how is a pressure vessel made and more

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Table of Contents 1. Acknowledgement ......................................................................................................................................... 5

2. List of all the figures and their sources .......................................................................................................... 6

3. Introduction .................................................................................................................................................... 9

4. The Foundations .......................................................................................................................................... 10

4.1. Vision ........................................................................................................................................................... 10

4.2. Mission ........................................................................................................................................................ 10

5. Overview ...................................................................................................................................................... 11

5.1. Background .................................................................................................................................................. 11

5.2. Major business sectors of HEISCO: ............................................................................................................ 11

5.3. Gulf Dredging & General Contracting Co. KSC (Public): .......................................................................... 12

6. The HSE Department ................................................................................................................................... 13

6.1. 5 S Policy ..................................................................................................................................................... 13

6.2. Safety Procedures and Equipment ............................................................................................................... 13

7. Before Fabrication Begins ........................................................................................................................... 14

7.1. Proposals and Tenders Department .............................................................................................................. 14

7.2. Engineering Services Department ................................................................................................................ 14

7.3. Quality Assurance / Control Department ..................................................................................................... 14

7.4. Projects Department ..................................................................................................................................... 14

7.5. Procurement and Material Control Department ........................................................................................... 15

8. Fabrication ................................................................................................................................................... 16

8.1. Introduction .................................................................................................................................................. 16

8.2. Pre-Fabrication ............................................................................................................................................. 16

8.2.1. CNC Flame Cutting ................................................................................................................................. 16

8.2.2. Shearing ................................................................................................................................................... 17

8.2.3. Band-saw Cutting Machine ..................................................................................................................... 17

8.2.4. Hydraulic Press ........................................................................................................................................ 17

8.2.5. Radial Drilling Machine .......................................................................................................................... 18

8.2.6. Punching Machine ................................................................................................................................... 18

8.2.7. CNC Integrated Cutting and Drilling Machines ...................................................................................... 18

8.3. Machine Shop .............................................................................................................................................. 18

8.3.1. Horizontal Lathe: ..................................................................................................................................... 19

8.3.2. Power hacksaw: ....................................................................................................................................... 19

8.3.3. Bench Grinder: ........................................................................................................................................ 19

8.3.4. Tool Cutting and Grinding: ..................................................................................................................... 19

8.3.5. Milling: .................................................................................................................................................... 20

8.3.6. Hydraulic Shaping: .................................................................................................................................. 20

8.4. Fabrication Shop .......................................................................................................................................... 20

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8.4.1. Main parts of a Pressure Vessel ............................................................................................................... 20

8.4.1.1. Fabrication of Cylindrical Shells ............................................................................................................. 21

8.4.1.2. End Dish .................................................................................................................................................. 21

8.4.2. Welding ................................................................................................................................................... 21

8.4.2.1. Types of welding: .................................................................................................................................... 22

8.4.2.1.1. Shielded Metal Arc Welding: .............................................................................................................. 22

8.4.2.1.2. Gas Tungsten Arc Welding: ................................................................................................................ 23

8.4.2.1.3. Flux Cored Arc Welding: .................................................................................................................... 23

8.4.2.1.4. Submerged Arc Welding: .................................................................................................................... 24

8.4.2.2. Welding in Pressure Vessels: .................................................................................................................. 25

8.4.2.2.1. Type A : Shell Long Seam .................................................................................................................. 25

8.4.2.2.2. Type B : Circular Seam ....................................................................................................................... 25

8.4.2.2.3. Type C : Nozzles ................................................................................................................................. 25

8.4.2.2.4. Type D : Fillet Welding ...................................................................................................................... 25

8.4.2.3. Other components of a pressure vessels: ................................................................................................. 25

8.4.3. Non-Destructive Testing: ........................................................................................................................ 26

8.4.3.1. Visual Inspection: .................................................................................................................................... 26

8.4.3.2. Dye Penetrant Test: ................................................................................................................................. 26

8.4.3.3. Magnetic Particle Inspection: .................................................................................................................. 27

8.4.3.4. Radiographic Testing: ............................................................................................................................. 27

8.4.3.5. Ultrasonic Testing: .................................................................................................................................. 27

8.4.3.6. Soap Water Testing: ................................................................................................................................ 28

8.4.3.7. Hydrostatic Testing (DONE AFTER PWHT): ........................................................................................ 28

8.4.4. Post Weld Heat Treatment: ...................................................................................................................... 28

8.4.4.1. Heat Treatment ........................................................................................................................................ 28

8.4.5. Surface Preparation and Painting: ........................................................................................................... 29

8.4.5.1. Surface Preparation: ................................................................................................................................ 29

8.4.5.2. Painting:................................................................................................................................................... 30

9. Piping A brief summary ............................................................................................................................ 31

9.1. ANSI Standard pipe schedule: ..................................................................................................................... 31

9.2. Materials used in piping: .............................................................................................................................. 31

9.2.1. Pipes: ....................................................................................................................................................... 31

9.3. Piping Components: ..................................................................................................................................... 32

10. Conclusion ............................................................................................................................................... 34

11. My Experience as an Intern at HEISCO .................................................................................................. 35

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1. Acknowledgement

It is always a pleasure to remind the fine people in the Engineering program for their

sincere guidance I received to uphold my practical as well as theoretical skills in engineering.

Firstly I would like to thank Dr Pradeep Parameswaran, Associate Dean of Academics, IIT

Mandi, for recommending me for my Industrial Training Program.

I would like to thank Mr Nabil Fayad, Human Resources & IT Manager and Mr Medhat

Khedr Operations Manager Fabrication Workshop, for allowing me to take part in this

Internship Program at M/s HEISCO, Kuwait.

I am extremely grateful to my mentor, Mr Fouad Elraey, Production Manager, for his guidance and support throughout the program.

