Internship Report FFC

AN INTERNSHIP At FAUJI FERTILIZER COMPANY

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TECHNOLOGY


Dawood University of Engineering & Technology

Internship

Report MUHAMMAD HASSAN Seat No: D_10_ES_1050

Final Year ( Electronics Engineering)


Internship Duration ( 14 February 2013 to 27 March 2013)

Submitted toSubmitted toSubmitted toSubmitted to: Technical Training Center : Technical Training Center : Technical Training Center : Technical Training Center

(TTC)(TTC)(TTC)(TTC) Mirpur MathailoMirpur MathailoMirpur MathailoMirpur Mathailo

DAWOOD UNIVERSITY OF ENGINEERING

ECHNOLOGY KARACHI


Engineering & Technology

Internship


Internship Duration ( 14 February 2013 to 27 March 2013)

: Technical Training Center : Technical Training Center : Technical Training Center : Technical Training Center

NGINEERING &


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Acknowledgement

Ultimately, I have completed my report with all the hard work which I have been doing for the last

six weeks. First and foremost, thank you Almighty Allah for

report. Without Your Willingness I would not have been able to complete any work.

I would never forget to mention the names, which played a great role in the successful completion

of this project, and helped me, whe

books for assistance and gave me ideas on different thoughts.

I would like to take this opportunity to express my deepest gratitude to

Mr.Anjum Beig who have given me their constant

patience in monitoring my progress.

I am also grateful to my coordinators

who were a great help for me by monitoring my learning and helping me understand the pro

Finally, I would like to extend my sincere gratitude to

Mr. Aftab Ahmed Mazari for his helpful nature and valuable guidance provided time and again.

Without your willingness, suggestions and insights, this project would not h

I am very much thankful to FFC which provided

with industrial practical knowledge in a 6 weeks internship program.

about all the kind panel boardmen and opera

Control Room and on the plant site, respectively.

At last, I can say that my work was just an effort but wouldn’t have been an effort discernibly

without the support of all acknowledged people.

PREFACE

The purpose of this report is to explain what I did and learned during my internship period with the Fauji

Fertilizer Company Mirpur Mathelo. The report is also a requirement for the partial fulfillment of FFC

MM internship program. The report focuses pri

environment, successes and shortcomings that the intern did encounter when handling various tasks

assigned to him by the coordinator .Because the various parts of the report reflect the intern’s

shortcomings, successes ,observations and comments, it would be imperative that the



Acknowledgement


six weeks. First and foremost, thank you Almighty Allah for giving me the strength to finish up this



of this project, and helped me, whenever I required any guidance from them, provided me with

books for assistance and gave me ideas on different thoughts.

I would like to take this opportunity to express my deepest gratitude to Mr.Arif JAMAL

have given me their constant encouragement constructive advises and their

patience in monitoring my progress.

I am also grateful to my coordinators Mr. Muhammad Fahad Sayeed & Mr. Umair Akbar Khan

who were a great help for me by monitoring my learning and helping me understand the pro

numerous interactions.

Finally, I would like to extend my sincere gratitude to

for his helpful nature and valuable guidance provided time and again.

Without your willingness, suggestions and insights, this project would not have been completed.

I am very much thankful to FFC which provided me a chance to integrate my classroom knowledge

with industrial practical knowledge in a 6 weeks internship program. I would not forget to mention

about all the kind panel boardmen and operators who had been a very useful guide in the Central

Control Room and on the plant site, respectively.


without the support of all acknowledged people.



MM internship program. The report focuses primarily on the assignments handled, working



esses ,observations and comments, it would be imperative that the




giving me the strength to finish up this



never I required any guidance from them, provided me with

Mr.Arif JAMAL &

constructive advises and their

Umair Akbar Khan

who were a great help for me by monitoring my learning and helping me understand the process in

for his helpful nature and valuable guidance provided time and again.

ave been completed.

to integrate my classroom knowledge

I would not forget to mention

tors who had been a very useful guide in the Central




marily on the assignments handled, working



esses ,observations and comments, it would be imperative that the


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recommendations are also given. Therefore the report gives a number of comments and

recommendations on the internship program. It is hoped that this report would serve as a cardinal

vehicle to the improvement of the internship program.

INTRODUCTION TO FFC

For an agricultural country like Pakistan, Urea carries a paramount importance. Keeping this in view

Fertilizer Company (FFC) was incorporated in 1978 as a private limited company with a vision to acquire

self - sufficiency in fertilizer production in the country. This was a joint venture between

(a leading charitable trust in Pakistan

is the leading urea producing compan

commenced commercial production of urea in 1982 with annual capacity of 570,000 metric tons.

plant of the FFC is located at GOTH MACHI in SADIQABAD.

After the excellent performance and the successful achievements of

second plant at the same place in the year 1993. First pla

plant is called the EXPANSION UNIT.

635,000 metric tons of urea.

In the year 2002, FFC acquired ex

Mirpur Mathelo, District Ghottki from National Fertilizer Corporation

process of the Government of Pakistan. It has annual production capacity of 574,000 metric tons

urea which has been revamped to 718,000 metr

SAFETY TRAINING

FFC produces about 60 % of market’s urea producti

only result in decrease of company production and sale but

market. This may affect the country’s agriculture growth

followed by price hiking.

FFC ensures safe work environment by providing safety training

all personnel on plant. As per the company pol

personnel on plant receive safety training prior taking

responsibilities

The training comprised of:





to the improvement of the internship program.

INTRODUCTION TO FFC

For an agricultural country like Pakistan, Urea carries a paramount importance. Keeping this in view

was incorporated in 1978 as a private limited company with a vision to acquire

sufficiency in fertilizer production in the country. This was a joint venture between

Pakistan) and Haldor Topsoe A/S of Denmark.Fauji Fertilizer Company Ltd

is the leading urea producing company in the Pakistan, with brand name “SONA UREA”

commenced commercial production of urea in 1982 with annual capacity of 570,000 metric tons.

TH MACHI in SADIQABAD.

After the excellent performance and the successful achievements of the first plant, FFC installed

second plant at the same place in the year 1993. First plant is called the BASE UNIT and

UNIT. This enhanced Production capacity with annual capacity of

In the year 2002, FFC acquired ex Pak Saudi Fertilizers Limited (PSFL) Urea Plant situated at

tki from National Fertilizer Corporation (NFC) through privatization


urea which has been revamped to 718,000 metric tons urea in 200

SAFETY TRAINING

FFC produces about 60 % of market’s urea production. Not preparing for plant safety may

only result in decrease of company production and sale but also in shortage of fertilizer in

market. This may affect the country’s agriculture growth and thus shortage of food

FFC ensures safe work environment by providing safety training to

the company policy all news

e safety training prior taking charge of their





For an agricultural country like Pakistan, Urea carries a paramount importance. Keeping this in view Fauji

was incorporated in 1978 as a private limited company with a vision to acquire

sufficiency in fertilizer production in the country. This was a joint venture between Fauji Foundation

.Fauji Fertilizer Company Ltd

“SONA UREA”.FFC

commenced commercial production of urea in 1982 with annual capacity of 570,000 metric tons. First

the first plant, FFC installed the

nt is called the BASE UNIT and the second

This enhanced Production capacity with annual capacity of

Urea Plant situated at

(NFC) through privatization


or plant safety may not

fertilizer in

and thus shortage of food for public


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� Importance of Safety at Plant

� Use of Personal Protective Equipment

� Use of Fire Extinguishers

� Ammonia Disaster

PERSONAL PROTECTIVE EQUIPMENT

Personal protective equipment (P.P.E) must not be

regarded as a substitute for safe working practices. Minimum

personal protective equipment is as follow.

• Safety Helmet

• Safety boot/shoes

• Escape respirator (Half Face Mask)

• Ear protection (designated areas)

• Safety Spectacles.

The correct use, care and regular cleaning of the above equipment is the

responsibility of each individua



afety at Plant

Use of Personal Protective Equipment

Use of Fire Extinguishers

PERSONAL PROTECTIVE EQUIPMENT

.P.E) must not be

substitute for safe working practices. Minimum

personal protective equipment is as follow.

Escape respirator (Half Face Mask)

Ear protection (designated areas)

“Your life is precious”

The correct use, care and regular cleaning of the above equipment is the

responsibility of each individual.



“Your life is precious”


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INSTUMENTATION & CONTROL ORIENTATION

TOPIC

� Introduction to instrumentation & control.

� Sample Control Loop.

� Introduction to Documentation,

� Types of instruments.

� Introduction to Intrinsic Safety.

CO-

ENGR.ENGR.ENGR.ENGR. MUHAMMAD FAHAD SAEMUHAMMAD FAHAD SAEMUHAMMAD FAHAD SAEMUHAMMAD FAHAD SAE

INSTRUMENTATION

Instrumentation is the art of measuring the value of some plant parameter

temperature to name a few and supplying a signal that is proportional to the measured

output signals are standard signal and can then be processed by other equipment to provide

alarms or automatic control. There are a number of standard

plant are the 4-20 mAmps Electronic

CONTROL TECHNOLOGY Control of the processes in the plant is an essential part of the plant operation. There must be enough

water in the boilers to act as a heat sink for the reactor but there must not be water flowing

the boilers towards the turbine. The level of the boiler must be kept within a certain range. The heat

transport pressure is another critical parameter that must be controlled. If it is too high the system will




Introduction to instrumentation & control.

ple Control Loop.

Introduction to Documentation, Drawings, P & I’s.

Types of instruments.

Introduction to Intrinsic Safety.

-ORDINATOR

MUHAMMAD FAHAD SAEMUHAMMAD FAHAD SAEMUHAMMAD FAHAD SAEMUHAMMAD FAHAD SAEEDEDEDED

Instrumentation is the art of measuring the value of some plant parameter Pressure, flow, level or

temperature to name a few and supplying a signal that is proportional to the measured parameter. The

standard signal and can then be processed by other equipment to provide

alarms or automatic control. There are a number of standard signals; however, those most common in the

Electronic signal and 3-15 psi pneumatic signal.

Control of the processes in the plant is an essential part of the plant operation. There must be enough

water in the boilers to act as a heat sink for the reactor but there must not be water flowing






EDEDEDED

, flow, level or

parameter. The

standard signal and can then be processed by other equipment to provide indication,

signals; however, those most common in the

Control of the processes in the plant is an essential part of the plant operation. There must be enough

water in the boilers to act as a heat sink for the reactor but there must not be water flowing out the top of




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burst, if it is too low the water will boil. Either condition impairs the ability of the heat transport system to

cool the fuel.

The usual objective of control theory is to calculate solutions for the proper corrective action from the

controller that result in system stability, that

it.

The first automatic feedback controller used in an industrial process was James Watt’s flyball governor,

developed in 1769 for controlling the speed of a steam engine.

CONTROL LOOP A control system consists of subsystems

� A simple control loop

A simple closed loop control requires feedback; information sent back direct from the

process or system to a controller which manipulates it keeping set point in view and

produces the corresponding output to control f inal control element.

Feedback control is a fundamental fact of modern industry and society. Driving an automobile is a

pleasant task when the auto responds rapidly to the driver’s commands. Many cars have power steering

and brakes, which utilize hydraulic amplifiers for amplification of the fo

wheel.

A simple block diagram of an automobile steering control system is shown,



ater will boil. Either condition impairs the ability of the heat transport system to


controller that result in system stability, that is, the system will hold the set point and not oscillate around


the speed of a steam engine.

of subsystems and plants(processes) assembled to control output of process.

