An experience had at IOCL during summer training.

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VOCATIONAL TRAINING REPORT
Indian Oil Corporation Ltd., Vadodara
Duration: 12.06.2017-22.07.2017
Submitted by:
Nitin Kumar (14EPPME017)
In partial fulfillment of requirements for the degree of
BACHELOR OF TECHNOLOGY
IN
MECHANICAL ENGINEERING
Pratap Institute of Technology & Science,
Palsana, Sikar-332001, Rajasthan, India

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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 LTD., Vadodara. The experience gained during this
period was fascinating to say the least. It was a tremendous feeling to observe the operation of
different equipment 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 in those who helped me undergo this valuable learning experience at IOCL,
Vadodara.
I am highly obliged to Mr. Vijender Kumar, Training & Development Department for providing
me this opportunity to learn at IOCL. I thank Mr. S Roychoudhary, DGM(MN) for guiding me
through the whole training period. I express my heartiest thanks to Mr. H. K. Chouhan for sharing
his deep knowledge about various pumps, compressors and other equipment in workshop.
I am grateful to Mr. Ronak Kaale for his simple yet effective explanation of Gujarat Refinery as a
whole and guiding me 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 10-13
5. NPSH (Net Positive Suction Head) 14
6. Cavitation 15
7. Screw Pumps 16-17
8. Pump Selection and Common Problems 18-21
9. Vibration 22-27
10. Valves 28-42
11. Heat Exchangers 43-49
12. Compressors 50-58
13. Findings 59
14. Bibliography 60

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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. (IOCL) 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 Bongaigaon
Refinery and Petrochemicals Limited (BRPL). The 10 refineries are located at Guwahati, 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
16,455. 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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Gujarat Refinery
Indian Oil Gujarat Refinery was dedicated to the Nation in 1966 changing the landscape of a town, a state and
the country. Today, Gujarat Refinery is the Flagship Refinery of Indian Oil.
The expansion in Gujarat Refinery has taken place in phases over the years from 2 million Metric Tonnes (MMT)
per year to the present capacity of 13.7 MMT per year and is gearing up for further expansion. Gujarat Refinery
and the city of Vadodara have been witness to each other’s phenomenal growth.
Today, Gujarat Refinery is the Mother Industry of Vadodara and is catering to the increasing energy demand
due to the fast-paced development and economic prosperity of the of the vibrant state of Gujarat. The Refinery
has been playing a catalytic role in encouraging over 200 small and big industries over the course of five decades.
One of the most complex refineries in India. Gujarat Refinery has about 40 operating units. Over the course of
five decades. The Refinery has kept up with the latest technological advancements and boasts of every modern
unit and technology that is available in the Indian Oil & Gas industry today.
Gujarat Refinery is also privileged with the distinction of setting up the country’s first Fluidized Catalytic Unit
(FCCU) in 1982 and the first Hydrocracker plant in 1993. The country’s first Diesel Hydro Desulphurization
Unit (DHDS) to reduce Sulphur content was setup in 1999 to meet BS-II quality of HSD. MS Quality
improvement project comprising of Continuous Catalytic Reforming Unit (CCRU) and revamp of DHDS were
carried out in the years 2006 and 2007 respectively to meet BS-III MS and HSD quality respectively. Further,
the Residue Upgradation Project (RUP) and MS/HSD quality improvement project were commissioned in 2010-
11. Gujarat Refinery is now gearing up for 100% supply of BS-IV fuels and capacity expansion to 18 MMT per
year.
In 2004 the world’s largest single train Linear Alkyl Benzene (LAB) Plant was setup in the refinery marking
IndianOil’s big-ticket entry into the petrochemicals field. Today, the refinery holds the 2nd
largest market shares
of LAB in India and exports to over 20 countries.
Gujarat Refinery’s flexibility to process various crude types allows it to meet stringent quality and environmental
norms. The Refinery processes indigenous and imported crudes into LPG, petrol, diesel, ATF and other value
added petroleum products.
The green belts spread across an area of 139 acres in and around the refinery speak volumes about its
commitment towards environment. With more than two lakhs strong tree population Gujarat Refinery’s three
green belts act as lungs for the refinery. A beautiful Eco Park has been developed inside the green belt area
surrounded by the pond which is a haven for various bird species.
Gujarat Refinery has full-fledged Effluent Treatments Plants consisting of physical, chemical, biological &
tertiary treatment facilities. Various measures have been adopted for control of gaseous emissions. Water
conservation is another important area being vigorously taken up in refineries through its quality control, re-use
of treated water and maximum use in cooling systems.
It has strong safety management system and infrastructure with focus on behavioral safety.
Being an integral part of the city of Vadodara. Gujarat Refinery is committed to improving the quality of life in
communities in and around the refinery and the city. CSR initiatives Gujarat Refinery has taken up projects for
ensuring Clean Drinking Water, Health and Medical Care and Education in the nearby villages and communities.
Guided by its corporate values of Care, Innovation, Passion and Trust. IndianOil’s Gujarat Refinery is committed
to ensuring greater self-reliance in supplying the vital energy products thereby bringing greater growth and
prosperity in and around Western India and the State of Gujarat.

