1

A

Project Report

On

In

AT

GAIL (INDIA) LIMITED,

PATA,AURAIYA (U.P.)

DURATION: Six Weeks

Submitted To : Submitted By:

Mr. P. K. Jain Aakash Mehta

CM U.I.E.T,Panjab University,Chd

Training Roll NO. – UE129001

2

INDEX

Sr. No. TOPIC PAGE NO.

1. Acknowledgement 3

2. GAIL(Inida) Ltd, At Glance 4

3. Introduction 5

Fire and Safety 6

4. Sealing System 10

5. Gland Packing 10

6. Mechanical Seal 13

7. Mechanical Seal v/s Gland Packing 15

8. Classification of Mechanical Seal 16

9. Seal Arrangement 16

10. Selecting a Mechanical Seal 20

11. Failure of Mechanical Seal 21

3

I owe a great many thanks to a great many people who helped and supported me during

the Project work.

Firstly, I would like to thank training department and especially Mr. P.K. Jain(CM training) for

providing me the opportunity as a vocational trainee in such a huge plant, equipped with

modern technology.

I express my sincere gratitude to Mr. Ajay Tripathi (DGM Mech),under whom I competed my

training program. I owe a sincere thanks to my mentor Mr. Dulal Gain(Sr. Manager) who helped

and supported me during my course of training.

I am also thankful to all the officers, supervisors and staff members for their cooperative and

helpful support for they spent their precious time with me to explain various objectives.

I also feel honored to be a part of GAIL India Ltd. that gave me the vast knowledge about cracker

unit and its different parts. It was a very nice and knowledgeable experienced for me to be a

part of GAIL India Lid. for this while. This experience is surely going to help me in the future.

Aakash Mehta

U.I.E.T, Panjab University,

Chandigarh

4

GAIL (INDIA) LIMITED

(AT A GLANCE)

GAIL (India) Limited is India’s flagship natural gas company, integrating all aspects of natural gas

value chain including Exploration & Production, Processing, Transmission, Distribution and

Marketing) and its related services. It is outstanding public sector enterprises in the country. In

rapidly changing scenario, it is spearheading the move to new era of clean fuel industrialization,

creating a quadrilateral of green energy corridors that connect major consumption centers in

India with major gas fields, LNG terminals and other cross border gas sourcing points. GAIL is

also expanding its business to become a player in the International market.

GAIL is one of the MAHARATNA enterprises and ranks among the top fifty companies in India.

Today, GAIL’s Business Portfolio includes:

5,800 km of natural gas high pressure trunk pipeline with a capacity to carry 130

MMSCMD of natural gas across the country.

07 LPG gas processing units to produce 1.2 MMTPA of LPG and other liquid

hydrocarbons.

North India’s only gas based integrated Petrochemical complex at Pata, Auraiya with a

capacity of producing 410000 TPA of polymer.

1,922 km of LPG transmission pipeline network with a capacity to transport 3.8 MMTPA

of LPG.

30 oil and gas Exploration blocks and 3 coal bed methane blocks.

13,000 km of OFC network offering highly dependable bandwidth for telecom service

providers.

Joint venture companies in Delhi, Mumbai, Hyderabad, Kanpur, Agra, Lucknow, Bhopal

and Pune, for supplying piped natural gas (PNG) to households and commercial users,

and compressed natural gas (CNG) to transport sector.

Participating stake in the Dahej LNG terminal and the upcoming Kochi LNG Terminal in

Kerala.

GAIL has successfully commissioned LNG terminal at Dabhol in January’13.

5

Established presence in the CNG and City Gas sectors in Egypt through equity

participation in 3 Egyptian companies: Fayum Gas Company SAE, Shell CNG SAE and

National Gas Company SAE.

INTRODUCTION

GAIL (India) Limited, PATA Petrochemical Complex is located in District Auraiya in Uttar Pradesh.

It is based on natural gas as feedstock from GAIL’s HVJ pipeline, which has been set up in

accordance with GAIL’s mission to maximize the value addition from each fraction of natural

gas.

The Plant consists of five major units i.e.

i) Gas Processing Unit (GPU)

ii) Gas Cracker Unit (GCU)

iii) High Density Poly-ethylene(HDPE)

iv) Linear Low Density Poly-ethylene (LLDPE) and LPG unit.

v) Integrated Offsite Processing(IOP)unit

HDPE and LLDPE are used by plastic processors to manufacture a large variety of products for

industrial, agricultural and domestic uses. The Plant also has an LPG recovery plant.

