Vocational Training at IOCL, Panipat ( Mechanical Department) Report


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Detailed report on vocational training undergone in mechanical department of IOCL, Panipat

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Vocational Training at IOCL, Panipat ( Mechanical Department) Report

  1. 1. 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)
  2. 2. 2 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.
  3. 3. 3 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.
  4. 4. 4 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
  5. 5. 5 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.
  6. 6. 6 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.
  7. 7. 7 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
  8. 8. 8 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.
  9. 9. 9 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;
  10. 10. 10 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
  11. 11. 11 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.
  12. 12. 12 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.
  13. 13. 13 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.
  14. 14. 14 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:
  15. 15. 15 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
  16. 16. 16 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.
  17. 17. 17 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.
  18. 18. 18 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.
  19. 19. 19 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
  20. 20. 20 (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.
  21. 21. 21 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.
  22. 22. 22 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
  23. 23. 23 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
  24. 24. 24 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.
  25. 25. 25 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
  26. 26. 26 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.
  27. 27. 27 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
  28. 28. 28 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.
  29. 29. 29 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.
  30. 30. 30 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.
  31. 31. 31 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
  32. 32. 32 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.
  33. 33. 33 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).
  34. 34. 34
  35. 35. 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
  36. 36. 36 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.
  37. 37. 37 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).
  38. 38. 38 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
  39. 39. 39 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.
  40. 40. 40 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