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I visited following departments and focused on Basic Mechanical Components and Mechanical
Maintenance.
1. Motor Sprit Quality Upgradation (MSQU)
2. Delayed Coker Unit (DCU)
3. Thermal Power Station (TPS)
4. Cogeneration Plant (CGP)
5. Atmospheric Unit (AU)
6. Mechanical Workshop
In above section I observed different machines like pumps, valves, safety equipment, boiler,
Jet engine, turbine, compressor, pipe structure, bearings, couplings, fans, gauges, automation
techniques, mechanical seals, etc.

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BASIC PROCESS IN REFINERY

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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 and
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
Liquid flow path inside a centrifugal pump
A centrifugal pump is a pump that consists of a fixed impeller on a rotating shaft that is enclosed
in 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 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 size of the impeller, the type of material being pumped, and the total head of the
system through which the liquid is moving.

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General components of Centrifugal Pump
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 refineries 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.
The cantilever pump has a much larger diameter shaft, since it has no lower sleeve bearings
that act to support the impeller and shaft.

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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 Pump
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 200o
C, intermediate support,
thicker pump casing, cooling seals oil lubrication bearings;
 Vertical and horizontal with packing seal can be designed according to the different
working condition;
 Beautiful outline design.

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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 Refinery
 For circulation of cooling water.
 In liquid storage tanks.
 For pump the fluid (crude oil, VGO, diesel, etc.) in reactors, coulombs, etc. with
high pressure.

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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 section.
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 increase 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 the 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 part of the pump.
NPSH Required (NPSHR): The minimum pressure required at the suction port of the pump
to keep the pump away 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 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 valve 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 pump, 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 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 to standard low suction energy pumps is
to insure that 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 screws 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
characteristic. The external housings also allow 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: 10kg/cm2
NPSH Available: 10 m
Applications
 Mostly used for high viscous fluid.
 Used where high pressure is needed.

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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:
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.

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2. Flow and Viscosity
In the Centrifugal Pump the flow is reduced when the viscosity is increased.
In the Positive Displacement Pump the flow is increased when the viscosity is increased.
Liquids with high viscosity fill the clearances of 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

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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.
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
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.

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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.
 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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VIBRATION
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.
(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

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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.
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

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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 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.

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Vibration Monitoring Sensors & Selections
Sensors & Sensors 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 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 costlier
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.

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 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 GUJARAT REFINERY
 Gate Valve
 Globe Valve
 Ball Valve
 Butterfly Valve
 Plug Valve

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1. Gate Valve
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 loss 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 recommended 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
BALL VALVE
The ball valve has a spherical plug as a closure member. Seal on ball valves is excellent, the ball
contact circumferentially uniforms the seat, which is usually made of soft materials.
Depending upon the type of body the ball valve can be more or less easily maintained. Drop
pressure relative its hole size is low.

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Application in Refinery
 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
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 in
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 cheaper actuator. The actuator can be manual, oleo hydraulic or
electric 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 deposited 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 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 handle fluid 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 requires high maintenance cost.
 Require more time for maintenance.