A simple control loop



the corresponding output to control f inal control element.

is a fundamental fact of modern industry and society. Driving an automobile is a


and brakes, which utilize hydraulic amplifiers for amplification of the force to the brakes or the steering




ater will boil. Either condition impairs the ability of the heat transport system to


is, the system will hold the set point and not oscillate around


and plants(processes) assembled to control output of process.



is a fundamental fact of modern industry and society. Driving an automobile is a


rce to the brakes or the steering



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The desired course is compared with a measurement of the actual course in order to generate a measure

of the error .This measurement is obtained by visual and tactile(body movement) feedback. There is an

additional feedback from the feel of the steering wheel by

the hand (sensor)

A basic, manually controlled closed-

regulating the level of fluid in a tank is shown in Figure

.The input is a reference level of fluid that the operator is

instructed to maintain.(This reference is memorized by the

operator.) The power amplifier is the operator, and the

sensor is visual .The operator compares the actual level

with the desired level and opens or closes the valve

(actuator), adjusting the fluid flow out,

desired level.

Introduction to Documentation, Drawings,

P & I's: Documentation is done to keep the recordinstruments & Chemical being used in plant. All the departments in the industry have their own literature about their concern things and they go through the literature of all the things that they need to use, to repair or install. Here in instrument department all the instruments have their records collected in files with their vendor's name and specifications. In industry we keep the records of following:

� History cards (Switches, Transmitters, Valves, P SV's).� Calibration cards. � Warehouse Documents which includes MOR (Manual Order

Request), MRF (Material Reservation Form), MIV (Material IssueVoucher), MWR (Maintenance Work Request).

� Set point changing form � Cabinet daily monitoring form� Power supply load checking� DCS vibration probe history etc.

In industries there are some field places whethis purposed designers make drawings on big Sheets that shows all the process and instruments involve in those processes. A line diagram that helps us to understand the whole process including funeach instrument is called Process & Instrument diagrams.




obtained by visual and tactile(body movement) feedback. There is an

additional feedback from the feel of the steering wheel by

-loop system for

regulating the level of fluid in a tank is shown in Figure

.The input is a reference level of fluid that the operator is

instructed to maintain.(This reference is memorized by the

operator.) The power amplifier is the operator, and the

sensor is visual .The operator compares the actual level

and opens or closes the valve

(actuator), adjusting the fluid flow out, to maintain the

Introduction to Documentation, Drawings,

Documentation is done to keep the record of all the things,

plant. All the departments in the industry have their own literature about their concern things and they go through the literature of all the things that they need to use, to repair or install. Here in instrument department all the instruments have

ecords collected in files with their vendor's name and specifications.

In industry we keep the records of following: History cards (Switches, Transmitters, Valves, P SV's).

Warehouse Documents which includes MOR (Manual Order MRF (Material Reservation Form), MIV (Material Issue MWR (Maintenance Work Request).

Cabinet daily monitoring form Power supply load checking DCS vibration probe history etc.

In industries there are some field places where the loops of a system is long Enough to understandesigners make drawings on big Sheets that shows all the process and instruments involve

in those processes. A line diagram that helps us to understand the whole process including funcalled Process & Instrument diagrams.




obtained by visual and tactile(body movement) feedback. There is an

industry have their own literature about their concern things and they go through the literature of all the things that they need to use, to repair or install. Here in instrument department all the instruments have

re the loops of a system is long Enough to understand .For esigners make drawings on big Sheets that shows all the process and instruments involve

in those processes. A line diagram that helps us to understand the whole process including function of


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TYPES OF INSTRUMENTS

Here in FFC MM we use several types of instruments that have their specific function and use according to the requirements .The major instruments which weTransmitters, Thermocouples, E /P, Speed Probes, Vibration Probes, Pressure gauges, Controllers, Recorders, Indicators, Switches, Temperature Indicators local, Petitioners’, Pressure switches Analyzers, SOV's, Tachometers.

FIELD INSTRUMENT

TOPIC

� Level, Flow, Pressure &Temperature measuring techniques

instrument being used.

� Switches (Level, Flow,

� Float type level indicator

� Transmitters & I/P’s

� SOV’s

� Analyzers

CO-

EEEENGR.UMAIR AKBARNGR.UMAIR AKBARNGR.UMAIR AKBARNGR.UMAIR AKBAR



TYPES OF INSTRUMENTS

Here in FFC MM we use several types of instruments that have their specific function and use according to the requirements .The major instruments which we use here are: Transmitters, Thermocouples, E /P, Speed Probes, Vibration Probes, Pressure gauges, Controllers, Recorders, Indicators, Switches, Temperature Indicators local, Petitioners’, Pressure switches Analyzers,

FIELD INSTRUMENTATION

Pressure &Temperature measuring techniques

instrument being used.

Flow, Temperature & Pressure)

Float type level indicator

Transmitters & I/P’s

-ORDINATOR

NGR.UMAIR AKBARNGR.UMAIR AKBARNGR.UMAIR AKBARNGR.UMAIR AKBAR



Here in FFC MM we use several types of instruments that have their specific function and use according

Transmitters, Thermocouples, E /P, Speed Probes, Vibration Probes, Pressure gauges, Controllers, Recorders, Indicators, Switches, Temperature Indicators local, Petitioners’, Pressure switches Analyzers,

Pressure &Temperature measuring techniques &


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PRESSURE Pressure is probably one of the most commonly measured variables in the Power plant. It includes the

measurement of steam pressure; feed water pressure, condenser

many more.

In many ways, pressure is the primary

� Flow (measuring pressure drop across restriction by creating differential pressure)

� Level (measuring the pressure c

“Pressure is the force exerted by fluid or gas and it is transmtted in all directions throughout the

fluid /gas.”

Pressure acts on surface area of vessel or chamber in which it is confined.

Mathematically

Pressure is actually the measurement of force acting on area of surface. We could represent this as:

Force = Pressure / Area

Pressure scale

Pressure varies depending on altitude above sea level, weather pressure fronts and other conditions. The

measure of pressure is, therefore, relative and pressure measurements are stated as either gauge or

absolute. Gauge pressure is the unit we encounter in everyday work (e.g., tire ratings are in gauge

pressure). A gauge pressure device will indicate zero pressure wh

(i.e., gauge pressure is referenced to atmospheric pressure). Absolute pressure includes the effect of

atmospheric pressure with the gauge pressure. An absolute pressure indicator would indicate

atmospheric pressure when completely vented down to atmosphere

Absolute Pressure = Gauge Pressure + Atmospheric Pressure



Pressure is probably one of the most commonly measured variables in the Power plant. It includes the

measurement of steam pressure; feed water pressure, condenser pressure, lubricating oil pressure and

primary element in many of the process measurement, such as:

Flow (measuring pressure drop across restriction by creating differential pressure)

Level (measuring the pressure created by vertical fluid column)

Pressure is the force exerted by fluid or gas and it is transmtted in all directions throughout the

Pressure acts on surface area of vessel or chamber in which it is confined.



f pressure is, therefore, relative and pressure measurements are stated as either gauge or


pressure). A gauge pressure device will indicate zero pressure when bled down to atmospheric pressure



n completely vented down to atmosphere - it would not indicate scale zero.

Absolute Pressure = Gauge Pressure + Atmospheric Pressure



Pressure is probably one of the most commonly measured variables in the Power plant. It includes the

pressure, lubricating oil pressure and

, such as:

Flow (measuring pressure drop across restriction by creating differential pressure)

Pressure is the force exerted by fluid or gas and it is transmtted in all directions throughout the



f pressure is, therefore, relative and pressure measurements are stated as either gauge or


en bled down to atmospheric pressure



it would not indicate scale zero.


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PRESSURE MEASURING DEVICES

� BAROMETER: For measuring atmospheric pressure.

� MANOMETER: An instrument that measures pressure in terms of height of a column of liquid. It

has three types:

a) U-shaped Manometer

b) Inclined Manometer

c) Ring Shaped Manometer

BOURDON TUBES: Bourdon tubes are circular

with oval cross sections. The pressure of the medium acts on

the inside of the tube. The outward pressure on the oval cross

section forces it to become rounded. Because of the curvature

of the tube ring, the bourdon tube

the direction of the arrow.

� BELOWS: Bellows type elements are constructed of tubular

membranes that are convoluted around the

membrane is attached at one end to the source and at the other end to an indicating device or

instrument. The bellows element can provide

the arrow when input pressure is applied.

� DIAPHARAM: A diaphragm is a circular

pressure fixture around the circumference. The pressure medium is on one

indication medium is on the other. The deflection that is created by pressure in the vessel would

be in the direction of the arrow indicated.

PRESSURE TRANSMITTERSMost pressure transmitters are built around the pressure capsule concept. They are usually capable of

measuring differential pressure (that is, the Note difference between a high pressure input and a low

pressure input) and therefore, are usually called DP

cells.

Capacitance Type Pressure Transmitter

A capacitance cell measures changes in capacitance. The capacitance of

the capacitance of a capacitor is directly proportional to the area of the

metal plates and inversely proportional to the distance between them. It

also depends on a characteristic of t



PRESSURE MEASURING DEVICES

For measuring atmospheric pressure.

An instrument that measures pressure in terms of height of a column of liquid. It

Bourdon tubes are circular-shaped tubes

The pressure of the medium acts on

the inside of the tube. The outward pressure on the oval cross

section forces it to become rounded. Because of the curvature

of the tube ring, the bourdon tube then bends as indicated in

Bellows type elements are constructed of tubular

membranes that are convoluted around the circumference. The


instrument. The bellows element can provide a long range of motion (stroke) in the direction of

the arrow when input pressure is applied.

A diaphragm is a circular-shaped convoluted membrane that is attached to the

pressure fixture around the circumference. The pressure medium is on one side and the


be in the direction of the arrow indicated.

PRESSURE TRANSMITTERS Most pressure transmitters are built around the pressure capsule concept. They are usually capable of


pressure input) and therefore, are usually called DP transmitters or DP

Capacitance Type Pressure Transmitter

A capacitance cell measures changes in capacitance. The capacitance of

the capacitance of a capacitor is directly proportional to the area of the

metal plates and inversely proportional to the distance between them. It

also depends on a characteristic of the insulating material between them.



An instrument that measures pressure in terms of height of a column of liquid. It


a long range of motion (stroke) in the direction of

shaped convoluted membrane that is attached to the

side and the


Most pressure transmitters are built around the pressure capsule concept. They are usually capable of



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This characteristic, called permittivity is a measure of how well the insulating material increases the ability

of the capacitor to store charge.

Two capacitors are joined together in such a way that they have

diaphragm. High and low pressures are applied at the two sides of the diaphragm which causes it to

deflect from high to low pressure side. This deflection causes a change in the capacitance of the

capacitors. Thus difference of pressure is converted into difference of capacitance.

Potentiometric Pressure Transmitter

It also works on the similar principle but uses a variable resistor to

measure pressure instead of capacitance. Two chambers are jo

with a common diaphragm and applied with high and low pressure.

Difference of pressure causes diaphragm to move a little towards

lower pressure side. As a result needle attached with it, moves over a

potentiometer changing its resistance between elect

Thus difference of pressure causes a corresponding change in the

resistance. Figure shows a similar assembly where a spring is used to

produce a constant pressure on one side of diaphragm.

Linear Variable differential Transformer

LVDT also works on the similar principle for measuring differential

pressure. Diaphragm is connected to an extension rod.

The extension control rod is made of a metal suitable for acting as

the movable core of a transformer. Moving the extension

primary and secondary windings of a transformer causes the

inductance between the two windings to vary, there

output voltage proportional to the position of the

extension.

FLOW

“The quantity of fluid passing a given point in a specific period of time is called

BASIC FLOW MESURING METHOD

There are various methods used to measure the flow rate of steam, water, lubricants, air, etc., in a

nuclear generating station.




