Johnson3. fModule 1: Introduction to pneumatics21

ATM 1112 – Basic Hydraulics and PneumaticsStudent notes . . . . . . . . . . . . . . . . . . . . . . . . . . .22Module 1: Introduction to pneumatics

ATM 1112 – Basic Hydraulics and Pneumatics 10 Module 1: Introduction to pneumatics 5 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