steam turbine report

1. INDUSTRIAL TRAINING REPORT ON MACHINING OF
CRITICAL ASSEMBLIES OF STEAM TURBINE
(JUNE – JULY 2015)
A Report
submitted is partial fulfillment of the
requirement for the award of the Degree of
BACHELOR OF TECHNOLOGY
IN
MECHANICAL ENGINEERING
BY
MOHIT MAMGAIN (121190104029)
Department of Mechanical Engineering
SEEMANT INSTITUTE OF TECHNOLOGY
PITTHORAGARH (U.K.)
2012-2016

2. DECLARATION CERTIFICATE
This is to certify that the work presented in the project entitled “PROJECT REPORT ON
MACHINING OF CRITICAL ASSEMBLIES OF STEAM TURBINE” in partial fulfilment
of the requirement for the award of degree of Bachelor in Technology in Mechanical
Engineering from Seemant institute of Technology, Pitthoragarh is an authentic work carried out
under my supervision and guidance.
To the best of my knowledge , the content of this project does not form a basis for the award of
any previous degree to anyone else.
Date :
(Mr. DEVNIDHI BISHT)
Dept. of Mechanical Engineering
Seemant Institute of Technology
Pithoragarh
Head Director
Dept. of MechanicalEngineering SeemantInstitute of
Technology Technology
SeemantInstitute of Technology Pithoragarh
Pithoragarh

3. 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.
I am very grateful to Mr. AJMANI ROHIT for providing me with an opportunity to
undergo training under his able guidance.
Furthermore, special thanks to Mr. Raj Singh for his help and support in Haridwar. Last,
but not the least, I would also like to acknowledge the support of my college friends,
who pursued their training with me. We shared some unforgettable moments together.
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 training work, moreover for
providing me with an opportunity to work and gain experience.
THANK YOU

4. ABSTRACT
In the era of Mechanical Engineering, Turbine, A Prime Mover ( Which uses the Raw Energy of
a substance and converts it to Mechanical Energy) is a well known Machine most useful in the
the field of Power Generation. This Mechanical energy is used in running an Electric Generator
which is directly coupled to the shaft of turbine. From this Electric Generator, we get electric
Power which can be transmitted over long distances by means of transmission lines and
transmission towers.
In my Industrial Training in B.H.E.L., Haridwar I go through all sections in Turbine
Manufacturing. First management team told me about the history of industry, Area, Capacity,
Machines installed & Facilities in the Industry.
After that they told about the Steam Turbine its types , parts like Blades, Casing, Rotor etc. Then
they told full explanation of constructional features and procedure along with equipement used.
Before telling about the machines used in Manufacturing of Blade, they told about the safety
precautions, Step by Step arrangement of machines in the block with a well defined proper
format. They also told the material of blade for a particular desire, types of Blades, Operations
performed on Blades, their New Blade Shop less with Advance Technology like CNC Shaping
Machine.
I would like to express my deep sense of Gratitude and thanks to MR. AJMANI ROHIT
in charge of training in Turbine Block in B.H.E.L., Haridwar. Without the wise counsel and able
guidance, it would have been impossible to complete the report in this manner. Finally, I am
indebted to all who so ever have contributed in this report and friendly stay at Bharat Heavy
Electricals Limited (BHEL).

5. INDEX
SR NO TOPIC PAGE NO.
1. INTRODUCTION
2. BHEL - AN
OVERVEIW
3. STEAM TURBINE
4. BHEL HARIDWAR
5. TURBINE PARTS
6. MANUFACTURING
PROCESS
7. PLANT LAYOUT
8. CLASSIFICATION OF
BLOCK 3
9. CONCLUSION
10.