C=E A / D

Two capacitors are joined together in such a way that they have one plate in common which is actually a



ifference of pressure is converted into difference of capacitance.

Potentiometric Pressure Transmitter

It also works on the similar principle but uses a variable resistor to

measure pressure instead of capacitance. Two chambers are joined

with a common diaphragm and applied with high and low pressure.

Difference of pressure causes diaphragm to move a little towards

lower pressure side. As a result needle attached with it, moves over a

potentiometer changing its resistance between electrical contacts.

Thus difference of pressure causes a corresponding change in the

resistance. Figure shows a similar assembly where a spring is used to

produce a constant pressure on one side of diaphragm.

Linear Variable differential Transformer

works on the similar principle for measuring differential

pressure. Diaphragm is connected to an extension rod.

is made of a metal suitable for acting as

Moving the extension between the

primary and secondary windings of a transformer causes the

inductance between the two windings to vary, there by varying the

output voltage proportional to the position of the control rod


its flow rate.”

BASIC FLOW MESURING METHOD





one plate in common which is actually a






P a g e | 12

Rate of flow is measured by the differential pressure method. Some form of restriction is placed in the

pipeline to create a pressure drop. The pressure before the restriction is higher than after restriction or

downstream. Such a reduction in pressure will cause an increase in the fluid velocity because the same

amount of flow must take place before the restriction as after it. Velocity will vary directly with the flow and

as the flow increases a greater pressure differential will occur

differential pressure across a restriction, one can measure the rate of flow.

ORIFACE PLATE

An Oriface plate is used to make a abrupt change in the pipe area and simply

consist of circular plate usually inserted between pipe flanges.

differential which is usually measured at upstream trapping and downstream trapping.

The downstream pressure is lower than

permanent loss in pressure called the head loss. This can be as high as 50% of

upstream pressure. In application where this

used.

The high and low-pressure taps of the primary device (orifice type shown) are fed by sensing lines to a

differential pressure (D/P) cell. The output of the D/P cell acts on a pressure to milliamps transducer,

which transmits a variable 4-20 ma signal.

In actuality the differential pressure increases in proportion to the square of the flow rate.

We can write this as:

In other words the flow rate (Q) is proportional; to the square root of the differential pressure.

Volumetric Flow Rate = Q

To convert the signal from the flow transmitter

one has to obtain or extract the square root of the signal from the flow transmitter.

extractor is an electronic (or pneumatic) device that takes the square root of the signal from the fl

transmitter and outputs a corresponding linear flow signal.





tion in pressure will cause an increase in the fluid velocity because the same


as the flow increases a greater pressure differential will occur across the restriction. So by measuring the

differential pressure across a restriction, one can measure the rate of flow.

An Oriface plate is used to make a abrupt change in the pipe area and simply

inserted between pipe flanges. This produces a pressure

differential which is usually measured at upstream trapping and downstream trapping.

is lower than the upstream pressure; the orifice causes

he head loss. This can be as high as 50% of

application where this cannot be tolerated, a venture tube is

pressure taps of the primary device (orifice type shown) are fed by sensing lines to a

pressure (D/P) cell. The output of the D/P cell acts on a pressure to milliamps transducer,

20 ma signal.


∆P ∝∝∝∝ Q2


Volumetric Flow Rate = Q ∝∝∝∝ α ∆P

To convert the signal from the flow transmitter, to one that is directly proportional to the flow

one has to obtain or extract the square root of the signal from the flow transmitter.

extractor is an electronic (or pneumatic) device that takes the square root of the signal from the fl

transmitter and outputs a corresponding linear flow signal.





tion in pressure will cause an increase in the fluid velocity because the same


across the restriction. So by measuring the

This produces a pressure

pressure taps of the primary device (orifice type shown) are fed by sensing lines to a

pressure (D/P) cell. The output of the D/P cell acts on a pressure to milliamps transducer,



one that is directly proportional to the flow-rate,

one has to obtain or extract the square root of the signal from the flow transmitter. The square root

extractor is an electronic (or pneumatic) device that takes the square root of the signal from the flow


P a g e | 13

� Flange Taps : Flange taps are the most widely used pressure tapping location

for orifices

A three-valve manifold has to be used to protect the DP capsule from being over

Orifice Plate with Flange Taps and Three Valve Manifold

VENTURI TUBE The orifice plate produces a large head loss.

of its gradually curved inlet and outlet cones, almost no permanent pressure drop occurs. This design

also minimizes wear and plugging by allowing the flow to sweep suspended solids through without

obstruction.

The Venturi tube normally uses a specific reduction

where it becomes heavy and excessively

large amounts of suspended solids, it creates l

orifice plate. The differential pressure taps in the Venturi

pipe diameters. The Venturi tube has good accuracy but has a high cost.



Flange taps are the most widely used pressure tapping location

valve manifold has to be used to protect the DP capsule from being over

ranged.

with Flange Taps and Three Valve Manifold

The orifice plate produces a large head loss. If this is unacceptable a venturi tube can be used. Because



Venturi tube normally uses a specific reduction in tube size, and is not used in larger diameter pipes

and excessively long. The advantages of the Venturi tube are its ability to handle

large amounts of suspended solids, it creates less turbulence and hence less insertion loss than the

orifice plate. The differential pressure taps in the Venturi tube are located at the minimum and maximum

has good accuracy but has a high cost.



Flange taps are the most widely used pressure tapping location

valve manifold has to be used to protect the DP capsule from being over-

with Flange Taps and Three Valve Manifold

venturi tube can be used. Because



size, and is not used in larger diameter pipes

long. The advantages of the Venturi tube are its ability to handle

loss than the

tube are located at the minimum and maximum


P a g e | 14

PITOT TUBE

Pitot tubes also utilize the principles captured In Bernoulli’s equation, to measure flow. Most pitot tubes actually consist of two tubes. One, the low pressure tube measures the static pressure in the pipe. The second, the high pressure tube is inserted in the pipe in such a way that the flowing fluid is stopped in the tube. The pressure in the highthe static pressure in the system plus a pressure dependant on the force required stopping the flow.Pitot tubes are more common measuring liquid flows. They suffer from a couple of problems. The pressure differential is usually small and hard to measure. The differing flow velocities across the pipe make the accuracy dependent on the flow profile of the fluid and the position of the pitot in the pipe.

ANNUBAR

An annubar is similar to a pitot tubemeasures the difference between the The volumetric flow is calculated from that difference using the pipe inside diameter,

The biggest difference between an annubaracross a section of a pipe or duct. In this way, the annubar averages the differential pressures encountered accounting for variations in flow acrossthe tip is located at a point in the pipe cross section where the flowing velocity is close to the average velocity.

BASIC FLOW MESURING METHODVery simple systems employ external sight glasse

the fluid. Others utilize floats connected to variable potentiometers or rheostats that will change the

resistance according to the amount of motion of the float. This signal is then inputted to transmi

send a signal to an instrument calibrated to read out the height or volume.

The level of liquid inside a tank can be determined from the pressure reading if the weight density of the

liquid is constant. Differential Pressure (DP) capsules are t

the pressure at the base of a tank.



also utilize the principles captured Bernoulli’s equation, to measure flow.

Most pitot tubes actually consist of two tubes. One, the low pressure tube measures the static pressure in the pipe. The second, the high pressure tube is inserted in

e in such a way that the flowing fluid is stopped in the tube. The pressure in the high-pressure tube will be the static pressure in the system plus a pressure dependant on the force required stopping the flow. Pitot tubes are more common measuring gas flows that liquid flows. They suffer from a couple of problems. The pressure differential is usually small and hard to measure. The differing flow velocities across the pipe make the accuracy dependent on the flow profile of the fluid and

pitot tube used to measure the flow of gas or liquid in a pipe. measures the difference between the static pressure and the flowing pressure of the media in the pipe.

is calculated from that difference using Bernoulli's principle and taking into account

annubar and a pitot tube is that an annubar takes multiple samples across a section of a pipe or duct. In this way, the annubar averages the differential pressures encountered accounting for variations in flow across the section. A pitot tube will give a similar reading if the tip is located at a point in the pipe cross section where the flowing velocity is close to the average

LEVEL

BASIC FLOW MESURING METHOD Very simple systems employ external sight glasses or tubes to view the height and hence the volume of


resistance according to the amount of motion of the float. This signal is then inputted to transmi

send a signal to an instrument calibrated to read out the height or volume.


liquid is constant. Differential Pressure (DP) capsules are the most commonly used devices to measure



The pitot tube of the media in the pipe. and taking into account

and a pitot tube is that an annubar takes multiple samples across a section of a pipe or duct. In this way, the annubar averages the differential pressures

the section. A pitot tube will give a similar reading if the tip is located at a point in the pipe cross section where the flowing velocity is close to the average

s or tubes to view the height and hence the volume of


resistance according to the amount of motion of the float. This signal is then inputted to transmitters that


he most commonly used devices to measure


P a g e | 15

� Glass Level Gauge The glass level gauge or sight glass is to liquid level

measurement as manometers are to pressure

measurement: a very simple and effective technology for

direct visual indication of process level.

In its simplest form, a level gauge is nothing more than a

clear tube through which process liquid may be seen.

The following photograph shows a simple example of a

sight glass level gauge:

� Bubbler Level Measurement System

If the process liquid contains suspended solids or is

chemically corrosive or radioactive, it is desirable to

prevent it from coming into direct contact with the level transmitter. In these cases,

a bubbler level measurement system, which utilizes a purge gas, can

shown in Figure, a bubbler tube is immersed to the bottom of the v

the liquid level is to be measured. A gas (called purge gas) is allowed to pass

through the bubbler tube. Consider that the tank is empty. In this case, the gas will

escape freely at the end of the tube and therefore the gas pressure inside

bubbler tube (called back pressure) will be at atmospheric pressure.

the liquid level inside the tank increases, pressure exerted by the liquid at the base

of the tank (and at the opening of the bubbler tube) increases.

pressure of the liquid in effect acts as a seal, which restricts the escape of, purge

gas from the bubbler tube. As a result, the gas pressure in the bubbler tube will

continue to increase until it just balances the hydrostatic pressure (P = SXH) of the

liquid. At this point the backpressure in the bubbler tube is exactly the same as the

hydrostatic pressure of the liquid and it will remain constant until any change in the liquid level occurs.

Any excess supply pressure will escape as bubbles through the liquid

� Ultrasonic Level Transmitter Ultrasonic level instruments measure the distance from the transmitter

(located at some high point) to the surface of a process material located

further below. The time-of-light for a sound pulse indicates this distance,

and is interpreted by the transmitter electronics as process level. These

transmitters may output a signal corresponding either to the fullness of the

vessel (fillage) or the amount of empty space remaining at the top of a

vessel (ullage).

��

The instrument itself consists of an electronics module containing all the power, computation, and signal processing circuits; plus an ultrasonic transducer to send and receive the sound waves. This transducer is typically piezoelectric in nature, being thsound waves, radio frequency and laser are also used to measure level in a tank.



The glass level gauge or sight glass is to liquid level

measurement as manometers are to pressure

measurement: a very simple and effective technology for

direct visual indication of process level.

In its simplest form, a level gauge is nothing more than a

clear tube through which process liquid may be seen.

