Cham Final

7/30/2019 Cham Final

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PROJECT REPORT

ON:

HYDRAULIC IMPROVMENTS AT BAF

BASES (CRM)

SUBMITTED BY:

1. NEELESH VT20110345

2. RAJEEV RANJAN VT20110909

3. RENSO PURTY VT20110540

UNDER GUIDANCE OF:

Mr. P.KAISER

Senior Manager

BAF/ECL/SPM


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JUNE 2011

CERTIFICATE

This is to certify that following students have successfully

completed the project on

HYDRAULIC IMPROVEMENTS AT BAF BASES

as a part of Vocational Training at CRM complex, TATA

STEEL, Jamshedpur during June14, 2011 to July 5, 2011under our guidance.

They have successfully completed this project and worked

very sincerely to our satisfaction.

1. NEELESH

2. RAJEEV RANJAN

3. RENSO PURTY

Mr. P. KAISER


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Senior Manager

BAF /ECL/SPM

ACKNOWLEDGEME

NT

Outstanding achievement is not possible in

hydraulic. It needs lot of help and assistance besides

a healthy environment, luckily I have.

First and foremost, I would like to express my hearty

thanks and indebtedness to Mr. PERWAIZ KAISERfor his enormous help and encouragement throughout

the project. It would have been impossible for me to

have a clear idea and way of approach without his

support.

I am thankful to all the employees of the department

who stood by my side to help me out in theunderstanding of the concepts and techniques in the

process.

I am also thankful to SNTI department for allowing me

to register for the project.


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CONTENTS:

1. INTRODUCTION

a. About Tata Steel

b. Introduction to Steel

Manufacturing

2. Cold Rolling Mill

a. Introduction

b. Basics

c. Pickling & Tandem Cold Mill

(PLTCM)

d. Batch Annealing Furnace (BAF)

e. Skin Pass Mill (SPM)

f. Galvanizing Lines (CGL)

3. Flow chart of BAF process

4. About Industrial hydraulics

5. Project in BAF hydraulics

6. Hydraulic Circuit in BAF


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7. Procedure of cylinder seal change

8. Internal diameter of clamping

cylinder & seal

9. Observation

9.1 Causes of hydraulic seal fail in

cylinders

9.2 Improvement

10. Solution &Conclusion


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INTRODUCTION:

About Tata Steel

TATA Enterprises with 82 companies and an annual turnoverexceeding US $ 8.8 billion employ more than 262,000 people. Tata

Company has forged a number of global alliances with eminent

international partners in several fields. In terms of capital market

performance as many as 40 listed Tata companies account for

nearly 5% of the total market capitalization of all listed companies.

Tata Steel, the Flagship Company of the Tata Group of Companieswas set up in 1907 by the great visionary and patriot industrialist

Jamshedji Nusserwanji Tata. Ever since its inception, the steel

company has upheld and cherished business principles for which it

is widely recognized as a corporate entity committed to taking care

of the interest of all its stakeholders, abiding by the intrinsic values

of trust, integrity and excellence.

Tata Steel - Asia's first and India's largest integrated private sectorsteel company began with a modest capacity of two 200 - tons blast

furnaces, four 4 -tons steam-driven blooming mills and a rail and

structural mill. Today it stands as a state-of-the-art 3.5 million tons

steel plant capable of making the most rigorous demands of its

customers. Keeping abreast of the emergent technologies, Tata

Steel is now on the verge of becoming one of the most cost

competitive producers of steel. The 1.2 million tones Cold RollingMill, commissioned on April 24, 2000 has added value to Tata Steel's

present product mix, strengthen market leadership and penetrate

new markets.

With present capacity of 4.5 MT, It is looking forward to increasing its

capacity to 15 MT by 2010. Tata Steel produces longs as well as

Flats. Its latest acquisition of NAT STEEL produces long products that

have its global presence in 7 different countries.


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TATA Steel is one of the lowest cost steel producer as well as it is

supplier of high-end steel like supplied to auto OEM.

Tata Steel is one of the best-integrated steel plants and is having

facilities right from raw material production to finishing stage rolling.

Introduction to steel manufacturing:

Steel making is basically done in threestages:

1. Iron making process

2. Conversion to steel

3. Rolling Process

Steel is manufactured by injecting oxygen through liquid iron.

This is done in huge vessels known as LD (Linz Donnawitz)

vessel. In this process oxygen is passed at supersonic velocity.

The oxygen used is 99.5 % pure. This is done to reduce the

carbon content in iron to less than 2%. Flow dia. below

describes the steel manufacturing process at TATA Steel.