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5. Globe Valve
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.
NON RETURNING VALVE
Operational Principle 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 rates; the higher the flow rate, the further
the ball or poppet has to move off its seat 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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38. Page | 38

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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.
PRESSURE SAFETY VALVE OR RELIEF VALVE
The pressure is relieved by allowing the pressurized fluid to flow an auxiliary passage out of the
system. The relief valve is designed or set to open at a predetermined set pressure to protect

40. Page | 40
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 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
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 like 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
sufficient quantities of gas or high volumes of liquid must be quickly discharged in order
to protect the integrity of the vessel or the pipeline. This protection can alternatively be
achieved by installing a high integrity pressure protection system (HIPPS).
Application
 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.
 Safety valves also evolved to protect equipment such as pressure vessels (fired or
not) and heat exchangers.
 The term safety valve should be limited to compressible fluid applications (gas,
vapor, or steam).

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 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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HEAT EXCHANGERS
A heat exchanger is a device used to transfer heat between a solid and a fluid, or between two or
more fluids. The fluids may be separated by a solid wall to prevent mixing or they may be in
direct contact. They are widely used in space heating, refrigeration, air conditioning, power
stations, chemical plants, petrochemical plants, petroleum refineries, natural-gas processing, and
sewage treatment. The classic example of a heat exchanger is found in an internal combustion
engine in which a circulating fluid known as engine coolant flows through radiator coils and air
flows pass the coils, which cools the coolant and heats the incoming air. Another example is the
heat sink, which is a passive heat exchanger that transfers the heat generated by an electronic or a
mechanical device to a fluid medium, often air or a liquid coolant.
HEAT EXCHANGER
There are three primary classification of heat exchangers according to their flow arrangement.
 In parallel flow heat exchangers, both the hot and cold fluids enter the heat
exchanger at the same end and move in the same direction.
 In counter flow heat exchangers, the hot and cold fluids enter the heat exchanger
at opposite ends and flow in opposite directions.
 In cross-flow heat exchangers, the two fluids usually move perpendicular to each
other.
For efficiency, heat exchangers are designed to maximize the surface area of the wall between
the two fluids, while minimizing resistance to flow through the exchanger. The exchanger’s
performance can also be affected by the addition of fins or corrugations in one or both directions,
which increase surface area and may channel fluid flow or induce turbulence.
The driving temperature across the heat transfer surface varies position, but an appropriate mean
temperature can be defined.

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TYPES OF HEAT EXCHANGERS
1. Double Pipe Heat exchanger
Double pipe heat exchangers are the simplest exchangers used in industries. On one
hand, these heat exchangers are cheap for both design and maintenance, making them
a good choice for small industries. On the other hand, their low efficiency coupled with
the high space occupied in large scales, has led modern industries to use more efficient
heat exchangers like shell and tube or plate. However, since double pipe heat
exchangers are simple, they are used to teach heat exchanger design basics to students
as the fundamental rules for all heat exchangers are the same.
2. Shell and Tube Heat exchanger
Shell and tube heat exchangers consist of series of tubes. One set of these tubes contains
the fluid that must be either heated or cooled. The second fluid runs over the tubes that
are being heated or cooled so that it can either provide the heat or absorb the heat
required. A set of tubes is called the tube bundle and can be made up of several types
of tubes: plain, longitudinally finned, etc. Shell and tube heat exchangers are typically
used for high-pressure applications (with pressures greater than 30 bar and temperature
greater than 260o
C). This is because the shell and tube heat exchangers are robust due
to their shape. Several thermal design features must be considered when designing the
tubes in the shell and tube heat exchangers: There can be many variations on the shell
and tube design. Typically, the ends of each tube are connected to plenums (sometimes