The following photograph shows a simple example of a

Bubbler Level Measurement System

If the process liquid contains suspended solids or is

e, it is desirable to

prevent it from coming into direct contact with the level transmitter. In these cases,

a bubbler level measurement system, which utilizes a purge gas, can be used. As

, a bubbler tube is immersed to the bottom of the vessel in which

the liquid level is to be measured. A gas (called purge gas) is allowed to pass

through the bubbler tube. Consider that the tank is empty. In this case, the gas will

escape freely at the end of the tube and therefore the gas pressure inside the

bubbler tube (called back pressure) will be at atmospheric pressure. However, as

the liquid level inside the tank increases, pressure exerted by the liquid at the base

of the tank (and at the opening of the bubbler tube) increases. The hydrostatic

sure of the liquid in effect acts as a seal, which restricts the escape of, purge

gas from the bubbler tube. As a result, the gas pressure in the bubbler tube will

continue to increase until it just balances the hydrostatic pressure (P = SXH) of the

. At this point the backpressure in the bubbler tube is exactly the same as the


Any excess supply pressure will escape as bubbles through the liquid.

Ultrasonic Level Transmitter Ultrasonic level instruments measure the distance from the transmitter

(located at some high point) to the surface of a process material located

light for a sound pulse indicates this distance,

nd is interpreted by the transmitter electronics as process level. These

transmitters may output a signal corresponding either to the fullness of the

vessel (fillage) or the amount of empty space remaining at the top of a

��

The instrument itself consists of an electronics module containing all the power, computation, and signal processing circuits; plus an ultrasonic transducer to send and receive the sound waves. This transducer is typically piezoelectric in nature, being the equivalent of a very high-frequency audio speaker. Besides sound waves, radio frequency and laser are also used to measure level in a tank.




The instrument itself consists of an electronics module containing all the power, computation, and signal processing circuits; plus an ultrasonic transducer to send and receive the sound waves. This transducer

frequency audio speaker. Besides


P a g e | 16

� Capacitive Level Measurement Capacitive level instruments measure electrical capacitance of a conductive rod ins

process vessel. As process level increases, capacitance increases between the rod and the vessel walls,

causing the instrument to output a greater signal. The basic principle behind capacitive level instruments

is the capacitance

The amount of capacitance exhibited between a metal rod inserted into the vessel and the metal walls of

that vessel will vary only with changes in

interior surface area of the vessel is fixed, as is the area of the rod once installed), only changes in ε or d

can affect the probe's capacitance.

Open Tank Level MeasurementThe simplest application is the fluid level in an open tank. Figure shows a typical open tank level

measurement installation using a pressure capsule level transmitter. If the tank is open to atmosphere,

the high-pressure side of the level transmitter will be connected to the base of the tank while the low

pressure side will be vented to atmosphere. In

this manner, the level transmitter acts as a

simple pressure transmitter. We have:

��

�� Differential pressure

∆� � ��

The level transmitter can be calibrated to output

4 mA when the tank is at 0% level and 20 mA

when the tank is at 100% level.

Closed Tank Level Measurement

Should the tank be closed and a gas or vapors exists on

top of the liquid, the gas pressure must

for. A change in the gas pressure will cause a change in

transmitter output. Moreover, the pressure exerted by the

gas phase may be so high that the hydrostatic pressure of

the liquid column becomes insignificant. Compensation

can be achieved by applying the gas pressure to both the

high and low-pressure sides of the level transmitter. This

cover gas pressure is thus used as a back pressure or

reference pressure on the low pressure side of the DP cell.

We have:

� �� !



Capacitive Level Measurement Capacitive level instruments measure electrical capacitance of a conductive rod inserted vertically into a



" �#$

%


that vessel will vary only with changes in permittivity (ε), area (A), or distance (d). Since A is constant (the

vessel is fixed, as is the area of the rod once installed), only changes in ε or d

can affect the probe's capacitance.

Open Tank Level Measurement The simplest application is the fluid level in an open tank. Figure shows a typical open tank level

ent installation using a pressure capsule level transmitter. If the tank is open to atmosphere,

pressure side of the level transmitter will be connected to the base of the tank while the low

be vented to atmosphere. In

ner, the level transmitter acts as a

simple pressure transmitter. We have:

�

� �

The level transmitter can be calibrated to output

4 mA when the tank is at 0% level and 20 mA

Closed Tank Level Measurement

Should the tank be closed and a gas or vapors exists on

top of the liquid, the gas pressure must be compensated

for. A change in the gas pressure will cause a change in

transmitter output. Moreover, the pressure exerted by the

gas phase may be so high that the hydrostatic pressure of

the liquid column becomes insignificant. Compensation

d by applying the gas pressure to both the

pressure sides of the level transmitter. This

cover gas pressure is thus used as a back pressure or

reference pressure on the low pressure side of the DP cell.

! � &

��' � ��



erted vertically into a




ermittivity (ε), area (A), or distance (d). Since A is constant (the

vessel is fixed, as is the area of the rod once installed), only changes in ε or d

The simplest application is the fluid level in an open tank. Figure shows a typical open tank level

ent installation using a pressure capsule level transmitter. If the tank is open to atmosphere,

pressure side of the level transmitter will be connected to the base of the tank while the low-


P a g e | 17

Differential Pressure

The effect of the gas pressure is cancelled and only the pressure due to the hydrostatic head of the liqui

is sensed. When the low-pressure impulse line is connected directly to the gas phase above the liquid

level, it is called a dry leg.

A full dry leg installation with three-valve manifold is shown in Figure. If the gas phase is

condensate will form in the low pressure impulse line resulting in a column of liquid, which exerts extra

pressure on the low-pressure side of the transmitter. A technique to solve this problem is to add a

knockout pot/condensing bottle below the transmit

condensate in the knockout pot will ensure that the impulse line is free of liquid.

In a wet leg system, the low-pressure impulse line is completely filled with liquid (usually the sa

as the process) and hence the name wet leg. A level transmitter, with the associated three

manifold, is used in an identical manner to the dry leg system. At the top of the low pressure impulse line

is a small catch tank. The gas phase or v

tank, with the inclined interconnecting line, maintains a constant hydrostatic pressure on the low

side of the level transmitter. This pressure, being a constant, can easily be compe

calibration.



∆� � � �� ' � ! � &

The effect of the gas pressure is cancelled and only the pressure due to the hydrostatic head of the liqui

pressure impulse line is connected directly to the gas phase above the liquid

Dry Leg System

valve manifold is shown in Figure. If the gas phase is


pressure side of the transmitter. A technique to solve this problem is to add a

knockout pot/condensing bottle below the transmitter in the low pressure side. Periodic draining of the

condensate in the knockout pot will ensure that the impulse line is free of liquid.

Wet Leg System pressure impulse line is completely filled with liquid (usually the sa

as the process) and hence the name wet leg. A level transmitter, with the associated three


is a small catch tank. The gas phase or vapors will condense in the wet leg and the catch tank. The catch

tank, with the inclined interconnecting line, maintains a constant hydrostatic pressure on the low

side of the level transmitter. This pressure, being a constant, can easily be compensated for by



The effect of the gas pressure is cancelled and only the pressure due to the hydrostatic head of the liquid

pressure impulse line is connected directly to the gas phase above the liquid

valve manifold is shown in Figure. If the gas phase is condensable,


pressure side of the transmitter. A technique to solve this problem is to add a

ter in the low pressure side. Periodic draining of the

pressure impulse line is completely filled with liquid (usually the same liquid

as the process) and hence the name wet leg. A level transmitter, with the associated three-valve


apors will condense in the wet leg and the catch tank. The catch

tank, with the inclined interconnecting line, maintains a constant hydrostatic pressure on the low-pressure

nsated for by


P a g e | 18

Measurement & control of temperature are possibly the most common operation in process control.

PRINCIPLES OF TEMPERAURE MEASUREMENT

There in general four types of temperature

temperature dependent:

• Expansion of substance with temperature, which produces change to length, volume &

pressure. In this simplest for this is the common in glass thermometer.

• Changes in electrical resistance

• Change in contact potential

• Change in radiated energy with temperature optical & radiation pyrometers.



TEMPERATURE & control of temperature are possibly the most common operation in process control.

PRINCIPLES OF TEMPERAURE MEASUREMENT

There in general four types of temperature sensor based on following physical properties, which are

Expansion of substance with temperature, which produces change to length, volume &

pressure. In this simplest for this is the common in glass thermometer.

Changes in electrical resistance with temperature, used in thermostats and RTD’s

Change in contact potential between dissimilar metals with temperature, thermocouples.

Change in radiated energy with temperature optical & radiation pyrometers.



& control of temperature are possibly the most common operation in process control.

on following physical properties, which are

Expansion of substance with temperature, which produces change to length, volume &

and RTD’s.

metals with temperature, thermocouples.

Change in radiated energy with temperature optical & radiation pyrometers.


P a g e | 19

� REISTANCE TEMPERATURE DETECTERS (RTD):

resistance is directly proportional to its change in temperature and is linear over a range of

temperatures. This constant factor called the temperature coefficient of electrical resistance.

The RTD can actually be regar

varies with temperature. The Platinum RTD’s are constructed with a resistance of 100 ohm

at 0 Celsius and are often reoffered to as PT

a)RTD using Wheatstone Bridge

To detect the small variations of resistance of the RTD, a temperature transmitter in the form of a Wheatstone bridge is generally used. The circuit compares the RTD value with three known and highly accurate resistors. In this circuit, when the current flow in the meter is zero (the voltage at point A equals the voltage at point B) the bridge is said to be in null balance. This would be the zero or set point on the RTD temperature output. As the RTD temperature increases, the voltage read by the voltmeter increases. If a voltage transducer replaces the voltmeter, a 4proportional to the temperature range being monitored, can be generated.

b) Three Wire RTD

A problem arises when the RTD is installed some distance away from the transmitter. Since the connecting wires are long, resistance of the wires changes as ambient temperature fluctuates. The variations in wire resistance would introduce an error in the transmitter. To eliminate this problem, a three-wire RTD is used. The connecting wires (w1, w2, w3) are made the same length and therefore the same resistance. The power supply is connected to one end of the RTD and the top of the Wheatstone bridge. It can be seen that the resistance of the right leg of the Wheatstone bridge ileg of the bridge is R3 + RW3 + RTD. Since RW1 = RW2, the result is that the resistances of the wires cancel and therefore the effect of the connecting wires is eliminated. Failure Modes: • An open circuit in the RTD or in the wiring between the RTD and the bridge will cause a high temperature reading. • Loss of power or a short within the RTD will cause a low temperature reading.

� THERMOCOUPLE

WORKING PRINCIPLE:



REISTANCE TEMPERATURE DETECTERS (RTD): For most metals the change in electrical



The RTD can actually be regarded as a high precision wire wound resistor whose resistance

. The Platinum RTD’s are constructed with a resistance of 100 ohm

at 0 Celsius and are often reoffered to as PT-100 sensors.

resistance of the RTD, a temperature transmitter in the form of a Wheatstone bridge is generally used. The circuit compares the RTD value with three known and highly accurate resistors. In

low in the meter is zero (the voltage at point A equals the voltage at point B) the bridge is said to be in null balance. This would be the zero or set point on the RTD

temperature increases, the voltage read increases. If a voltage transducer replaces the voltmeter, a 4-20 mAmps signal, which is

proportional to the temperature range being monitored, can be generated.

wire RTD is used.

therefore the same resistance. The power supply is connected to one end of the RTD and the top of the Wheatstone bridge. It can be seen that the resistance of the right leg of the Wheatstone bridge is R1 + R2 + RW2. The resistance of the left leg of the bridge is R3 + RW3 + RTD. Since RW1 = RW2, the result is that the resistances of the wires cancel and therefore the effect of the connecting wires is eliminated.

in the RTD or in the wiring between the RTD and the bridge will cause a high

• Loss of power or a short within the RTD will cause a low temperature reading.



ost metals the change in electrical



ded as a high precision wire wound resistor whose resistance

. The Platinum RTD’s are constructed with a resistance of 100 ohm

20 mAmps signal, which is

power supply is connected to one end of the RTD and the top of the Wheatstone bridge. It can be seen s R1 + R2 + RW2. The resistance of the left

leg of the bridge is R3 + RW3 + RTD. Since RW1 = RW2, the result is that the resistances of the wires

in the RTD or in the wiring between the RTD and the bridge will cause a high


P a g e | 20

When two dissimilar metals are twisted together at one end and if this end is heated

other end are ket at lower temperature T2, the current will flow around circuit. The current depends on the

metals and the temperatures T1 & T2.This ph

known as SEE BACK EFFECT. Device using this effect are

called THERMOCOUPLES.

