MIT AIRCRAFT SYSTEM LAB

8/12/2019 MIT AIRCRAFT SYSTEM LAB

1/79

DEPARTMENT OF

AERONAUTICAL AND AUTOMOBILE

ENGINEERING

MANIPAL INSTITUTE OF TECHNOLOGY

MANIPAL

6th

Semester Aeronautical Engineering

MIT/AAE/MEC MNL/06

NAME: _____________________________________

BATCH: ____________________________________

ROLL NO: ___________________________________

REGISTER NUMBER: ______________________

AIRCRAFT SYSTEMS LAB

(AAE 310)


2/79

CONTENTS

Class

No. Name of the experiment

Page

Nos.

Obser

vation

Book

Marks

Manual

marks

Signature

of the

faculty

with date1 i) Operation of a single acting cylinder.

ii)Use of 3/2 way valve with push button

normally open type

iii)Operation of a double acting cylinder, Quickexhaust valve, Dual pressure valve

iv)Use of dual pressure valve, Shuttle valve,

Double pilot 5/2 way valve

1-2

3-4

5-6

7-8

2 i) Use of time delay valve normally closed

ii) Use of pressure sequence valve

iii)Use of pressure sequence valve and timedelay valve

9-10

11-12

13-14

3 i)Controlling the stroke length of a double

acting cylinder using roller lever valve

ii)Use of pneumatic counteriii)Simultaneous actuation of multiple cylinders

15-16

17-18

19-20

4 i) Simultaneous actuation of multiple cylinders

ii)Direct and indirect actuation of a singleacting cylinder

iii)Actuation of double acting cylinder usingsingle solenoid 5/2 way valve

iv)Use of AND logic, a) direct actuationb) indirect actuation

v)Use of OR logic, indirect actuation

21-22

23-24

25-26

27-28

29-30

31-32

5 i)Control of a double acting cylinder using 5/2

way double solenoid valveii)Indirect actuation with reversal by means of

an electrical limit switch

iii)Double acting cylinder, direct actuation with

oscillating motion of the piston rodiv)Double acting cylinder indirect actuation

with oscillating motion of the piston rod

v)Electric latching circuit with dominatingswitch-off signal for actuation of single

acting cylinder and double acting cylinder

33-34

35-36

37-38

39-40

41-42


3/79

6 i)Electric latching circuit with dominating

switch-on signal for actuation of single actingcylinder and double acting cylinder

ii)Oscillating motion of the piston rod of a

double acting cylinder with monitoring of the

end position by means of magnetic proximitysensors

iii)Pressure dependent reversal with monitoringof the end position by means of magnetic

proximity switches

iv)Coordinated motion control of multiple

cylinders with auxiliary conditions

43-44

45-46

47-48

49-51

7 i) Use of proximity sensorsii) Use of proximity sensors

iii)Use of pressure to electric converter

52-53

54-55

56-57

8 i) Use of ON delay timer

ii) Use of ON delay timeriii)Use of electrical counter

58-59

60-61

62-63

9 i) To study the characteristic of a hydraulicpump

ii) Understanding the mode of operation of 4/2

directional control valveiii)Understanding the mode of operation of 4/3

directional control valve

iv)Understanding flow control in the inlet sideof the cylinder (meter in flow control) to

study advantages and disadvantages

v)Understanding flow control in the outlet sideof the cylinder (meter out flow control) to

study advantages and disadvantages of the

circuit

vi)Understanding the mode of operation ofpressure reducing valve

64

65

66

67

68

69


4/79

Aim: Operation of a single acting cylinder.

Problem description: The allocating device supplies aluminium valve blanks to amachining station. By operating a push button, the piston rod of the single acting cylinder

is made to advance. After releasing the actuating button, the piston rod returns.

Apparatus: Single acting cylinder, 3/2 way valve with push button normally closed.

Working of the circuit:

Step 1-2Through operating the 3/2 way valve via the push button, air is applied to the chamber on

the piston rod side of cylinder. The piston rod of the cylinder advances, and pushes a

valve blank out of the magazine. If valve continues to be operated, the piston rod remains

in the forward end position.

Step 2-3

After releasing the valve actuating button, the air in the cylinder is exhausted via the 3/2way valve. The force of the return spring pushes the piston back to its initial position. The

valve blanks are supplied from the magazine by gravity.


5/79


6/79

Aim: Use of 3/2 way valve with push button normally open type.

Apparatus: Single acting cylinder, One way flow control valve, Quick exhaust valve,3/2 way valve with push button normally open type

Problem description: The parcel separating device feeds parcel post from a slopingconveyor slide to an X-ray appliance.

Operating a push button causes very rapid retraction of the single acting cylinder with the

attached parcel tray. After releasing the valve actuator, the piston rod advances. Forwardmotion time of the cylinder is to be variable.


In the initial position, the single acting cylinder is advanced. The piston chamber ispressurized via the 3/2 way normally open push button valve.

Step 1-2By actuating the 3/2 way push button valve, the volume of air in cylinder is exhausted via

the quick exhaust valve. The cylinder returns rapidly. If the push button continues to be

actuated, the piston rod remains in the retracted end position. The next parcel slides into

the parcel tray.

Step 2-3

If the valve actuator is then released, the piston rod advances and lifts the parcel. Thedesired time of advance is set by means of the one way flow conrol valve.


7/79


8/79

Aim:Operation of a double acting cylinder, Quick exhaust valve, Dual pressure valve.

Problem description: Operation of two identical valves by push button causes theforming tool of an edge folding device to thrust downwards and fold over the edge of a

flat sheet. If both or even just one push button is released, double acting cylinder slowly

returns to the initial position.

Apparatus:Double acting cylinder, One way flow control valve, Quick exhaust valve,

Single pilot 5/2 valve, Dual pressure valve, 3/2-way valve with push button normally

closed2 Nos.

Working of the circuit: In the initial position, the piston rod of cylinder assumes the

retracted end position. The power valve is in the left hand switching position.

Step 1-2If both the 3/2-way valves are actuated, pressure is applied at the output of the dual

pressure valve. The 5/2 way valve reverses. The piston chamber of cylinder is suppliedwith unrestricted compressed air via the one way flow control valve. The cylinder travels

to its forward end position. As the chamber on the piston rod side is rapidly exhausted

through the quick exhaust valve, the cylinder motion is very fast. If both 3/2 way valves

remain actuated, the cylinder remains in the forward end position.