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called water boxes) through holes in tube sheets. The tubes may be straight or bent in
the shape of a U, called U-tubes.
 Tube diameter: Using a small tube diameter makes the heat exchanger both economical and
compact. However, it is more likely for the heat exchanger to foul up faster and the small
size makes mechanical cleaning of the fouling difficult. To prevail over the fouling and
cleaning problems, larger tube diameters can be used. Thus to determine the tube diameter,
the available space, cost and fouling nature of the fluids must be considered.
 Tube thickness: The thickness of the wall of the tubes is usually determined to ensure:
 There is enough room for corrosion
 That flow-induced vibration has resistance
 Axial strength
 Availability of spare parts
 Hoop strength (to withstand internal tube pressure)
 Buckling strength (to withstand overpressure in the shell)
 Tube length: heat exchangers are usually cheaper when they have a smaller shell diameter
and a long tube length. Thus, typically there is an aim to make the heat exchanger as long as
physically possible whilst not exceeding production capabilities. However, there are many
limitations for this, including space available at the installation site and the need to ensure
tubes are available in lengths that are twice the required length (so they can be withdrawn
and replaced). Also, long, thin tubes are difficult to take out and replace.
 Tube pitch: when designing the tubes, it is practical to ensure that the tube pitch (i.e., the
centre-centre distance of adjoining tubes) is not less than 1.25 times the tubes' outside
diameter. A larger tube pitch leads to a larger overall shell diameter, which leads to a more
expensive heat exchanger.
 Tube corrugation: this type of tubes, mainly used for the inner tubes, increases the turbulence
of the fluids and the effect is very important in the heat transfer giving a better performance.
 Tube Layout: refers to how tubes are positioned within the shell. There are four main types
of tube layout, which are, triangular (30°), rotated triangular (60°), square (90°) and rotated
square (45°). The triangular patterns are employed to give greater heat transfer as they force
the fluid to flow in a more turbulent fashion around the piping. Square patterns are employed
where high fouling is experienced and cleaning is more regular.
 Baffle Design: baffles are used in shell and tube heat exchangers to direct fluid across the
tube bundle. They run perpendicularly to the shell and hold the bundle, preventing the tubes
from sagging over a long length. They can also prevent the tubes from vibrating. The most
common type of baffle is the segmental baffle. The semicircular segmental baffles are
oriented at 180 degrees to the adjacent baffles forcing the fluid to flow upward and
downwards between the tube bundle. Baffle spacing is of large thermodynamic concern
when designing shell and tube heat exchangers. Baffles must be spaced with consideration
for the conversion of pressure drop and heat transfer. For thermos economic optimization it
is suggested that the baffles be spaced no closer than 20% of the shell’s inner diameter.
Having baffles spaced too closely causes a greater pressure drop because of flow redirection.
Consequently, having the baffles spaced too far apart means that there may be cooler spots in
the corners between baffles. It is also important to ensure the baffles are spaced close enough

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that the tubes do not sag. The other main type of baffle is the disc and doughnut baffle,
which consists of two concentric baffles. An outer, wider baffle looks like a doughnut, whilst
the inner baffle is shaped like a disk. This type of baffle forces the fluid to pass around each
side of the disk then through the doughnut baffle generating a different type of fluid flow.
Fixed tube liquid-cooled heat exchangers especially suitable for marine and harsh applications
can be assembled with brass shells, copper tubes, brass baffles, and forged brass integral end
hubs.

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3. Plate Heat Exchanger
Another type of heat exchanger is the plate heat exchanger. One is composed of
multiple, thin, slightly separated plates that have very large surfaces areas and fluid
flow passages for heat transfer. This stacked-plate arrangement can be more effective,
in a given space, than the shell and tube heat exchanger.
4. Plate and Shell Heat Exchanger
A third type of heat exchanger is a plate and shell heat exchanger, which combines
plate heat exchanger with shell and tube heat exchanger technologies. The heart of
the heat exchanger contains a fully welded circular plate pack made by pressing
and cutting round plates and welding them together. Nozzles carry flow in and out
of the plate pack (the 'Plate side' flow path). The fully welded plate pack is
assembled into an outer shell that creates a second flow path (the 'Shell side'). Plate
and shell technology offers high heat transfer, high pressure, high operating
temperature, using and close approach temperature. In particular, it does
completely without gaskets, which provides security against leakage at high
pressures and temperatures.
5. Adiabatic Wheel Heat Exchanger
A fourth type of heat exchanger uses an intermediate fluid or solid store to hold
heat, which is then moved to the other side of the heat exchanger to be released.
Two examples of this are adiabatic wheels, which consist of a large wheel with fine
threads rotating through the hot and cold fluids, and fluid heat exchangers.
6. Plate Fin Heat Exchanger
This type of heat exchanger uses "sandwiched" passages containing fins to
increase the effectiveness of the unit. The designs include crossflow and counter
flow coupled with various fin configurations such as straight fins, offset fins and
wavy fins.
Plate and fin heat exchangers are usually made of aluminum alloys, which
provide high heat transfer efficiency. The material enables the system to operate
at a lower temperature difference and reduce the weight of the equipment. Plate

