SUMMER TRAINING REPORT

ON

“HEAVY FABRICATION”

Submitted ByPlash Chopra

Mechanical engg.

Performed at

Bharat Heavy Electricals LimitedRanipur, Haridwar

(From 15 June to 14 July 2012)

MILLENNIUM INSTITUTE OF TECHNOLOGY SAHARANPUR (UP)

ACKNOWLEDGEMENT

“An engineer with only theoretical knowledge is not a complete engineer. Practical knowledge is very important to develop and apply engineering skills”. It gives me a great pleasure to have an opportunity to acknowledge and to express gratitude to those who were associated with me during my training at BHEL.

Special thanks to Mr .H. Haldhar for providing me with an opportunity to undergo training under his able guidance.I am very great full to our training and placement officer Mr. KAPIL GOYAL for his support.

I express my sincere thanks and gratitude to BHEL authorities for allowing me to undergo the training in this prestigious organization. I will always remain indebted to them for their constant interest and excellent guidance in my project work, moreover for providing me with an opportunity to work and gain experience.

Plash ChopraB.Tech Final Year Mechanical Engineering

MILLENNIUM Inst. Of Technology , Saharanpur(UP)

CONTENTS

INTRODUCTION

COMPANY PROFILE

TRAINING DEPARTMENT

LAYOUT OF BLOCK-2

WORK UNDERGONE & EXPERIENCE

CONCLUSION

INTRODUCTION

In 1956 India took a major step towards the establishment of its first heavy electrical engineering manufacturing plant at Bhopal. It progressed rapidly and three more factories went into production in 1965. In 1969 BHEL supplied its first unit to Basin Bridge Thermal Power Station in Tamil Nadu. Within a decade BHEL had commissioned the 100th unit at Santaldih,WB.The present scenario of BHEL consists of 11 manufacturing divisions, 9 service centers, 4 power sector regional center, about 350 large consumers(in India ) and many countries also. The companies inherent potential coupled with its strong performance make this one of the “NAVRATNAS”, which are supported by the government in their endeavor to become future global players. AND TODAY BHEL CAN BE PROUD TO ANNOUNCE THAT 75% OF TOTAL POWER INDUSTRY OF OUR COUNTRY COMES FROM THE BHEL ITSELF IN LESS THAN 4 DECADES OF ITS HISTORY.

BHEL UNITS

UNIT PERIOD TYPE

1. Bhopal Established 1956Production started1960

Heavy Electrical Plant

2. Haridwar HEEP CFFP

Established 1963Production started1967 Established 1974Production started1976

Heavy Electrical Equipment Plant, Central Foundry Forge Plant

3.Hyderabad HPEP

Established 1963Production started1965

Heavy Power Equipment Plant

4.Tiruchi HPBP SSTP

Established 1963Production started1965 Production started1979

High Pressure Boiling Plant

5.Jhansi TP

Production started1976 Transformer Plant

6.Banglore EDN EPD ISG

Established 1963Established 1972 Established 1977

Control equipment divisionElectro Porcelain division

7.Ranipet BAP

Established 1976

8.Goindwal Established 1983

9.Jagdishpur IP

Production started1984 High tension ceramic Insulation Plates

10.Rudrapur Production started1984

11.Gurgoan Solar Photovoltaic Cells

COMPANY PROFILE

BHEL HARDWAR

LOCATION Situated in the foot hills of Shivalik range in Haridwar. The main administrative building is at a distance of about 8km from Haridwar.

ADDRESS Bharat Heavy Electrical Limited Ranipur, Hardwar PIN 249403

AREA BHEL Hardwar consists of two manufacturing units, namely Heavy Electrical Equipment Plant (HEEP) and Central Foundry Forge Plant (CFFP), having area

HEEP: 845 sq km

CFFP: 1.0 sq km

THERE ARE 8 BLOCKS IN HEEP

BLOCKS PRODUCTS

I. Electrical Machine Turbo generator, generator exciter , motor (ac,dc)

II. Fabrication Large size fabricated assemblies/components

III. Turbine & Auxiliary

Steam ,hydro ,gas turbines, turbine blade , special tooling

IV. Feeder Winding of Turbo ,hydro gen. ,insulation for ac & dc motors

V. Fabrication Fabricated parts of steam turbine , water boxes ,storage tank ,hydro turbine parts.

VI. Fabrication Stamping and die manufacturing

Fabricated oil tanks, hollow guide blades, rings, stator frames, and rotor spindle. All dies. Stamping for gen. and motors

VII. Wood working Wooden packing, spacers

VIII. Heaters & coolers

LP heaters, ejectors, glands, steam and oil coolers, oil tank, bearing covers.