6. FIGURE INDEX
S.NO. FIGURE PAGE
1. Steam turbine
2. Turbine blades
3. Turbine casing
4. Turbine rotors
5. Furnace
6. Prepared mould
7. Boring process
8. Layout diagram
9. Over speed & vacuum balancing
tunnel (OSVBT)
10. Steam turbine casing and rotors in
assembly area

7. 1. INTRODUCTION
BHEL is the largest engineering and manufacturing enterprise in India in the energy
related infrastructure sector today. BHEL was established more than 40 years ago when
its first plant was setup in Bhopal ushering in the indigenous Heavy Electrical
Equipment Industry in India a dream which has been more than realized with a well
recognized track record of performance it has been earning profits continuously
since1971-72.
BHEL caters to core sectors of the Indian Economy viz., Power Generation's &
Transmission, Industry, Transportation, Telecommunication, Renewable Energy,
Defense, etc. The wide network of BHEL's 14 manufacturing division, four power Sector
regional centers, over 150 project sites, eight service centers and 18 regional offices,
enables the Company to promptly serve its customers and provide them with suitable
products, systems and services – efficiently and at competitive prices. BHEL has
already attained ISO 9000 certification for quality management, and ISO
14001certification for environment management. The company’s inherent potential
coupled with its strong performance make this one of the “NAVRATNAS”, which is
supported by the government in their endeavor to become future global players.
2. B.H.E.L- An Overview
BHEL or the Bharat Heavy Engineering Limited is one of the largest engineering and
manufacturing organizations in the country and the BHEL, Haridwar is their gift to
Uttaranchal. With two large manufacturing plants, BHEL in Haridwar is among the
leading industrial organizations in the state. It has established a Heavy Electrical
Equipment Plant or HEEP and a Central Foundry Forge Plant or CFFP in Haridwar.
The Heavy Electrical Equipment Plant in Haridwar designs and
manufactures turbo generators, AC and DC motors, gas turbines and huge steams. The
Central Foundry Forge Plant in Haridwar deals with steel castings and manufacturing of
steel forgings.
BHEL is an integrated power plant equipment manufacturer and one of the largest
engineering and manufacturing companies in India in terms of turnover. BHEL was
established in 1964, ushering in the indigenous Heavy Electrical Equipment industry in
India - a dream that has been more than realized with a well-recognized track record of
performance. The company has been earning profits continuously since 1971-72 and
paying dividends since 1976-77 .BHEL is engaged in the design, engineering,
manufacture, construction ,testing, commissioning and servicing of a wide range of
products and services for the core sectors of the economy, viz. Power, Transmission,
Industry, Transportation, Renewable Energy, Oil & Gas and Defence. BHEL has 15
manufacturing divisions, two repair units, four regional offices, eight service centres,
eight overseas offices and

8. 15 regional centres and currently operate at more than 150 project sites across India
and abroad. BHEL places strong emphasis on innovation and creative development of
new technologies. Our research and development (R&D) efforts are aimed not only at
improving the performance and efficiency of our existing products, but also at using
state-of-the-art technologies and processes to develop new products. This enables us
to have a strong customer orientation, to be sensitive to their needs and respond quickly
to the changes in the market.
BHEL has a share of around 59% in India's total installed generating capacity
contributing 69% (approx.) to the total power generated fromutility sets (excluding non-
conventional capacity) as of March 31, 2012. We have been exporting our power and
industry segment products and services for approximately 40 years. We have exported
our products and services to more than 70 countries. We had cumulatively installed
capacity of over 8,500 MW outside of India in 21 countries, including Malaysia, Iraq, the
UAE, Egypt and New Zealand. Our physical exports range from turnkey projects to after
sales services.
3. STEAM TURBINE
FIGURE 1
A steam turbine is a mechanical device that extracts thermal energy from pressurized
steam, and converts it into rotary motion .Its modern manifestation was invented by Sir
Charles Parsons in 1884. It has almost completely replaced the reciprocating piston
steam engine primarily because of its greater thermal efficiency and higher power-to-
weight ratio. Because the turbine generates rotary motion, itis particularly suited to be
used to drive an electrical generator – about

9. 80% of all electricity generation in the world is by use of steam
turbines. The steam turbine is a form of heat engine that derives much of its
improvement in thermodynamic efficiency through the use of multiple stages in the
expansion of the steam, which results in a closer approach to the ideal reversible
process.
3.1. ADVANTAGES
1. Ability to utilize high pressure and high temperature steam.
2. High efficiency.
3. High rotational speed.
4. High capacity/weight ratio.
5. Smooth, nearly vibration-free operation.
6. No internal lubrication.
7. Oil free exhausts steam.
3.2. DISADVANTAGES
For slow speed application reduction gears are required. The steam turbine cannot be
made reversible. The efficiency of small simple steam turbines is poor.
4. BHEL HARIDWAR
4.1. LOCATION
It is situated in the foot hills of Shivalik range in Haridwar. The main administrative
building is at a distance of about 8 km from Haridwar.
4.2. ADDRESS
Bharat Heavy Electrical Limited (BHEL) .
Ranipur, Haridwar PIN- 249403
4.3. UNITS
There are two units in BHEL Haridwar as followed:
1) Heavy Electrical Equipment Plant (HEEP)