Step 2-3

If at least one of the push buttons is released, power valve is no longer pressurized. Thevalve reverses through the spring. The actuator travels to its initial position under

conditions of flow restriction.


9/79


10/79

Aim: Use of dual pressure valve, Shuttle valve, Double pilot 5/2 way valve

Problem description: Surveyors measuring rods in3 or 5 m length are marked in redwith 200 mm graduations. There is a choice of two push buttons to start the forward

movement of measuring rods via cylinder, which has the exhaust air throttled. The idle

stroke, also started by a push button, can only take place when the double acting cylinderhas reached its forward end position.

Apparatus:Double acting cylinder, One way flow control valve, Double pilot 5/2 valve,

Dual pressure valve, Shuttle valve, 3/2-way valve with push button normally closed3Nos., 3/2-way roller lever valve normally closed.

Working of the circuit: In the initial position, the piston rod of cylinder assumes the

retracted end position. The pilot operated 5/2 way bi-stable valve with memory suppliesair to the piston rod chamber and exhausts the chamber on the inlet side of the piston.

Step 1-2If at least one of the 3/2 way push button valves is actuated, memory valve reverses and

the piston rod advances slowly with throttled exhaust air - with this the surveyors

measuring rod is pushed forward. In the forward end position, the piston rod actuates the

roller lever valve by means of the trip cam. If no push button has been actuated, thecylinder remains in the forward end position.

Step 2-3After pressing the push button of the directly actuated 3/2 way valve for the return stroke,

memory valve reversesthe piston rod is rapidly retracted.

The commencement of the return stroke through the push button can be initiated onlywhen the forward end position has been reached and roller lever valve thus actuated. If a

counter signal is present at 5/2-way valve, the return stroke can not be initiated.


11/79


12/79

Aim:Use of time delay valve normally closed.

Problem description: A double acting cylinder guides cylinder pins towards ameasuring device. The pins are separated by means of a continuous to and fro movement.

The oscillating motion can be started by means of a valve with selector switch.

The duration of forward stroke and return stroke of the cylinder is to be adjustable. Thecylinder is to remain in the forward end position for t = 5 seconds.

Apparatus: Double acting cylinder, One way flow control valve-2 Nos, Double pilot 5/2valve, 5/2 way valve with selector switch, Dual pressure valve, 3/2-way roller lever valve

normally closed2 Nos, Time delay valve normally closed.

Working of the circuit: In the initial position the piston rod of the cylinder assumes theretracted position. The trip cam actuates the roller lever valve. One of the two start

conditions is fulfilled.

Step 1-2If the detented valve is actuated, the second condition of the dual-pressure valve is

fulfilled, and the final control element is switched through. The piston rod extends with

exhaust air throttled. The duration of the advance stroke is adjusted with one way flowcontrol valve. In the forward end position, the trip cam actuates the roller lever valve. The

time delay valve is pressurized. The reservoir is filled via the restrictor. After the set time

of t = 5.0 seconds, the 3/2 way valve of the time delay valve is switched. A one signal ispresent at the output port. The final control element returns to its initial position.

Step 2-3

Reversing the memory valve causes the piston rod to retract with exhaust air throttled.The duration of return stroke is set by means of the one way flow control valve. When the

roller lever valve is re actuated, the return stroke is carried out.

Continuous cycleIf the start valve is de pressed and remains in the actuated position, the piston rod carries

out a continuous to and fro movement. Only when the detent is returned to its initial

position, is the motion sequence concluded at the end of the cycle.


13/79


14/79

Aim: Use of pressure sequence valve normally closed.

Problem description: Badges are to be produced from a very thin metal sheet.

A press with a stamping die is available for this purpose. The double acting cylinder

should extend when both the push buttons S1 and S2 are pressed simultaneously. Thereturn stroke is to occur automatically only after the forward end position and presetpressure have been reached to get the consistent quality.

The cylinder should immediately retract if emergency push button E is pressed.

Apparatus: Double acting cylinder, Pressure gauge, One way flow control valve, Dual

pressure valve, Shuttle valve, Double pilot 5/2 way valve, 3/2 way valve with push

button normally closed 2 Nos. , 3/2-way roller lever valve normally closed, Pressuresequence valve.

Working of the circuit: In the initial position, the cylinder assumes the retracted endposition. The final control valve supplies pressure to the chamber on the piston rod side

of the cylinder.

Step 1-2If both the push buttons are actuated, the dual pressure valve passes on a signal to the 5/2

way valve on its left side. This causes the reversal of the final control element. The

cylinder extends slowly with supply air throttled. The pressure regulator limits thepressure to a maximum of p = 4 bar. In the forward end position, the trip cam of the

cylinder actuates the roller lever valve S1. This causes pressure to be applied to the

pressure sequence valve. The pressure sequence valve is actuated when a pressure of p =

3 bar has been reached in the piston chamber. Adjust the flow control so that the slowincrease in pressure causes the cylinder to pause in the forward end position.

Step 2-3

Once the pressure sequence valve has been switched, the final control element is reversedthrough the shuttle valve. The cylinder travels to its initial start position. In the case of

emergency, the push button valve E is actuated during the forward stroke. It will reverse

final control element immediately and the cylinder will retract.


15/79


16/79

Aim: Use of pressure sequence valve normally closed and time delay valve.

Problem description: An electrically heated welding rail is pressed onto a rotatable colddrum by a double acting cylinder and welds a continuous plastic sheet into pieces of

tubing. The forward stroke is triggered by means of a push button. The maximum

cylinder force is set at 4 bar via a pressure regulator with pressure gauge (This preventsthe welding rail damaging the metal drum). The return stroke is not initiated until theforward end position has been acknowledged and the pressure in the piston area has

reached 3 bar.

The supply air is restricted for the movement of the cylinder. Restarting is only possiblewhen the retracted end position has been reached and a time of t = 2 seconds has elapsed.

Reversing a 5/2 way valve with selector switch causes the control to be switched to

continuous cycle.