TRAINING DEPARTMENTManufacturing Facilities-

Preparation ,Bay -1It has the following sections

a) Marking cutting and straightening section.b) Gas cutting section including CNC flame cutting section & CNC Plasma

cutting section.c) Press section (400T and 800T, Brake press).d) Shearing M/c section.

Assembly and Welding Section .Bay -2

a) Assembly and welding section for large size units up to 75 tons.b) Heat treatment section.c) Shot blasting and cleaning section.

Sections in Bay -3

a) Assembly and welding sections of small size units unto 10 tons. b) Pipe sections.

Sections in Bay -4

a) Machine section : It is designed for machining parts and units during fabrication stage. This section supplies small parts and units of Steam turbine, generators, hydro-turbine etc….The unique machines viz. CNC multi spindle drilling machines and Horizontal ram borer are installed to help in machining of various components like drilling of tube plates of different types apart from machining of big assemblies such as front wall, casing, water boxes etc…..

b) Diaphragm section : Welded diaphragms of steam turbines are assembled, welded and stress relieved in this section.

c) Coolers section : In this section tubes of coolers are cut to the required size, then turned and thereafter winding and soldering of spirals on tubes is carried out by automatic machines. These are then assembled to form coolers which are then assembled and hydraulically tested.

Manufacturing processes-

Manufacturing starts with Preparation of individual parts before assembly, in Bay -1.

a) The metal is first marked and cut by the following machines:- - Gullotine Shearing machine for cutting and trimming steel sheets and plates up to 25mm thick with straight contours.

- Stationary and portable Oxy-acetylene cutting machines for cutting machines for cutting parts out of steel plates.

- An unique Flame cutting machine is used for cutting steel plates by CNC programming. - CNC Plasma cutting M/c for cutting S.S & higher alloys. - Combination punch, shear and bar cutters, circular saws and bar shears are used for cutting angles, shapes, flats and rods.

b) Straightening Rollers are used for straightening plates and large sized blanks and a 160 ton friction press for straightening small sized blanks. A roll bending machine is used for straightening and bending rolled beams and angles.

c) A 800 ton hydraulic bending and 400 ton press and a 250 ton friction press are used for cold and hot bending from rolled sheets and shapes. Parts to bend are pre heated in a 700 KW electric furnace, when ever needed.

d) Finished parts are inspected at the working place.

After Preparation is complete the next step is Assembly and Welding in Bay -2 and 3 is as follows:

a) Components of units are assembled and tack welded for subsequent welding as per drawing and instructions on process cards.

b) Manual arc welding arc welding is employed in restricted and inaccessible places or where semi-automatic or automatic welding is not possible or has not been established.

c) Semi-Automatic submerged arc welding, GTAW and Argon Carbon-di-Oxide shielded arc welding are also used for increased productivity and better quality.

All assembly work is carried out on bed plates. Small size structures are welded with the help of manipulators.

Welding of high pressure cylinders of steam turbines is carried out after preliminary heating up to 250° C.

Heat treatment is carried out in electric furnaces of bogie hearth, bell and pit types after welding is completed.

In multi layer welding, the roots of seams are gouged and then cleaned by mechanical means.

All assembly and welding sections have connections for compressed air, oxygen & acetylene as well Argon carbon-di-oxide mixture and water for semi automatic welding.

Weld quality inspection is adopted in accordance with the relevant specifications.

Inspection of weld quality and flaw detection is carried out by means of X-ray machines, gammagraphy machines of cobalt and iridium isotopes and ultrasonic flaw detectors.

Pressure vessels that is boilers, heaters, condensers and coolers undergo hydraulic tests on special test beds meant for hydraulic testing. Kerosine leakage test is also done in case of thin walled vessels.

Process being followed in pipe section is mentioned below:a) Pipes with diameter of 10-60 mm and 38-108 mm are cut on pipe cutting

machines and oxy-aceytlene cutters.b) Cold bending of pipes is carried out on a pipe bending machine. Bending of

carbon and alloy steel pipes of 114 mm dia and above is performed by heating them in electric furnaces and then by hot bending.

c) Facing of pipes and beveling for welding is carried out on a horizontal boring machine with portable type pipe chamfering machine.

d) For assembly and welding of pipes bed plates and manipulators are used.e) Heat treatment of pipes is done in electric furnace mentioned earlier.f) Surface cleaning is done manually or by shot blasting. Pipe assemblies are dimensionally checked and quality of welds is tested

by X-ray and Gammagraphy.

Process being followed in machining section is as follows:a) Casting, forging, rolled section and welded structures are delivered to

sections where assembly and welding are done in accordance with specifications set forth in drawings.

b) Pre weld machining for large sized parts for steam turbines and hydro turbines are carried out in block-3.

c) Provision is made for the application of highly productive cemented carbide tiped cutting tools, high speed cutting with maximum utilization with machine tool capacity and rapid section locating and clamping fixture.