10. The core business of HEEP includes design and manufacture oflarge stesm and gas
turbines, turbo generators, generators, large AC/DC motors and so on.
2) Central Foundry Forge Plant (CFFP)
CFFP is engaged in manufacture of steel castings up to 50 tons per piece weight and
steel forgings up to 55 tons per piece.
5. TURBINE PARTS
5.1. TURBINE BLADES
1. Cylindrical reaction blades for HP, IP and LP Turbines
2. 3-DS blades, in initial stages of HP and IP Turbine, to reduce secondary losses.
3. Twisted blade with integral shroud, in last stages of HP, IP and initial stages of LP turbines,
to reduce profile and Tip leakage losses
figure 2
4. Free standing LP moving blades Tip sections with supersonic design.
5. Fir-tree root
6. Flame hardening of the leading edge
7. Banana type hollow guide blade
8. Suction slits for moisture removal

11. 5.2. TURBINE CASING
Casings or cylinders are of the horizontal split type. This is not ideal, as the heavy flanges of the
joints are slow to follow the temperature changes of the cylinder walls. However, for assembling
and inspection purposes there is no other solutionThe casing is heavy in order to withstand the
Figure 3
high pressures and temperatures. It is general practice to let the thickness of walls and flanges
decrease from inlet- to exhaust-end. The casing joints are made steam tight, without the use of
gaskets, by matching the flange faces very exactly and very smoothly. The bolt holes in the
flanges are drilled for smoothly fitting bolts, but dowel pins are often added to secure exact
alignment of the flange joint. Double casings are used for very high steam pressures. The high
pressure is applied to the inner casing, which is open at the exhaust end, letting the turbine
exhaust to the outer casings.

12. 5.3. TURBINE ROTORS
The design of a turbine rotor depends on the operating principle of the turbine. The impulse
turbine with pressure drop across the stationary blades must have seals between stationary blades
and the rotor. The smaller the sealing area, the smaller the leakage; therefore the stationary
blades are mounted in diaphragms with labyrinth seals around thes haft. This construction
requires a disc rotor. Basically there are two types of rotor:
5.3.1. DISC ROTORS
All larger disc rotors are now machined out of a solid forging of nickel steel; this should give the
strongest rotor and a fully balanced rotor. It is rather expensive, as the weight of the final rotor is
approximately 50% of the initial forging. Older or smaller disc rotors have shaft and discs made
in separate pieces with the discs shrunk on the shaft. The bore of the discs is made 0.1% smaller
in diameter than the shaft. The discs are then heated until they easily are slid along the shaft and
located in the correct position on the shaft and shaft key. A small clearance between the discs
prevents thermal stress in the shaft.
Figure 4
5.3.2.DRUM ROTORS
The first reaction turbines had solid forged drum rotors. They were strong, generally well
balanced as they were machined over the total surface. With the increasing size of turbines the
solid rotors got too heavy pieces. For good balance the drum must be machined both outside and
inside and the drum must be open at one end. The second part of the rotor is the drum end cover
with shaft.
5.4. BLADING MATERIALS
Among the different materials typically used for blading are 403 stainless steel, 422 stainless
steel, A-286, and Haynes Satellites Alloy Number 31 and titanium alloy. The403 stainless steel
is