Apparatus: Double acting cylinder, One way flow control valve, Pressure gauge, Dual

pressure valve, Shuttle valve, Double pilot 5/2 valve, 5/2 way valve with selector switch,

3/2-way valve with push button normally closed, 3/2-way roller lever valve normallyclosed2 Nos, Time delay valve normally closed, Pressure sequence valve.

Working of the circuit: In the initial position, the cylinder assumes the retracted end

position. The final control valve supplies pressure to the chamber on the piston rod sideof the cylinder. The roller lever valve is depressed and the time delay valve is actuated. A

one signal is present at the right hand input of the dual pressure valve.

Step 1-2If the push button is actuated, the shuttle valve passes on a signal to the dual pressure

valve. This causes the reversal of the final control element. The cylinder extends slowly

with supply air throttled. The pressure regulator limits the pressure to a maximum of p =

4 bar. In the forward end position, the trip cam of the cylinder actuates the roller levervalve. This causes pressure to be applied to the pressure sequence valve. The pressure

sequence valve is actuated when a pressure of p = 3 bar has been reached in the piston

chamber. Adjust the flow control so that the slow increase in pressure causes the cylinderto pause in the forward end position.

Step 2-3Once the pressure sequence valve has been switched, the final control element is

reversed. The cylinder travels to its initial start position. Re actuation of the roller levervalve causes power to be supplied to the pilot port of the time delay valve. Once the

specified time of t= 2 seconds has elapsed, the dual pressure valve is supplied with air to

the right of the time delay valve so that a renewed start is possible.

Continuous cycleIf the selector switch of the valve is reversed, the control is switched to continuous cycle.

Returning the detent to its initial position causes the control to stop at the end of the

cycle.


17/79


18/79

Aim: Controlling the stroke length of a double acting cylinder using roller lever valve.

Problem description: After the liquid paint colors have been poured together into abucket, they are mixed in by the vibrating machine.

When a push button has been pressed, the extended cylinder retracts completely andexecutes a to and fro movement in the rear stroke range. The oscillating is limited to theretracted end position by a roller lever valve as well as a second roller lever valve in the

central position. The frequency of oscillating is adjustable within its limits by setting a

pressure regulator controlling the amount of air supply. Set an operating pressure of p = 4bar.

After a specified interval, the oscillator is switched off. The double acting cylinder

extends completely and actuates the third roller lever valve. Set a vibration time of t = 5seconds.

Apparatus:Double acting cylinder, Double pilot 5/2 way valve2 Nos., Shuttle valve,3/2-way valve with push button normally closed, 3/2-way roller lever valve normally

closed3 Nos, Time delay valve normally closed.

Working of the circuit: In the initial position, the cylinder assumes the forward endposition and actuates the roller lever valve. The final control element assumes the right

hand switching status. The memory valve is also in the right hand switching position.

Step 1-2Actuating the push button valve reverses the memory valve. Air is present at the pilot

port of the time delay valve. The final control element is reversed via the actuated roller

lever valve and the shuttle valve; the cylinder retracts. Traveling over the roller lever

valve does not yet have any effect. The trip cam actuates the roller lever valve in theretracted end position.

Step 2-3

With the roller lever valve actuated, the final control element reverses. The cylinderpartially extends and actuates the central roller lever valve.

Step 3-4The cylinder is reversed again by actuation of the central roller lever valve. The reversing

procedure for the valves, and lasts only a few milliseconds so that the trip cam does nottravel over the roller lever valve.

Step 4-5

See step 2-3

Oscillating movementThe cylinder oscillates backwards and forwards between the roller lever valves until the

specified time of t = 5 seconds has expired.

Steps n-2 to nAfter the time delay valve has been switched, the memory valve is reversed. Roller lever

valves are no longer supplied with compressed air. The cylinder travels to the initial

position (forward end position).


19/79


20/79

Aim: Use of pneumatic counter

Problem description: Washers for injection pumps are to be cleaned in a cleaning bath.A double acting cylinder is used to dip a container with washers in and out of the

cleaning bath. A push button is used to start the cleaning cycle. After reaching the

forward end position, cylinder should oscillate between roller lever valves S2 and S3 for10 times and on completion should stop in retracted position, S1. Next cycle should bepossible only after 20 seconds.

Apparatus: Double acting cylinder, Double pilot 5/2 way valve2 Nos., Shuttle valve,3/2-way valve with push button normally closed, 3/2-way roller lever valve normally

closed3 Nos., Time delay valve normally closed, pneumatic counter.

Working of the circuit:In the initial position, the cylinder assumes the retracted positionposition and actuates the roller lever valve S1. The final control element assumes the left

hand switching status.

Step 1-2Compressed air will be available in the inlet side of the push button valve after a delay

time set in the time delay valve. Actuating the push button valve reverses the memory

valve and the cylinder will extend. Traveling over the roller lever valve S2 will givesignal to the counter to decrement. At the end of the stroke roller lever valve S3 gets

pressed.

Step 2-3With the roller lever valve S3 actuated, the final control element reverses. The cylinder

retracts and actuates the central roller lever valve S2.

Step 3-4

The cylinder is reversed again by actuation of the central roller lever valve. The reversingprocedure for the valves, and lasts only a few milliseconds so that the trip cam does not

travel over the roller lever valve.

Step 4-5See step 2-3

Oscillating movementThe cylinder oscillates forwards and backwards between the roller lever valves until the

counter gets decremented to zero.

Steps n-2 to nWhen the counter gets decremented to zero due to the actuation of S2, the counter will

release an output signal and reverse position of the memory valve(with port no. 4blocked). Roller lever valve S2 is no longer supplied with compressed air. After actuation

of S3, the cylinder will retract and pressing of S2 will not have any effect. The air supply

from the output of time delay valve will reset the counter and counter output again gets

blocked. The cylinder will retract to the initial position and press S1 and will be ready forthe next cycle after the time delay.


21/79


22/79

Aim: Simultaneous actuation of multiple cylinders.

Problem description: Quarry stones are fed from a crushing roller to two vibratingsieves by means of an overhead conveyor belt. The fine upper sieves oscillate in

opposing push pull motion to the coarser lower screen. The sieve oscillating frequency of

the two double acting cylinders is set to f = 1 Hz via the quantity of air supplied in loaddependent relation. Reversal takes place in the retracted end position via two roller levervalves. A third single acting cylinder unclogs the sieves via two cables. The stone sorter

is switched on and off by a valve with selector switch.