The end that is in contact with the process is called the hot or

measurement junction. The one that is kept at constant

temperature is called cold or reference junctio

The relationship between total circuit voltage (emf) and the

emf at the junctions is:

Circuit emf = Measurement emf

If circuit emf and reference emf are known, measurement emf can be calculated and the relative

temperature determined. To convert the emf generated by a thermocouple to the standard 4

signal, a transmitter is needed.

Failure Modes:

• An open circuit in the thermocouple detector means that there is no path for current flow, thus it

will cause a low (off-scale) temperature reading.

• A short circuit in the thermocouple detector will also cause a low temperature reading because it

creates a leakage current path to the ground and a smaller measured voltage.

When thermocouple is exposed

difference of temperature.

Thermal Wells

The process environment where temperature mo

often not only hot, but also pressurized and po

corrosive or radioactive. To facilitate removal of the tem

sensors (RTD and TC), for examination or replacement and to prov

mechanical protection, the sensors are

wells.

Thermocouple types

� Bimetallic Thermometer

A bimetallic strip is constructed by bonding two metals with different coefficients of thermal expansion. If heat is applied to one end of the strip, the metal with the higherexpansion will expand more readily than the lower one. As a result, the whole metallic strip will bend in the direction of the metal with the lower coefficient. One main advantage of the bimetallic



When two dissimilar metals are twisted together at one end and if this end is heated to temperature

ket at lower temperature T2, the current will flow around circuit. The current depends on the

metals and the temperatures T1 & T2.This phenomenon is

Device using this effect are

The end that is in contact with the process is called the hot or

measurement junction. The one that is kept at constant

temperature is called cold or reference junction.

The relationship between total circuit voltage (emf) and the

Circuit emf = Measurement emf - Reference emf


temperature determined. To convert the emf generated by a thermocouple to the standard 4

An open circuit in the thermocouple detector means that there is no path for current flow, thus it

scale) temperature reading.

A short circuit in the thermocouple detector will also cause a low temperature reading because it

a leakage current path to the ground and a smaller measured voltage.

exposed to atmosphere it will show zero voltage because there is no

The process environment where temperature monitoring is required is

not only hot, but also pressurized and possibly chemically

radioactive. To facilitate removal of the temperature

for examination or replacement and to provide

sensors are usually mounted inside thermal

A bimetallic strip is constructed by bonding two metals with different coefficients of thermal expansion. If heat is applied to one end of the strip, the metal with the higher coefficient of expansion will expand more readily than the lower one. As a result, the whole metallic strip will bend in the direction of the metal with the lower coefficient. One main advantage of the bimetallic



to temperature T1 &

ket at lower temperature T2, the current will flow around circuit. The current depends on the


temperature determined. To convert the emf generated by a thermocouple to the standard 4-20 mA

An open circuit in the thermocouple detector means that there is no path for current flow, thus it

A short circuit in the thermocouple detector will also cause a low temperature reading because it

zero voltage because there is no


P a g e | 21

strip is that it can be used to operate ovcoil (for larger swing) and placed on an adjustable pivot. Another common configuration of the bimetallic strip is coiled in a helix to increase the swing or displacement similar to the coil aboshape, the strip is more rugged and less subject to vibration.

� Thermostat

Like the RTD, the thermistor is also a temperature sensitive resistor. Of the major categories of sensors, the thermistor exhibits by far the largest parameter change with temperature. Thermistors are generally composed of semiconductor materials. Although positive temperature coefficient units are available, most thermistors have a negative temperature coefficienttheir resistance decreases with increasing temperature. The negative TC can be as large as several percent per degree Celsius, allowing the thermistor circuit to detect minute changes in temperature which could not be observed with an RTD or thermocouple circuit. The price we pay for this increased sensitivity is loss of linearity. The thermistor is an extremely non-linear device.

� PYROMETERS Pyrometer, an instrument for measuring temperature.pyrometer and the radiation pyrometer.sufficiently hot, it will give off visible light, ranging from dull red to blueenough to glow, however, it gives off infrared radiation.

An optical pyrometer determines the temperature of a very hot object by the color of the visible light it gives off. The color of the light can be determined by comparing it with the color of an electrically heated metal wire. In one type of pyrometer, the temperature of the wire is varied by varying the strength of the current until the operator of the instrument deterobject. A dial, operated by the current that heats the wire, indicates the temperature.

A radiation pyrometer determines the temperature of an object from the radiation (infrared and, if present, visible light) given off by the object. The radiation is directed at a heatthermocouple, a device that produces an electric current when part of it is heated. The hotter the object, the more current is generated by the thermocouptemperature.



strip is that it can be used to operate over a range of temperatures when the strip is fashioned into a coil (for larger swing) and placed on an adjustable pivot. Another common configuration of the bimetallic strip is coiled in a helix to increase the swing or displacement similar to the coil aboshape, the strip is more rugged and less subject to vibration.

Like the RTD, the thermistor is also a temperature sensitive resistor. Of the major categories of sensors, the thermistor exhibits by far the largest parameter change with temperature. Thermistors are generally composed of semiconductor materials.

h positive temperature coefficient units are available, most negative temperature coefficient (TC):i.e.

their resistance decreases with increasing temperature. The negative TC can be as large as several percent per degree

ng the thermistor circuit to detect minute changes in temperature which could not be observed with an RTD or thermocouple circuit. The price we pay for this increased sensitivity is loss of linearity. The thermistor is

an instrument for measuring temperature. Two common types of pyrometers are the optical pyrometer and the radiation pyrometer. A heated object gives off electromagnetic radiation. If the object is

visible light, ranging from dull red to blue-white. Even if the object is not hot enough to glow, however, it gives off infrared radiation.

An optical pyrometer determines the temperature of a very hot object by the color of the visible light it The color of the light can be determined by comparing it with the color of an electrically heated

metal wire. In one type of pyrometer, the temperature of the wire is varied by varying the strength of the current until the operator of the instrument determines that the color of the wire matches the color of the object. A dial, operated by the current that heats the wire, indicates the temperature.

A radiation pyrometer determines the temperature of an object from the radiation (infrared and, if present, sible light) given off by the object. The radiation is directed at a heat-sensitive element such as a

thermocouple, a device that produces an electric current when part of it is heated. The hotter the object, the more current is generated by the thermocouple. The current operates a dial that indicates



er a range of temperatures when the strip is fashioned into a

coil (for larger swing) and placed on an adjustable pivot. Another common configuration of the bimetallic strip is coiled in a helix to increase the swing or displacement similar to the coil above. In this

thermocouple circuit. The price we pay for this increased sensitivity is loss of linearity. The thermistor is

Two common types of pyrometers are the optical A heated object gives off electromagnetic radiation. If the object is

white. Even if the object is not hot

An optical pyrometer determines the temperature of a very hot object by the color of the visible light it The color of the light can be determined by comparing it with the color of an electrically heated

metal wire. In one type of pyrometer, the temperature of the wire is varied by varying the strength of the mines that the color of the wire matches the color of the

A radiation pyrometer determines the temperature of an object from the radiation (infrared and, if present, sensitive element such as a

thermocouple, a device that produces an electric current when part of it is heated. The hotter the object, le. The current operates a dial that indicates


P a g e | 22

VIBRATION & SPEED MONITORING

TOPICSTOPICSTOPICSTOPICS

� Measuring Methods.

� Study of Different Monitoring Equipment.

� (Bentley Nevada-3500 & 7200)

� Study of Loop Drawings & Installations at FFC

INTRODUCTION TO VIBRATION MONITORING SYSTEMMost of us are familiar with vibration; a vibrating object moves to and fro, back and forth. A vibrating

object oscillates.

Vibration amplitude may be measured as a displacement, a velocity, or acceleration. Vibration amplitude

measurements may either be relative, or absolute.

MEASUREMENT OF VIBERTION

Unlike most process measurements, the measurement of a rotating machine’s vibration is primarily for the

benefit of the process equipment rather than the process itself. Vibration monitoring on a compressor, for




Measuring Methods.

Study of Different Monitoring Equipment.

3500 & 7200)

Study of Loop Drawings & Installations at FFC-MM plant.

CO-ORDINATOR

ENGR.UMAIR AKBARENGR.UMAIR AKBARENGR.UMAIR AKBARENGR.UMAIR AKBAR

INTRODUCTION TO VIBRATION MONITORING SYSTEMMost of us are familiar with vibration; a vibrating object moves to and fro, back and forth. A vibrating


measurements may either be relative, or absolute.

VIBERTION






MM plant.

INTRODUCTION TO VIBRATION MONITORING SYSTEM Most of us are familiar with vibration; a vibrating object moves to and fro, back and forth. A vibrating





P a g e | 23

instance may very well be useful in extendin

to the control of the process.

PARAMETERS TO MEASURE

� Radial Vibration

Shaft dynamic motion or casing vibration which is measured in a direction perpendicular to the shaft axis,

often called lateral vibration.

� Thrust Position

The average position, or change in position, of a rotor in the axial direction with respect to some fixed

reference. Typically, the reference is the thrust bearing support structure or other casing member to which

the probe is mounted. The probe may observe the thrust collar directly or some other integral, axial shaft

surface, as long as it is within about 305 mm (12 inches) of the thrust bearing.

Vibration measurement

� Non-contact Method

a) Eddy current probe/ proximity probe (displacement transducer)

� Contact method

b) Velocity probe (LVDT: Velocity

c) Acceleration probe (accelerometer:

PROXIMITY PROBE

Proximity transducer converts the mechanical vibrations to an electrical signal that is proportional to displacement of vibration. The proximity transducer is used to directly measure rotor movement in both axial and radial planes.

Vibration measurement units at the output of the proximitor are expressed in mils or micrometer peak to peak. The standard Bently Nevada Corporation proximity transducer scale factor is 200mV/mil (7.87V/mm) for the 8mm 3300 system.

This system consists of three individual parts

� Probe � Extension Cable � Proximity Driver (Oscillator

Driver)

The proximity driver is an electronic device that performs two basic functions:



instance may very well be useful in extending the operating life of the compressor, but little to the benefit

PARAMETERS TO MEASURE




he probe is mounted. The probe may observe the thrust collar directly or some other integral, axial shaft

surface, as long as it is within about 305 mm (12 inches) of the thrust bearing.

measurement technique

probe/ proximity probe (displacement transducer)

probe (LVDT: Velocity transducer)

probe (accelerometer: piezoelectric device

Proximity transducer converts the mechanical vibrations to an electrical signal that is proportional to displacement of vibration. The proximity transducer is used to directly measure rotor movement in both

nits at the output of the proximitor are expressed in mils or micrometer peak to peak. The standard Bently Nevada Corporation proximity transducer scale factor is 200mV/mil (7.87V/mm) for the 8mm 3300 system.

