SUMMER TRAINING REPORT

Indian Oil Corporation Ltd,Panipat

Duration: 24.06.13-19.07.2013

Submitted By:

Vishal Srivastava

10ESKME122

In partial fulfilment of requirements for the degree of

BACHELOR OF TECHNOLOGY IN

MECHANICAL ENGINEERING

SWAMI KESHVANAND INSTITUTE OF TECHNOLOGY,

MANAGEMENT AND GRAMOTHAN

Ramnagaria, Jagatpura Jaipur-302 017, Rajasthan India

Submitted to:

Dr. N.K. Banthiya

HOD (Mechanical)

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PREFACE

Industrial training plays a vital role in the progress of future engineers.

Not only does it provide insights about the industry concerned, it also

bridges the gap between theory and practical knowledge. I was fortunate

that I was provided with an opportunity of undergoing industrial training

at INDIAN OIL CORPORATION L TD. Panipat. The experience gained

during this short period was fascinating to say the least. It was a

tremendous feeling to observe the operation of different equipments and

processes. It was overwhelming for us to notice how such a big refinery is

being monitored and operated with proper coordination to obtain desired

results. During my training I realized that in order to be a successful

mechanical engineer one needs to possess a sound theoretical base along

with the acumen for effective practical application of the theory. Thus, I

hope that this industrial training serves as a stepping stone for me in

future and help me carve a niche for myself in this field.

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ACKNOWLEDGEMENT

My indebtedness and gratitude to the many individuals who have helped

to shape this report in its present form cannot be adequately conveyed in

just a few sentences. Yet I must record my immense gratitude to those

who helped me undergo this valuable learning experience at IOCL

Panipat.

I am highly obliged to Mr. Yogesh Joshi, Training and Development

Department for providing me this opportunity to learn at IOCL. I thank

Shri Anand Prakash, Chief Manager (Maintenance Department) for guiding

me through the whole training period. I express my heartiest thanks to

Shri Sirajuddin Ahmed, for sharing his deep knowledge about various

pumps and other equipments in workshop. I would also like to thank Mr.

Samir Das in valve section for explaining us about different valves and

their repairing. My special thanks to the SPM Instruments team for the on

field experience of vibration testing of equipments and Shri Sanjay Lamba

for showing us detailed procedure of analysis of vibrations.

I am grateful to Shri Sanjay Gathwal, Senior Mechanical Engineer for his

simple yet effective explanation of Panipat Refinery as a whole and

guiding us about various other aspects of career as a mechanical

engineer.

Last but not the least I am thankful to Almighty God, my parents, family

and friends for their immense support and cooperation throughout the

training period.

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TABLE OF CONTENTS

1. Preface 2

2. Acknowledgement 3

3. Introduction 5-6

4. Centrifugal Pumps 7-10

5. NPSH(Net Positive Suction Head) 11

6. Cavitation 12

7. Screw Pumps 13-14

8. Pump Selection and common problems 15-18

9. Vibrations 19-24

10. Valves 25-38

11. Findings 39

12. Bibliography 40

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INTRODUCTION

Petroleum is derived from two words – “petro” means rock and

“oleum” means oil. Thus the word “petroleum” means rock oil. This is a

mixture of hydrocarbons; hence it cannot be used directly and has got

to be refined. Petroleum is refined in petroleum refinery.

Indian Oil Corporation Ltd. (IOC) is the flagship national oil company

in the downstream sector. The Indian Oil Group of companies owns

and operates 10 of India's 19 refineries with a combined refining

capacity of 1.2 million barrels per day. These include two refineries of

subsidiary Chennai Petroleum Corporation Ltd. (CPCL) and one of

Bongaigaon Refinery and Petrochemicals Limited (BRPL). The 10

refineries are located at Guwahati, Barauni, Koyali, Haldia, Mathura,

Digboi, Panipat, Chennai, Narimanam, and Bongaigaon.

Indian Oil's cross-country crude oil and product pipelines network span

over 9,300 km. It operates the largest and the widest network of

petrol & diesel stations in the country, numbering around 16455.

Indian Oil Corporation Ltd. (Indian Oil) was formed in 1964 through

the merger of Indian Oil Company Ltd and Indian Refineries Ltd. Indian

Refineries Ltd was formed in 1958, with Feroze Gandhi as Chairman

and Indian Oil Company Ltd. was established on 30th June 1959 with

Mr S. Nijalingappa as the first Chairman.