I express my immense pleasure and deep sense of gratitude to Mr Prasad Varghese, Workshop Manager and the rest of the team:

Mr Benjamin Samuel (Lead Engineer Welding), Mr Ganesh (Snr. Engineer Welding), Mr Karthik Das (Supervisor Welding)

Mr Balamurugan (Lead Engineer Pressure Vessel Fabrication), Mr Ambrose (Production Supervisor)

Mr Meena (Site Engineer), Mr Rami (Production Engineer)

Mr Veeramani (Lead Engineer Design, Pressure Vessels), Mr Sabaa Mourad (Technical Manager, Design, Pressure Vessels), Mr Hateem (Design, Steel Structure)

Mr Shady (Project Manager), Mr Ismail (Project Engineer), Mr Rajkumar (Sr. Engineer - Material Procurement)

Mr Ahmad Khalil (Lead Engineer Pre Fabrication Activities), Mr Murali (Foreman Prefabrication), Mr Dileep (Foreman Steel Plate Rolling)

Mr Subramanian, Senior Proposals Engineer

Mr Sherief (Superintendent Surface Preparation and Painting), Mr Mehmoud (Painting Inspector)

Mr Rajesh (Material Engineer Material Control)

Mr Hani (Snr. Engineer Design)

Mr Rengapriyan (MRB Documentation), Mr Prajeesh (Document Controller)

A special thanks to Mrs Prithi Crasta, Superintendent Learning and Performance Management, Ms Janit Montesclaros HR Officer, Ms Doaa Marzouq HR Officer, Mr Manish Technical Clerk Fabrication Workshop and Mrs Sheena Thomas Office / Dept. Administrator who gave maximum support and guidance during my entire training at HEISCO.

Last but not the least Mr Regunathan T. (HSE Manager) without whom I would have never known about this Summer Training Program and I would have missed this valuable experience I gained this summer vacation.

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2. List of all the figures and their sources

Cover Image

Galvanized Pressure Vessel

http://www.heisco.com/innerpages.aspx?id=21&root=no

Figure 1

Torch Flame

http://www.toolingsystemsgroup.com/Images/steel-plate-mfg/flame-cut-

steel/2009-06-03-steel-parallel-flame-cut-by-oxy-fuel-burn-table-Steel-Craft-

Technologies.jpg

Figure 2

CNC Flame Cutter cutting steel block

https://en.wikipedia.org/wiki/File:FuelRichBlowTorchFlame.jpg

Figure 3

Workers operating the Sheering Machine

Courtesy of George Vijay Koshy

Figure 4

Hydraulic press in the Pre-Fabrication Area


Figure 5

Hydraulic press in the Steel Works area


Figure 6

Radial Drilling Machine


Figure 7

CNC Integrated Beam Cutting and Drilling Machine


Figure 8

Machine Shop

Self-Clicked

Figure 9

Horizontal Lathe Machine

Self-Clicked

Figure 10

Hydraulic Shaping Machine


Figure 11

Plate Rolled using roller

Self-Clicked

Figure 12

Rolled Sheets


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Figure 13

End Dish


Figure 14

FCAW Equipment

Self-Clicked

Figure 15

TIG welding performed on a steel structural work


Figure 16

Schematic Diagram of SMAW

http://www.corrosionist.com/Shielded_metal_arc_welding_(SMAW).htm

Figure 17

Schematic Diagram of TIG welding

http://www.learneasy.info/MDME/MEMmods/MEM30007A/processing/processing.

html

Figure 18

Schematic Diagram of FCA Welding

http://www.lincolnelectric.com/en-us/support/welding-solutions/Pages/shielded-

flux-cored-electrodes.aspx

Figure 19

Schematic Diagram of SAW

http://dokterayla.com/submerged/submerged-arc-welding.html

Figure 20

SAW equipment at Mina Abdullah

Self-Clicked

Figure 21

Electrode and Flux Ovens in Mina Abdullah

Self-Clicked

Figure 22

Long Seam Weld and Cir-Seam Weld

Self-clicked

Figure 23

Nozzles with flanges welded to reinforcement pads further welded to Dish End


Figure 24

Different sizes of scrap saddles kept outside the Pressure Vessel Fabrication Workshop

for disposal

Self-clicked

Figure 25

Post Weld Heat Treatment Box


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Figure 26

Cautionary sign used during PWHT

Self-clicked

Figure 27

Steel Structures kept for Grit Blasting


Figure 28

Grit Containers


Figure 29

Paint Containers kept outside to be used


Figure 30

Steel Structures painted to different layers Primer, Intermediate High Build Epoxy,

Final

Self-clicked

Figure 31

A T-Joint and a Reducer


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3. Introduction

This report, as the title says, is written in a sequence describing how a Pressure Vessel is

made. Whenever an activity of a particular department is come across, the department is

described.

Although I have stated that my training program was in the Fabrication Department, over the

month I was at HEISCO I received opportunities to visit many other important departments

like the Tendering Department, the Finance and Accounting Department, the Business

Development department, just to name a few.

What is a Pressure Vessel?

A Pressure Vessel is a closed container that contains fluid maintained at a particular pressure,

different from ambient pressure. As a result, it must be able to withstand that pressure for

prolonged periods of time and also tolerate movements of the liquid bulk. Leakage of fluid

should not occur. The inlets and outlets (nozzles, manholes, and instrumentation lines) must

be re-enforced and not present a weak spot. The vessel should be able to withstand changes

in environment and stresses from piping that is linked to it. It should be able to support all

piping structures emerging from it and be accessible for manual inspection.

There are two types of pressure vessels - horizontally and vertically. The main difference

between these is that:

Horizontal vessels require skids and saddles to support them.

Vertical vessels have recessed domes that form the underside. They are installed with

high tension bolts on grid like steel supports (skirts) that are imbedded in concrete,

and have vertical supports running along the body.

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4. The Foundations

4.1. Vision To become the customers first preference Company for Shipbuilding, Ship Repair,

Fabrication, Construction, Industrial Maintenance, Dredging and Off-shore services in

Kuwait.

4.2. Mission To provide complete service to our customers in the Shipbuilding, Ship Repair,

Fabrication, Construction, Industrial Maintenance, Dredging and Off-shore works. To achieve sustained growth rate by meeting schedule and quality requirements of

customers.