This system consists of three individual parts:

Oscillator Demodulator

The proximity driver is an electronic device that performs two basic functions:



g the operating life of the compressor, but little to the benefit




he probe is mounted. The probe may observe the thrust collar directly or some other integral, axial shaft

Proximity transducer converts the mechanical vibrations to an electrical signal that is proportional to displacement of vibration. The proximity transducer is used to directly measure rotor movement in both


P a g e | 24

• Generates the radio frequency (RF) signals using an oscillator circuit• Conditions the RF signal to

Once proximitor power up, it will generate a RF signal at specific frequency. This frequency is dependent on the of the probe coil and capacitance value of extension and probe cable.the probe coil, which creates a RF field around the probe tip. The RF field is proportional to the coil diameter in the probe tip and input voltage to the proximitor.

When conductive material is present in RF field, eddy current flows in the surface of thaamplitude is at maximum when distance between probe and material is minimum and vice versa. The rapid movement of the target causes the RF signal to modulate. The demodulator circuit deals with slow or fast changing amplitude in the same way

FAMILIZATION TO BENTLY NEVADA

Bentley Nevada thrust & vibration monitoring

use in large number large industrial turbine installation around the world.

The 7200 Series monitoring system was

from 1975 until the introduction of the 3300 Series System in 1989. The system has now reached “phase

5” obsolescence which means it is no longer supported by the manufacturer. However, Paramount

Electronics will be able to continue to repair these units for many years to come.

The same is true for the 1800, 2201, 5000, 7000, 9000, 11000 Series Monitor Systems



Generates the radio frequency (RF) signals using an oscillator circuit Conditions the RF signal to extract usable data using demodulator circuit

Once proximitor power up, it will generate a RF signal at specific frequency. This frequency is dependent on the of the probe coil and capacitance value of extension and probe cable. The RF signal emitted from the probe coil, which creates a RF field around the probe tip. The RF field is proportional to the coil diameter in the probe tip and input voltage to the proximitor.

When conductive material is present in RF field, eddy current flows in the surface of thaamplitude is at maximum when distance between probe and material is minimum and vice versa. The rapid movement of the target causes the RF signal to modulate. The demodulator circuit deals with slow or fast changing amplitude in the same way.

FAMILIZATION TO BENTLY NEVADA

monitoring system was originally manufacture by bently Nevada & is in

use in large number large industrial turbine installation around the world.

The 7200 Series monitoring system was BENTLY NEVADA’S full-featured "flagship" monitoring system



lectronics will be able to continue to repair these units for many years to come.

The same is true for the 1800, 2201, 5000, 7000, 9000, 11000 Series Monitor Systems



Once proximitor power up, it will generate a RF signal at specific frequency. This frequency is dependent The RF signal emitted from

the probe coil, which creates a RF field around the probe tip. The RF field is proportional to the coil

When conductive material is present in RF field, eddy current flows in the surface of that material. RF amplitude is at maximum when distance between probe and material is minimum and vice versa. The rapid movement of the target causes the RF signal to modulate. The demodulator circuit deals with slow

ently Nevada & is in

featured "flagship" monitoring system




P a g e | 25

HONEYWELL ESD SYSTEM


� Familiarization with Honeywell FSC PLC.

� Troubleshooting PLC

PROGRAMMABLE LOGIC CONTROLLER

Programmable logic controllers (PLCs) are the control hubs for a wide variety of automated

processes. Programmable logic controllers are used

from machining to automated assembly. They were designed to

circuits for machine control. PLCs have been gaining popularity on the factory floor and wi

remain predominant for some time to come. Other areas of application of PLCs are industrial automation

and control of industrial equipment. Most of this is because of the advantages they offer:

� Cost effective & Flexible

� Computational abilities

� Troubleshooting aids



HONEYWELL ESD SYSTEM

Familiarization with Honeywell FSC PLC.

Troubleshooting PLC

CO-ORDINATOR

EEEENGRNGRNGRNGR .... SYED UMAIR HUSSAINSYED UMAIR HUSSAINSYED UMAIR HUSSAINSYED UMAIR HUSSAIN

PROGRAMMABLE LOGIC CONTROLLER

Programmable logic controllers (PLCs) are the control hubs for a wide variety of automated

Programmable logic controllers are used extensively in diverse industrial applications ranging

ssembly. They were designed to replace the necessary sequential relay

PLCs have been gaining popularity on the factory floor and wi

some time to come. Other areas of application of PLCs are industrial automation




Programmable logic controllers (PLCs) are the control hubs for a wide variety of automated systems and

industrial applications ranging

replace the necessary sequential relay

PLCs have been gaining popularity on the factory floor and will probably

some time to come. Other areas of application of PLCs are industrial automation



P a g e | 26

� Reliable components

One may very correctly ask that why not to use a personal computer for these tasks in place a

specialized PLC. The answer is very simple; PLC

� Is intended for use on factory floors & in harsh environments

� Is more durable & Less expensive

� Can be placed in remote or rugged industrial locations

� Can perform at a high level for many years.

� Can withstand shock, vibration, humidity, EMI, RFI, dust, mist, and splash

� Can also be used for compiling data coming from many source

network

STANDARD PLC VS INDUSTRIAL SAFETY PLC

There are three fundamental differences between a safety

architecture, inputs, and outputs.

� ARCHITECTURE

A PLC has one microprocessor which execu

RAM for making calculations, ports for communications and I/O

contrast, a safety PLC has redundant

by a watchdog circuit and a synchronous detection circuit.

� INPUTS

Standard PLC inputs provide no internal means for testing the functionality of the input circ

contrast, Safety P LCs has an internal ‘output’ circuit associated with each input for the purpose of

‘exercising’ the input circuitry. Inputs are driven both high and low for very short cycles during runtime to

verify their functionality.

� OUTPUTS

The PLC has one output switching d

point after each of two safety switches located behind the output driver and a third test point downstream

of the output driver. E ach of the two safety switches is

is detected at either of the two safety switches due to switch or microprocessor failure, or at the test point

downstream from the output driver, the operating system of a safety

system failure. At that time, a safety

equipment shutdown.

EMERGENCY SHUTDOWN SYSTEM

Emergency shut-down system (ESD) or Safety Instrumented Systems (SIS) is defined as a system designed to respond to conditions in the plant which may be hazardous in them or, if no action was taken, could eventually give rise to a hazard. The ESD must generate the correct outputs to mitigate the hazardous consequences or prevent the hazard.




The answer is very simple; PLC

Is intended for use on factory floors & in harsh environments

le & Less expensive

Can be placed in remote or rugged industrial locations

Can perform at a high level for many years.

Can withstand shock, vibration, humidity, EMI, RFI, dust, mist, and splash

Can also be used for compiling data coming from many sources and uploading on a computer

STANDARD PLC VS INDUSTRIAL SAFETY PLC

There are three fundamental differences between a safety PLC and a standard PLC in terms

has one microprocessor which executes the program, a Flash area which stores the program,

rts for communications and I/O to detect and control the machine. In

has redundant microprocessors, Flash and RAM that are continuously monitored

by a watchdog circuit and a synchronous detection circuit.

Standard PLC inputs provide no internal means for testing the functionality of the input circ

an internal ‘output’ circuit associated with each input for the purpose of


one output switching device, whereas a safety PLC digital output logic circuit contains a test


of the output driver. E ach of the two safety switches is controlled by a unique microprocessor. If a failure


downstream from the output driver, the operating system of a safety PLC will automatically acknowledge

ailure. At that time, a safety PLC will default to a known state on its own, facilitating an orderly

EMERGENCY SHUTDOWN SYSTEM

down system (ESD) or Safety Instrumented Systems (SIS) is defined as a system ond to conditions in the plant which may be hazardous in them or, if no action was taken,

could eventually give rise to a hazard. The ESD must generate the correct outputs to mitigate the hazardous consequences or prevent the hazard.




s and uploading on a computer

in terms of

tes the program, a Flash area which stores the program,

to detect and control the machine. In

AM that are continuously monitored

Standard PLC inputs provide no internal means for testing the functionality of the input circuitry. By

an internal ‘output’ circuit associated with each input for the purpose of


output logic circuit contains a test


ique microprocessor. If a failure


automatically acknowledge

default to a known state on its own, facilitating an orderly

down system (ESD) or Safety Instrumented Systems (SIS) is defined as a system ond to conditions in the plant which may be hazardous in them or, if no action was taken,

could eventually give rise to a hazard. The ESD must generate the correct outputs to mitigate the


P a g e | 27

Safety instrumented systems are separate and independent from regularare composed of similar elements, includingFailure and/or spurious trips could result in expensive procedural and downtime consequences. Thus, the reliability on safety and availability, need to be tested periodically before the next maintenance, but not interrupt the operation. Due to the critical nature of such systems ESD system are typically composed of sensors, logic solvers and final control elements. The actuated shutdown valve is expected to remain static in one position for a long period of time and reliarises, i.e. to spring into safe mode position.

Emergency Shutdown System at FFC

The ESD system installed at FFC plant is manufactured by Honeywell which they called as

Control (FSC) system. This system satisfies

highly reliable, high-integrity safety system for safety

Total Plant Solution (TPS) system, integrated into Plant Scale, or in sta

system forms the basis for functional safety

the environment combined with optimum availability for plant operation.

HONEYWELL FAIL

BASIC ARCHITECTURE

The basic architecture of the FSC system. Two major system parts can be distinguished:

• the Central Part, and

• The Input/output interfaces.

� Central Part

The Central Part (CP) is the heart of designed for safety-critical applications which can be tailored to the needs of any application.important Central Part modules are: a) Control Processor: reads the processuser in graphical Functional Logic Diagrams (FLDs). The results of the control program are then transmitted to the output interfaces.



stems are separate and independent from regular distributed control systemsare composed of similar elements, including sensors, logic solvers, actuators and support systems.Failure and/or spurious trips could result in expensive procedural and downtime consequences. Thus, the reliability on safety and availability, need to be tested periodically before the next maintenance, but not

pt the operation. Due to the critical nature of such systems ESD system are typically composed of sensors, logic solvers and final control elements. The actuated shutdown valve is expected to remain static in one position for a long period of time and reliably operate only when an emergency situation arises, i.e. to spring into safe mode position.

Emergency Shutdown System at FFC

The ESD system installed at FFC plant is manufactured by Honeywell which they called as

em satisfies SIL3 standard. The Honeywell Fail Safe Control system is a

integrity safety system for safety-critical control applications. As part of Honeywell's

system, integrated into Plant Scale, or in stand-alone applications, the FSC

functional safety, thus providing protection of persons, plant equipment and

the environment combined with optimum availability for plant operation.

HONEYWELL FAIL-SAFE CONTROL (FSC)

ARCHITECTURE

system. Two major system parts can be distinguished:

Input/output interfaces.

Basic Architecture of FSC

The Central Part (CP) is the heart of the FSC system. It is a modular microprocessor system specifically critical applications which can be tailored to the needs of any application.

important Central Part modules are: reads the process inputs and executes the control program as created by the

user in graphical Functional Logic Diagrams (FLDs). The results of the control program are then transmitted to the output interfaces.



control systems but and support systems.

Failure and/or spurious trips could result in expensive procedural and downtime consequences. Thus, the reliability on safety and availability, need to be tested periodically before the next maintenance, but not

pt the operation. Due to the critical nature of such systems ESD system are typically composed of sensors, logic solvers and final control elements. The actuated shutdown valve is expected to remain

ably operate only when an emergency situation

The ESD system installed at FFC plant is manufactured by Honeywell which they called as Fail Safe

standard. The Honeywell Fail Safe Control system is a

critical control applications. As part of Honeywell's

alone applications, the FSC

, thus providing protection of persons, plant equipment and

system. Two major system parts can be distinguished:

the FSC system. It is a modular microprocessor system specifically critical applications which can be tailored to the needs of any application. The most

inputs and executes the control program as created by the user in graphical Functional Logic Diagrams (FLDs). The results of the control program are then


P a g e | 28

b) Watchdog: monitors the operation and the operating conditions ooperation of the processor is monitored by verifying if the processor executes all its tasks within a pre-calculated time frame, which depends on the configuration. The operating conditions monitored include the data integrity power (both under voltage and overvoltage). If the Watchdog detects a fault in the operation of the Control Processor or its operating conditions, it will deactivate the safetyinterfaces of the FSC system, independent of the Control Processor status.

c) Communication Processor:computer equipment via serial communication links (uses RS232, RS485 protocols). Dedicated modules are also available which provide communication capabilities with other systems.