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Panipat Refinery

Panipat Refinery has doubled its refining capacity from 12 MMT/yr to 15

MMT/yr with the commissioning of its Expansion Project. Panipat Refinery

is the seventh refinery of Indian Oil. It is located in the historic district of

Panipat in the state of Haryana and is about 23 km from Panipat City. The

original refinery with 6 MMTPA capacity was built and commissioned in

1998 at a cost of Rs. 3868 crore (which includes Marketing Pipelines

installations).

The major secondary processing units of the Refinery include Catalytic

Reforming Unit, Once through Hydrocracker unit, Resid Fluidised Catalytic

Cracking unit, Visbreaker unit, Bitumen blowing unit, Sulphur block and

associated Auxiliary facilities. In order to improve diesel quality, a Diesel

Hydro Desulphurization Unit (DHDS) was subsequently commissioned in

1999.

Referred as one of India’s most modern refineries, Panipat Refinery was

built using global technologies from IFP France; Haldor-Topsoe, Denmark;

UNOCAL/UOP, USA; and Stone &Webster, USA. It processes a wide range

of both indigenous and imported grades of crude oil. It receives crude

from Vadinar through the 1370 km long Salaya-Mathura Pipeline which

also supplies crude to Koyali and Mathura Refineries of Indian Oil.

Petroleum products are transported through various modes like rail, road

as well as environment-friendly pipelines. The Refinery caters to the high-

consumption demand centers in North-Western India including the States

of Haryana, Punjab, J &K, Himachal, Chandigarh, Uttaranchal, as well as

parts of Rajasthan and Delhi.

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PUMPS

A pump is a device that moves fluids or sometimes slurries by

mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift,

displacement, and gravity pumps.

Pumps operate via many energy sources and by some mechanism

(typically reciprocating or rotary), and consume energy to perform

mechanical work by moving the fluid by manual operation, electricity,

engine or wind power.

Common Pumps Used In IOCL

1. Centrifugal Pumps

A centrifugal pump is a pump that consists of a fixed impeller on a

rotating shaft that is enclosed in a casing, with an inlet and a discharge

connection. As the rotating impeller swirls the liquid around, centrifugal

force builds up enough pressure to force the water through the discharge

outlet. This type of pump operates on the basis of an energy transfer, and

has certain definite characteristics which make it unique. The amount of

energy which can be transferred to the liquid is limited by the type and

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size of the impeller, the type of material being pumped, and the total

head of the system through which the liquid is moving.

Centrifugal pumps are designed to be used as a portable pump, and are

often referred to as a trash pump. It is named so because the water that

is being pumped is not clean water. It is most often water containing soap

or detergents, grease and oil, and also solids of various sizes that are

suspended in the water.

The major types of centrifugal pumps used in the refinery are:

1. Vertical Cantilever Pump

It is a specialized type of vertical sump pump designed to be

installed in a tank or sump but with no bearing located in the lower

part of the pump. Thus, the impeller is cantilevered from the motor,

rather than supported by the lower bearings.

A cantilever pump is considered a centrifugal pump configured with

the impeller submerged in the fluid to be pumped. But unlike a

traditional vertical column sump pump, there are no bearings below

the motor supporting the impeller and shaft.

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The cantilever pump has a much larger diameter shaft, since it has

no lower sleeve bearings that act to support the impeller and shaft.

In general, cantilever pumps are best for relatively shallow sumps,

usually around 8 to 10 feet maximum. This is because the deeper

the sump, the larger the shaft diameter that is required to

cantilever the impeller.

2. Split Case Pumps

This type of pump has a split casing at the suction side. It prevents

the turbulence and formation of eddies at inlet.

Split Case pumps are designed to pump clean water or low viscosity

clean liquids at moderate heads more economically, which is widely

used for liquid transfer and circulation of clean or slightly polluted

water. And the typical applications are Municipal water supply,

Power plants, Industrial plants, Boiler feed and condensate systems,

Irrigation and dewatering and marine service.

Advantages:

Less noise and vibration, suitable to a lifting speed working

condition;

Inverted running is available for the same rotor, the risk of water

hammer is lower;

Unique design for high temperature application up to 200 ℃,

intermediate support, thicker pump casing, cooling seals oil

lubrication bearings;

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Vertical or horizontal with packing seal or mechanical seal can be

designed according to the different working condition;

Beautiful outline design.