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COLD ROLLING MILL

IntroductionThe HR Coil coming from HSM is Cold Rolled because

1. Shape and Profile are better in CR as compared to HR.

2. Surface finish in HR Coil is not good.

3. Gauge accuracy of HR is not good.

The Cold Rolling Mill (CRM) ofTATA Steelis fully automated. The CRMuses Hot Rolled coil as its input and produces Cold Rolled galvanized

and Cold Rolled Annealed coils.

Reputed makers like Hitachi, Mitsubishi, IHI, LOI, CMI, ABB, SIEMENS etc

have supplied equipments.

Cold rolled steel sheets are produced by way of series of cold rollingprocesses, using hot rolled steel coils as the starting material. In the

cold strip mill, the scale on the hot rolled coils is removed by the

process called pickling (producing a product referred to as pickled coil).

The pickled coil is then cold rolled at room temperature to a thickness

of 0.15 to 3.2 mm. The cold rolling process is followed by the annealing

process and temper rolling. Compared to hot rolled sheets, cold rolled

sheets are thinner

Have superior thickness accuracy, and a smooth, attractive surface.

Cold rolled sheets are also superior in mechanical properties, especially

in workability.

These features mean that cold rolled sheets are suitable for

application which require small thickness of under 1.2 mm, which is

outside the conventional size range of hot rolled steels sheets, and

require not only stricter thickness accuracy but also an attractive

surface and excellent formability.


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Cold rolled steels sheets are also used as the substrate for various kinds

coated steels sheets such as zinc galvanized steel sheets, tin mill black

plates, and others


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Basics of CRM

1. The hot strip mill sends hot rolled coil (thickness 2 to 6 mm)

width (800-1500mm) to the CRM.

2. First the hot coil passes through the pickling section containingHCL acid in order to remove scales, making them ready for coldrolling.

3. Trimming section where the edges of the pickled hot rolled coilsare trimmed, if needed.

4. The coils are then fed into the main mill, viz. Tandem Cold Mill(TCM) (6 Hi, 5 stand mill). The CR strip thickness is 0.25 to 3.2mm. The strip thickness and shape is controlled within a verytight tolerance.

5. After cold rolling, the strip is either processed through annealing(BAF) + skin passing (SPM) or through any of the two galvanizinglines.

6. Part of coils which are sent through BAF + SPM, are firstprocessed in ECL.

7. About 2/3rd of CR goes to the Batch Annealing Furnaces (BAF)where the coil are stacked, covered and heated in closedatmosphere in a 100% hydrogen environment. This processimproves the mechanical properties of the strip and helps instress relieving. These coils are then processed through SkinPass Mill (SPM). Skin passing removes Luder bands, impartdesired surface finish, and improve flatness.

8. About 1/3rd of the production from PL-TCM goes to theGalvanizing Lines (CGL#1 & CGL#2), where the zinc coating isapplied on the strip by taking it through molten zinc bath. Thiszinc coating gives a sacrificial layer on the cold rolled strip forcorrosion protection.

9. Most of the coils are then taken through recoiling & Inspectionlines (RCL 1, 2 & 3) and are then packaged either manually orthrough coil packaging line.


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Pickling & Tandem Cold Mill (PLTCM)

Pickling is an important stage in the steel processing sequence. After hot

rolling and prior to cold rolling of strip. The aim of this operation is toeliminate oxide formed on the surface during hot rolling.

Pickling consist of treatment of the surface of the strip with

inorganic acid either hydrochloric or sulphuric. In order to improve the

efficiency of pickling it is preceded by mechanical de scaling (with help of

tension leveller) to crack and partially eliminate the oxides. The pickling

process then removes the remaining oxides and leaves a clean surface.

Pickling rate is faster with Hydrochloric Acid (HCL) then sulphuric acid.

Owing to enhancement of productivity along with other advantage we use

HCL acid as the pickling medium.

Various types of baths / tanks are used for pickling, for Tata steel CRM

shallow bath HCL continuous pickling has been chosen as the pickling

process.

Major purposes of pickling

To eliminate scales from hot rolled strip.

Improve cold rolling operatibility


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Ensure the appearance of strip

Improve the efficiency and quality of processes downstream, thesize of coil increased by welding.

A strip is trimmed on both the edges to a specified width.

Any portion of strip that are bound to be detrimental to downstreamprocesses or that to turn defective are eliminated

COLD ROLLING MILL

After the hot rolled coil surface is free from scale; it is rolled at room

temperature, referred to as cold rolling. For cold rolling mill complex it has

been decided to go in for a coupled pickling line (with shallow bath

pickling) and a 5-stand tandem mill (each 6-hi). This line has the capability

to produce strips with thickness accuracy better than +- 1%.

