Shell fabrication.pptx

THE PROCESS OF PLATE TO SHELL
MANUFACTURING

SR NO TOPIC PAGE
NO
1 Introduction Of L&T 4
2 Stages For Manufacturing Of Shell 7
3 Stages Of PCR [ Plate Cutting Request] 8
4 Identification, Marking And Cutting Of Plates 8
5 Rolling & Rolling Process 12
6 Edge Breaking 16
7 Rolling Selection Factors 17
8 Shell Inspection After Rolling 21
9 Long Seam Set-Up 21
10 Problem Can Occur While Long Seam Set-Up 24
11 Offset Limits For Butt Welds As Per Code [ Asme Sec. Viii Div 1 ] 26
12 SAW Process 29
13 Chipback 31
14 Shell # Shell joining 33
15 Dished End Manufacturing 35
16 Shell # Dished end joining 37
17 Nozzle Fabrication 40
18 Skirt Manufacturing Process 42
19 Skirt Installation Process 43
20 Hydrostatic Pressure Test Process 44

 INTRODUCTION OF L&T HAZIRA
Larsen & Toubro is a major technology, engineering, construction, manufacturing and financial services conglomerate,
with global operations. L&T addresses critical needs in key sectors - Hydrocarbon, Infrastructure, Power, Process
Industries and Defense - for customers in over 30 countries around the world.
L&T is engaged in core, high impact sectors of the economy and our integrated capabilities span the entire spectrum of
‘design to deliver’. With over 7 decades of a strong, customer focused approach and a continuous quest for world-class
quality, it have unmatched expertise across Technology, Engineering, Construction, Infrastructure Projects and
Manufacturing, and maintain a leadership in all our major lines of business.
Every aspect of L&T's businesses is characterized by professionalism and high standards of corporate governance.
Sustainability is embedded into its long-term strategy for growth.
The Company’s manufacturing footprint extends across eight countries in addition to India. L&T has several
international offices and a supply chain that extends around the globe.
L&T’s Hazira campus is a multi-facility campus that covers a Modular Fabrication Facility (MFF), and
Heavy Engineering & Shipbuilding, and Power equipment manufacturing facilities. This modern, coastal
complex is situated on a 200 acre plot near Surat in Gujarat.

The factory buildings cover over 34,500 sq. m. and the complex has a load-out quay on the banks of the river
Tapti close to the Arabian Sea.
Hazira campus is equipped to manufacture extra-large and very heavy equipment for power projects, chemical,
refinery, petrochemical & fertilizer industries, which can be shipped out via waterways.
The Modular Fabrication Facility (MFF) at Hazira, one of the largest of its kind in South Asia, is capable of
manufacturing several large modules simultaneously with an annual fabrication capacity of 50,000 MT.
In addition, L&T’s Hazira complex has one of the world’s largest Forging facilities, large scale Material
handling capabilities, a roll-on-roll-off slipway, and a Shipbuilding facility for high-tech vessels.
L&T Heavy Engineering business is organized under self-reliant Strategic Business Units (SBUs) catering to the
needs of core sector industries through supply of equipment to Process Plant Industries, and the Nuclear Power,
Defense& Aerospace sector.
The division operates at the upper end of the technology spectrum and has been at the forefront of introducing
new processes, products and materials into manufacturing sector, for over six decades.