Apparatus:Double acting cylinders 2 Nos., Single acting cylinder, Double pilot 5/2

way valve3 Nos., 3/2-way roller lever valve normally closed 2 Nos, 5/2 way valve

with selector switch

Working of the circuit: In the initial position, double acting cylinder A(upper sieve)

and single acting cylinder C (unclogger) assume the retracted end position; the double

acting cylinder B(lower sieve) rests in the forward end position. Roller lever valve 1is actuated.

Step 1-2

After operation of the valve with selector switch final control elements (double pilot 5/2way valves) are reversed. Cylinders A and C move forward. Cylinder B retracts and

actuates the roller lever valve.

Step 2-3Through the actuation of roller lever valve 2, all final control elements again reverse.

Cylinder B moves forward. Cylinder C retracts. Cylinder A likewise retracts and

again actuates the roller lever valve 1.

Continuous cycle

As long as the 5/2 way valve with selector switch remains in the switched condition, themotion sequence will be repeated. If the valve is brought to the initial start position, the

system remains in its initial position at the end of a cycle.


23/79


24/79

Aim: Simultaneous actuation of multiple cylinders.

Problem description: Pieces of stainless steel sheet of 0.6 mm thickness are placed byhand into the input station. After a valve has been operated by push button, the ejector

cylinder retracts with exhaust air restricted while, at the same time, clamping cylinder

also advances with its exhaust air restricted; the sieve blank is pushed along and clamped.The time for retraction of ejector cylinder and extension of clamping cylinder is to beadjustable.

During an adjustable clamping time of t= 5 seconds, a laser cutting head produces a finemesh sieve. After this operation, the clamping cylinder is retracted without restriction,

following which the ejector cylinder pushes out the finished sieve, which is free of burred

edges by a forward thrusting action.

Apparatus: Double acting cylinders2 Nos., Double pilot 5/2 way valve3 Nos., 3/2-

way roller lever valve normally closed3 Nos, 3/2 way valve with push button normally

closed, One way flow control valve 2 Nos., Quick exhaust valve, Time delay valvenormally closed.

Working of the circuit: In the initial position, the reversing valve supplies air to the line

S2. The clamping cylinder is retracted and actuates the roller lever valve. Ejector cylinderis advanced and actuates the roller lever valve.

Step 1-2If push button is operated, reversing valve switches and supplies air to line S1, line S2 is

exhausted. Both power valves are reversed. The ejector cylinder is retracted with its

exhaust air restricted; at the same time clamping cylinder goes forward, likewise with

exhaust air restricted and actuates roller lever valve. Clamping time t1= 0.5 seconds is set

by means of one way flow control valves. Actuation of roller lever valve supplies

pressure to the pilot port of time delay valve. During the set clamping time of t2 = 5

seconds, the air reservoir of the time delay valve is filled.

Step 2-3Switching through time delay valve actuates reversing valve. Line S2 is pressurized, line

S1 exhausted. After reversal of power valve, clamping cylinder is retracted withoutrestriction and, in its retracted end position, actuates roller lever valve.

Step 3-4After the actuation of roller lever valve, power valve is reversed. Ejector cylinder

advances rapidly. The fast forward motion is achieved through quick exhaust valve and

the shortest possible length of tubing between the cylinder and quick exhaust valve.


25/79


26/79

Aim: Direct and indirect actuation of a single acting cylinder.

Problem description: By using a turning device parts are to be further transported on aconveyor track facing the right direction.

By pressing the push button switch parts are turned by the piston rod of a cylinder andproceed, correctly positioned. When the push button is released the piston rod is returnedto its start position.

Apparatus: Single acting cylinder, 3/2 way single solenoid valve normally closed,Electrical signal input plate, Relay 3-off.


Direct actuation: By pressing the push button switch S1, the electric circuit for thesolenoid coil Y1 is closed and the 3/2 way solenoid valve is actuated. The piston rod of

the single acting cylinder advances to the forward end position.

After releasing the pushbutton switch S1, the electric circuit for the solenoid coil Y1 is

opened and the 3/2 way solenoid valve is switched back to its initial position. The piston

rod returns to its rear end position.

Indirect actuation: By pressing the push button switch S1 the electric circuit for the

relay K1 is closed and the contact K1 is made. The electric circuit for solenoid coil Y1 is

closed and the 3/2 way solenoid valve is actuated. The piston rod of the single actingcylinder advances to the forward end position.

After releasing the pushbutton switch S1 the electric circuit for the relay K1 is opened

and the contact K1 is brought to its normal position. The electric circuit for the solenoidcoil Y1 is opened and the 3/2 way solenoid valve is switched back to its initial position.

The piston rod returns to the retracted end position.


27/79


28/79

Aim: Actuation of double acting cylinder using single solenoid 5/2 way valve.

Problem description: Using a lid lifting device snap on lids is to be pressed onto plasticbuckets.

By pressing a push button switch the domed press is advanced and the snap-on lid ispressed on. When the push button switch is released, the domed press is returned to itsstart position.

Apparatus: Single acting cylinder, Double acting cylinder, 5/2 way single solenoid valvenormally closed, Electrical signal input plate, Relay 3-off.

Working of the circuit: By pressing the pushbutton switch S1 the electric circuit for the

relay K1 is closed and the contact K1 is made. The electric circuit for the solenoid coilY1 is closed and the 5/2 way solenoid valve is reversed. The piston rod of the double

acting cylinder advances to the forward end position.

After releasing the push button switch S1 the electric circuit for the relay K1 is opened

and the contact K1 is returned to the normal position. The electric circuit for solenoid coil

Y1 is opened and the 5/2 way solenoid valve is switched back to its initial position. The

piston rod returns to the retracted end position.

The circuit is rigged up for the double acting cylinder also.


29/79


30/79


31/79


32/79

Aim: Use of AND logic, indirect actuation.

Problem description: Using a cutting device sheets of paper are to be cut to size.

By pressing two push button switches the cutting blade is advanced and the sheet of

paper is cut. After releasing one pushbutton switch the cutting blade is returned to its startposition.