� Input/output Interfaces

The FSC system provides a wide range of digital and analog indifferent characteristics to meet the demands of a wide r There are two plant control systems:1) DISTRIBUTED CONTROL SYSTEM 2) EMERGENCY SHUT DOWN SYTEM

Distributed control system works under normal process conditions & ESD system brings the plant in safe shutdown conditions in case the process parameters go beyond their control limits. TYPICAL LOOP OF ESD:

Functional Logic Diagram (FLD)



monitors the operation and the operating conditions of the Control Processor. The operation of the processor is monitored by verifying if the processor executes all its tasks within a

calculated time frame, which depends on the configuration. The operating conditions monitored include the data integrity of the processor memory and the voltage range of the supply power (both under voltage and overvoltage). If the Watchdog detects a fault in the operation of the Control Processor or its operating conditions, it will deactivate the safety

erfaces of the FSC system, independent of the Control Processor status.

Communication Processor: allows the FSC system to exchange information with other computer equipment via serial communication links (uses RS232, RS485 protocols). Dedicated

also available which provide communication capabilities with other systems.

The FSC system provides a wide range of digital and analog input and output interfaces, each different characteristics to meet the demands of a wide range of field equipment.

There are two plant control systems: 1) DISTRIBUTED CONTROL SYSTEM 2) EMERGENCY SHUT DOWN SYTEM

Distributed control system works under normal process conditions & ESD system brings the plant in safe case the process parameters go beyond their control limits.

PLC PROGRAMMING

Functional Logic Diagram (FLD)



f the Control Processor. The operation of the processor is monitored by verifying if the processor executes all its tasks within a

calculated time frame, which depends on the configuration. The operating conditions of the processor memory and the voltage range of the supply

power (both under voltage and overvoltage). If the Watchdog detects a fault in the operation of the Control Processor or its operating conditions, it will deactivate the safety-critical output

allows the FSC system to exchange information with other computer equipment via serial communication links (uses RS232, RS485 protocols). Dedicated

also available which provide communication capabilities with other systems.

put and output interfaces, each with

Distributed control system works under normal process conditions & ESD system brings the plant in safe


P a g e | 29

The FSC system's safety-critical control functions are determined by the safety functions assigned to the system for the specific application. The FSC user software supports the design of the control program by the user. The control functions are defined via graphical Functional Logic Diagrams (FLD). Functional Logic Diagram, which demonstrates the flexibility of the proFLD programming includes the facility of encapsulation or modularization using function blocks, which are comparable to subroutines in high-level programming languages. This allows function blocks to be used to create complex functions. Function blocks only need to be tested once and can then be reused without the need for testing them again.

An FLD is split into four main areas:

• the information area (bottom)

• the input area (left),

• the control function area (center)

• the output area (right) The FLD control function area, which is the central area of the FLD, contains the actual implementation of the control function. The function is realized by interconnecting predefined symbols which provariety of functions including logical, numerical and timefunctions, user-definable blocks are supported:

• Function Blocks — standard FLDs for repetitive use within the control program

• Equation Blocks — for tabular definition of complex functions, e.g. non



critical control functions are determined by the safety functions assigned to the the specific application. The FSC user software supports the design of the control program by

the user. The control functions are defined via graphical Functional Logic Diagrams (FLD). Functional Logic Diagram, which demonstrates the flexibility of the programming technique used in FSC Navigator. FLD programming includes the facility of encapsulation or modularization using function blocks, which are

level programming languages. This allows function blocks to be used ate complex functions. Function blocks only need to be tested once and can then be reused without

Functional Logic Diagram

An FLD is split into four main areas:

control function area (center)

area, which is the central area of the FLD, contains the actual implementation of the control function. The function is realized by interconnecting predefined symbols which provariety of functions including logical, numerical and time-related functions. Apart from these standard

definable blocks are supported:

standard FLDs for repetitive use within the control program

or tabular definition of complex functions, e.g. non-linear equations



critical control functions are determined by the safety functions assigned to the the specific application. The FSC user software supports the design of the control program by

the user. The control functions are defined via graphical Functional Logic Diagrams (FLD). Functional gramming technique used in FSC Navigator.

FLD programming includes the facility of encapsulation or modularization using function blocks, which are level programming languages. This allows function blocks to be used

ate complex functions. Function blocks only need to be tested once and can then be reused without

area, which is the central area of the FLD, contains the actual implementation of the control function. The function is realized by interconnecting predefined symbols which provide a

related functions. Apart from these standard

linear equations


P a g e | 30

YOKOGAWA DCS


� Familiarization with DCS

� Developing control algorithms

� Training & simulation using test function(troubleshooting)

Distributed control systemA distributed control system (DCS) refers to a control system usually of a manufacturing system, process

or any kind of dynamic system, in which the controller elements

but are distributed throughout the system with each component sub

controllers. The entire system of controllers is connected by networks for communication and monitoring.

DCS is a very broad term used in

a variety of industries, to monitor

and control distributed equipment.

A Distributed Control System is a

part of manufacturing industry.

DCS is used in industrial and civil

engineering applications to

monitor and control distributed

equipment with remote human

intervention. A DCS typically uses

custom designed processors as

controllers and uses both

proprietary interconnections and

communications protocol for

communication. Input and output

modules form component parts of the DCS.

sends information to output modules. The input modules receive information from input instruments in the

process (or field) and transmit instructions to the output instruments in the field. Computer

electrical buses connect the processor and modules through multiplexer or de



YOKOGAWA DCS

n with DCS hardware, software & architecture.

Developing control algorithms

Training & simulation using test function(troubleshooting)

CO-ORDINATOR

ENGR.SYED UMAIR HUSSAINENGR.SYED UMAIR HUSSAINENGR.SYED UMAIR HUSSAINENGR.SYED UMAIR HUSSAIN

Distributed control system A distributed control system (DCS) refers to a control system usually of a manufacturing system, process

or any kind of dynamic system, in which the controller elements are not central in location (like the brain)

but are distributed throughout the system with each component sub-system controlled by one or more


modules form component parts of the DCS. The processor receives information from input modules and


process (or field) and transmit instructions to the output instruments in the field. Computer

electrical buses connect the processor and modules through multiplexer or de-multiplexers. Buses also



software & architecture.

Training & simulation using test function(troubleshooting)

A distributed control system (DCS) refers to a control system usually of a manufacturing system, process

are not central in location (like the brain)

system controlled by one or more


The processor receives information from input modules and


process (or field) and transmit instructions to the output instruments in the field. Computer buses or

multiplexers. Buses also


P a g e | 31

connect the distributed controllers with the central controller and DCS typically contains one or more

computers for control and mostly use bot

System (DCCS) in general provides: for communication.

YOKOGAWA DCS ARCHITECTURE

Presently, FFC is using DCS system manufactured by

Yokogawa a Japanese company. General architecture of

Yokogawa CS3000 is described as follows. It consists of the

following main parts:

1. FCS cabinets

2. Human interface machines (HIM)

3. Engineering work station (EWS)

All transmitters installed all over the plant sent their information

in the form of current signal to the DCS system. All the field

wires terminate at the nest which contains the I/O cards. Four of

the nest then connects to the one node interface unit (NIU).

These nodes then connect to the central processing unit called

Field Control Unit (FCU) through RI/O buses. Vnet cables

provide interface between FCS cabinets and to the Human

Interface Unit. HMI are also connected to each other over

Ethernet and also to Engineering work station (EWS). The

following completely illustrate the whole systems and

connections between different parts of it.

FIELD CONTROL STATION (FCS)

The FCS controls the plant. By the difference of used I/O modules, there are two models of the FCS;

namely the FCS for FIO and the FCS for RIO. In addition to the above models, there is t

FCS.

FCS for RIO

This FCS uses the Remote I/O (RIO) modules, which have many installation bases and M4 screw

terminals to connect signal cables. According to the application capacity, there are the standard model

and the enhanced model.

Human Interface Station (HIS)

The HIS is mainly used for operation and monitoring

process variables, control parameters, and alarms necessary for

users to quickly grasp the operating status of the




computers for control and mostly use both propriety interconnections and protocols Distributed Control

System (DCCS) in general provides: for communication.

YOKOGAWA DCS ARCHITECTURE

Presently, FFC is using DCS system manufactured by

Yokogawa a Japanese company. General architecture of

CS3000 is described as follows. It consists of the

2. Human interface machines (HIM)

All transmitters installed all over the plant sent their information

gnal to the DCS system. All the field

wires terminate at the nest which contains the I/O cards. Four of

the nest then connects to the one node interface unit (NIU).

These nodes then connect to the central processing unit called

ough RI/O buses. Vnet cables

provide interface between FCS cabinets and to the Human

Interface Unit. HMI are also connected to each other over

Ethernet and also to Engineering work station (EWS). The

following completely illustrate the whole systems and

nnections between different parts of it.


namely the FCS for FIO and the FCS for RIO. In addition to the above models, there is t



Human Interface Station (HIS)

The HIS is mainly used for operation and monitoring – it displays

process variables, control parameters, and alarms necessary for

users to quickly grasp the operating status of the plant. It also




h propriety interconnections and protocols Distributed Control


namely the FCS for FIO and the FCS for RIO. In addition to the above models, there is the Compact type




P a g e | 32

incorporates open interfaces so that supervisory computers can access trend data messages, and

process data.

• Console Type HIS

This is a new console type human interface station, at which a general purpose PC is installed. There are

two types of console type HISs: one is enclosed

another is open display style, the configuration of which is selectable.

• Desktop Type HIS

This HIS uses a general purpose PC

CONTROL VALVES & PSV'sTOPICSTOPICSTOPICSTOPICS



o that supervisory computers can access trend data messages, and


two types of console type HISs: one is enclosed display style, the appearance of which is usual style, and

another is open display style, the configuration of which is selectable.

This HIS uses a general purpose PC

CONTROL VALVES & PSV's



o that supervisory computers can access trend data messages, and


display style, the appearance of which is usual style, and


P a g e | 33

� Types and Terminology’s

� Testing and calibration procedures.

� Control Valves positioned, actuators & accessories.

ENGR.ENGR.ENGR.ENGR.

Control valves are valves used to control conditions such asby fully or partially opening or closing in response to signals received from point" to a "process variable" whose value is provided byconditions.

The opening or closing of control valves is done by mof electrical, hydraulic or pneumaticused to control the opening or closing of the actuator based on Electric, or Pneumatic Signals. These control signals, traditionally based on 3-15psi (0.2-1.0bar), more common now are 4-20mA signals for industry.

Types of Control Valve Bodies

1. Gate Valve

A Gate Valve is mainly use for on/off control. opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar. The gate faces can form a wedge shape or they can be parallel. Gate valves are sometimes used for regulating flow, but many are not suited for that purpose, having been

designed to be fully opened or closed.

typical gate valve has no obstruction in the flow path, resulting in very low friction loss.

Gate valves are characterized as having either a rising or a nonrising stem. Rising stems provide a visual

indication of valve position. Nonrising stems are used where vertical space is limited or underground.

2. Globe Valve

Globe valves are named for their sphby an internal baffle which has an opening forming a seat onto which a movable disc can be screwed in to close (or shut) the valve. In globe valves, the disc is connected to a stem which is action. When a globe valve is manually operated, the stem is turned by a hand wheel. Although globe



Terminology’s.