L&T Heavy Engineering has state-of-the-art manufacturing facilities which are capable of meeting the challenges of technology,
quality conformance & delivery, while ensuring cost competitiveness.
Our capability spectrum not only covers in-house engineering, R&D centers and world class fabrication facilities, but also
includes a highly experienced team, committed to a safe and sustainable work culture.
Hazira Manufacturing Complex (HZMC) is L&T’s state-of-the-art manufacturing facility located on the banks of River Tapti
near the Arabian Sea (about 16 km away from Surat, Gujarat). The facility spreads over more than 750 acres of land with a
1.6 km long water front facility. It employs more than 5000 people directly and more than 12,500 people indirectly.
One of the best manufacturing facilities in the world, HZMC showcases a symphony of cutting edge equipment and
technology, largest and heaviest capacities and the best pool of engineering talent and skilled manpower.
It caters to critical, large sized equipment for Process Plant, Nuclear and Defense sectors and is equipped with heavy thick
rolling machines of 3050 MT capacity which can Roll plates up to maximum width of 4500mm and thickness up to 250 mm
(Hot Rolling), CNC gas/plasma cutting machines which can cut up to 450 mm thick alloy steel plates, Water jet cutting
machine with working pressure of 3800 bar, Floor Mounted Horizontal Boring machines (12.5 m horizontal and 5 m vertical
traverse), Vertical Boring machines with swing of 12 m and capacity of 250 MT, 4 Horizontal/Vertical Deep hole drilling
machine with maximum drill depth up to 1200 mm, Heat Treatment Furnaces (for jobs up to 50m long) and quenching
facilities, advanced welding equipment, positioners and power sources, Hydro Test Beds with capacity of 60 MT/sq. m.,
testing facilities, ISO 17025:2005 NABL approved testing lab, Linear Accelerator for High thickness radiography, PAUT,
TOFD capabilities.

THE PROCESS OF PLATE TO SHELL
MANUFACTURING
 STAGES FOR MANUFACTURING OF SHELL :
 Preparation of PCR
 Preparation of PCL
 Blasting of Shell Plate from inside surface
 Identification, Marking and cutting of plates
 Edge breaking, long. seam WEP & lug welding in one segment
 Rolling of half segments
 Set-up of long. seam
 Long. Seam welding & NDT

1) Preparation Of PCR :
 Make PCR hard copy Indicating length, width, edge breaking allowance, rolling I/D, long seam WEP and PTC details.
 Make PCR entry in BaaN and forward hard copy PCRs to Material control for making PCL
2) Making of PCL :
 Prepare PCL based on PCR hard copy.
 PTC to be given in PCL
 Release PCL in BaaN and forward hard copy PCL to PFS
3) Blasting Of Shell Plate From Inside Surface :
• Receipt and unload the plates at plate yard by plate yard supervisor.
• Capture heat no & paint the L&T plate no on plate thickness by plate yard workman.
• Inform sand blasting supervisor by PFS co-ordinator and facilitate to complete the blasting of plates by PFS supervisor.

1 DRG Release In System & Shop
2 PCR Preparation Based On Detailing
3 PCR Entry In System
4 PCL Preparation [ Plate Cutting Layout ]
5 QC First Stage Of Inspection And System Clearrence
6 SFC [ Shop Floor Co-ordination ] give time for marking and cutting
7 Store Issue Plate Base On Outbond & PCL
8 SFC IS Receive Plate And Start Marking
9 QC Is Inspection Marking And Give Permition For Cutting
10 SFC Complete Cutting & QC Give Stamp To Work Piece
11 Return Balance Plate is Send To Store & Store Is Close PCL
 STAGES OF PCR [ Plate Cutting Request]

 IDENTIFICATION, MARKING AND CUTTING OF PLATES :
 Offer plate in BaaN for first stage clearance and get released for cutting by PFS supervisor
 Measure actual length & width of plate.
 Cut the width of plate (if extra)
 Measure the actual thickness of plate & calculate average thickness. Write this data in format no.1/45330
 Carry out marking on plate as per above calculation & fill the format no.1/45330
Write Job No., Item No. & L&T Plate no with yellow paint on inside surface of plate.

 Tools Requirement For Plate Marking :
 Measuring tap
 Center punch
 Hammer
 Chalk stick
 Plate Marking Procedure :
 Check the palate thickness, size, material and it’s identification punching.
 Take the rub-off the palate’s original punching.
 Use calibrated tape for marking & measuring.
 Clean the surface of the plate
 Do identification punching on plate as per its original punching.
 Check plate thickness at min 10-16 point for average thick.
 Do trimming & reference line & PTC & MTC marking on the plate as per PCR.
 Do marking of rolling id on plate.
 Take the inspection stamp on the plate & used the palate. After completing the inspection use the plate.