To provide value added services at competitive prices by evolving cost efficient

measures and regular upgrading of resources.

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5. Overview

5.1. Background Heavy Engineering Industries & Shipbuilding Co. K.S.C (Public) (HEISCO) formerly known

as Kuwait Shipbuilding & Repair yard Co. (KSRC), is a major Engineering, Procurement, and

Construction (EPC) contracting company based in Kuwait with a diversified range of business.

It was established in 1974 to meet the needs of the shipping and maritime industry in

Northern Arabian Gulf. HEISCO is the most efficient and experienced shipyard in the area with

all the resources necessary to fulfil the repair, maintenance and inspection requirements of

ship owners, both local and overseas.

In 1982, HEISCOs activities were expanded into fields of industrial contracting, oil and power

sector construction, maintenance and inspection. After the privatization program of the

government of Kuwait in 1995, Gulf Dredging & General Contracting Co. has become a

subsidiary of HEISCO.

5.2. Major business sectors of HEISCO: 1. Shipbuilding, Ship repair, and special services: This division is located in Shuwaikh

Port. It is equipped with facilities such as a floating dock (for vessels up to 35,000tons),

Syncrolift (5,000 ton capacity), crane facilities and deals in afloat and alongside repairs,

modification and conversion of vessels and shipbuilding of vessels, leading to a wide

scope of operations.

2. Oil and Gas Operations: HEISCOs activities into the fields of industrial contracting, oil

and power sector construction, industrial maintenance, process equipment

manufacturing and inspection services.

The two broad divisions are Construction and Industrial Maintenance

3. Construction operations: The main business units involve Oil and Gas (Flow line),

Pipeline, Oil and Gas (Construction), Electrical and Instrumentation, Tank farms, Civil

engineering.

4. Industrial Maintenance: The main business units are Maintenance and

Miscellaneous Services.

5. Fabrication Services: HEISCOs modern fabrication facilities are capable of the design,

Manufacture, and supply of process equipment serving oil & gas, Refineries,

Petrochemicals and Power Sectors in Kuwait.

6. Trading Operations: Provides quality products at optimum cost to other operations of

HEISCO and also cater to the Kuwait market.

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5.3. Gulf Dredging & General Contracting Co. KSC (Public): It was formed in 1975 as a joint shareholding company of government of Kuwait and

Ballast Nedam of Netherlands. The company started off solely in dredging and later diversified

into marine construction. The Civil construction division was established later to carry out

Civil and Infrastructure works and executed a number of complex projects.

Offshore Operations: Dredging, Reclamation, Port / Harbour / Marina / Wharf construction,

breakwaters, off shore pipelines, piling, marine transportation of bulk cargo, maintenance

services.

Onshore Operations: Construction and infrastructure, Steel structure works, soil treatments,

de-watering, Piling, Value engineering.

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6. The HSE Department

The company maintains HSE as a priority item. Responsibilities of position are well defined

and all individuals are held accountable for compliance.

Responsibilities:

Maintain standards of safety and comply with companys health, safety and environment

management system requirements.

Take reasonable care of own health and safety and that of others in the workplace.

Follow and maintain company standards of quality in accordance with quality system

requirements.

6.1. 5 S Policy This is the policy followed by the company to ensure the best efficiency of work and

uninterrupted workflow with respect to handling of raw material and finished products.

Store, Sort, Shine, Standardize and Sustain.

6.2. Safety Procedures and Equipment Personal Protective Equipment: All personnel must wear the fire resistant coveralls,

safety helmet, ear protection, goggles and safety shoes within the workshop. Specialized

tasks may require use of face shields, gloves, protective suits, etc.

General rule: All employees are expected to mind their surroundings and exercise

common sense in all activities. Smoking is allowed only in certain areas. Employees are

not to be under influence of any other substances when reporting for duty.

Fire measures: Alarms, glass breaking units, and fire extinguishers are present at key

points throughout the compound. They may be water, foam (chemical fires), dry powder,

or carbon dioxide (electrical fires) based. Hoses and fire hydrants provide water for fire-

fighting. Pre-determined assembly points are marked for evacuating personnel.

First Aid: There are 5 First Aid kits and 10 employees trained and certified by the KRCS

(Kuwait Red Crescent Society).

Safe Operating Procedure: It is a checklist prepared by this department to ensure that all

precautionary measures are taken before the start of any operation.

In case of an emergency: Ensure self-safety Safety of fellow workmen Inform

supervisor Incident controller / Emergency co-ordinator alerted Emergency services

alerted- Move to assembly areas Report missing equipment Clear path for rescue

teams.

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7. Before Fabrication Begins

Before the fabrication process of a Pressure Vessel begins, there are activities that are

necessary, and departments that play important roles.

7.1. Proposals and Tenders Department A company survives on the projects it receives. The role of bringing in new projects and

assessing the enquiries received to help the company decide which projects are within its

scope and which would boost its reputation. When a new enquiry is received, this department

works along with the Designing Department to make preliminary estimations which is

necessary to tell the client the quoted price and time taken to complete that project.

7.2. Engineering Services Department This departments role is to provide engineering / technical solutions as required by

various HEISCO departments and projects. One of which is to make preliminary designs for

estimation purposes as well as make detailed designs of the fabrication department so that

they could fabricate what the client wants. There are different departments within HEISCOs

Engineering Services department each focusing on a unit of HEISCOs fabrication and

construction operations Pressure Vessels, Steel Structures, Civil Works, Flow lines, Pipe

lines, Storage Tanks

7.3. Quality Assurance / Control Department They implement the Quality Management system of the company, establish procedures,

conduct quality related trainings and perform quality audits. This department plays important

roles before and during the projects. They are the ones to make a document which lists down

all the procedures involved in a fabrication process, the related quality check to be

implemented and when does the client come and inspect a fabrication process, an ITP

(Inspection Test Procedure). This document is prepared once the project is awarded and is

reviewed and revised by the client. This department is also responsible of ensuring that only

the latest revised documents are used for fabrication and other processes.