Apparatus: Single acting cylinder, Double acting cylinder, 5/2 way single solenoid valve

normally closed, Electrical signal input plate, Relay 3-off.

Working of the circuit: By pressing the pushbutton S1 and S2 the electric circuit for the

relay K1 is closed and the contact K1 is made. The electric circuit for the solenoid coil

Y1 is closed and the solenoid valve is reversed. The piston rod of the single actingcylinder advances to the forward end position.

After releasing the push button switch S1 or S2 the electric circuit for the relay K1 isopened and the contact K1 is brought into the normal position. The electric circuit for the

solenoid coil Y1 is opened and the 5/2 way solenoid valve is switched back to its initial

position. The piston rod of the single acting cylinder returns to the retracted end position.



33/79


34/79

Aim: Use of OR logic, indirect actuation.

Problem description: Using a tipping device liquid is to be poured from a vat.

By pressing a pushbutton switch the vat is tilted and the liquid is emptied. After releasing

then pushbutton switch the vat is returned to the upright position.

Apparatus: Single acting cylinder, Double acting cylinder, 5/2 way single solenoid valve

normally closed, Electrical signal input plate, Relay 3-off.

Working of the circuit: By pressing the pushbutton switch S1 or S2 the electric circuit

for the solenoid coil Y1 is closed and the 5/2 way solenoid valve is reversed. The piston

rod of the single acting cylinder returns to the retracted end position.

After releasing the pushbutton switch S1 and S2 the electric circuit for the solenoid coil

Y1 is opened and the 5/2 way solenoid valve is switched back to its initial position by

means of the reset spring. The piston rod of the single acting cylinder advances to theforward end position.



35/79


36/79

Aim: Control of a double acting cylinder using 5/2 way double solenoid valve.

Problem Description: Bulk material is to be emptied from a hopper. By pressing a pushbutton switch the hopper is opened and the bulk material is emptied out. By pressing

another push button switch the hopper is closed again,

Apparatus: Double acting cylinder, 5/2 way double solenoid valve normally closed,Electrical signal input plate, Relay 3-off.

Working of the circuit: By pressing the pushbutton switch S1 the electric circuit for therelay K1 is closed and the contact K1 is made. The electric circuit for the solenoid coil

Y1 is closed and the 5/2 way double solenoid valve is reversed. The piston rod of the

double acting cylinder advances to the forward end position. After releasing push button

switch S1 the electric circuit for the relay K1 is opened and the contact K1 is brought intothe normal position thereby opening the electric circuit for the solenoid coil Y1.

By pressing the pushbutton switch S2 the electric circuit for the relay K2 is closed andthe contact K2 is made. The electric circuit for the solenoid coil Y2 is closed and the 5/2

way double solenoid valve is switched back to its initial position. The piston rod of the

double acting cylinder returns to the retracted end position. After releasing the push

button switch S2 the electric circuit for the relay K2 is opened and the contact K2 isbrought into the normal position thereby opening the electric circuit for the solenoid coil

Y2.


37/79


38/79

Aim: Indirect actuation with reversal by means of an electrical limit switch.

Problem Description: Parts are to be pushed away from a multi track gravity feedmagazine into a clamping device.

By pressing a push button switch the parts are pushed out of the multi track gravity feedmagazine by a slide. After the slide has reached the forward end position it is returned toits start position.

Apparatus: Double acting cylinder, 5/2 way double solenoid valve, Electrical signalinput plate, Relay 3-off, Limit switch electrical actuated from the left.

Working of the circuit: By pressing the pushbutton switch S1 the electric circuit for the

relay K1 is closed and the contact K1 is made. The electric circuit for the solenoid coilY1 is closed and the 5/2 way double solenoid valve is reversed. When the pushbutton

switch S1 is released the electric circuit for the relay K1 is opened and the contact K1 is

brought to the normal position. The electric circuit for the solenoid coil Y1 is opened.The piston rod of the double acting cylinder advances to the forward end position and

actuates limit switch S2. The electric circuit for the relay K2 is closed and the 5/2 way

double solenoid valve is switched back to its initial position. The piston rod of the double

acting cylinder returns to its rear end position. The electric circuit for the relay K2 isopened and the contact K2 is brought into the normal position. The electric circuit for the

solenoid coil Y2 is opened.


39/79


40/79

Aim: Double acting cylinder, direct actuation with oscillating motion of the piston rod.

Problem Description: Using a conveyor belt, parts are to be transported in linear timedsequence to work stations which are arranged in line after one another.

When the latching push button switch is pressed the main wheel is indexed by theoscillating piston rod of a cylinder via a pawl. When the pushbutton switch is pressedagain the drive is switched off.

Apparatus: Double acting cylinder, 5/2 way double solenoid valve, Electrical signalinput plate, Limit switch electrical actuated from the left, Limit switch electrical actuated

from the right.

Working of the circuit: When latching pushbutton switch S3 is pressed the electriccircuit for the solenoid coil Y1 is closed and the 5/2 way double solenoid valve is

reversed. The piston rod of the double acting cylinder advances to the forward end

position and switches limit switch S2. After leaving the rear end position, the electriccircuit for the solenoid coil Y1 is opened via limit switch S1.

The electric circuit for the solenoid coil Y2 is closed via limit switch S2 and the 5/2 way

double solenoid valve is switched back to its initial position. The piston rod of the doubleacting cylinder returns to its retracted end position and switches limit switch S1. After

leaving the forward end position, the electric circuit for the solenoid coil Y1 is closed by

means of limit switch S1 via the actuated latching pushbutton switch S3. The piston rodof the double acting cylinder advances again to the forward end position.


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Aim: Electric latching circuit with dominating switch-off signal for actuation of single

acting cylinder and double acting cylinder.

Problem : Using a sliding table a plank of wood is to be pushed under a belt sanding

machine.

By pressing a push button switch the sliding table with the plank of wood positioned on itis pushed under the belt sanding machine. By pressing another push button switch the

sliding table is returned to its start position.

Apparatus: Single acting cylinder, Double acting cylinder, 3/2 way single solenoid

valve, 5/2 way double solenoid valve, Electrical signal input plate, Relay 3-off.