TANDEM COLD MILL


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Batch Annealing Furnace (BAF)

After cold rolling, annealing is done to soften the sheet for obtaining

superior mechanical properties for deep drawing application.

Annealing process restore ductility increases internal stresses and

restores formability of the cold rolled strips. Two widely different

annealing technologies are

a) Batch or box annealing Furnace (BAF)b) Continuous annealing

For aluminium killed low carbon steels, which form a major

portion of the product-mix, Batch Annealing has a distinct advantage

over continuous annealing.

For the Tata steels cold rolling complex, 100% batch annealing

has been chosen as the annealing route.

The batch annealing has following advantages.

a) Development of 100% h2 batch annealingb) Flexibility in input raw materialc) Process simplicityd) Economic lot sizee) Flexibility in capacity addition.


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Skin Pass Mill (SPM)

It is necessary to impart a small amount of deformation (typically

between 0.5 to 1.5%, depending on the grade) to annealed steel

strips for primarily

a) Preventing stretcher-strains mark during subsequent formingapplicationb) Imparting the desired surface texture (roughness) on the strip.

For CRM complex a skin pass mill of 1 mtpa capacity has been

selected having following facility.

a) 4 hi single stand mill with work roll bendingb) Wet type skin passing (using temper agent)

c) Work roll texturing using the Electrode Discharge texturing(EDT) method.


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Skin Pass Mill

Galvanizing Lines (CGL)

Galvanizing the coils protects steel sheets from corrosion attack by

acting as a barrier between steel and the environment.

Zinc and Zinc alloys have the ability to react at scratches and other

damages through an electrochemical (galvanic) action between

steel and zinc.

In the galvanic process zinc sacrifices itself to protect structural

integrity of the steel.

TWO LINES

1) One for construction( CGL # 1)2) One for auto/ white goods (CGL #2).


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CGL#1

BAF FLOW CHART:-


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STEPS INVOLVED IN BAF:


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1. Rolled steels are placed on the base and each rolled steels

are separated with the help of convector.

2. After that inner cover was placed on the rolled coils .3. N2 gas is passed through the inner cover to make the

atmosphere inert by the removal of air.

4. After that N2 gas was replaced by H2 gas.

5. When inner cover is filled with H2 gas then heating hood is

placed over the inner cover.6. After that the process of heating was done with the help of

COG, compressed air & spark.

7. When the heating was completed then the heating hood was

removed & apply cooling hood.

8. The process of cooling was performed with the help ofblower.

9. When the cooling is completed then cooling hood was

removed carefully with the help of crane.

10. Finally, inner cover was removed and the steel coils were

passed to CCSU.


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4. about industrial hydraulics:

Hydraulics is the transmission and control of forces and movements by

means of fluids. The fluids used to transmit the forces and movements aregenerally incompressible fluids, like water and oil. External forces applied

on it will increase the pressure of the fluid, which resist the external forces,

but the volume the fluid will remain constant. There are normally two

fields of application of hydraulics, which are completely distinct both in

their basic principles and in their potential application. When a load is

moved or hanged by the pressure energy of the system, as in a hydraulic

jack, it is called Hydrostatic power transmission, but, when high velocity

of fluid or very high kinetic energy of the fluid is used to get the high

rotation of a water turbine, it is called Hydrodynamic power transmission.

Industrial Hydraulics basically deals with the hydrostatic power

transmission.

Characteristic features of hydraulic systems:-

1. It is a self lubricated system.

2. Simplicity of operation.

3. Sensitive, smoothly variable speed controls.

4. The equipment is economical in space and weight.

5. Simple safe guarding against overloads, by means of a pressure limiting

valve.

6. Ease in monitoring and checking the hydraulic system by means of pr.

gauge.

7. Ease of transmitting motion and power from prime mover to machine.

8. As a gear box, it provides positive drive, hence no chances of slippage

between driver and driven elements.


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5. Project in BAF hydraulics:

SPECIFICATION OF CLAMPING CYLINDER:

There are 8 cylinders in BAF which are placed alternatively in the

base of furnace.

Four of them are non return valve (NRV) which holds the pressure.

Other four are non- non return valve (N-NRV) which does not hold

the pressure.

NRV have only inlet valve which allow the fluid to flow only in

single direction.

N-NRV has both inlet and exhaust valve which allow the fluid to

flow in both direction.