Specifications of a Centrifugal Pump in Refinery

Offered Capacity: 317 LPM

RPM: 1450

Efficiency: 93%

Mounting: Horizontal

Sealing: Mechanical Seal

Power Rated: 7 KW

Applications of Centrifugal Pump in Panipat

Refinery

For circulation of cooling water

For pump the fluid (crude oil, VGO, diesel etc.) in reactors,

coulombs etc. with high pressure.

In liquid storage tanks

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Net Positive Suction Head (NPSH) Overview

Net Positive Suction Head (NPSH) NPSH Available is a function of the

system in which the pump operates. It is the excess pressure of the liquid

in feet absolute over its vapor pressure as it arrives at the pump suction.

In an existing system, the NPSH Available can be determined by a gauge

on the pump suction.

The Hydraulic Institute defines NPSH as the total suction head in feet

absolute, determined at the suction nozzle and corrected to datum, less

the vapor pressure of the liquid in feet absolute. Simply stated, it is an

analysis of energy conditions on the suction side of a pump to determine

if the liquid will vaporize at the lowest pressure point in the pump.

The pressure which a liquid exerts on its surroundings is dependent upon

its temperature. This pressure, called vapor pressure, is a unique

characteristic of every fluid and increased with increasing temperature.

When the vapor pressure within the fluid reaches the pressure of the

surrounding medium, the fluid begins to vaporize or boil. The temperature

at which this vaporization occurs will decrease as the pressure of the

surrounding medium decreases.

A liquid increases greatly in volume when it vaporizes. One cubic foot of

water at room temperature becomes 1700 cu. ft. of vapor at the same

temperature.

It is obvious from the above that if we are to pump a fluid effectively, we

must keep it in liquid form. NPSH is simply a measure of the amount of

suction head present to prevent this vaporization at the lowest pressure

point in the pump.

NPSH can be defined as two parts:

NPSH Available (NPSHA): The absolute pressure at the

suction port of the pump.

NPSH Required (NPSHR): The minimum pressure required at

the suction port of the pump to keep the pump from cavitating.

NPSHA is a function of your system and must be calculated, whereas

NPSHR is a function of the pump and must be provided by the pump

manufacturer. NPSHA must be greater than NPSHR for the pump system

to operate without cavitating. Thus, we must have more suction side

pressure available than the pump requires.

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CAVITATION

Cavitation is a term used to describe the phenomenon, which occurs in a

pump when there is insufficient NPSH Available. When the pressure of the

liquid is reduced to a value equal to or below its vapor pressure the liquid

begins to boil and small vapor bubbles or pockets begin to form. As these

vapor bubbles move along the impeller vanes to a higher pressure area

above the vapor pressure, they rapidly collapse.

The collapse or "implosion" is so rapid that it may be heard as a rumbling

noise, as if you were pumping gravel. In high suction energy pumps, the

collapses are generally high enough to cause minute pockets of fatigue

failure on the impeller vane surfaces. This action may be progressive, and

under severe (very high suction energy) conditions can cause serious

pitting damage to the impeller.

Cavitation is often characterized by:

Loud noise often described as a grinding or “marbles” in the pump

Loss of capacity (bubbles are now taking up space where liquid

should be)

Pitting damage to parts as material is removed by the collapsing

bubbles

Vibration and mechanical damage such as bearing failure

Erratic power consumption

The way to prevent the undesirable effects of cavitation in standard low

suction energy pumps is to insure that the NPSH Available in the system

is greater than the NPSH required by the pump.

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2. Screw Pumps

Main Elements of Screw Pump Design

The pumping element of a two screw pump consists of two intermeshing

screws rotating within a stationary bore/housing that is shaped like a

figure eight.

The rotor and housing/body are metal and the pumping element is

supported by the bearings in this design.

The clearances between the individual areas of the pumping screws are

maintained by the timing gears.

When a two screw pump is properly timed and assembled there is no

metal-to-metal contact within the pump screws.

The pumping screws and body/ housing can be made from virtually any

machinable alloy. This allows the pump to be applied for the most severe

applications in aggressive fluid handling. Hard coatings can also be

applied for wear resistance.

The stages of the screw are sealed by the thin film of fluid that moves

through the clearances separating them.