Description :
L
w
ROLLING DIR.
3 Units
 Job no: 12345
 Plate no: 78964
 Length: 6367
 Width: 2280
 Thick: 105.00

First clean the plate surface.
And after that check the plate length, width & diagonal as PCR, everything found ok. Plate dimension are.
 Length: 6367 mm
 Width: 2280 mm
After that did identification punching on the plate’s both width end and also on center of the plate as per plate original
punching.
 Detail Of Identification Punching :
 Job no: 12345
 Plate no: 78945
 It no: 0000
 Sh #no: 1
 H – 1234567 – 001
 Material: SA 533M GR B CL2
Measure the thickness at 16 place and calculate the average thickness of plate for & do rolling id marking.

PLATE
NO.
ACTUAL THK AVREGE
THK.
78945
1 2 3 4 5 6 7 8
107.58
108.7 107.8 107.2 107.2 107.1 107.5 107.4 107.9
- - - - - - - -
9 10 11 12 13 14 15 16
106.2 107 107.4 108.9 107.9 107.7 17.8 107.7
 Did rolling ID marking on the plate.
 After completing this entire task offer the plate for identification inspection and after clear the inspection use
the plate

 ROLLING :
Rolling is a type of Fabricating process in which the plate is passed in between the pair of rollers in order to elongate
and stretch the material/plate to form the required cylinder/shell of the required dimensions.
 Types Of Rolling Process :
1) Hot rolling
2) Warm rolling
3) Cold rolling
4) Pinch rolling
5) Pyramid rolling / normal rolling

 Hot Rolling :
 If the temperature of the metal is above its recrystallization temperature then the process is termed as hot rolling.
Whenever yield strength of the plate material is beyond the capacity of rolling machine, the plate shall be rolled at
elevated temperature
 The plate shall be heated in a plate-heating furnace to stress relieving / normalizing temperature as per the approved
heat treatment request

 Warm Rolling :
 Warm rolling Rolling of Plate of Various material above there lower critical temperature is called warm rolling.
 Rolling at a temperature below its Recrystallization temperature is called as a warm rolling.
 Reason of warm Rolling:
 When the thickness of the material to be rolled is greater than the capacity of the machine, warm rolling is carried
out.

 Cold Rolling :
 Cold rolling, Rolling of Various materials at room temperature is called as cold rolling.

 Pinch Rolling :
 Bending at the plate ends which is carried out by shifting the bottom rollers to either left or right direction.

 Pyramid Rolling / Normal Rolling :
 The normal rolling carried out to roll the plate is called the Pyramid or Normal rolling.
PYRAMID ROLLING
TOP ROLLER
BOTTOM
ROLLER
BOTTOM
ROLLER
NORMAL ROLLING

 EDGE BREAKING
 It is the process of bending the edges of the plate before it is fully rolled. Before anything is to be rolled, edge
breaking is to be carried out.
Edge breaking is necessary in order to make the edges of the plate as per the template profile we required, which
enables the plate to be a round shell.
As the top roller is not perpendicularly at the center of any bottom roller, Edge breaking is required. Otherwise
the edges of the plate after rolling will remain straight which makes it unable to be a shell.
So, the bottom rollers are shifted either in the left or the right direction of the top roller as shown in the figure 1.2
Edge breaking allowance = 1.5T
(Where, T = Thickness)

 ROLLING SELECTION FACTORS :
1) Capacity of rolling machine
2) Thickness of the plate
3) Width of the plate
4) Yield Strength of plate
5) Type of Material
1. Capacity of rolling machine: - The capacity of the rolling machine would be limited, so we cannot roll the plate beyond
that limit.
1. Thickness of the plate: - As mentioned above, there would be some limit of the plate thickness beyond which we cannot
roll the plate.
2. Width of the plate: - The max. Width of the plate to be rolled depends upon the length of the rollers.
Yield strength of the plate: - The main selection factor of the type of rolling process is the yield strength of the material to be
used. Suppose the yield strength of the material to be rolled is beyond the capacity of the rolling m/c in cold rolling, then
warm rolling is preferred.