Process being followed in painting section is as follows:a) Painting materials used and painting processes adopted, conform to the

standards for tropical climates.b) Owing to different operating conditions and decoration requirements of

units and parts of turbines and electrical machines, different processes for painting are adopted.

c) Some components and units undergo only prime coating in the steel structure section, with subsequent painting in the painting section of the machine and assembly section.

WORK UNDERGONE & EXPERIENCE

During my training period at the block-2 I came to know about the main processes which went through the block.Most of the manufacturing process have been told about earlier. Some more machineries and processes are given here.Some of them were like plasma cutting, NDT testing, Hydraulic presses,turning, gas cutting etc.

The various processes and machinery are as follows:

A)Hydraulic Press:A hydraulic press is a hydraulic mechanism for applying a large lifting or compressive force. It is the hydraulic equivalent of a mechanical lever, and is also known as a Bramah press after the inventor, Joseph Bramah. Hydraulic presses are the most commonly-used and efficient form of modern press.

The hydraulic press depends on Pascal's principle: the pressure throughout closed system is constant. At one end of the system is a piston with a small cross-sectional area driven by a lever to increase the force. Small-diameter tubing leads to the other end of the system. A fluid, such as oil, is displaced when either piston is pushed inward. The small piston, for a given distance of movement, displaces a smaller amount of volume than the large piston, which is proportional to the ratio of areas of the heads of the pistons. Therefore, the small piston must be moved a large distance to get the large piston to move significantly. The distance the large piston will move is the distance that the small piston is moved divided by the ratio of the areas of the heads of the pistons.

B)Oxy-Fuel Welding And Cutting: Oxy-fuel welding (commonly called oxyacetylene welding or oxy welding or in the U.S. gas welding) and Oxy-fuel cutting are processes that use fuel gases and oxygen to either weld or cut metals.

There are a few differences between the two. In Oxy-fuel welding, a welding torch is used to weld metals. In Oxy-fuel cutting, a cutting torch is used to heat up ferrous metal to kindling temperature (about 980°C). A stream of pure oxygen is trained on the hot metal which chemically combines with the iron which then flows out of the cut, or kerf, as an iron-oxide slag

Torches that do not mix pure oxygen with the fuel inside the torch, but burn it with atmospheric air, are not oxy-fuel torches and can be identified by their single tank. (Oxy-fuel welding/cutting needs two tanks, fuel and oxygen.) Most metals cannot be melted with such single-tank torches, so they can only be used for soldering and brazing, not welding.

Apparatus used in Oxy-Fuel welding and cutting:

The apparatus used in gas welding consists basically of an oxygen source and a fuel gas source (usually cylinders), two pressure regulators and two flexible hoses (one of each for each cylinder), and a torch. This sort of torch can also be used for soldering and brazing. The cylinders are often carried in a special wheeled trolley.

There have been examples of oxyhydrogen cutting sets with small (scuba-sized) gas cylinders worn on the user's back in a backpack harness, for rescue work and similar.

There are also examples of pressurized liquid fuel cutting torches, usually using gasoline. These are used for their increased portability.

C)Planers: A planer is a type of metalworking machine tool that is analogous to a shaper, but larger, and with the entire workpiece moving beneath the cutter, instead of the cutter moving above a stationary workpiece. The work table is moved back and forth on the bed beneath the cutting head either by mechanical means, such as a rack and pinion gear, or by a hydraulic cylinder.

Planers and shapers were used generally for two types of work: generating accurate flat surfaces and cutting slots (such as keyways). Planers and shapers are now obsolescent, because milling machines have eclipsed them as the machine tools of choice for doing such work.

D)Plasma Cutting: Plasma cutting is a process that is used to cut steel and other metals (or sometimes other materials) using a plasma torch. In this process, an inert gas (in some units, compressed air) is blown at high speed out of a nozzle; at the same time an electrical arc is formed through that gas from the nozzle to the surface being cut, turning some of that gas to plasma. The plasma is sufficiently hot to melt the metal being cut and moves sufficiently fast to blow molten metal away from the cut.

Cutting Methods: Plasma cutters have also been used in CNC machinery. Manufacturers build CNC cutting tables, some with the cutter built in to the table. The idea behind CNC tables is to allow a computer to control the torch head making clean sharp cuts. Modern CNC plasma equipment is capable of multi-axis cutting of thick material, allowing opportunities for complex welding seams on CNC welding equipment that is not possible otherwise.

E)Three roll bending machine: Roll benders use three rolls (typically) to bend solids, extrusions and tube and pipe to various diameters by adjusting one or two rolls. The pyramid style roll benders have one moving roll, usually the top roll.