Finally, in a two screw design, the bearings are completely outside of the

pumped fluid. This allows them to have a supply of clean lubricating oil

and be independent of the pumped fluid characteristics. The external

housings also allows for cooling which means the quality of the lube oil

can be maintained in high temperature or horsepower applications.

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Working

These pumps are based on the basic principle where a rotating cavity or

chamber within a close fitting housing is filled with process fluid, the

cavity or chamber closes due to the rotary action of the pump shaft(s),

the fluid is transported to the discharge and displaced, this action being

accomplished without the need for inlet or outlet check valves.

Specifications of a Screw Pump

Name: Emergency Lube Oil Pump

Driver: Electric Motor

Liquid Handled: Lube Oil

Pumping temperature: 65o C

Specific Gravity: 0.88

Rated Capacity: 237 LPM

Suction Pressure: Atmospheric

Discharge Pressure: 10 Kg/cm2

NPSH available: 10 m

Applications

Mostly used for high viscous fluid.

Used where high pressure is needed.

Pump Selection on basis of Process Parameters

Selecting between a Centrifugal Pump or a Positive Displacement Pump is

not always straight forward. Following factors are considered while

selecting a pump:

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1. Flow Rate and Pressure Head

The two types of pumps behave very differently regarding pressure

head and flow rate:

The Centrifugal Pump has varying flow depending on the system

pressure or head.

The Positive Displacement Pump has more or less a constant flow

regardless of the system pressure or head. Positive Displacement

pumps generally give more pressure than Centrifugal Pumps.

2. Flow and Viscosity

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In the Centrifugal Pump the flow is reduced when the viscosity is

increased.

In the Positive Displacement Pump the flow is increased when

viscosity is increased.

Liquids with high viscosity fill the clearances of a Positive

Displacement Pump causing a higher volumetric efficiency and a

Positive Displacement Pump is better suited for high viscosity

applications. A Centrifugal Pump becomes very inefficient at even

modest viscosity.

3. Mechanical Efficiency and Pressure

Changing the system pressure or head has little or no effect on the flow

rate in the Positive Displacement Pump.

Changing the system pressure or head has a dramatic effect on the flow

rate in the Centrifugal Pump.

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4. Mechanical Efficiency and Viscosity

Viscosity also plays an important role in pump mechanical

efficiency. Because the centrifugal pump operates at motor speed

efficiency goes down as viscosity increases due to increased frictional losses within the pump. Efficiency often increases in a PD

pump with increasing viscosity. Note how rapidly efficiency drops off

for the centrifugal pump as viscosity increases.

5. Net Positive Suction Head – NPSH

In a Centrifugal Pump, NPSH varies as a function of flow determined

by pressure

In a Positive Displacement Pump, NPSH varies as a function of flow

determined by speed. Reducing the speed of the Positive

Displacement Pump, reduces the NPSH.

Common Problems encountered in Pumps

The types of pumps that are most commonly used in a Refinery

plant are centrifugal pumps. These pumps use centrifugal action to

convert mechanical energy into pressure in a flowing liquid. The

main components of the pump that are usually prone to problems

are impellers,

shafts, seals and bearings.

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An important aspect of the impeller is the wear rings. If the impeller

is too close to the stationary element, the impeller or the casing will

be worn out. The other part is the shaft. It runs through the center

of the pump and is connected to the impeller at the left end.

Seal is a very important part in the pump. Seals are required in the

casing area where the liquid under pressure enters the casing.

The last main part of the pump is the bearing. The pump housing

contains two sets of bearings that support the weight of the shaft.

The failures causing the stoppage of the pumps are primarily

experienced by these parts and will be termed as failure modes.

There are 12 major failure modes (bad actors) for the most

pumps. The following is the definition adopted to characterize the

various modes of failure:

♦Shaft: The pump failed to operate because of shaft problem, such

as misalignment, vibration, etc.

♦Suction Valve: A failure due to something wrong with the pump

suction, such as problems in valve, corroded pipes or slug

accumulated in the suction.

♦Casing: A failure due to defective casing, such as misalignment or

corrosion.

♦Operation Upset Failure of a pump due to operational mistakes,

such as closing

a valve which should not be closed.

♦Coupling A failure due to coupling distortion or misalignment.

♦Gaskets A failure due to a gasket rupture or damage caused by

leaks.