NAME OF UNIT PRODUCT CAPACITY (MTPA) LICENSOR

GSU SWEET GAS 12.66 MMSCMD TFE(FRANCE)

GPU C2/C3 3,97,000 EIL

LPG RECOVERY LPG 2,58,250 EIL

GCU ETHYLENE 4,46,000 STONE & WEBSTER, USA

HDPE HDPE 2,00,000 MITSUI, JAPAN

LLDPE LLDPE/HDPE 2,10,000 NOVACOR, CANADA

TENE-1 BUTENE-1 10,000 IFP, FRANCE

6

Fire and safety emergency numbers: 33444, 31444

Fire tetrahedron:

Principals of Extinguishing Fires-

Cool the fuel below it’s ignition point.

Remove the oxygen supply.

Separate the fuel from the oxygen.

Choice of fire fighting media: Water

Foams

Inert gases

Chemical powders

Halons

7

Classes of fire:

5 classes of fire:

Class A- Paper, wood, textiles and rubbish. Water is used as extinguishing media, which provides cooling effect.

Class B- Liquids, such as, alcohol, oil, grease, diesel, paints, etc. Dry Chemical Powder (DCP) or Aqueous Film Forming Foam (AFFF) are used as extinguishing media. They cut the oxygen supply.

Class C- Gas fire, like fire in LPG, LNG. Water can be used or DCP can be used for extinguishing the fire.

Class D- Occur in certain metals like magnesium, sodium, potassium, titanium or zirconium. Special DCP is used for extinguishing purpose.

Class E- Electrical fire CO2 or DCP can be used. Foam or water should never be used for extinguishing electrical fire.

Fire Protection Systems-

There are 2 types of fire protection system:

1. Active Fire Protection System- The duty of this system is to extinguish the fire, control the fire or provide exposure protection to prevent domino effects. It includes agents like water sprays, foam and DCP. It includes:

Hydrocarbon detection system like LEL or gas detectors.

Fire alarm system like automatic fire and alarm system, manually operated fire alarm system, emergency sirens or pagers.

Fixed fire protection system like: Water based fixed fire fighting systems like fire water network, deluge valve, hydrants,

monitors etc.

Non water based fixed fire fighting system like CO2, environment friendly clean agent flooding systems, DCP system etc.

Deluge sprinkler system: It’s main purpose is to keep vessels and structural steel cool by application of water via sprinklers to the entire fire area.

8

2. Passive Fire Protection System- They are designed and installed at the time the plant is built

and remain passively in place until needed. For e.g. insulating material or fireproofing that is applied to steel structural members and equipment supports in the plant.

Flammable (explosive) Limit and Range: In the case of gases or vapours, which form flammable mixtures with air, there is a minimum concentration of vapour in air below which the propagation of flame does not occur in contact with a source of ignition. This is called Lower Explosive Limit (LEL). Similarly, there is a maximum concentration of vapour above which the propagation of flame does not occur on contact with a source of ignition. This is called Upper Explosive Limit (UEL). This range of minimum to maximum concentration is termed as Flammable (Explosive) range. For e.g., LEL for hydrogen is 4% and UEL is 75%. Thus 4 to 75 % is the flammable range for

hydrogen.

Types of Siren: Depending on the severity of fire, there are 3 types of siren-

1. For small fire- No siren.

2. For large fire- Siren is blown 3 times for a total time period of 2 minutes. Each siren is blown

for 30 seconds continuously and after a gap of 15 seconds, siren is blown again for 30

seconds.

3. For disaster- Siren is blown for a total time interval of 2 minutes. Each siren is blown for 30

seconds at an interval of 30 seconds.

Fire Fighting Techniques: Water spray system is effective for small leakages.Supplement hose streams are required for

heavy leakages and also for cooling of nearby structures.

In case of vapors or gas leakage always remember to move in cross-wind direction.

While using fire extinguishers, always adopt the following sequence-

P- Remove the pin.

A- Aim towards the base of fire.

S- Squeeze

S- Sweep

9

Whenever there is any disaster or fire, first report about the incident to the fire and safety

department or the area’s control room. Tell about your identity, location of disaster or fire

and the type of emergency. Then move to the nearest ASSEMBLY POINT.

Manual Call Point (MCP): Manual alarm call points are designed for the purpose of raising an alarm manually if a fire or

emergency condition exists. By breaking the glass of MCP with a hammer alarm signal can be

raised and the alarm is sent to the fire alarm control panel.