Testing and calibration procedures.

Control Valves positioned, actuators & accessories.

CO-ORDINATOR

ENGR.ENGR.ENGR.ENGR. SYED UMAIR HUSSAINSYED UMAIR HUSSAINSYED UMAIR HUSSAINSYED UMAIR HUSSAIN

Control Valves

to control conditions such as flow, pressure, temperatureby fully or partially opening or closing in response to signals received from controllers that compare a "

" to a "process variable" whose value is provided by sensors that monitor changes in such

The opening or closing of control valves is done by means pneumatic systems. Positioners are

used to control the opening or closing of the actuator based on Electric, or Pneumatic Signals. These control signals,

1.0bar), more common now

is mainly use for on/off control. It opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar. The gate faces can form a wedge shape or they can

es are sometimes used for regulating flow, but many are not suited for that purpose, having been

designed to be fully opened or closed. When fully open, the


alves are characterized as having either a rising or a nonrising stem. Rising stems provide a visual


Globe valves are named for their spherical body shape. The two halves of the valve body are separated by an internal baffle which has an opening forming a seat onto which a movable disc can be screwed in to close (or shut) the valve. In globe valves, the disc is connected to a stem which is operated by screw action. When a globe valve is manually operated, the stem is turned by a hand wheel. Although globe



temperature, and liquid level controllers that compare a "set

that monitor changes in such


alves are characterized as having either a rising or a nonrising stem. Rising stems provide a visual


erical body shape. The two halves of the valve body are separated by an internal baffle which has an opening forming a seat onto which a movable disc can be screwed in to

operated by screw action. When a globe valve is manually operated, the stem is turned by a hand wheel. Although globe


P a g e | 34

valves in the past had the spherical bodies which gave them their name, many modern globe valves do not have much of a spherical shape, buan internal mechanism.

Globe valves are used for applications requiring throttling and frequent operation.

3. Butterfly Valve

A butterfly valve is a particular type of valve that uses circular vane or a disc as the shuthave a quick opening/closing quartercontrol the flow of liquid through a piping system. They typically pivot on axes perpendicular to the directionCompared with ball valves, butterfly valves do not have pockets to trap fluids when the valve is in the closed position. Butterfly valves are frequently used as throttling devices, controlling the levels of flow in various positions: entirely closed, entirely open or partially open. They can control various substances of air, liquid or solid currents and are situated on a spindle that allows for flow in a single direction.

4. Ball Valve

A ball valve (like the butterfly valve, one of a family of valves called quarter turn valves) is a valve that opens by turning a handle attached to a ball inside the valve. The ball has a hole, or port, through the middle so that when the port is in line with both ends of thclosed, the hole is perpendicular to the ends of the valve, and flow is blocked. The handle posiyou "see" the valve’sposition Ball valves are durable and usually work to achieve perfect shutoff even after years of disuse. They are therefore an excellent choice for shutoff applications (and are often preferred to globe valves and gate valves for this purpose). They do not offer the fine control that may be necessary in throttling applications but are sometimes used for

this purpose.



valves in the past had the spherical bodies which gave them their name, many modern globe valves do not have much of a spherical shape, but the term globe valve is still often used for valves that have such

Globe valves are used for applications requiring throttling and frequent operation.

A butterfly valve is a particular type of valve that uses either a circular vane or a disc as the shut-off mechanism. Butterfly valves have a quick opening/closing quarter-turn mechanism that is used to control the flow of liquid through a piping system. They typically pivot on axes perpendicular to the direction of flow inside the flow chamber. Compared with ball valves, butterfly valves do not have pockets to trap fluids when the valve is in the closed position. Butterfly valves are frequently used as throttling devices, controlling the levels of flow in

positions: entirely closed, entirely open or partially open. They can control various substances of air, liquid or solid currents and are situated on a spindle that allows for flow in a single direction.

the butterfly valve, one of a family of valves called quarter turn valves) is a valve that opens by turning a handle attached to a ball inside the valve. The ball has a hole, or port, through the middle so that when the port is in line with both ends of the valve, flow will occur. When the valve is closed, the hole is perpendicular to the ends of the valve, and flow is blocked. The handle position lets you "see" the valve’sposition.

Ball valves are durable and usually work to fter years of disuse.

They are therefore an excellent choice for shutoff applications (and are often preferred to globe valves and gate valves for this purpose). They do not offer the fine control that may be necessary in

metimes used for

Ball Valve



valves in the past had the spherical bodies which gave them their name, many modern globe valves do t the term globe valve is still often used for valves that have such

the butterfly valve, one of a family of valves called quarter turn valves) is a valve that opens by turning a handle attached to a ball inside the valve. The ball has a hole, or port, through the

e valve, flow will occur. When the valve is


P a g e | 35

Solenoid Operated Valve (SOV)

Solenoid valves are electrically operated devices that control the flow of liquids. Solenoid valves are electro

mechanical devices that use a wire coil and a movable plunger, called a solenoid,

solenoid controls the valve during either the open or closed positions. Thus, these kinds of valves do not regulate

flow. They are used for the remote control of valves for directional control of liquids. Solenoid valves

main parts: the solenoid and the valve.

magnetic field acts upon the plunger,

There are two general types of solenoid valves: direct

a plunger that is in direct contact with the primary opening in the body. This plunger is used to open and close the

orifice. The pilot-operated solenoid valve works with a diaphragm rather than a plunger. This valve uses differential

pressure to control the flow of fluids. The air

the fluids to flow through.

Check Valves/Non-return Valves (NRV)

Check valves, also referred to as "non

fluid, air or gas to flow in only one direction. When the fluid moves in the pre

Any backflow is prevented by the moveable portion of the valve. A swinging disc, ball, plunger or poppet moves out

of the way of the original flow. Since these devices are slightly larger than the through hole, the pressure of

backflow will cause them to tightly seal, preventing reversal of flow. Gravity or a spring assists in the closing of the

valve.



Solenoid valves are electrically operated devices that control the flow of liquids. Solenoid valves are electro

devices that use a wire coil and a movable plunger, called a solenoid, to control a particular valve. The

the valve during either the open or closed positions. Thus, these kinds of valves do not regulate

remote control of valves for directional control of liquids. Solenoid valves

After the coil receives a current, the actuating magnetic field is created. The

magnetic field acts upon the plunger, resulting in the actuation of the valve, either opening or closing it.

neral types of solenoid valves: direct-acting and pilot-operated. Direct-acting solenoid valves have

plunger that is in direct contact with the primary opening in the body. This plunger is used to open and close the

valve works with a diaphragm rather than a plunger. This valve uses differential

control the flow of fluids. The air-venting valve is opened to allow the pressure to equalize and permit

Valves (NRV)

Check valves, also referred to as "non-return" or "one-way directional" valves, are very simple valves that allow

fluid, air or gas to flow in only one direction. When the fluid moves in the pre-determined direction, the valve opens.

low is prevented by the moveable portion of the valve. A swinging disc, ball, plunger or poppet moves out


al, preventing reversal of flow. Gravity or a spring assists in the closing of the



Solenoid valves are electrically operated devices that control the flow of liquids. Solenoid valves are electro-

to control a particular valve. The

the valve during either the open or closed positions. Thus, these kinds of valves do not regulate

remote control of valves for directional control of liquids. Solenoid valves have two

After the coil receives a current, the actuating magnetic field is created. The

resulting in the actuation of the valve, either opening or closing it.

acting solenoid valves have

plunger that is in direct contact with the primary opening in the body. This plunger is used to open and close the

valve works with a diaphragm rather than a plunger. This valve uses differential

venting valve is opened to allow the pressure to equalize and permit

way directional" valves, are very simple valves that allow

determined direction, the valve opens.

low is prevented by the moveable portion of the valve. A swinging disc, ball, plunger or poppet moves out


al, preventing reversal of flow. Gravity or a spring assists in the closing of the


P a g e | 36

Positioner

Positioner is a device used to position a valve with regard to a signal. The positioner

compares the input signal (3-15 psi) with a mechanical feedback

then produces the force necessary to move the actuator output until the mechanical

output position feedback corresponds with the pneumatic signal value. There are three

modes of a positioned that it can be set:

• Fail to close

• Fail to open

• Last position

Regulator

A regulator is a device that regulates the supply of air from the supply line to some

device, e.g from 7 kg to 1.4kg.Regulator has two main parts

• Regulation Part: This includes a spring, compressed valve, diaphragm and

feedback system needed for regulation.

• Filter: This is the filtering part on the input used to filter any dust particles or moisture in the air.

Pressure Safety Valve (PSV)

A pressure safety valve is a valve mechanism for the automatic release of a substance from a

vessel, or other system when the pressure or temperature exceeds preset limits. It is a mechanical safety and last line

of protection against disaster in case both DCS a

compressors, pumps, etc from over pressure and from rupturing by bleeding the extra pressure on the atmosphere.

Its simplest example is the weight PSV on the pressure cooker used in homes for c



Positioner is a device used to position a valve with regard to a signal. The positioner

15 psi) with a mechanical feedback link from the actuator.

then produces the force necessary to move the actuator output until the mechanical

output position feedback corresponds with the pneumatic signal value. There are three

modes of a positioned that it can be set:

A regulator is a device that regulates the supply of air from the supply line to some

device, e.g from 7 kg to 1.4kg.Regulator has two main parts

This includes a spring, compressed valve, diaphragm and

feedback system needed for regulation.

This is the filtering part on the input used to filter any dust particles or moisture in the air.

mechanism for the automatic release of a substance from a

when the pressure or temperature exceeds preset limits. It is a mechanical safety and last line

of protection against disaster in case both DCS and ESD system fails. These are used to protect vessels, tanks,


Its simplest example is the weight PSV on the pressure cooker used in homes for cooking.



It

the

This is the filtering part on the input used to filter any dust particles or moisture in the air.

mechanism for the automatic release of a substance from a boiler, pressure

when the pressure or temperature exceeds preset limits. It is a mechanical safety and last line

These are used to protect vessels, tanks,



P a g e | 37

PThis six week internship at production unit FFC MM developed an understanding of urea fertilizer

production especially to the field instrumentation and control technology. Experience and exposure was

not only limited to process flow but was

techniques and problem handling and troubleshooting.

The plant division and design, management and oper

safe and smooth process.

Literature review from TTC library, study of technical data and manuals of different

discussion with engineers and technical staff and visit to plant sit

cooperative coordination of management and staf

period.

Although, the internship program was good but I think there are some areas which can still be improved.

Schedule for entire internship should be planned on daily basis. Office and work environ

would help interns to build a professional attitude and eliminate the feeling of being left alone. Frequent

plant visits can make the Internship Program more Intriguing and help the interns to explore industry.

Library at Technical Training Center should be equipped with a computer section where Interns should be

provided with internet facility.



Personal Feedback This six week internship at production unit FFC MM developed an understanding of urea fertilizer


imited to process flow but was widened to operating logics, process control & production

problem handling and troubleshooting.

The plant division and design, management and operation enhanced the concept and perspective about

Literature review from TTC library, study of technical data and manuals of different equipment

discussion with engineers and technical staff and visit to plant site added a sound knowledge. The

cooperative coordination of management and staff raised the morale in the journey of Lifelong


Schedule for entire internship should be planned on daily basis. Office and work environ



enter should be equipped with a computer section where Interns should be



This six week internship at production unit FFC MM developed an understanding of urea fertilizer


ol & production

perspective about

equipments,

knowledge. The

ifelong learning


Schedule for entire internship should be planned on daily basis. Office and work environment exposure



enter should be equipped with a computer section where Interns should be