Double pinch type roll benders have two adjustable rolls, usually the bottom rolls, and a fixed top roll. Large arcs, circles and spirals are typical applications for roll benders.

The roll bending machine in BHEL has following specifications:

Maximum working length:8000 mm.

Minimum diameter of forming:1300 mm.

Plate thickness:32 mm,

Upper rolled dia.:7550 mm.

Lower roll dia.:680 mm.

Speed of forming :5 m per minute.

Speed of lowering upper roll :60 mm per minute.

Speed of raising upper roll :120 mm per minute

F) Boot Press Furnace: This press was having following furnace :

Power:750KW.Furnace size : length-4000 mm

Width :2400 mm.

Height :1600 mm.

Zones: 5

G)Centre lathe with three and four jaws: A metal lathe is generic description for a rigid machine tool designed to remove material from a workpiece, through the action of a cutting tool. They were originally designed to machine metals; however, with the advent of plastics and other materials, and with their inherent versatility, they are used in a wide range of applications, and a broad range of materials.

A center lathe is a dual head machine where the work remains fixed and the heads move towards the workpiece and machine a center drill hole into each end. The resulting workpiece may then be used "between centers" in another operation. The usage of the term metal lathe may also be considered somewhat outdated these

days, plastics and other composite materials are in wide use and with appropriate modifications, the same principles and techniques may be applied to their machining as that used for metal.

A center lathe or engine lathe may be considered the basis for the metal lathe and is the type most often used by the general machinist or hobbyist.The center lathe may be considered a useful starting point. The engine lathe is the name applied to a traditional 20th century lathe. It is assumed that the 'engine' was added to the description to separate them from the 'foot lathes' (lathes turned by pedals) or other hand rotated pieces of machinery. Early engine lathes were generally 'cone heads', in that the spindle usually had attached to it a multi-step pulley designed to accept a flat belt. Different spindle speeds could be obtained by moving the flat belt to different steps on the cone pully. It was assumed that a cone head lathe would be powered by a Line shaft which was the industrial standard of the time

H)Manipulator:Parts that cannot be welded easily by ordinary welding, specially internal curved parts are welded by manipultaors .

I)Non Destructive Testing: Nondestructive testing (NDT) has been defined as comprising those test methods used to examine an object, material or system without impairing its future usefulness. The term is generally applied to non medical investigations of material integrity.

The main NDT processes at the fabrication block are as follows:

1)Visual inspection : It is the simplest ,cheapest and most widely used method amongst all the NDTs.A simple visual test reveal gross surface defects easily and quickly . However for detection of final defects, device/equipments having high degree of precision and illumination are required.

2)Radiography: In this test the X-rays and gamma rays are used to detect deep seated internal defects. The short wavelengths of X-ray permitted to penetrate through the opaque material. Gamma rays are the electro-magnetic radiations that are emitted from an unstable nucleus.

3)Penetrant Testing - Penetrant solution is applied to the surface of a precleaned component. The liquid is pulled into surface-breaking defects by capillary action. A developer is applied to pull the trapped penetrant back to the surface where it is

spread out and forms an indication. The indication is much easier to see than the actual defect

J) Vertical boring machine C-208: The specification of this machine is as follows:

Chuck diameter = 4 m

Maximum chuck speed = 30 rpm

Minimum chuck speed = .2 rpm

Use to make Guide blade carrier

Feed can be given at any time .

Pendant is used for the performance on the job.

Operations performed are turning, facing, boring, taper machining.

K)CNC Flame Cutting

Setup in BHEL in 1982 and imported from Germany.

Maximum depth of cutting: 250mm -300mm.

Gas used – oxyacetylene

Program are saved and made by the programmer.

Different nozzle are used for different jobs.

L)CNC Plasma Cutting Machine

Arc is maintained between a non consumable electrode and work piece.

High temperature is reached upto 35000°c

Cu nozzle is used through which tungsten electrode is fed.

Maximum cutting thickness is 80 mm.

Much faster.

Narrow heat affected zone.

Used for cutting non ferrous metal

CONCLUSION

Gone through a rigorous four weeks training under the guidance of capable engineers and workers of BHEL Haridwar in Block-2 headed by Mr. H. Haldhar situated in Ranipur, Haridwar Uttarakhand.

The training ,was specified under the Heavy Fabrication Department. Working under the cam machining department the basic grinding, scaling and machining was shown on heavy to medium duty lathes planted in the same line where the specified work was undertaken.

The training brought to my knowledge the various machining and fabrication processes went in not only in the manufacturing of cams but other iron casted products. Thus the training was successfully accomplished under very able guidance of the engineers.