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6. HYDRAULIC CIRCUIT in baf :


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7. Procedure of cylindrical seal change:

7.1. Assembled required tools:

Assorted o rings picks

Socket wrench,1/2 drive

Piston ring compressor for 4bore

5/16allen wrench adapter for 1/2

Hone for 4 bore, 240 grit silicon carbide

3/16 Allen wrench

Ring removal pliers

Torque wrench, drive

Hydraulic fluid for seal lube (same as operating fluid)


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7.2. SEALS:-

ITEM 9A

ITEM 9B

ITEM 9C

TUBE SEAL o-

RING

ROD WIPER ROD SCRAPER

ITEM 9D ITEM 9E ITEM 9F


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ROD SEAL TUBE SEAL BACK-UP SPACEL SEAL

ITEM 9G

(MAGNET

RETAI)

7.3 COMPLETE CYLINDER DISASSEMBLY:-

Cylinder Prior to Disassembly:-

Secure the cylinder in a vise. For view of cylinder prior to

dissembled.


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Removal of the Flange Retaining

Screws:-

Extend the piston rod (Item 3) several

inches and inspect the rod end for burrs

and sharp edges. Remove any if present.

Use a socket wrench with a drive and

a 5/16 Allen wrench adapter to remove

the (8) screws

(Item 5)

Removal of the Flange:-

After removing the (8) flange retaining screws,

carefully slide the flange (Item12) off the rod.


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FLAN

GE (ITEM 12)

Removal of the Bushing Cartridge

After removing the flange, extend the piston rod several more inches.

Carefully slide the bushing cartridge (Item 10) off the rod.

Removal of the Rod Seal, Wiper and Scraper:


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After removing the bushing cartridge it is now possible to remove the

rod seal Item 9D), the wiper (Item 9B) and the scraper (Item 9C) from

the bushing cartridge. Be careful not to scratch the seal cavities. Use

a small, rounded edge screwdriver to aid in seal removal.

REMOVAL OF THE ROD SEAL,

WIPER AND SCRAPER


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Removal of the Transducer Cover:After the flange is removed, use a 3/16 Allen wrench to remove the (3)

transducer cover mounting screws (Item 16). Now, remove the transducer

cover (Item 15). See Figure 8.

3/16 Allen wrench

ITEM 16TRANSDUCER COVER

MOUNTING SCREW

FIGURE 8

REMOVAL OF TRANSDUCER

COVER

Removal of the Cap Retaining Screws


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After the transducer cover is removed, use a socket wrench with a drive

and a 5/16 Allen wrench adapter to remove the (8) cap retaining screws

(Item 6).

RETAINING SCREWS

Socket wrench, drive with

5/16 Allen wrench adapter

Removal of the CapAfter removing the (8) cap retaining screws, carefully remove the cap (Item

2).

Removing

the Tube Seal O-ring and the TubeSeal Back-Up:


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It is now possible to remove the tube seal o-ring (Item 9A) and the tube

seal back-up (Item 9E) from the cap (Item 2). Be careful not to scratch the

seal cavities. Use a small, rounded-edge screwdriver to aid in the o-ring

removal. See Figure 11.

ITEM 2

FIGURE 11

CAP REMOVING THE

TUBE SEAL O-RING AND TUBE SEAL

BACKUP

ITEM 9A ITEM 9E

TUBE SEAL O-RING TUBE SEAL BACKUP

Removal of the Piston/Rod Assembly:


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Place the cylinder in a vertical rod-up position. Pull the piston/rod

assembly (Item 3) out of the head/tube assembly (Item 1). Do not allow

the piston rod surface to contact the head/tube assembly during removal.

See Figure 12.

ITEM 1

TUBE

ITE

M 3

PISTON

REMOVAL OF THE PISTON RINGS:-


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To remove the (4) piston rings (Item 8) use ring removal pliers.

Inspect the piston and smooth any scratched surface using fine

grit emery cloth.

CLEANING THE HEAD/ TUBE ASSEMBLY:-


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Clean the inside of the head/tube assembly (Item 1) and inspect for

deep gouges and scratches. Light scratches and score marks can be

removed with honing or fine grit emery cloth. A heavily scored

surface required a new head/tube assembly.

7.4 CYLINDER REASSEMBLY:-


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INSTALLING THE PISTON RING:-

To install the (4) new piston rings (Item 8) fill the two centre

grooves on the piston first. Make sure splits are opposed.

REINSTALLING THE PISTON/ROD ASSEMBLY:-

After the (4) piston rings have been installed, place the

head/tube assembly in the vertical position. Lubricate the rings

and piston with system hydraulic fluid. Using a ring

compressing tool. Push the piston into the tube.