♦Control Valve A failure due to malfunction of the control valve due to

pressure or flow in the line of service.

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VIBRATIONS

FUNDAMENTALS OF VIBRATION

Most of us are familiar with vibration; a vibrating object moves to and fro,

back and forth. A vibrating object oscillates. We experience many

examples of vibration in our daily lives. A pendulum set in motion

vibrates. A plucked guitar string vibrates. Vehicles driven on rough terrain

vibrate, and geological activity can cause massive vibrations in the form

of earthquakes.

In industrial plants there is the kind of vibration we are concerned about:

machine vibration.

Machine Vibration

Machine vibration is simply the back and forth movement of

machines or machine components. Any component that moves back

and forth or oscillates is vibrating

Machine vibration can take various forms. A machine component

may vibrate over large or small distances, quickly or slowly, and

with or without perceptible sound or heat. Machine vibration can

often be intentionally designed and so have a functional purpose.

(Not all kinds of machine vibration are undesirable. For example,

vibratory feeders, conveyors, hoppers, sieves, surface finishers and

compactors are often used in industry.)

Almost all machine vibration is due to one or more of these

causes:

(a) Repeating forces (b) Looseness (c) Resonance

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(a) Repeating Forces

Repeating forces in machines are mostly due to the rotation of

imbalanced, misaligned, worn, or improperly driven machine components.

Worn machine components exert a repeating force on machine

components due to rubbing of uneven worn parts. Wear in roller bearings,

gears and belts is often due to improper mounting, poor lubrication,

manufacturing defects and over loading.

Improperly driven machine components exert repeating forces on

machine due to intermittent power supply. Examples include pump

receiving air in pulses, IC engines with misfiring cylinders, and

intermittent brush commutator contact in DC Motors.

b) Looseness

Looseness of machine parts causes a machine to vibrate. If parts

become loose, vibration that is normally of tolerable levels may

become unrestrained and excessive.

Looseness can cause vibrations in both rotating and non rotating

machinery.

Looseness can be caused by excessive bearing clearances, loose

mounting bolts, mismatched parts, corrosion and cracked

structures.

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c) Resonance

Machines tend to vibrate at certain oscillation rates. The oscillation

rate at which a machine tends to vibrate is called its natural

oscillation rate. The natural oscillation rate of a machine is the

vibration rate most natural to the machine, that is, the rate at

which the machine 'prefers' to vibrate.

if a machine is 'pushed' by a repeating force with a rhythm

matching the natural oscillation rate of the machine? The machine

will vibrate more and more strongly due to the repeating force

encouraging the machine to vibrate at a rate it is most natural with.

The machine will vibrate vigorously and excessively, not only

because it is doing so at a rate it 'prefers' but also because it is

receiving external aid to do so. A machine vibrating in such a

manner is said to be experiencing resonance. A repeating force

causing resonance may be small and may originate from the motion

of a good machine component. Such a mild repeating force would

not be a problem until it begins to cause resonance. Resonance,

however, should always be avoided as it causes rapid and severe

damage.

Why Monitor Machine Vibration?

Monitoring the vibration characteristics of a machine gives us an

understanding of the 'health' condition of the machine. We can use

this information to detect problems that might be developing.

If we regularly monitor the conditions of machines we will find any

problems that might be developing, therefore we can correct the

problems even as they arise. In contrast, if we do not monitor

machines to detect unwanted vibration the machines are more likely

to be operated until they break down.

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Below we discuss some common problems that can be avoided by

monitoring machine vibration

(a) Severe Machine Damage

(b) High Power Consumption

(c) Machine Unavailability

(d) Delayed Shipments

(e) Accumulation of Unfinished Goods

f) Unnecessary Maintenance

(g) Quality Problems

h) Bad Company Image

(i) Occupational Hazards

Types of Vibration Monitoring Parameters

PRINCIPLE

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

acceleration. Vibration amplitude measurements may either be relative,

or absolute. An absolute vibration measurement is one that is relative to

free space. Absolute vibration measurements are made with seismic

vibration transducers.

Displacement

Displacement measurement is the distance or amplitude displaced from a

resting position. The SI unit for distance is the meter (m), although

common industrial standards include mm and mils. Displacement

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vibration measurements are generally made using displacement eddy

current transducers.