13. essentially the industry’s standard blade material and, on impulse steam turbines, it is probably
found on over 90 percent of all the stages. It is used because of its high yield strength, endurance
limit, ductility, toughness, erosion and corrosion resistance, and damping. It is used within a
Brinell hardness range of 207 to 248 to maximize its damping and corrosion resistance. The 422
stainless steel material is applied only on high temperature stages (between 700 and 900°F or
371 and 482°C), where its higher yield, endurance, creep and rupture strengths are needed.
The A-286 material is a nickel-based super alloy that is generally used in hot gas expanders with
stage temperatures between 900 and 1150°F (482 and 621°C). The Haynes Satellites Alloy
Number 31 is a cobalt-based super alloy and is used on jet expanders when precision cast blades
are needed. The Haynes Satellite Number 31 is used at stage temperatures between 900 and
1200°F (482 and 649°C). Another blade material is titanium. Its high strength, low density, and
good erosion resistance make it a good candidate for high speed or long-last stage blading.
6. MANUFACTURING PROCESS
6.1. INTRODUCTION
Manufacturing process is that part of the production process which is directly concerned with the
change of form or dimensions of the part being produced. It does not include the transportation,
handling or storage of parts, as they are not directly concerned with the changes into the form or
dimensions of the part produced. Manufacturing is the backbone of any industrialized nation.
Manufacturing and technical staff in industry must know the various manufacturing processes,
materials being processed, tools and equipments for manufacturing different components or
products with optimal process plan using proper precautions and specified safety rules to avoid
accidents. Beside above, all kinds of the future engineers must know the basic requirements of
workshop activities in term of man, machine, material, methods, money and other infrastructure
facilities needed to be positioned properly for optimal shop layouts or plant layout and other
support services effectively adjusted or located in the industry or plant within a well planned
manufacturing organization. Today’s competitive manufacturing era of high industrial
development and research, is being called the age of mechanization, automation and computer
integrated manufacturing. Due to new researches in the manufacturing field, the advancement
has come to this extent that every different aspect of this technology has become a full-fledged
fundamental and advanced study in itself. This has led to introduction of optimized design and
manufacturing of new products. New developments in manufacturing areas are deciding to
transfer more skill to the machines for considerably reduction of manual labor.
6.2. CLASSIFICATION OF MANUFACTURING PROCESSES
For producing of products materials are needed. It is therefore important to know the
characteristics of the available engineering materials. Raw materials used manufacturing of
products, tools, machines and equipments in factories or industries are for providing commercial
castings, called ingots. Such ingots are then processed in rolling mills to obtain market form of
material supply in form of bloom, billets, slabs and rods. These forms of material supply are
further subjected to various manufacturing processes for getting usable metal products of
different shapes and sizes in various manufacturing shops. All these processes used in

14. manufacturing concern for changing the ingots into usable products may be classified into six
major groups as
1. Primary shaping processes
2. Secondary machining processes
3. Metal forming processes
4. Joining processes
5. Surface finishing processes and
6. Processes effecting change in properties
6.2.1 PRIMARYSHAPING PROCESSES
Primary shaping processes are manufacturing of a product from an amorphous material. Some
processes produces finish products or articles into its usual form whereas others do not, and
require further working to finish component to the desired shape and size. The parts produced
through these processes may or may not require to undergo further operations. Some of the
important primary shaping processes are:
1. Casting
2. Powder metallurgy
3. Plastic technology
4. Gas cutting
5. Bending and
6. Forging
Figure 5

15. Figure 6
6.2.2. SECONDARYOR MACHINING PROCESSES
As large number of components require further processing after the primary processes. These
components are subjected to one or more number of machining operations in machine shops, to
obtain the desired shape and dimensional accuracy on flat and cylindrical jobs. Thus, the jobs
undergoing these operations are the roughly finished products received through primary shaping
processes. The process of removing the undesired or unwanted material from the work-piece or
job or component to produce a required shape using a cutting tool is known as machining. This
can be done by a manual process or by using a machine called machine tool. In many cases these
operations are performed on rods, bars and flat surfaces in machine shops.
These secondary processes are mainly required for achieving dimensional accuracy and a very
high degree of surface finish. The secondary processes require the use of one or more machine
tools, various single or multi-point cutting tools (cutters), jobholding devices, marking and
measuring instruments, testing devices and gauges etc. forgetting desired dimensional control
and required degree of surface finish on the work-pieces. The example of parts produced by
machining processes includes hand tools machine tools instruments, automobile parts, nuts, bolts
and gears etc. Lot of material is wasted as scrap in the secondary or machining process. Some of
the common secondary or machining processes are:
1. Turning 8. Threading
2. Knurling 9. Milling
3. Drilling 10. Blanking
4. Boring 11. Planning
5. Shaping 12. Gear Cutting
6. Grinding 13. Thread cutting and
7. Unconventional machining processes namely machining with Computer Numerical
Control (CNC) machine tool