Assembly Point: Assembly point signifies the areas of safety where persons should assemble in the event of an

emergency or fire.

10

BROADLY IN ROTATING EQUIPMENTS SEALINGS SYSTEM CAN BE CLASSIFIED IN TWO TYPES :

1. GLAND PACKING SEALS – These seals are not 100% leak proof – Therefore, these types

of sealing systems are used where handling fluid is non-hazardous and low cost like water.

2. MECHANICAL SEALS – These seals are being widely used in process industries and almost

100% leak proof.

1) GLAND PACKING SEAL

To achieve zero leakage between a moving member and a relatively stationary part

a wide range of seals and rings are employed. However the most common least

expensive and versatile is the Gland packing. Gland packing provides a dynamic seal

for a rod shaft or stem via housing or gland which is packed with resilient or semi-

resilient material providing a localized contact area which offer a physical barrier to

leakage.

11

Properties The Gland Packing Must Possess

Good anti-friction properties Good chemical resistance to fluid contained Should not get affected by the temperature of application Should be reasonably compressible and have a good resilience Should retain the lubricants Should not affect the shaft Should not contaminate the fluid being contained.

Packing The Gland

Ensure that all the old packing is removed and the stuffing box is clean and free from foreign matter.

Always re-pack with new packing. Choose packings recommended for the fluid to be contained. Select correct size of packing to fit the stuffing box dimensions. Wrap packing on the shaft and cut into rings of correct size. Fit each packing individually by tapping or with split sleeves. Stagger joints in consecutive packing rings. Fit gland follower and check that the shaft rotates freely. Tighten gland nuts evenly with spanner until the packing "drags" when turning the shaft

by hand.

Slection Of Grade and Size

To facilitate the selection of suitable grade of gland packings, certain guidelines are given in this catalogue under the heading 'Medium for Selections'. In the case of specific applications, the Technical Cell of Hindustan Composites is always available for customer guidance.

12

The following recommendations are general for the selection of suitable dimension:

Shaft Ranges Width of packing

16 to 28 mm dia. 8 mm

30 to 46 mm dia. 10 mm

50 to 75 mm dia. 12.5 mm

75 to 120 mm dia. 16 mm

125 to 300 mm dia. 19 mm

PROBLEMS WITH GLAND PACKING

1. Excessive power consumption

2. More plant down time

3. Atmospheric pollution

4. Effect on plant life

5. Loss of pumpage

6. Higher maintenance cost

13

2) Mechanical Seal

A mechanical seal is a device that helps join systems or mechanisms together by preventing

leakage (e.g. in a plumbing system), containing pressure, or excluding contamination. The

effectiveness of a seal is dependent on adhesion in the case of sealants and compression in the

case of gaskets.

Who Uses Mechanical Seals?

Everyone in the industrialized world uses mechanical seals. Various pieces of rotary or

rotating equipment, pumps in particular, depend on mechanical seals to control leakage.

Familiar rotary equipment devices include automobile water pumps, washing machines, dish

washers, compressors, swimming pool pumps and farm service pumps. Mechanical seals are

used anywhere that liquid and gases are transferred by rotating equipment.

Why Use Mechanical Seals?

The importance of seal design is widely understood in the process, aerospace,

automotive and other industries. Often, when a seal fails, a considerable amount of money is

involved in replacing it and in the most extreme cases process equipment worth tens of millions

may have to be shut down until the seal is replaced.

14

In many applications, mechanical seals provide a safeguard against hazardous materials

escaping into the environment. Another important consideration in seal design is energy

consumption since the frictional properties of the seal often have a big impact on the amount

of power consumed by the machinery on which it is used.

ADVANTAGES IN MECHANICAL SEAL 1. 10 to 15 % power saving

2. Better sealing life

3. Insignificant leakage

4. Minimum pollution

5. Increased plant life

ESSENTIAL ELEMENTS OF MECHANICAL SEAL

Seal faces: one rotating with the shaft and one stationary in the pump casing, cover or

flange.

Secondary seals: one to seal the rotating face to the shaft and one to seal the stationary

face to the pump cover or flange.

Metal parts: to transmit torque and to provide an axial mechanical force to load the

faces.

15

Mechanical Seals vs. Gland Packing

Although mechanical seals had been around for many decades, by 1955 industry had converted

only a small percentage of pumps from packing to mechanical seals. This is due to various

reasons:

• To install a seal, the pump would have to be taken off-line and disassembled.

• Packing could be installed quickly, or an extra ring added, without disassembly.

• Packing was, and is still thought to be, cheaper.