 L&T Rolling M/Cs (Pfs-Pps) Specification :
 SCHAFER HEAVY ROLLING M/C (PFS)
 SCHAFER MEDIUM ROLLING M/C (PPS)
 SCHAFER HEAVY ROLLING M/C :- (PFS)

 CAPACITY:- a. For 1250 mm Main Roller dia.
 Cold Condition:- 125 THK at 1800 mm dia.
 Hot Condition:- 250 For 850 mm Inter mediate Roller dia.
45 mm THK at 1020 mm dia.
 WIDTH : 4500 mm
 BOTTOM DIA. :650 mm
 TOP ROLLER VERTICAL STROCK: 520 mm
 MOTOR CAP. : 600 KW
 DIST. BETW. TWO BOTTOM ROLLER : 910 mm
BOTTOM ROLLER SHIFTING :-400 mm

 Schafer Medium Rolling M/C :- (Pps)
 MAKE:- SCHAFER-GERMAN-1988
 CAPACITY:- A). For 610 mm Main Roller dia.33 THK at
730 mm dia.
B). For 425 mm Inter mediate Roller dia. 14 mm THK at
500 mm dia.
 WIDTH :-4500 mm
 BOTTOM DIA. :- 425 mm
 TOP ROLLER VERTICAL STROCK:-
 MOTOR CAP. :- 60 KW
 DIST. BETW. TWO BOTTOM ROLLER :- 400 mm
 BOTTOM ROLLER SHIFTING :- 145 mm

 Preparatory Activities :
 The completion of following activities shall be confirmed prior to the rolling procedure:
 Verification of dimensions (length, width and diagonal) of shell plate after cutting as per plate cutting request (PCR).
 The difference in diagonals of shell plate shall be verified and confirmed to be within the limit Rolling direction, inside
surface & WEP shall be verified and confirmed to be in accordance with the applicable PCR. The rolling direction and
the surface to be retained inside on rolling shall be marked on the plate.
 Pre-bending allowance is provided in accordance with the PCR on plates above 75 mm thickness.
 NDT if any on WEP, shall be cleared.
 Circumferential edges of plates above 50 mm in thickness shall be rounded off to minimum 3 mm radius to avoid
cracking.
 The shell plate weight shall be derived from drawing or by multiplying the actual volume of material with the density, to
decide the right capacity of crane and lifting tackles.
 Inside surface of Shell plate shall be cleaned by soft broom or by compressed air.
 A D/4 template shall be prepared / made available to check the profile while rolling. The profile of the template shall
be verified and confirmed on a lay out of shell inside radius.

SHELL INSPECTION AFTER ROLLING :
I/D CHECK IN HP PLANE
PEAK IN
PEAK OUT
BOTTOM
ROLLER
TOP
ROLLER
BOTTOM
ROLLER
OVALITY = ID max – ID min
ACTUAL THK.

 LONG SEAM SET-UP :
 Long seam set-up is done after rolling of plate for long seam welding. Long seam welding is process of joining of two
ends of rolled plate to form a complete shell. long seam set-up can be done in two ways.
 Single Segmented
 A single plate is rolled completely to form a shell. In this case only one welding seam will be there.
 Multiple Segmented
 When dia of the shell became to large at that time shell made from to plate at that time two or more long seam are
present in shell.
 Description :
 Job no: 12345
 Plate no: 98765
 Sh # no: 1
 Mat. : SA 533M GR B CL 2

 Pre preparation :
 Prepare run in run out plate
 Cleared the inspection stages
 Prepare PTC as per requirement
1) Items Required For Long Seam S/Up :
 Lug Welded on thickness of the plate segments.
 WEP Machining for the long seam...
 Handling lugs availability
 Locking Cleats availability
 Jack, Pump and manifolds
 Template for ID or OD
 Welding M/Cs
 Slings and D’shackle + Chain
 Scaffolding
Extra packing.