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and fin heat exchangers are mostly used for low temperature services such as
natural gas, helium and oxygen liquefaction plants, air separation plants and
transport industries such as motor and aircraft engines.
Advantages of plate and fin heat exchangers:
 High heat transfer efficiency especially in gas treatment.
 Larger heat transfer area.
 Approximately 5 times lighter in weight than that of shell and tube heat exchanger.
 Able to withstand high pressure.
Disadvantages of plate and fin heat exchangers:
 Might cause clogging as the pathways are very narrow.
 Difficult to clean the pathways.
 Aluminum alloys are susceptible to Mercury Liquid Embrittlement Failure.
7. Pillow Plate Heat Exchanger
A pillow plate exchanger is commonly used in the dairy industry for cooling milk
in large direct-expansion stainless steel bulk tanks. The pillow plate allows for
cooling across nearly the entire surface area of the tank, without gaps that would
occur between pipes welded to the exterior of the tank.
The pillow plate is constructed using a thin sheet of metal spot-welded to the
surface of another thicker sheet of metal. The thin plate is welded in a regular
pattern of dots or with a serpentine pattern of weld lines. After welding the
enclosed space is pressurized with sufficient force to cause the thin metal to bulge
out around the welds, providing a space for heat exchanger liquids to flow, and
creating a characteristic appearance of a swelled pillow formed out of metal.
Fluid heat exchangers
This is a heat exchanger with a gas passing upwards through a shower of fluid (often
water), and the fluid is then taken elsewhere before being cooled. This is commonly used
for cooling gases whilst also removing certain impurities, thus solving two problems at
once. It is widely used in espresso machines as an energy-saving method of cooling
super-heated water to use in the extraction of espresso.

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Optimization
There are three goals that are normally considered in the optimal design of heat exchangers:
(1) Minimizing the pressure drop (pumping power),
(2) Maximizing the thermal performance and
(3) Minimizing the entropy generation (thermodynamic)
Maintenance
 Plate and frame heat exchangers can be disassembled and cleaned periodically.
Tubular heat exchangers can be cleaned by such methods as acid
cleaning, sandblasting, high-pressure water jet, bullet cleaning, or drill rods.
 In large-scale cooling water systems for heat exchangers, water treatment such as
purification, addition of chemicals, and testing, is used to minimize fouling of the
heat exchange equipment. Other water treatment is also used in steam systems for
power plants, etc. to minimize fouling and corrosion of the heat exchange and
other equipment.
 A variety of companies have started using water borne oscillations technology to
prevent biofouling. Without the use of chemicals, this type of technology has
helped in providing a low-pressure drop in heat exchangers.

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COMPRESSORS
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its
volume.
As gas are compressible, the compressor also reduces the volume of a gas. Liquids are relatively
incompressible, while some can be compressed, the main action of pump is to pressurize and
transport liquids.
Types of compressors
The main types of gas compressors are illustrated and discussed below:
CLASSIFICATION OF COMPRESSOR

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1. Reciprocating Compressor
Reciprocating compressors use pistons driven by a crankshaft. They can be either stationary or
portable, can be single or multi-staged, and can be driven by electric motors or internal
combustion engines. Small reciprocating compressors from 5 to 30 horsepower (hp) are
commonly seen in automotive applications and are typically for intermittent duty.
Larger reciprocating compressors well over 1,000 hp (750 kW) are commonly found in large
industrial and petroleum applications. Discharge pressures can range from low pressure to very
high pressure (>18000 psi or 180 MPa). In certain applications, such as air compression, multi-
stage double-acting compressors are said to be the most efficient compressors available, and are
typically larger, and costlier than comparable rotary units. Another type of reciprocating
compressor is the swash plate compressor, which uses pistons which are moved by a swash plate
mounted on a shaft - see Axial Piston Pump.
RECIPROCATING COMPRESSOR
(The photo depicts a motor-driven, six-cylinders reciprocating compressor that can operate with
two, four or six cylinders.)
Household, home workshop, and smaller job site compressors are typically reciprocating
compressors 1½ hp or less with an attached receiver tank.