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REINSTALLING THE TUBE SEAL O-RING AND TUBE SEAL

BACK-UP:-

Clean all the tube seal o-ring (Item 9A) and tube seal back-up (Item

9E) cavities in the cap. Lubricate the tube seal and back-up with clean

system hydraulic fluid before installing into the cap. Use a small,

rounded- edge screwdriver to aid in reinstallation.


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REINSTALLING THE CAP:-After the tube seal o-ring and the tube seal back-up are installed in the

cap carefully place the cap(Item 2) onto the tub (Item 1) and tighten

the (8) cap retaining screws(Item 6) to 50 ft ibs using a torque wrenchwith drive and a 5/16 Allen wrench adapter. Always tighten

screws across each other rather than adjacent, to allow a more

uniform pressure on the tube seal o-ring.


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Reinstalling the Transducer Cover:After the cap (Item 2) is reinstalled, place the head/tube assembly in the

vertical position. Gently set the transducer cover (Item 15) onto the

head/tube assembly. Using a 3/16 Allen wrench, tighten the (3) transducer

cover mounting screws (Item 16).

ITEM 16

TRANSDUCER

COVERMOUNTING SCREW

ITEM 15

TRANSDUCER

COVER

3/16 Allen wrench


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ITEM 19

REINSTALLING THE

TRANS

DUCER COVER

Reinstalling the Rod Seal, Wiper and ScraperBefore reinstalling the bushing cartridge onto the

piston rod, reinstall the rod seal (Item 9D), the

wiper (Item 9B) and the scraper (Item 9C) into

the bushing cartridge (Item 10). Lubricate the

seals and seal cavities with clean system

hydraulic fluid. Use a small, rounded-edge

screwdriver to aid in seal installation. Be carefulnot to

scratch

the seal

cavities.

See

Figure

20.

ITEM 9D ITEM 9B ITEM9C

ROD SEAL ROD WIPER ROD SCRAPER


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FIGURE

20

ITEM 10

REINSTALLING THE ROD SEAL BUSHING CARTRIDGE

WIPER AND SCRAPER

Reinstalling the Bushing Cartridge:

After the rod seal, wiper and scraper have been installed into the bushingCartridge, lubricate the bushing cartridge with clean system hydraulic fluid

and carefully slide the bushing onto the piston rod.

REINSTALLING THE BUSHING CARTRIDGE

Reinstalling the flange:


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After the bushing cartridge has been installed, gently slide the flange

(Item12) onto the piston. Tighten the (8) flange retaining screws (item 5)

using a socket wrench with a drive and a 5/16 allen wrench adapter.

Always tighten screws across from each other, rather than adjacent. SeeFigure 22.

ITEM12 FIGURE 22

FLANGE REINSTALLING

THE FLANGE

Testing of the Reassembled Cylinder:Test assembled cylinder to 3,000 PSI minimum to check for external leaks.

To test for leakage past the piston rings, extend the cylinder to its full

extended stroke. Turn off the hydraulic system and release pressure.

Disconnect front port hose at supply end (leave connected to cylinder).

End of hose must be open to atmosphere (no quick coupler or quick

coupler with internal check).Place open end of hose in a container to catch

possible hydraulic fluid. Pressurize rear port so cylinder is at

full extension. Dead head at full pressure, check for fluid by

passing rings.


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8.INTERNAL DIAMETER OF CLAMPING

CYLINDER:-


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9. Observation:-


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9.1 CAUSES OF HYDRAULIC SEAL FAIL IN CYLINDERS:-

Inexpensive Hydraulic Seal can cost us thousands in

downtime and loss of production if it fails.. If we have a

problem in seal, focus on these points to help

determine the cause of fail:-

Improper installation is a major cause of hydraulic seal failure.The important things to watch during seal installation are: (a)

cleanliness, (b) protecting the seal from nicks and cuts, and (c)

proper lubrication.

Other problem areas are over tightening of the seal gland wherethere is an adjustable gland follower or folding over a seal lip

during installation. Installing the seal upside down is a common

occurrence, too. The solution to these problems is common sense

and taking reasonable care during assembly

9.2 improvements:-

For improving the properties of seal and to prevent the seal failure we

have taken following actions:-

Earlier we are using the local seal (SPERAGE) which is

replaced by the new seals named INERPAC which has better

reliability and strength.

Insulation around the hydraulic cylinder has also prevented theseal failure to some extent.


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10. SOLUTION $ CONCLUSION:-

# It is not necessary to buy replacement seals from the hydrauliccylinder manufacturer. Many hydraulic seal suppliers have the same

exact seals that are used in most hydraulic cylinders and can easily

cross reference or match up a replacement. In many cases, if there is a

recurring problem with a seal, our seal specialist can recommend a

solution and increase the life of the seal.

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