SKETCH OF SET-UP & TEMPERORRY ATTACHMENT

 Buttering :
 Buttering is process which is done between ‘L’ cleat shell segments.
 To prevent the base metal from the damage of extra attachment
 In the welding of ‘L’ cleat & shell segment creat some defect because of their chemical composition.
 So, we use electrode E309L, It stops defect which are creates between them.
 Buttering area detail
390*150 mm

 Extra clit detail :
 500*70*55 thk mm
 Check welds edge preparation as per drg.
 Clear the inspection stages as per requirement.
 Did Wire wheel 50-mm area around seam.
 Bring the two segments near and get require root gap.
 Check the offset & skew shall be under acceptance criteria with the help of scale & try square.
 And also check the peak-in/out with D/4 length template.
 Peak out: 13 mm
 Off-set found
 Offset was 32 mm

 PROBLEM CAN OCCUR WHILE LONG SEAM
SET-UP LIKE
 skew
 offset
 SKEW :
 Rollers not aligned
Plate edges not kept parallel to roller axis plate diagonals
not checked.
 SKEW
15 TO 20MM AND LOW THICKNESS

 OFF-SET :
 Thickness difference measured from I/s or o/s on joining
edges is called offset
 Offset is found during
(A) Plate to Plate Set-up, Long Seam Set-up
(B) Circ. Seam Set-up
offset
 OFFSET LIMITS FOR BUTT WELDS AS PER CODE [ASME SEC. VIII DIV 1 ]
MAXIMUM OFFSET IN BUTT WELD
JOINT THICKNESS "t" LONG SEAM (CATEGORY A)
13 MM & ELBOW 1/4th t
Over 13 mm to 19 mm 3.2 mm
Over 51 mm 1/16th t. max. 10 mm

 Hydraullic Jack Capacity: 100
TONE  Precautions :
 For peak in/out take care while edge breaking of plate.
 For offset maintain the proper root gap at both l/s seam end.
 After correct all this problem tack welds the ends of
segments, welding parameters as per job SWP.
 Measure the outside circumference at both the ends and at
center by measuring tape.
 Circumference was as per the requirement.
 O/S CIRC: 18286 MM
 WIDTH OF SHELLAT 4 ORIANTATION
 AT 90 DEGREE: 2647 MM AT 180 DEGREE: 2647 MM
 AT 240 DEGREE: 2636 MM AT 360 DEGREE: 2640 MM

 The we check the offset, found ok
 Then we attach run in - run out plates & PTC as per job requirement.
 Recheck the circumference at both the ends & at center.
O/S CIRC: 18286 MM
 Then check the ovality by distometers,
1) Ovality 2 mm
2) Circularity 10 mm
 After clear all the steps Offer the set-up for inspection
 Long Seam Welding :
 Long seam welding is a process which is use for joining of two segments to make a
shell.
 SAW [Submerged Arc Welding] is used in the long seam welding process in the PFS.
 Preheating is required for minimum temperature Before the long seam welding
process.

 Preheating :
 Heating the base metal along the weld joint to a predetermined minimum temperature immediately before
starting the weld.
 Heating by Oxy fuel flame or electric resistant coil.
 Heating from opposite side of welding wherever possible
 Temperature to be verified by thermo chalks prior to starting the weld.
 Why Preheating Required In SAW ?
 Preheating eliminates possible cracking of weld and HAZ Applicable to
 Hardenable low alloy steels of all thickness
 Carbon steels of thickness above 25 mm.
 Restrained welds of all thickness
 Preheating temperature varies from 75°C to 200°C depending on hardenability of material, thickness & joint
restrain.

 SAW PROCESS:
 Submerged Arc Welding is welding process, which utilizes a bare consumable metallic electrode
producing an arc between itself and the work piece within a granular shielding flux applied around the
weld.
The arc heats and melts both the work pieces edges and the electrode wire.
 The molten electrode material is supplied to the surfaces of the welded pieces, fills the weld pool and joins
the work pieces.
Since the electrode is submerged into the flux, the arc is invisible.
 The flux is partially melts and forms a slag protecting the weld pool from oxidation and other atmospheric
contaminations.