7.4. Projects Department They are the eyes of the client at HEISCO. A department run by project engineers, they

control different departments and processes so that the project runs smoothly. They are the

ones answerable to the client for any delay or non-conformity that occurs during the project.

This department also coordinates with the Procurement and Material Control department to

decide which suppliers to choose, to lay down conditions and make agreements with the

suppliers and to know the exact location of the raw materials.

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7.5. Procurement and Material Control Department This is the only department that are permitted to communicate with the suppliers on the

behalf of HEISCO. They act like a mediator between Projects and the Suppliers. They are

responsible for the management and the procurement of raw materials and updating the

database of the stocks available within the company in the two stores in HEISCO, one at

Shuwaikh Head Office and one in Mina Abdullah, also the disposal of scraps.

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8. Fabrication

8.1. Introduction Fabrication process constitutes the majority of the project work, at least about 40% of the

entire project. It is the most time consuming of all the work. It is also the most expensive and

thus the risk associated is very high. Therefore daily inspections are done of the workshop

and the presence of clients QC inspector is required for most processes so as to ensure that

work done is as required by them.

Fabrication constitutes many processes and each process is done by a group of

workers led by a foreman. The foremans work is supervised by a supervisor. The supervisor

reports to the Lead Engineer. Just like how a supervisor administers the work at the workshop,

there is a senior engineer who oversees the designs. He too is to report to the Lead Engineer.

The HEISCO Fabrication Workshop is located in the Shuaibha Industrial Area. It has the

facilities for Design, Manufacture & Supply or Process Equipment serving Oil & Gas,

Refineries, Petrochemicals and Power Sectors in Kuwait. Its quality management system

certification is to ISO 9001:2008 standards. HEISCOs facilities are authorized to use ASME U,

U2, PP, S and National Board R stamps, API monograms for separators (API 12J) and storage

tanks (API 12D & 12F).

Now we will begin with the very first process after the materials arrival and its QC inspection.

8.2. Pre-Fabrication Processes done on the material just arrived and the fabrication of single parts, all fall into

the category of pre-fabrication.

Various pre-fabrication machines at HEISCO are as follows:

8.2.1. CNC Flame Cutting A jet of flammable gas is created using

pressurized cylinders of oxygen and acetylene

and passed out of a

nozzle. On its

ignition, a sharp needle like flame of temperatures about

3500 C is formed, which moves above the required steel

plate, cutting shapes like a paper cutter cutting paper.

CNC means computerized numerical control, an

automatic system which has a program inputted by the

worker created by design engineers, which controls the

path of the nozzle and the pressure of the flame jet.

Figure 1: Torch Flame

Figure 2: CNC Flame Cutter cutting steel block

Figure 1: CNC Flame Cutter cutting steel block

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8.2.2. Shearing This process is used to cut thin sheets

of metal to get strips, and strips to get

small plates. This process is done by simply

applying pressure on the metal and cuts it

just like how knife cuts butter.

8.2.3. Band-saw Cutting Machine A band saw is a power tool which uses a blade consisting of a continuous band

of metal with teeth along one edge to cut various work pieces. The band usually rides

on two wheels rotating in the same plane, although some band saws may have three

or four wheels. Band-sawing produces uniform cutting action as a result of an evenly

distributed tooth load. They are particularly useful for cutting irregular or curved

shapes, but can make straight cuts. The minimum radius of a curve that can be cut on

a particular saw is determined by the width of the band and its kerf.

8.2.4. Hydraulic Press A machine that works on

Pascals law, able to generate tons

of pressure to bent thick sheets of

steel. HEISCO workshop has two hydraulic presses with capacities

of 400 and 500tons. They are used

to bend (plastic deformation)

metal pieces into required shapes,

using a die. Dies are

interchangeable.

Figure 3: Workers operating the Sheering Machine

Figure 4: Hydraulic press in the Pre-Fabrication Area

Figure 5: Hydraulic press in the Steel works area

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8.2.5. Radial Drilling Machine Used to create holes of various sizes on

metal slabs. The machine can be used for holes

up to 62 inches deep. Slow drilling speeds are

used for harder metals. Cooling and lubrication is

done with a mixture of machine oil and water.

Tools are available to bore an existing cavity,

introduce threads etc. Fully automatic / manual /

semi-automatic modes of operation available.

8.2.6. Punching Machine This process is used to generate holes in thinner work pieces, and is faster than

drilling. The machine has a capacity of up to 140 tons force, and sheets of 10mm

thickness can be punched. The punch is held by chuck and is interchangeable,

depending on the size of the hole required.

8.2.7. CNC Integrated Cutting and Drilling Machines This machine cuts as well as drills

the job. There are two machines of

this type in HEISCO, one for beams

and other for metal sheets / plates.

The process is fully automated, and

only location of holes and position of

cutting is to be entered by operator.

Drilling can be done simultaneously

along three axis and takes very short

time. Cutting is done by a laser guided circular saw. Each spindle on each axis has

multiple drill bits that can be automatically interchanges based on requirements.

8.3. Machine Shop These machines are used to repair tools,

reshape existing parts, and create missing

parts from scratch. This shop is not

specifically a part of the pre-fabrication unit

as it does a lot more than that.

Various tools are used at the machine shop:

Figure 6: Radial Drilling Machine

Figure 7: CNC Integrated Beam Cutting and Drilling Machine

Figure 8: Machine Shop

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8.3.1. Horizontal Lathe: A lathe is a machine tool which rotates the work piece on its axis to perform various

operations such as cutting, sanding, knurling, drilling, or deformation, facing, turning,

with tools that are applied to the work piece to create an object which

has symmetry about an axis of rotation.

The Machine shop has two semiautomatic horizontal

single spindle lathe machines, for a maximum capacity

of 5m and 8m.

The lathe uses a chuck to hold the workpiece in place.

It has slots through which jaws are inserted, that are

in contact with job. These are secured by high tension

screws.