Working of the circuit: By pressing the pushbutton switch S1(ON) the electric circuitfor the relay K1 is closed via the un actuated pushbutton switch S2(OFF) and the bank of

contacts is made. The latching circuit with contact K1 keeps the electric circuit closed

for the relay K1 after the release of the pushbutton switch S1(ON). The electric circuit forthe solenoid coil Y1 is closed with contact K1 and the 3/2(5/2) way solenoid valve is

reversed. The piston rod of the single acting(double acting) cylinder advances to the

forward end position.

By pressing pushbutton switch S2 (OFF) the electric circuit for the relay K1 is opened

and the bank of contacts is brought to the normal position. The electric circuit for the

solenoid coil Y1 is opened and the 3/2 (5/2) way solenoid valve is reversed. The pistonrod of the single acting (double acting) cylinder returns to the retracted end position.


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Aim: Electric latching circuit with dominating switch-on signal for actuation of single

acting cylinder and double acting cylinder.

Problem :Parts are to be clamped using a clamping device.

By pressing a pushbutton switch the moveable claming jaw is pushed forward and thepart is clamped. By pressing another pushbutton switch the clamping jaw is returned toits start position.

Apparatus: Single acting cylinder, Double acting cylinder, 3/2 way single solenoidvalve, 5/2 way double solenoid valve, Electrical signal input plate, Relay 3-off.

Working of the circuit: By pressing the pushbutton switch S1 (ON) the electric circuit

for the relay K1 is closed and the bank of contacts is made. The latching circuit withcontact K1 via the unactuated pushbutton switch S2(OFF) keeps the electric circuit

closed for the relay K1 after the release of the pushbutton switch S1(ON). The electric

circuit for the solenoid coil Y1 is closed via the contact K1 and the 3/2 (5/2) waysolenoid valve is reversed. The piston rod of the single acting (double acting) cylinder

advances to the forward end position.

By pressing the pushbutton switch S2(OFF) the electric circuit for the relay K1 is openedand the bank of contacts is brought into the normal position. The electric circuit for the

solenoid coil Y1 is opened and the 3/2(5/2) way solenoid valve is switched back to its

initial position. The piston rod of the single acting(double acting) cylinder returns to theretracted end position.


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Aim: Oscillating motion of the piston rod of a double acting cylinder with monitoring of

the end position by means of magnetic proximity sensors.

Problem : Using a diverting device parts are to be removed from one conveyor track

onto another in linear sequence.

By pressing a pushbutton switch the oscillating piston rod of a cylinder pushes theturntable via a pawl in stepped sequence. The parts are diverted and transported onwards

in the opposite direction. By pressing another pushbutton switch the drive unit is

switched off.

Apparatus: Double acting cylinder, 5/2 way double solenoid valve, Electrical signal

input plate, Relay 3-off, Magnetic proximity switches with cylinder mounting.

Working of the circuit:By pressing the pushbutton switch S1(ON) the electric circuit is

closed for relay K1 via the unactuated pushbutton switch S2(OFF) and the bank of

contacts is made. After releasing pushbutton switch S1(ON) the electric circuit for therelay K1 is kept closed via the latching circuit with contact K1. The electric circuit for the

relay K2 is closed with contact K1 and the contact K2 is actuated. The electric circuit for

the solenoid coil Y1 is closed and the 5/2 way double solenoid valve is reversed. The

piston rod of the double acting cylinder advances to the forward end position positionactuating sensor B2. After leaving the rear end position, the electric circuit for the relay

K2 is opened via sensor B1 and the contact K2 is brought to the normal position.

The electric circuit for the relay K3 is closed via sensor B2 and the contact K3 is made.

The electric circuit for the solenoid coil Y2 is closed and the 5/2 way double solenoid

valve is switched back to its initial position. The piston rod returns to the rear end

position and actuates sensor B1. After leaving the forward end position the electric circuitfor relay K3 is opened via sensor B2 and the contact K3 is brought to the normal position.

The electric circuit for the relay K2 is closed via sensor B1 and the contact K2 is made.The electric circuit for the solenoid coil Y1 is closed and the 5/2 way double solenoid

valve is reversed. The piston rod of the double acting cylinder advances again to the

forward end position.

By pressing the pushbutton switch S2(OFF), the electric circuit for the relay K1 is opened

and the bank of contacts is brought to the normal position.


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Aim: Coordinated motion control of multiple cylinders with auxiliary conditions.

Problem : Using a transfer station blocks are to be transferred from a magazine to aprocessing station.

The blocks are pushed out of the magazine by cylinder A and transferred to theprocessing station by cylinder B. The piston rod of cylinder B may only return when thepiston rod of cylinder A has reached the retracted end position. The magazine is

monitored by means of a limit switch. If there are no more blocks in the magazine, it is

not possible to start the cycle. This is indicated by means of an audible signal. Thecontrol is to be operated in a single cycle.

Apparatus: Double acting cylinder 2 Nos., 5/2 way double solenoid valve 2 Nos.,

Electrical signal input plate, Electrical indicator and distributor plate, Relay 3-off,Proximity switch with cylinder mounting.

Working of the circuit: In the circuit, the limit switch S3 is replaced by the latchingpushbutton switch on the electrical signal input plate.

Empty magazine: When the latching pushbutton switch S3 is un actuated the electric

circuit for the audible indicator H1 is closed via contact S3. The electric current supplyfor the main circuit is switched off via contact S3.

Full magazine:When the latching pushbutton switch S3 is actuated the electric circuitfor the audible indicator H1 is opened via contact S3. The electric current supply for the

main circuit is switched off via contact S3.

By pressing the pushbutton switch S4 the electric circuit for the relay K1 is closed andthe bank of contacts made. When the pushbutton switch S4 is released, the electric circuit

for the relay K1 remains closed via the latching circuit with K1. The electric circuit for

the solenoid coil Y1 is closed with contact K1 and the 5/2 way solenoid valve is reversed.The piston rod of cylinder A advances to the forward end position and actuates sensor

B2.

The electric circuit for the relay K2 is closed and the contact K2 is made. The electriccircuit for the solenoid coil Y2 is closed and the 5/2 way double solenoid valve is

reversed. The piston rod of cylinder B advances to the forward end position and actuates

limit switch S2. After leaving the retracted end position the electric circuit for the relayK1 is opened via limit switch S1 and the bank of contacts is brought into the normal

position. The electric circuit for the solenoid coil Y1 is opened and the 5/2 way solenoid

valve is switched back to its initial position. The piston rod of cylinder A returns to the

retracted end position and actuates sensor B1.