Velocity

Velocity is the rate of change of displacement with respect to change in

time. The SI unit for velocity is meters per second (m/s), although

common industrial standards include mm/s and inches/s. Velocity

vibration measurements are generally made using either swing coil

velocity transducers or acceleration transducers with either an internal or

external integration circuit.

Acceleration

Acceleration is the rate of change of velocity with respect to change in

time. The SI unit for acceleration is meters per second2 (m/s2), although

the common industrial standard is the g. Acceleration vibration

measurements are generally made using accelerometers.

Vibration Monitoring Sensors & Selections

Sensors & Sensor Selection:

In industry where rotating machinery is everywhere, the sounds made by

engines and compressors give operating and maintenance personnel first

level indications that things are OK. But that first level of just listening or

thumping and listening is not enough for the necessary predictive

maintenance used for equipment costing into the millions of dollars or

supporting the operation of a production facility.

The second layer of vibration analysis provides predictive information on

the existing condition of the machinery, what problems may be

developing, exactly what parts may be on the way to failure, and when

that failure is likely to occur. Now, you may schedule repairs and have the

necessary parts on hand. This predictive maintenance saves money in

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faster, scheduled repairs and prevents failures that are much more

expensive in terms of repairs or lost production.

Applications

Application of these vibration sensors, with their associated

equipment, provides effective reduction in overall operating

costs of many industrial plants. The damage to machinery the

vibration analysis equipment prevents is much more costly than the

equipment and the lost production costs can greatly overshadow the

cost of equipment and testing.

Predicting problems and serious damage before they occur offers a

tremendous advantage over not having or not using vibration

analysis.

Specific areas of application include any rotating machinery such as

motors, pumps, turbines, bearings, fans, and gears along

with their balancing, broken or bent parts, and shaft

alignment.

The vibration systems find application now in large systems such

as aircraft, automobile, and locomotives while they are in

operation.

Dynamic fluid flow systems such as pipelines, boilers, heat

exchangers, and even nuclear reactors use vibration analysis to find

and interpret internal problems.

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VALVES

What is a valve?

A valve is a mechanical device which regulates either the flow or the pressure of the fluid. Its function can be stopping or starting the flow,

controlling flow rate, diverting flow, preventing back flow, controlling

pressure, or relieving pressure.

Basically, the valve is an assembly of a body with connection to the pipe

and some elements with a sealing functionality that are operated by an

actuator. The valve can be also complemented whit several devices such

as position testers, transducers, pressure regulators, etc.

Common Valves Used In PANIPAT REFINERY

Gate valve

Globe valve

Ball valve

Butterfly valve

Plug valve

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1. Gate valve

Application In Refinery

Gate valves have an extended use in the petrochemical industry

due to the fact that they can work with metal-metal sealing. They are used in clean flows.

When the valve is fully opened, the free valve area coincides with

area of the pipe, therefore the head lose of the valve is small.

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Limitations

This valve is not recommended to regulate or throttling service since the closure member could be eroded. Partially opened the

valve can vibrate.

Opening and closing operations are slow. Due to the high friction wear their use is not recommend their use in often required

openings.

This valve requires big actuators which have difficult automation. They are not easy to repair on site.

2. Ball valve

The ball valve has a spherical plug as a closure member. Seal on ball

valves is excellent, the ball contact circumferentially uniform the seat,

which is usually made of soft materials

Depending on the type of body the ball valve can be more or less easily

maintained. Drop pressure relative its hole size is low.

Application in Refinery

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They are used in steam, water, oil, gas, air, corrosive fluids, and can also

handle slurries and dusty dry fluids. Abrasive and fibrous materials can

damage the seats and the ball surface.

Limitations

The seat material resistance of the ball valve limits the working

temperature and pressure of the valve. The seat is plastic or metal

made.

Ball valves are mostly used in shutoff applications. They are not

recommended to be used in a partially open position for a long time

under conditions of a high pressure drop across the valve, thus the

soft seat could tend to flow through the orifice and block the valve

movement.

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3. Butterfly valve

The development of this type of valve has been more recent than

other ones. A major conviction on saving energy in the installations

was an advantage for its introduction, due its head loss is small. At the beginning they were used in low pressure installations service,

but technologic improvements, especially in the elastomer field let

their extension to higher performances.

As any quarter turn valve, the operative of the butterfly valve is

quiet easy. The closure member is a disc that turns only 90º; to be

fully open/close.