Two types of chuck are available:

Three jaw chuck (only cylindrical shaped, machined pieces)

Four jaw chuck (Pieces of varying sizes and eccentricity)

Speed control is performed using a gearbox, with high speeds for softer materials and

higher speeds for harded materials. There are controls for clockwise and counter

clockwise rotation, neutral mode and complete manual / automatic mode.

Threading can be performed on the lathe too by setting appropriate pitch (in mm or

inches) and selecting left hand / right hand thread.

The cutting tool may be High Speed Steel (HSS), Carbon tip or Diamond tip.

8.3.2. Power hacksaw: The hacksaw is used for sawing apart large diameter jobs. Clamps are used to fix work

piece at required height and orientation. The machine runs on a hydraulic pump that

powers a reciprocating mechanism, that lowers itself during every return stoke,

pushing out waste material from the gap.

8.3.3. Bench Grinder: Used for tool sharpening and reconditioning of the job.

8.3.4. Tool Cutting and Grinding: This machine is used to cut or redefine profiles for cutting tools. Based on number of

teeth, the number of degrees to be fixed is determined (360 / no. of teeth). Profile of

a single tooth is decided by setting angle with respect to grinding surface.

Figure 9: Horizontal Lathe Machine

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8.3.5. Milling: This machine operates similarly to the lathe, except with vertical movement of

spindle. It is capable of moving along all 3 axes, and can be rotated as well, leading to

large variety of jobs that can be accommodated.

The main platform has grooves along which supports can be slid, to hold work piece

in place while machining.

Fully automatic / manual / semi-automatic modes of operation available.

8.3.6. Hydraulic Shaping: Uses horizontal stroking motion to shape metal

surfaces. It can be used to produce tapered

designs. The machine operates through a quick

return mechanism that raises the tool on return

stroke to prevent breakage.

8.4. Fabrication Shop Actual fabrication is done after all the single parts are prepared after the pre-fabrication

process. The main activity involved fabrication is welding. But before we discuss welding

in depth, we will come back to pressure vessels.

8.4.1. Main parts of a Pressure Vessel Pressure Vessels have two main parts:

Cylindrical Shell

End dish

Figure 10: Hydraulic Shaping Machine

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8.4.1.1. Fabrication of Cylindrical Shells Steel plates of the required thickness is purchased from the suppliers after inspection

is rolled using a 4 roller automatic rolling machine. Sheet metal is fed from one side.

Lateral movement of the sheet is restrained by ensuring it is perfectly perpendicular

to the rollers and in contact with the opposing roller, as

any deviation can cause formation of cone. Stainless

steel sheets must not be allowed to directly contact

rollers paper barrier is used. Central roller, which is

capable of movement, clamps down on the sheet.

The metal is rolled, with continuous manual checking of

curvature using templates. The rolled plate passes over

the top support and back into the rollers. Rolling is

performed in 2-3 passes to avoid it from becoming an

oval. A tolerance of 3mm in the diameter is observed.

After rolling, the free ends are joined together using

tacks.

8.4.1.2 End Dish These are imported from abroad. They are made to

specification, using processes like forging and is made

from cladded Mild Steel.

Welding is the next process in line.

8.4.2. Welding Welding is a portable casting method in which metals temperature is risen to the point that

it melts and components to be joined are kept in contact so that

they solidify to form a single continuous body.

The invention of this method removed the limitations

imposed by transportation and flexibility of making connections.

Big structures single parts could be easily transported and welded

on site in any required manner to form a structure with strength

and appearance as though it was made using one single body.

Prior to welding, joint preparation is performed. The type

of joint is chosen as per drawing, strength requirements etc.

Edges may be grinded to single bevel, double bevel, J-section etc.

The specifications such as groove angle, bevel angle, land / face dimensions etc. are observed.

Prior to welding, the two primary surfaces are fit-up by tacks.

Figure 11: Plate Rolled using roller

Figure 12: Rolled Sheets

Figure 13: End Dish

Figure 14: FCAW equipment Note: Black cylinders carry CO2

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Steps involving in welding are:

Rooting

Capping

Hot Pass

Filing

8.4.2.1. Types of welding: During the process of welding, the metal is in molten form, and thus on exposure to

atmospheric gases could cause reactions forming metal oxides and nitrides which are brittle

in nature and thus the strength of the joint wouldnt be strong. This is not preferred. There

are techniques to prevent this from happening. Molten metal can be shielded from the

atmosphere using various techniques. Different techniques give rise to different types of

welding processes.

Following are the types of welding process followed at HEISCO:

8.4.2.1.1. Shielded Metal Arc Welding: It is a manual arc welding process that uses

a consumable electrode coated in flux to

lay the weld. An electric current in the

form of either AC or DC current, from a

welding power supply, is used to form an

electric arc between the electrode and the

metal to be joined. The flux plays the major role in protection here. The flux is made up of

ceramic and has metal oxides and nitrides present. When high temperatures are

reached, these metal oxides, being lighter, float on the surface of the molten metal

avoiding it from making contact with the atmosphere. The flux also releases gases

around the molten joint which forms a shield between the joint and the atmosphere.

Figure 15: TIG welding being performed on a steel

structure work

Figure 16: Schematic diagram of SMAW

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8.4.2.1.2. Gas Tungsten Arc Welding: This method is also known as Tungsten Inert

Gas Welding (TIG). Tungsten, having high

melting point much higher than steel, is

able to be heated to Steels melting point,

used in welding and not be consumed in the

weld. Thus tungsten here is a non-

consumable electrode.

The weld area is protected from

atmospheric contamination by inert gas

shielding (argon or helium). GTAW is most commonly used to weld thin sections of

stainless steel and non-ferrous metals such as aluminium, magnesium, copper alloys

but the process is very slow.

8.4.2.1.3. Flux Cored Arc Welding: It is a semi-automatic or automatic arc welding

process. FCAW requires a continuous feed of

consumable tubular electrode containing flux,

and constant voltage. The role of the flux is to

vaporise during the welding process, giving off

smoke and ensuring that molten metal is not

allowed to oxidise with atmospheric oxygen.

In this process, because the feed rate of the flux

cored arc is fast, splattering often occurs and thus

only highly skilled welders are preferred for

conducting this process, and even more skilled

ones for over-head welding.