 Fusion Welding Process
 Automatic / Semi-Automatic
 Arc Between Consumable Electrode And Work
 Arc Covered Under granular Flux
 Wire / Electrode Continuously Fed To Weld Pool
 Wire / Arc Under Flux Moves Along The Groove
 Wire, BM & Flux Close to Arc Melt Under Flux
 On Cooling Weld Metal Solidifies
 Molten Flux Forms Thick Slag Coating On Weld
••••••••••••••• •••
+ –
Wire
Flux
Slag
Weld
Base Metal
Hopper
Power Source
Flux
+
Arc

 Flux For SAW:
 Sodium Chloride
 Potassium Chloride
 Titanium Dioxide
 Sodium Silicate
 Deoxidizing Agents
 Types of Flux
 Fused Flux
 Agglomerated Flux
 Neutral Flux
 Active Flux
 Neutral Flux
s
 Wire compatible to base metal
 Single flux suitable for several materials.
 Active Flux :
 Single flux suitable for specific application.
 Wire may be different from base metal.
 To be welded within the recommended parameters

 Function Of Flux In SAW :
 Stabilizes Arc
 Prevents contamination of weld metal
 Cleans the weld from unwanted impurities
 Increases Fluidity of molten metal
 Generates inert gas shielding while metal transfers
 Forms slag after melting & covers weld
 Allows deposited metal to cool slowly
 Compensates alloying elements Within the weld
 Eliminates spatter generation
 Helps in even & uniform bead finish

 CHIPBACK :-
 What Is Chipback ?
 Removal of weld metal & base metal From other side of a partially welded joint.
 Why Chipback Is Required ?
 To ensure complete penetration
 Chip back shall be done till sound weld metal is reached.
 Ensure sound weld metal by D.P / M.P
•BASE METAL
•BASE METAL
•CHIPBACK
WELD

 How To Do Chipback
 Chip back should be:
 Deep enough to expose sound weld metal
 Wide enough to maneuver an electrode.
 Precautions During Chipback
 Chip back groove radius shall be minimum 4r.
 The chip back groove edges shall not be parallel.
 All gouged surfaces shall be ground by 2 - 3mm.
 Interpass shall be same as that for welding.
 Methods Of Chipback :
 Air - arc gouging
 Gas gouging ( NG oxygen , DA oxygen)
 Manual grinding
 Ferrous Blatters

 Post Heating :
 Raising the pre heating temperature of the weld joint to a predetermined temperature
range (250° C to 350° C) for a minimum period of time (3 Hrs) before the weld cools
down to room temperature.
 Post heating performed when welding is completed or terminated any time in between.
 Heating by Oxy fuel flame or electric resistant coil.
 Heating from opposite side of welding wherever possible.
 Temperature verified by thermo chalks during the period.
 Why post heating ?
 Post heating eliminates possible delayed cracking of weld and HAZ
 Applicable to
 Thicker hardenable low alloy steels
 Restrained hardenable welds of all thickness.
 Post heating temperature and duration depends on hardenability of material, thickness &
joint restrain.

SHELL # SHELL JOINING
Sr.No. Shell # Shell Joining (Vertical)
1 Circ.seam WEP preparation on shell
2 Lifting & place the shell
3 Lug remove & grinding
4 Shell lifting & position vertical
5 Circ.seam set up shell # shell
6 Tack welding of Circ.seam and inspection
7 Circ. seam welding face side
8 Circ. seam C/B grinding
9 Circ. seam welding C/B side
10 Circ. seam welding visual & PT inspection
11 Circ. seam welding UT & RT
12 Final dimension inspection of shell

Sr.No. Shell # Shell Joining (Horizontal)
1 Saddle arrangement in shop as per drawing
2 Turning the shell horizontal position
3 Lifting shell and load on saddle
5 Circ.seam set up shell # shell

 Shell # Shell horizontal joining :
 Load Shell with axis horizontal on Tank rotator.
 Keep principle orientations along vertical or horizontal axis, preferably.
 Keep another idler in front for supporting second shell while setup.
 Hold the second shell with crane & align the Shell axis with that of 1st shell.
 Align bottom orientation of the shells. Ensure required root gap by appropriate spacers.
 Ensure offset = calculated offset from Inside.
 Lock the setup by welding appropriate locking cleat.
Repeat steps 6 & 7 for balance orientations. In case offset is more, remove it by jacking or wedging.
 Check offset in balance circumference. Repeat steps 6 & 7 to ensure offset within permissible
limits.
Check surface /axial alignment & ensure it is within specified limits. Generally 1mm /m & max. 19
mm allowed.