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Advantages

This is a quick operation.

Few wear of the shaft, little friction and then less torque

needed means a cheaper actuator. The actuator can be manual, oleo hydraulic or electrical motorized, with automation available.

Butterfly valves geometry is simple, compact and revolute,

therefore it is a cheap valve to manufacture either saving material

and post mechanization.

Its reduced volume makes easy its installation. Gate and globe

valves are heavier and more complex geometry, therefore butterfly

valve can result quiet attractive at big sizes regarding other types of

valves.

Application in Refinery

Butterfly valves are quite versatile ones. They can be used at

multiples industrial applications, fluid, sizes, pressures,

temperatures and connections at a relative low cost.

Butterfly valves can work with any kind of fluid, gas, liquid and also

with solids in suspension. As a difference from gate, globe or ball

valves, there are not cavities where solid can be deposit and

difficult the valve operative.

Limitations

Pressure and temperature are determinant and correlated designing

factors. At a constant pressure, rising temperature means a lower

performance for the valve, since some materials have lower capacity. As

well gate, globe and ball valves, the butterfly valve can be manufactured

with metallic seats that can perform at high pressure and extreme

temperatures.

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4. PLUG VALVE

Plug valves have a plug as a closure member. Plug can be

cylindrical or conical. Ball valves are considered as another group

despite that they are some kind of plug valve.

Plug valves are used in On/Off services and flow diverting, as they

can be multiport configured.

Advantages

They can hand fluids with solids in suspension.

Lift plug valve type are designed to rise the plug at start valve

operation, in order to separate and protect plug-seat sealing

surfaces from abrasion

Limitations

It require high maintenance cost

Require more time for maintenance

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5. GLOBE VALVE

A Globe valve may be constructed with a single or double port and plug

arrangement. The double port type is generally used in a CONTROL VALVE

where accurate control of fluid is required. Due to the double valve plug

arrangement, the internal pressure acts on each plug in opposition to

each other, giving an internal pressure balance across the plugs.

Advantages

This gives a much smoother operation of the valve and better

control of the process. Some control valves are 'Reverse Acting'.

Where a valve normally opens when the plug rises, in the reverse

acting valve, the valve closes on rising. The operation of the valve

depends on process requirements. Also depending on requirements,

a control valve may be set to open or close, on air failure to the

diaphragm.

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The Globe valve is used where control of fluid flow or pressure is

required and it can be operated in any position between open and

closed.

6. Non Returning Valve

A check valve may be defined simply as a mechanical device typically

used to let fluid, either in liquid or gas form, to flow through in one

direction. They usually have two ports or two openings – one for the fluid

entry and the other for passing through it. Often part of household items,

they are generally small, simple, and inexpensive components.

Operational Principal of Check Valve

Check valves are available with different spring rates to give particular

cracking pressures. The cracking pressure is that at which the check valve

just opens. If a specific cracking pressure is essential to the functioning of

a circuit, it is usual to show a spring on the check valve symbol. The

pressure drop over the check valve depends upon the flow rate; the

higher the flow rate, the further the ball or poppet has to move off its

seat and so the

There are two main types of check valve :

1. The 'LIFT' type. (Spring loaded 'BALL' & 'PISTON' Types).

2. The 'SWING' (or Flapper Type).

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35

SAFETY VALVES

A safety valve is a valve mechanism which automatically releases a

substance from a boiler, pressure vessel, or other system, when the pressure or temperature exceeds preset limits.

It is one of a set of pressure safety valves (PSV) or pressure relief

valves (PRV), which also includes relief valves, safety relief valves, pilot-operated relief valves, low pressure safety valves, and vacuum pressure

safety valves.

PRESSURE SAFETY VALVE OR RELIEF VALVE:

The relief valve (RV) is a type of valve used to control or limit

the pressure in a system or vessel which can build up by a process upset,

instrument or equipment failure, or fire.

Schematic diagram of a

conventional spring-loaded

pressure relief valve.

The pressure is relieved by allowing the pressurized fluid to flow from an

auxiliary passage out of the system. The relief valve is designed or set to

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open at a predetermined set pressure to protect pressure vessels and

other equipment from being subjected to pressures that exceed their

design limits. When the set pressure is exceeded, the relief valve

becomes the "path of least resistance" as the valve is forced open and

a portion of the fluid is diverted through the auxiliary route. The diverted

fluid (liquid, gas or liquid–gas mixture) is usually routed through

a piping system known as a flare header or relief header to a central,

elevated flare where it is usually burned and the

resulting combustion gases are released to the atmosphere

It should be noted that PRVs and PSVs are not the same thing, despite

what many people think; the difference is that PSVs have a manual lever

to open the valve in case of emergency.