Figure 17: Schematic diagram of TIG welding

Figure 18: Schematic diagram of FCA welding

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8.4.2.1.4. Submerged Arc Welding: In this process a consumable solid (flux-cored)

electrode is fed continuously. The molten weld and

the arc zone are protected from atmospheric

contamination by being

submerged under a blanket of

granular fusible flux consisting of

silica, manganese oxide and other

compounds.

This welding is commonly used to

weld huge plates together, thus

used in the long seam and circular

seam welds of a pressure vessel,

which would be discussed soon.

SMAW electrodes and granular fusible flux used in SAW when

exposed too long outside absorb moisture and spoil the quality of weld when used. It is

important to remove moisture and store them properly. Therefore the electrodes and

granular flux are heated in an oven at around 350 C for about 2 hours they are baked,

then stored till next use in another oven maintained at 150 C.

Figure 19: Schematic diagram of SAW

Figure 20: SAW equipment at Mina Abdullah

Figure 21: Electrode oven for baking (both green), granular flux baking oven (grey, left side), electrode storage ovens (other grey ovens and blue) and a flux storage oven (yellow with orange top) at HEISCO Pressure Vessel Fabrication Workshop

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8.4.2.2. Welding in Pressure Vessels: There are mainly four types of joints in a Pressure Vessel:

8.4.2.2.1. Type A: Shell Long Seam It is the joint which joins rolled sheets end to end, forming a

cylindrical shell. The welding distorts its circularity, hence re-

rolling needs to be done.

8.4.2.2.2. Type B: Circular Seam It is the joint which joins cylindrical shells end to end to form

a longer cylinder and also to join shells with the Dish End.

8.4.2.2.3. Type C: Nozzles Joints between the nozzles and the reinforcement pads fall into this category.

8.4.2.2.4. Type D: Fillet Welding Joints between the reinforcement pads and the cylindrical shell and most other welds

fall into this category.

After any primary welding, back-chipping is performed and welding performed at reverse side

to, for increased strength

8.4.2.3. Other components of a pressure vessels: Other features of pressure vessels include nozzles,

manholes etc. The position of these are marked with

reference to the angle reference lines marked during fit-up.

Manholes, nozzles and lifting lugs have weak spots where

they are attached to the vessel. Hence, these are always

welded to the vessel using a re-enforcement pad, which

uses large fillet welds that offer good strength.

For manholes, the flange outer ring and re-enforcement

pad are bevelled in opposite ways, and then joined by pull

penetration welds.

Nozzle welding depends on the type of nozzles those

perpendicular to vessel surface (axial) and those parallel to

vessel axis (offset). The calculation of position of these and

Figure 22: The horizontal weld is the long seam weld and the weld along the circumference is the circular seam weld

Figure 23: Nozzles with flanges welded to reinforcement pads further welded to Dish End

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their orientation is important. Design calculations determine the position and

geometry of the whole that is to be cut out to accommodate them. Spirit levels and

plumb lines are used to ensure perfect alignment with vessel axis, when they are

welded.

The support structures of the

vessels, like skids and saddles, are

also fabricated in the workshop.

They are mostly made up of I-

beams that interlock together to

form a grid like design. The main

beams support the saddles on

which vessel rests. Extra

attachments are provided to

support piping, as well as spillage areas and drains. Platforms for workers to stand on

to access nozzles are also fabricated, and installed on-site.

The welding method to be used for different joints are decided by the Senior Welding

Engineer by consulting the Lead Engineer is any doubts exist and the document that contains

the procedure is called a WPS Welding Procedure Specification. This procedure instructs a

welder the preheat temperature to be used, the in pass temperature, the flux feed rate,

voltage, current, the bevel angle, chemical composition of the plates welded, chemical

composition of the electrode all parameters are defined within a specified tolerance. A

change in any single parameter beyond the specified tolerance calls for a new WPS.

Many trials and destructive tests are conducted on test plates testing whether the

weld joints strength is greater than or at least equal to if it were a continuous body. After

these tests a Procedure Qualification Report, PQR, is made, using which the WPS is made.

However, destructive tests cannot be performed on the weld on the joints of the project. So

in order to check for any defects present in the weld of a project non-destructive tests are

performed.

8.4.3. Non-Destructive Testing: Below are the set of NDTs performed on each joint of a Pressure Vessel after its welding:

8.4.3.1. Visual Inspection: The most preliminary of all NDTs, the visual inspection, involves inspectors inspecting the

welds for any visually visible cracks, or defects.

8.4.3.2. Dye Penetrant Test: This is done to check for any pores on the surface that is not visually visible. It follows the

principles of capillary action and blotting.

Figure 24: Different sizes of scrap saddles kept outside the Pressure Vessel Fabrication Workshop for disposal

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Steps:

1. First the weld surface is thoroughly cleaned.

2. A red dye is applied on the weld surface and left for about 20 minutes. Within this

time the red dye would be absorbed by the small cavities / pores through capillary

action.

3. The surface is again cleaned and a developer is coated on it and left for hours.

4. The dye absorbed through capillary action gets absorbed by the developer and those

parts produce spots because of blotting. Thereby letting us know of the existence of

pores.

The above mentioned two tests only help in finding out defects present only on the surface. To

know of the cracks within the weld we follow the following NDTs

8.4.3.3. Magnetic Particle Inspection: This method follows the principle that where ever a cavity is present, magnetic field

gets accumulated there because of the difference in medium. Therefore if powdered

magnetic particles are placed on the surface below which cavity is present, they

accumulate there. For this purpose, first step is to apply White Contrast Paint on the

ferromagnetic material, then spray the MPI ink (Magnetic Flux). After a settling time,

the yoke is brought near the surface and polarization of ink reveals discontinuities.

Magnetic particle testing can only be tested for cavities or cracks just beneath the

surface, about 6mm or so. Beyond that we need to use other NDT methods.