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2. Rotary Screw Compressor
ROTARY SCREW COMPRESSOR
Rotary screw compressors use two meshed rotating positive-displacement helical screws to force
the gas into a smaller space. These are usually used for continuous operation in commercial and
industrial applications and may be either stationary or portable. Their application can be from 3
horsepower (2.2 kW) to over 1,200 horsepower (890 kW) and from low pressure to moderately
high pressure (>1,200 psi or 8.3 MPa).
Rotary screw compressors are commercially produced in Oil Flooded, Water Flooded and Dry
type.

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3. Diaphragm Compressor
DIAPHRAGM COMPRESSOR
(A three-stage diaphragm compressor)
A diaphragm compressor (also known as a membrane compressor) is a variant of the conventional
reciprocating compressor. The compression of gas occurs by the movement of a flexible
membrane, instead of an intake element. The back and forth movement of the membrane is driven
by a rod and a crankshaft mechanism. Only the membrane and the compressor box come in
contact with the gas being compressed.
Diaphragm compressors are used for hydrogen and compressed natural gas (CNG) as well as in
a number of other applications.
The photograph included in this section depicts a three-stage diaphragm compressor used to
compress hydrogen gas to 6,000 psi (41 MPa) for use in a prototype compressed hydrogen and
compressed natural gas (CNG) fueling station built in downtown Phoenix, Arizona by the
Arizona Public Service company (an electric utility company). Reciprocating compressors were
used to compress the natural gas.
The prototype alternative fueling station was built in compliance with all of the prevailing safety,
environmental and building codes in Phoenix to demonstrate that such fueling stations could be
built in urban areas.

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4. Centrifugal Compressor
CENTRIFUGAL COMPRESSOR
(A single stage centrifugal compressor)
Centrifugal compressors use a rotating disk or impeller in a shaped housing to force the gas to
the rim of the impeller, increasing the velocity of the gas. A diffuser (divergent duct) section
converts the velocity energy to pressure energy.
They are primarily used for continuous, stationary service in industries such as oil refineries,
chemical and petrochemical plants and natural gas processing plants. Their application can be
from 100 horsepower (75 kW) to thousands of horsepower.
With multiple staging, they can achieve extremely high output pressures greater than 10,000 psi
(69 MPa). Many large snowmaking operations (like ski resorts) use this type of compressor.
They are also used in internal combustion engines as superchargers and turbochargers.
Centrifugal compressors are used in small gas turbine engines or as the final compression stage
of medium sized gas turbines. Sometimes the capacity of the compressors is written in NM3/hr.
Here 'N' stands for normal temperature pressure (20°C and 1 atm) for example 5500 NM3/hr.

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5. Scroll Compressor
A scroll compressor, also known as scroll pump and scroll vacuum pump, uses two interleaved
spiral-like vanes to pump or compress fluids such as liquids and gases. The vane geometry may
be involute, Archimedean spiral, or hybrid curves. They operate more smoothly, quietly, and
reliably than other types of compressors in the lower volumerange.
SCROLL COMPRESSOR
(A scroll compressor)
Often, one of the scrolls is fixed, while the other orbits eccentrically without rotating, thereby
trapping and pumping or compressing pockets of fluid or gas between the scrolls.
This type of compressor was used as the supercharger on Volkswagen G60 and
G40 engines in the early 1990s.