After leaving the forward end position the electric circuit for the relay K2 is opened via

sensor B2, and the contact K2 is brought into the normal position. The electric circuit forthe solenoid coil Y2 is opened. The electric circuit for the relay K3 is closed and the


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contact K3 is made. The electric circuit for the solenoid coil Y3 is closed and the 5/2 way

double solenoid valve is switched back to its initial position. The piston rod of cylinder B

returns to the retracted end position. The electric circuit for the relay K3 is opened vialimit switch S2 and the contact K3 is brought into the normal position. The electric circuit

for the solenoid coil Y3 is opened.


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Aim: Use of proximity sensors.

Problem: A station is to be used to check whether the lids of cans are present. If a canwithout a lid is encountered, this must be pushed one side by a pneumatic cylinder. The

lids and cans are interrogated by means of sensors.

Apparatus: Single acting cylinder, 3/2 way single solenoid valve, Electrical signal inputplate, Relay 3-off, Inductive proximity switch, Capacitive proximity switch.

Working of the circuit: In the circuit, when a metallic object (presence of metallic can)is placed in front of the inductive proximity sensor B, the electric circuit for relay K2 is

closed and the contact K2 is closed. When a metallic/non metallic object (presence of

metallic/non metallic cap) is placed in front of the capacitive proximity sensor A, the

electric circuit for relay K1 is closed and the contact K1 is opened.

When a can without a lid is presented in front of the sensors, the solenoid Y1 gets

energized due to the current flowing through the normally closed contact K1 andnormally open contact K2 getting closed due to the presence of can. The solenoid coil

Y1 gets energized and single acting cylinder extends forward.


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Aim: Use of proximity sensors.

Problem: A pneumatic cylinder is used to stamp a notch in the work piece. Thestamping operation must be initiated when two of three signal generators are activated.

The signal components a, b and c are fitted to provide sensing functions. When the work

piece is removed from the device, the cylinder returns to its rearmost end position.

Solve the problem by using single acting cylinder and double acting cylinder.

Apparatus: Single acting cylinder, Double acting cylinder, 3/2 way single solenoidvalve, 5/2 way double solenoid valve, Electrical signal input plate, Relay 3-off, Inductive

proximity sensor, Capacitive proximity sensor, Optical proximity sensor.


Single acting cylinder: In the circuit, when a metallic object (presence of work piece)

is placed in front of any two of the sensors, the corresponding relays get energized. The

relay contacts get closed and solenoid coil Y1 gets energized and the single actingcylinder extends. When the object is removed from the front of sensors, the solenoid Y1

gets de energized due to the relay contacts getting opened. The piston of the cylinder

retracts to its initial position

Double acting cylinder:In the circuit, when a metallic object (presence of work piece)

is placed in front of any two of the sensors, the corresponding relays get energized. The

relay contacts get closed and solenoid coil Y1 gets energized and the double actingcylinder extends. When the object is removed from the front of sensors, the solenoid Y1

gets de energized due to the relay contacts getting opened. The piston of the cylinder

retracts to its initial position

When the object is removed from the front of sensors, the current will flow through the

normally closed contacts of the relays and the solenoid Y2 gets de energized. The piston

of the cylinder retracts to its initial position


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Aim: Use of pressure to electric converter.

Problem: Articles are to be stamped using a stamping device. By pressing two pushbuttons simultaneously the movable stamping die is pushed down and the article is

stamped. After desired pressure is reached the die returns to its initial position even

though the push buttons are still pressed.

Next cycle should be possible only after the push buttons are released.

Apparatus:Double acting cylinder, 5/2 way double solenoid valve, Pressure gauge, Oneway flow control valve, Electrical signal input plate, Relay 3 off2 Nos., Pressure to

electric converter, Timer relay, Limit switch right actuated.

Working of the circuit: When both the push buttons are pressed simultaneously, therelay coils K1 and K2 get energized and they in turn energise coil K3. Solenoid coil Y1

gets energized and piston extends to the forward position. The limit switch S1 gets

pressed and energise the pressure to electric (P/E) converter. Once the preset pressure isreached, the P/E converter gives output and the relay coil K5 gets energized. The relay

contact K5 closes and energise solenoid coil Y2. The piston retracts to rear end position.

The next cycle is possible only after the push buttons are released. This is ensured by theuse of ON delay timer K4. When both push buttons are pressed simultaneously, the

normally closed contact of the ON delay timer K4 gets opened after the delay time. Thus

the solenoid coil Y1 gets de energized.


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Aim: Use of ON delay timer.

Problem: A double acting cylinder is used for embossing the slide rules.The cylinder extends only when both the push buttons are pressed simultaneously within

three seconds to ensure complete safety of the operator. (i.e. both hands must be out of

danger area when startingThe cylinder should retract immediately if any of the push button is released.


input plate, Relay 3 off, Timer relay

Working of the circuit: When both the push buttons are pressed simultaneously, the

relay coils K1 and K2 energize the relay K3. The relay contact K3 closes and solenoid

coil Y1 gets energized. The piston of the double acting cylinder extends to the forwardposition.

If both the push buttons are not pressed simultaneously within the time preset in the ONdelay timer, the normally closed contact of ON delay timer K4 opens and the solenoid

coil Y1 will not get energized.

If any one of the push button is released, the solenoid Y2 gets energized throughnormally closed contact of relay coil K3 and piston of the cylinder will retract.


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Aim: Use of ON delay timer.

Problem: A push button is to control the forward stroke. After the piston rod has reachedthe forward end position, the components are to be pressed together for 20 seconds. Then

the piston rod is to return automatically to initial position.

The return stroke must occur even if the start push button is still depressed.

A new start signal may only become effective after the initial position has been reached

and after the push button has been released.


input plate, Relay 3 off, Timer relay, Limit switch right actuated, Limit switch left

actuated,

Working of the circuit: When the push button is pressed, the relay coil K1 gets

energized and the relay contact K1 closes. The solenoid coil Y1 gets energized and thepiston rod of the cylinder starts extending. At the end of the stroke, the limit switch S2

gets pressed and ON delay timer K2 gets energized after the preset delay time. The timer

relay contact closes and the solenoid coil Y2 gets energized. The piston of the cylinder

starts retracting.