8.4.3.4. Radiographic Testing: This method makes use of X-rays produced by radioactive isotope. Penetrating

radiations pass through the solid body (weld), onto a photographic film, resulting in

an image of the objects internal structure being deposited on film. Energy of

radiations absorbed depends on thickness and density. Areas where less absorption

occurs (defects) show up as over exposed (dark) in the film. Thus, porous areas, cracks,

etc. will show up in contrast on film. Also, presence of tungsten in weld can be

identified by bright spots (due to larger density of tungsten).

Advantages: Permanent record of weld quality, positive method for detecting all

defects.

Disadvantages: Costly, slow process, hazardous operating condition for humans.

8.4.3.5. Ultrasonic Testing: This method of testing makes use of mechanical vibrations similar to sound waves but

of higher frequency. A beam of ultrasonic energy is directed into the object. The beam

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travels through the object with significant loss, except when it in intercepted and

reflected by a discontinuity.

8.4.3.6. Soap Water Testing: This method is used to check for gaps between the reinforcement pad and the shell.

Air at 1 bar pressure is pumped into the completed vessel, which is completely sealed.

Soap water is poured over the welds. Bubbles observed on the surface are an indicator

of porosity.

8.4.3.7. Hydrostatic Testing (DONE AFTER PWHT): The completed vessel is filled with water at high pressure, 1.5 times the design

pressure, and is maintained at such conditions for about 2 hours. During the test,

inspectors come to check visually if any leakage is occurring. A pressure chart is

plotted. Any variation overtime would indicate leakage. This verifies the vessels

overall integrity and any drops in pressure over the time period is an indicator of flaws.

This test is done after PWHT.

After welding is done, because of the sudden heating and cooling, stress is produced at the

joints, which poses a threat to the strength of the joint. This stress is released through a

process called Post Weld Heat Treatment.

8.4.4. Post Weld Heat Treatment: PWHT involves the heating of structures after all welding activity has been completed. The

heating causes a change in the metallic structure at a microscopic level old grain structures

of the material break down, relieving the stress. The structures are held at a fixed

temperature for a particular period of time, after which it is gradually cooled. The gradual

cooling leads to formation of new, uniform, stronger metal grains and increases overall

strength.

8.4.4.1. Heat Treatment It is a large chamber, with insulation

covered walls (glass wool, thermo Cole) and

flooring (fire resistant bricks).

Heat is imparted to the chamber by means

of 12 burners that use a combination of diesel and air to burn and release heat.

The chamber has a central partition that can be adjusted to meet size of the job. For

smaller projects, only a certain portion of the chamber need to be used along with

fewer burners.

Figure 25: Post Weld Heat Treatment Box

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Controls of the PWHT chamber lie outside in the control room, and are done remotely

using solenoid switches. The automated control bank can be used to fix conditions of

temperature, mass flow rate of air, holding time etc.

Along with controls, the feedback from thermocouples attached to the product during

the process will be made. In this manner, temperatures of various portions of the job

can be monitored on a time temperature plot. The graph also indicates whether

sufficient holding time has elapsed. The recording starts once the job has been heated

to at least 100 / 200 C. The Quality Control

instruction sheet gives the specific details

for heat treatment.

The furnace is started by injecting a LPG flame into an air stream, and then diesel,

after a time delay for ignition.

8.4.5. Surface Preparation and Painting:

After the PWHT and the hydrostatic test, the vessel is painted before dispatching.

Painting is done so that the hot vessels shells external side is not in contact with moisture

and air. Also sometimes the vessel could be used as a de-salter, therefore its internal walls

are exposed to salt and could degrade very quickly.

Before painting can be done, its surface is prepared i.e. a profile of a

particular grade is produced so that the paint sticks to the surface.

8.4.5.1. Surface Preparation: Grit Blasting is used to remove the layer of iron oxide on the products.

The process is carried out in the grit blasting chamber, where a high velocity stream of

pressurized air (7 bar) and fine abrasives are directed at the metal surface. On contact,

this stream dislodges the layer of rust, leaving behind rough but clean metal abrasives

are used for blasting like garnet and steel granules.

Cleaning in this manner yields different grades of

surface:

SA 1 (rusting still present)

SA 2 (roughly clean)

SA 2 (Nearly white metal most commonly

used standard)

SA 3 (white metal)

Figure 26: Cautionary sign used during PWHT

Figure 27: Steel Structures kept for Grit Blasting

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After cleaning, the product can only be exposed to air for a maximum of 4 hours. Within

this time period painting must be performed. Certain products require galvanisation,

which is applied by sweep blasting.

8.4.5.2. Painting: Painting occurs in three layers:

Primer coat (metallic zinc rich epoxy primer)

Intermediate coat (high build, two component epoxy

coating)

Final coat (acrylic polyurethane)

Curing of paint can be through chemical reaction, oxidation,

exposure to moisture etc.

Paint layer thickness is measure in microns. Minimum

tolerances for thickness must be observed.

Mixing ratio 4 : 1 of compound A and B (paint + hardener)

Volume percentage of solid the percentage of paint that is deposited on metal surface.

Drying time the time taken for chemical reaction to complete and paint to set.

Volatile organic compound (portion of paint that vaporises)

Specific thinner to be used for dilution and use in spraying

apparatus.

For pressure vessels, different areas are painted differently

-

Example - Storage tank:

Coat tar (base), Normal epoxy (outside), Interior-bottom (fibre-glass), Interior-top

(Phenolic epoxy)

After the painting, and QC inspection of the painting, the job is dispatched to the clients

store or to the site where it is to be erected.

Figure 28: Grit Containers

Figure 30: Steel Structures painted to different layers primer, intermediate high build epoxy, final (Left to Right)

Figure 29: Paint containers kept outside to be used

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9. Piping A brief summary

The piping fabrication procedure begins with analysis of the design provided by client. The

materials required are listed and classified as available, missing, or to be purchased.

Unlike steel structures, piping projects cannot be undertaken without having all raw

materials.

Piping drawing specifies the number of schedules (sections of pipe), with the required

dimensions and angles. For piping, the fabrication occurs in sections, with the complete line

being set up on-site. In the workshop, they are cut down to size, and welding of flanges etc.

is performed, after which they are dispatched to be linked on site.