TEMPERATURE SAFETY VALVE:

Water heaters have thermostatically controlled devices that keep them

from overheating.

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Both gas and electric water heaters have temperature-limiting devices

that shut off the energy source when their regular thermostat fails

Thermostatically controlled gas valves found on most residential gas

water heaters have a safety shutoff built into the gas valve itself. When

they react to excessive temperature, the gas flow to the burner is

stopped.

PROTECTION USED IN INDUSTRY:

The two general types of protection encountered in industry are thermal

protection and flow protection.

For liquid-packed vessels, thermal relief valves are generally

characterized by the relatively small size of the valve necessary to provide

protection from excess pressure caused by thermal expansion. In this case a small valve is adequate because most liquids are nearly

incompressible, and so a relatively small amount of fluid discharged

through the relief valve will produce a substantial reduction in pressure.

Flow protection is characterized by safety valves that are considerably larger than those mounted for thermal protection. They are generally

sized for use in situations where significant quantities of gas or high

volumes of liquid must be quickly discharged in order to protect the

integrity of the vessel or pipeline. This protection can alternatively be achieved by installing a high integrity pressure protection

system (HIPPS).

APPLICATION:

1. Vacuum safety valves (or combined pressure/vacuum safety valves) are used to prevent a tank from collapsing while it is being emptied, or

when cold rinse water is used after hot CIP (clean-in-place) or SIP

(sterilization-in-place) procedures.

2. Safety valves also evolved to protect equipment such as pressure

vessels (fired or not) and heat exchangers.

3. The term safety valve should be limited to compressible fluid

applications (gas, vapor, or steam).

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4. Many fire engines have such relief valves to prevent the over

pressurization of fire hoses.

Valve Type Application Other information

Ball Flow is on or off Easy to clean

Butterfly Good flow control at high capacities Economical

Globe Good flow control Difficult to clean

Plug Extreme on/off situations More rugged, costly than ball valve

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FINDINGS

For any academic discipline, especially practical streams like engineering

field knowledge should go hand in hand with theoretical knowledge. In

university classes our quest for knowledge is satisfied theoretically.

Exposure to real field knowledge is obtained during such vocational

training. We have learnt a lot about pumps, safety valves, flow control

valves, compressors, machine vibrations and their analysis and many

more things of working in an industry. We might have thoroughly learnt

the theory behind these but practical knowledge about these were mostly

limited to samples at laboratory. At IOCL we actually saw the equipments

used in industry. Though the underlying principle remains same but there

are differences as far as practical designs are considered.

We also got to know additionally about other features not taught or

known earlier. This has helped to clarify our theoretical knowledge a lot.

Apart from knowing about matters restricted to our own discipline we also

got to know some other things about the processing of crude and

manufacturing of various petrochemical products and fuels which we

might not have necessarily read within our curriculum. Such vocational

trainings, apart from boosting our knowledge give us some practical

insight into corporate sector and a feeling about the industry

environment. The close interactions with guides, many of whom are just

some years seniors to us have also helped us a lot. It is they who, apart

from throwing light on equipments, have also shown the different aspects

and constraints of corporate life. Discussions with them have not only

satisfied our enquiries about machines and processes but also enlightened

about many other extracurricular concepts which are also important. Thus

our training in IOCL has been a truly enlightening learning experience.

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BIBLIOGRAPHY

1. IOCL Pump set datasheet

2. http://www.blackmersmartenergy.com/comparativedata/centr

ifugal-pumps-vs-positive-displacement-pumps.html

3. http://www.pumpschool.com

4. http://www.pumpscout.com

5. http://www.webbpump.com/

6. http://water.me.vccs.edu/

7. http://valveproducts.net/industrial-valves

8. https://controls.engin.umich.edu/wiki/index.php/ValveTypesS

election

9. http://www.wermac.org/valves/valves_ball.html

http://www.iklimnet.com/expert_hvac/valves.html

10. Fundamentals of Vibrations by FM-Shinkawa