Before this solenoid coil Y1 gets de energized due to the normally closed contact K2

breaking the current path to Y1.Thus the return stroke will occur even if the push buttonis pressed.

The new start cycle will occur only after the initial position has been reached and after

the push button has been released. This is ensured by breaking the power supply to Y1by the normally closed contact of on delay timer K5.


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Aim: Use of electrical counter

Problem: Washers for injection pumps are to be cleaned in a cleaning bath. A doubleacting cylinder is used to dip a container with washers in and out of the cleaning bath. A

push button is used to start the cleaning cycle. After reaching the forward end position,

cylinder should oscillate between reed switch S2 and limit switch S3 for 10 times and oncompletion should stop in retracted position and actuate limit switch,S1. Next cycleshould be possible only after 20 sec.

Apparatus: Double acting cylinder, 5/2 way double solenoid valve, Electrical signalinput plate, Relay 3 off, Timer relay, Electric Counter, Limit switch left actuated, Limit

switch right actuated, Magnetic proximity sensor.

Working of the circuit: The limit switch S1 is in the actuated position and on delaytimer will get energized after the delay time. The timer contacts K1 will close and the

counter gets reset. When the push button is pressed, the solenoid coil Y1 gets energized

and cylinder will start extending. When piston moves in the region of reed switch S2, therelay coil K2 gets energized, the relay contact K2 closes. The counter relay K3 will get

input and gets decremented by one. At the end of the stroke, limit switch S3 gets pressed,

solenoid coil Y2 gets energized and the piston rod starts retracting.

When the piston rod moves over S2, the relay coil K2 gets energized and the solenoid

coil Y1 will get energized due to the relay contact K2 getting closed. Again the counter

gets decremented by one.

In the tenth forward stroke when S2 gets actuated, the counter will get decremented to

zero and counter relay coil K3 will give output. K3 contact will open and actuation of S2

during the last return stroke will not have any effect on the memory valve. The pistonretracts to the initial position and the counter gets reset due to the actuation of limit

switch S1.


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Aim: To study the characteristic of a hydraulic pump.

Apparatus: Hydraulic power pack, Relief valve, Pressure gauge, Flow measuring jar,

Hydraulic hoses.

Working of the circuit: Construct the circuit according to diagram. Loosen knob of therelief valve completely and start the pump. Measure flow rate of and note down the

pressure. Vary the pressure by rotating knob of relief valve and measure flow rate. For

different pressures, measure oil flow rate. Plot the curve of oil flow rate Q verses pressureP.

Conclusion:


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Aim: Understanding the mode of operation of 4/2 directional control valve.

Apparatus: Hydraulic power pack, Relief valve, Double acting cylinder, 4/2 direction

control valve, Hydraulic hoses, Pressure gauge.

Working of the circuit: Construct the circuit according to diagram. Set the systempressure to the desired value by using the relief valve. To extend cylinder out, bring the

lever to position a. Here port P is connected to A and B to T. To retract the cylinder,

bring the lever to position b. Here port P is connected to B and A to T. Pressure readingwill show maximum when stroke completes in each position.

Conclusion:


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Aim: Understanding the mode of operation of 4/3 directional control valve.

Apparatus: Hydraulic power pack, Relief valve, Double acting cylinder, 4/3 directioncontrol valve, Hydraulic hoses, Pressure gauge.

Working of the circuit: Construct the circuit according to diagram. Set the systempressure to the desired value by using the relief valve. To extend cylinder out, bring thelever to position a. Here port P is connected to A and B to T. To stop the cylinder

movement at any instant, bring the lever to O position. In this position all the ports are

shorted, that means pressure line P is connected to T, A and B. Hence no pressurized oilflows in any of the port. To retract the cylinder, bring the lever to position b. Here port

P is connected to B and A to T. Pressure reading will show maximum when stroke

completes in each position.

Conclusion:


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Aim: Understanding flow control in the inlet side of the cylinder (meter in flow control)

to study advantages and disadvantages.


control valve, Hydraulic hoses, One way flow control valve, Pressure gauge.

Working of the circuit: Construct the circuit according to diagram. Set the systempressure to the desired value by using the relief valve. With O position in 4/3 directional

control valve, all ports are shorted. Adjust the knob of the one way flow control valve to

the required value. Switch on the pump. Bring the lever of 4/3 directional control valveinto a position, cylinder will extend out with certain speeddepending upon setting in

flow control valve. By bringing lever into b position, cylinder will retard freely

unaffected by setting in the flow control valve.

Conclusion:


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Aim: Understanding flow control in the outlet side of the cylinder (meter out flow

control) to study advantages and disadvantages of the circuit.


control valve, Hydraulic hoses, One way flow control valve, Pressure gauge.

Working of the circuit: Construct the circuit according to diagram. Set the systempressure to the desired value by using the relief valve. With O position in 4/3 directional

control valve, all ports are shorted. Adjust the knob of the one way flow control valve to

the required value. Switch on the pump. Bring the lever of 4/3 directional control valveinto a position, cylinder will extend out with certain speed depending upon setting in

flow control valve. By bringing lever into b position, cylinder will retard freely

unaffected by setting in the flow control valve.

Conclusion:


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Aim: Understanding the mode of operation of pressure reducing valve.

Apparatus: Hydraulic power pack, Relief valve, Double acting cylinder 2 Nos., 4/3direction control valve, 4/2 direction control valve, Hydraulic hoses, pressure reducing

valve, Pressure gauge.

Working of the circuit: Construct the circuit according to diagram. Set the systempressure to the desired value by using the relief valve. Switch on the pump. Bring the

lever of 4/3 directional control valve into a position, cylinder will extend out . The

pressure gauge connected to this cylinder will display the pressure set by the pressurerelief valve. Bring the lever of 4/2 directional control valve into a position, cylinder will

extend out. Now vary the pressure setting on the pressure reducing valve. The pressure

gauge connected to the second cylinder will display lower pressure depending on the

setting in the pressure reducing valve.

Conclusion:


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MIT AIRCRAFT SYSTEM LAB

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