• Maintenance people were not informed/educated about mechanical seals and felt more

comfortable with packing.

• Plant personnel gave little thought to the cost of product loss, energy, housekeeping,

etc., because it had always been sealed the same way.

• There were few guidelines that dictated leakage control and few people seriously

considered its dramatic cost.

SEAL ASSEMBLY

16

CLASSIFICATION OF MECHANICAL SEAL

Mechanical Seal Can be classified as following:

Mechanical Seal

Single Seal Multiple Seal

Inside Seal

OutSide Seal

M

Double Back To Back

Double Face to Back

Tandem

Staged

17

SEAL ARRANGEMENTS Seal arrangements can broadly classified as

1) Single Seal Arrangement

2) Double Seal Arrangement

1) Single Seal Arrangement

The majority of mechanical seal applications are single seals.

Multi-coil spring pusher type mechanical seals work only in clean fluid in dirty

media multi-coil spring get clogged become in affective in such applications

single coil seal are affective

18

2) Double Seal Arrangement

Here again there are two types of arrangements depending upon requirements :

Tandem arrangement

Back to back arrangement

TANDEM ARRANGEMENTS

When two seals are arranged facing in the same direction then the mechanical seals

arrangement is called Tandem seal arrangement.

In tandem mechanical seals the outer seal is flushed with compatible fluid at lower

pressure then stuffing box pressure.

Inner mechanical seal always take higher pressure.

As per API 610 the outer seals must be able to with stand full pressure as well in the event

of inner mechanical seal failure.

This arrangement is used for very high pressure application as well as a safety for some

dangerous or cry genie fluids.

19

BACK TO BACK ARRANGEMENTS

In this case the seals are arranged back to back and buffer / barrier fluid used, remain at

1.5 Kg/cm2 higher than the stuffing box pressure.

These types of seals are used for agitators and reactors.

This arrangement is also used for abrasive media and media that contain substances in

solution which crystallize and deposit cause wear of sealing faces and reduce seal life.

20

ESSENTIAL REQUIREMENT OF SEAL

Essential requirements for proper operation of a mechanical seal

Seal faces must be flat and polished.

Seal faces must be installed perpendicular to the shaft.

Spring force must be sufficient to maintain contact of the faces.

SELECTING A MECHANICAL SEAL

Shaft seal diameter The shaft seal diameter must be selected to fit the pump shaft. If no seal with the required diameter is available, the shaft diameter can be changed with a bushing.

Type of pumped medium

The chemical resistance of the shaft seal materials to the pumped medium has to be considered.The viscosity of the pumped medium affects the lubrication and leakage of the seal. The viscosity of most media depends on the temperature. A single shaft seal can be used for a dynamic viscosity below 2500 cP (centipoise). For a higher viscosity, a back-to-back seal arrangement should be used.

Temperature The elastomeric parts of the seal must be able to withstand the temperature of the medium around the seal. This might be different from the temperature of the pumped medium. If the temperature is above the boiling point of the pumped medium, lubrication is poor. This must be considered when selecting seal design and materials. Sealing pressure The sealing pressure is the pressure around the seal. For high pressures, a balanced seal should be used.

Shaft speed of rotation

If the speed of rotation is low, shaft seals with hard/hard material pairings might produce noise because the lubricating film in the seal gap is extremely thin. At speeds above 15 m/sec, a balanced seal with a rotating seat must be used to reduce seal unbalance.

21

FAILURE OF MECHANICAL SEAL

About half of all pumps in the maintenance shop today, were pulled out of service

because they were leaking or wouldn’t hold pressure. This is most likely a leaking

gasket or o-ring or damage of carbon face.

9% of Mechanical seal fails due to wrong seal selection.

8% of Mechanical seal fails due to Seal Quality and Quality of Equipment

24% Seal Fails due to wrong installation. [

59% Seal fails due to Surrounding (Seal piping plan etc)

CAUSES OF FAILURE

High Temperature

Too much heat in the system may present some of the same evidence as chemical attack.

As the temperature rises the o-ring seal may soften. As the temperature continues to rise

beyond the oring’s temperature limit, the rubber seal will harden and maybe crack. You must

know the temperature limits (upper and lower) and the chemicals they are compatible with.

Pressure

Pressure is actually linked with the temperature and the tolerance. The pressure that an

o-ring can seal is a function of the temperature of the application and the tolerance (extrusion

gap) of the containment groove. You can seal 100 tons of pressure if you can control the

extrusion gap and the temperature

22