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Parts of Reciprocating Compressor
Introduction
The important parts of the reciprocating compressor are: cylinder, piston, piston rings,
connecting rod, crankshaft, suction valve, discharge valve, suction port, discharge port
etc. All these parts have been described in details below (refer the image below):
1. Cylinder
In small compressors the cylinder is made by directly boring into the main body
of the compressor, which is usually made up of cast iron. In case of the large
multi-cylinder compressors, the cylinder is made separately and it is fitted into the
main body of the compressor. This type of cylinder is also called as the liner or
sleeve. In such compressors if any of the cylinders gets worn out or damaged, it
can be replaced easily by the new liner, without having to replace the whole
compressor.
2. Piston
The piston performs upwards and downwards motion inside the cylinder, this is
also called as the reciprocating motion. During its motion the piston enables suction
and compression of the working fluid. The piston is made of cast iron or aluminium.

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During its motion inside the cylinder the working fluid should not leak through the
gap between the cylinder walls and the piston to the crankcase, hence piston is
covered with the piston rings. The piston rings are not required in the smaller
compressors. The gap between the piston and the cylinder is also filled with the
lubricating oil, which also prevents the leakage of the compressed refrigerant to the
crankcase.
3. Piston Rings
The piston rings are circled around the piston. When the piston performs
reciprocating motion inside the cylinder, it is the piston rings that come in contact
with the walls of the cylinder. There is lots of friction between the cylinder walls
and the piston rings, thus they have to be replaced from time-to-time for proper
functioning of compressor. This helps increasing the life of the piston and prevents
replacement of the complete piston.
4. Crankshaft
The piston can perform reciprocating motion inside the cylinder because of the
rotary motion of the crankshaft. The crankshaft is the main shaft of the
compressor. On one side it is connected to the electric motor directly by the
coupling or by the belt and pulley arrangement. The rotation of the motor shaft
brings about the rotation of the crankshaft. On the other side the crankshaft is also
connected to the connecting rod, which is then connected to the piston at it other
end. The rotary motion of the crankshaft is converted into the reciprocating motion
of the piston by connecting rod. In case of the multi- cylinder compressors, the
number of connecting rods connected to the crankshaft is same as the number of
cylinders.
5. Connecting Rod
The connecting rod is the connecting link between the piston and the crankshaft.
On one side the connecting rod is connected to the piston by piston pin and on the
other side it is connected to the crankshaft by connecting rod cap. Both these
connections of the connecting rod enable converting the rotary motion of the
crankshaft into the reciprocating motion of the piston inside the cylinder. The
connecting rod is usually made up of carbon steel forging.
6. Suction Valve and Discharge Valve
Through the suction valve the low pressure refrigerant is sucked inside the
cylinder and through the discharge valve the compressed high pressure refrigerant
is discharged to the discharge line, from where the refrigerant goes to the

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condenser. The operation of the suction valve is such that is opens when the piston
moves downwards and closes when the refrigerant is being discharged. The
discharge valve opens only when piston reaches to certain level inside the cylinder
and refrigerant has reached to the desired level of pressure. When the refrigerant
is delivered from the cylinder, the discharge valve closes.
7. Suction and Discharge Pipelines
Through the suction piping the low pressure refrigerant is taken inside the cylinder
via suction valve. The high pressure compressed refrigerant is delivered though
the discharge line.

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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 college classes my quest for knowledge is satisfied
theoretically. Exposure to real field knowledge is obtained during such vocational training. I have
learnt a lot about pumps, valves, compressors, heat exchangers, machine vibrations and their
analysis and many more things of working in an industry. I might have thoroughly learnt the theory
behind these but practical knowledge about these were mostly limited to samples at laboratory. At
IOCL I actually saw the equipment used in industry. Though the underlying principles remains
same but there are differences as far as practical designs are considered.
I also got to know additionally about other features not taught or known earlier. This has helped
to clarify my theoretical knowledge a lot. Apart from knowing about matters restricted to my own
discipline I also got to know some other things about the processing of crude and manufacturing
of various petrochemical products and fuels which I might not have necessarily read within in my
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 senior to me have also helped me a lot. It is they
who, apart from throwing light on equipment, 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 others extracurricular concepts which are also
important. Thus my 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/centrifugal-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/ValveTypesSelection
9. http://www.wermac.org/valves/valves_ball.html
10. http://www.iklimnet.com/expert_hvac/valves.html
11. Fundamentals of vibrations by FM-Shinkawa