The selection of a pipe depends on the fluid being transported, pressure, mass flow rate,

temperatures involved, etc.

9.1. ANSI Standard pipe schedule: It is a chart specifying the thickness of pipe for industrial use, given values of outer

diameter, schedule, and available pipe sizes (1/8, , 1, 2, 4) volume per m for every m3 is

specified.

9.2. Materials used in piping: 9.2.1. Pipes:

Carbon steel Alloy steel Stainless steel Duplex SS, Super duplex SS

The standard material used is ASME B31.1 / NACE.

9.2.2 Flanges: Based on maximum pressure that can be withstood (150, 300,

600psi...)

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9.3. Piping Components: The main components are:

9.3.1 Straight sections: These are pipes that are bought directly from manufacturers, with standard sizes.

Edge preparation (bevelling) has been performed. As per requirement in workshop,

the pipes are cut down to size using gas cutting (re-bevelling required).

9.3.2 Flange A flange is an external or internal ridge, or rim (lip), for strength, as the flange of

an iron beam such as an I-beam or a T-beam; or for attachment to another object, as

the flange on the end of a pipe, steam cylinder, etc.

Flanges are of two types:

Ring type joint

Raised face (flange has a raised face that fits into a

corresponding depressed section in the pairing

flange).

9.3.3 Gasket: A gasket is a mechanical seal which fills the space between

two or more mating surfaces, generally to prevent leakage

from or into the joined objects while under compression.

Gaskets allow "less-than-perfect" mating surfaces on machine parts where they can

fill irregularities. Gaskets are commonly produced by cutting from sheet materials.

9.3.4 Sleeve: Connection between two parallel pipes, when pressure to be transmitted is less.

9.3.5 T Joint: This is a three way junction in pipeline layout, allowing the merging of two flows into

one or splitting of a single flow. Equal Ts have the same length for all 3 inlets, and

unequal Ts vary as per design.

9.3.6 Nipple: It is a thin inlet into the pipe, usually at an angle to the pipe axis instead of

perpendicular. It holds instrumentation lines, sensors etc.

9.3.7 Elbow joint: These are used to change direction of flow in pipelines. They may be of long radius

(greater than 1.5 times pipe diameter) or short radius. They are purchased in

standard angle of 30, 45 and 90.

Figure 31: A T joint and a Reducer (Top to Bottom)

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9.3.8 Reducer: It is a component that is used to reduce the cross sectional area of the pipe it is linked

to. In the case of a major pipe splitting into several small lines along its path, use of a

reducer avoids the need to provide extra pressure from the source, as well as adjusts

for the drop in volume flowing.

They are of two types:

1. Concentric Links two pipes such that their axis are aligned.

2. Eccentric Links two pipes such that their axis are parallel but displaced. This

is beneficial when designing piping supports of same size.

9.4 Welding in Pipes: When a pipe is to be joined to an elbow joint or reducer, circumferential welding is

performed. The surfaces are fit-up together and held in place using tacks. In piping, back

chipping is not possible, hence TIG welding is used that yields a fine root.

The automated welding machine is used for higher productivity. It supports the two

adjoining pipes, and can be set to rotate at a constant speed and perform welding. This

yields high quality welds. Sensors constantly measure the current required, distance to

surface etc.

For the junction of two pipes, the corresponding profiles are cut out on both to ensure a

perfect fit.

For welding for smaller pipes to larger pipes, two types of joints are present:

1. Weldolet: Adjoining pipe is secured to the main pipe without intersecting it.

2. Sockolet: Pipe axis intersect, and re-enforcement pad is used.

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10. Conclusion

The Fabrication Services Operation plays a major role in HEISCOs Oil and Gas Sector. This

department needs to be continuously monitored, maintained and updated to compete in the

international market. It is all about Quality, Time and Price.

HEISCOs Fabrication Department sees safety as an utmost priority and takes all the

necessary measures and actions so that its workers are always safe. Periodical audits,

emergency response contests, colour code system, safe operation procedure checklist and

many more measure to prevent any sort of safety hazard are present here.

The most impressive of all aspects of HEISCO that I observed is its management. There are

standard documents for each administrative activity, well defined procedures, departments

assigned to be responsible for a particular work, instructions on how to pass information from

one department to another so that no confusion occurs, and more, so that the company

functions smoothly without any doubts or loopholes.

All in all, I am very happy and satisfied to have come to HEISCO for my Summer Training

Program.

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11. My Experience as an Intern at HEISCO

It was a summer very well spent.

I learnt a lot, directly as well as indirectly, a lot more than what I had tried to learn in my past

three semester holidays.

I met a lot of great engineers and people, people with experiences to share and learn from.

I didnt learn just engineering, planning or fabrication processes here, I learnt how to plan my

future, and what I must look for and do while I am in college and what to do after I graduate.

The administration at HEISCO was very inspirational to me.

I am a member of the Designing Team of IIT Mandi, and we often get requests from various

clients to make posters, design booklets, pamphlets, T-Shirts, etc. But many a time it so

happens that there is sort of communication gap between designers and the client,

sometimes some information is missed out by the client, other times the client assumes

designing to be simple and keeps requesting for modifications. The methods used at HEISCO

like, AWI, DWI, proved to be quite helpful for our problem and I have already started

coordinating with my fellow veteran designers to formulate AWIs and DWIs for our team.

I was able to experience how it feels like to actually go to an office punctually because of the

schedule given to me, and how to survive and grow in a professional world.

Previously I used to see pressure vessels and pipes like black boxes, I only bothered about

how it worked and what it was used for. But now when I see a pressure vessel, I can see the

efforts of the material procurement department, the quality inspection of each and every

component and process, the budget being fixed, designers designing the vessel, workers

being led by a foreman being guided by a supervisor who reports to the senior engineer and

lead engineer, a whole network of people interdependent on each other, trusting, trust

checking, cooperating

I have learnt to appreciate every type job.

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how is a pressure vessel made and more

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