16. Figure 7
7. BLOCK 3 LAY-OUT
Figure 8

17. 8. CLASSIFICATION OF BLOCK 3
8.1. BAY-1 IS FURTHER DIVIDED INTO THREE PARTS
8.1.1. HMS
In this shop heavy machine work is done with the help of different NC &CNC machines
such as center lathes, vertical and horizontal boring & milling machines. Asia’s largest vertical
boring machine is installed here and CNC horizontal boring milling machines from Skoda of
Czechoslovakia.
8.2.2. Assembly Section
In this section assembly of turbines are done. Blades of turbine are1st assemble on
the rotor & after it this rotor is transported to balancing tunnel where the balancing is done. After
balancing the rotor, rotor &casings both internal & external are transported to the customer.
Total assembly of turbine is done in the company which purchased it by B.H.E.L.
3. OSBT (Over Speed Balancing Tunnel)
In this section, rotors of all type of turbines like LP(low pressure), HP(high pressure) &
IP(Intermediate pressure) rotors of Steam turbine ,rotors of Gas & Hydro turbine are balanced .In
a large tunnel, Vacuum of 2 torr is created with the help of pumps & after that rotor is placed on
pedestal and rotted with speed of 2500-4500 rpm. After it in a computer control room the axis of
rotation of rotor is seen with help of computer & then balance the rotor by inserting the small
balancing weight in the grooves cut on rotor.
Figure 9
For balancing and over speed testing of rotors up to 320 tons in weight, 1800 mm in length and
6900 mm diameter under vacuum conditions of 1 Torr.
8.2. BAY –2 IS DIVIDED IN TO 2 PARTS:
8.2.1. HMS
In this shop several components of steam turbine like LP, HP & IP rotors, Internal & external

18. casing are manufactured with the help of different operations carried out through different NC &
CNC machines like grinding, drilling, vertical & horizontal milling and boring machines, center
lathes, planer, Kopp milling machine.
8.2.2. Assembly Section
In this section assembly of steam turbines up to 1000 MWIs assembled. 1st moving blades are
inserted in the grooves cut on circumferences of rotor, then rotor is balanced in balancing tunnel
in bay-1.After is done in which guide blades are assembled inside the internal casing & then
rotor is fitted inside this casing. After it this internal casing with rotor is inserted into the
external.
8.3 . BAY 3 IS DIVIDED INTO 3 PARTS:
8.3.1. Bearing Section
In this section Journal bearings are manufactured which are used in turbines to overcome
the vibration & rolling friction by providing the proper lubrication.
8.3.2. Turning Section
In this section small lathe machines, milling & boring machines, grinding machines &
drilling machines are installed. In this section small jobs are manufactured like rings, studs, disks
etc.
8.3.3. Governing Section
In this section governors are manufactured. These governors are used in turbines for
controlling the speed of rotor within the certain limits. 1st all components of governor are made
by different operations then these all parts are treated in heat treatment shop for providing the
hardness. Then these all components are assembled into casing. There are more than 1000
components of Governor.
8.4. BAY-4 IS DIVIDED INTO 3 PARTS:
8.4.1. TBM (Turbine Blade Manufacturing) Shop
In this shop solid blade of both steam & gas turbine are manufactured. Several
CNC & NC machines are installed here such as Copying machine, Grinding machine, Rhomboid
milling machine, Duplex milling machine, T- root machine center, Horizontal tooling center,
Vertical & horizontal boring machine etc.

19. Figure 10
8.4.2. Turning Section
Same as the turning section in Bay-3, there are several small Machine like lathes
machines, milling, boring, grinding machines etc.
Figure 11
8.4.3. Heat Treatment Shop
In this shop there are several tests performed for checking the Hardness of different
components. Tests performed are Sereliting, Nitriding, DP Test.
9. CONCLUSION
Gone through 1 month training under the guidance of capable engineers and workers of
BHEL Haridwar in Block-3 “TURBINE MANUFACTURING” headed by Senior Engineer of
Department Mr . Ajmani Rohit situated in Ranipur, Haridwar,(Uttarakhand).
The training was specified under the Turbine Manufacturing Department. Working under the
department I came to know about the basic grinding, scaling and machining processes which was
shown on heavy to medium machines.