 DISHED END MANUFACTURING :
 Steps For Petal # Petal Set Up :
 First receive petals.
 Do WEP (weld edge preparation) machining on Petals for longitudinal Seam welding.
 Carry out NDT (non-destructive testing) on weld Edge.
 Material thickness while removing Temporary attachment.
 Also ensure that set up station for petals is ready.
 After that set 1st petal on set up station with then Reference of marking
 Done on set up station.
 After levelling the help of hydraulic jack.
 In same way each petals are s/u on station.
 After completing set up do cleat s/up and welding at Inside.
 Parallel also do lug marking + lug welding on Petals at outside for lifting the dished end.
 Below Shown Realistic Images of Petal Set-up Station with Set-up.
After that take dimension of that s/up in which Include Circumference offset, ovality, thickness etc.

 Problem faced in set/up:
 Offset
 Circumference/Height
 Root gap
 Causes:
 Weld edge preparation machining not done properly.
 Problem in forming of petals.
 Set up of petals not done properly.
 Remedies:
 Ensure machining fixture is aligned properly.
 Ensure correct dimension during forming.
 Proper set up & leveling of petals.

SHELL # DISHED END JOINING
Sr.No. Shell # Dished end joining (Horizontal)
1 Lug remove of dished end and shell
3 Circ.seam set up shell # Dished end

 Shell # Dished end joining:
1) BEFORE STARTING SETUP : -
 Machine Readiness :
 Check power source.
 Ensure all connections are connected properly including earthling.
 Job Readiness for Setup:
 Ensure identification of shell and dished end.
 Obtain inspection clearance for starting setup of Shell and Dished end.
(Ensure completion of previous LTFPS stages before circ. seam setup.)
 Arrange the cement block / stool for setup in vertical condition.
 Check ovality of shell at both the open ends and should be within tolerance.
 Place & align the Shell on stool.

 Mark reference line on shell & dished end at 100 mm from open end on both ID and OD.
 Obtain inspection clearance for welding of temporary supports / lugs on dished end.
 Weld the temporary supports / lug on dished end .
 Place & align the dished end on shell 4 and match all four orientations within 1 mm.
 Mismatch (Offset) shall not be more than given tolerance.
 Carry out punching on shell and dished end for RT/UT spot.
2) DURING SETUP :
 Ensure acceptance of welding consumables for circ.set up.
 Welding parameters should be set as per the respective WPS of the seam.
 Using temporary attachments as planes & by matching the above centerlines.
 Carry out Setup by GTAW process.
 Fill up WDS for tack welding.
 Recheck orientation lines (0º, 90º, 180º & 270º) of the complete assembly are within given
tolerance.
 Confirm concentricity is within tolerance.
 Offer setup for inspection by ensuring other parameters as per protocol. Obtain inspection
clearance from Inspector.

 Before Starting Welding Of Shell # Dished End : -
 Machine Readiness :
 Check power source & Control unit
 Ensure all connections are connected properly.
 Ensure filler wire is given WPS.
 Check earthling arrangement.
 Job Readiness for Welding:
 Welding parameters shall be set as per WPS of the seam.
 Start welding. Record all the welding parameters in WDS.
 First 2 layers shall be welded by GTAW.
 Check concentricity after completion of GTAW.
 Place & align the shell # dished end on tank rotators.

 During welding :
 Ensure acceptance of welding consumables for welding.
 Welding parameters shall be set as per WPS of the seam.
 Start welding. Record all the welding parameters in WDS.
 Complete the welding by GMAW process.
 Carry out chip back grinding.
 Verify concentricity, same should be within given tolerance.
 Obtain inspection clearance & carry out PT of chip back area.
 Carry out chip back welding by GMAW. Record all the welding parameters in
WDS.
 After welding: -
 Verify concentricity, same should be within given tolerance.
 Carry out flush grinding of seam.
 Obtain inspection clearance; carry out PT, UT & RT of seam.

Sr.No. (A) Nozzle fabrication
1 Plate marking and cutting
2 Plate rolling, forming
3 Plate checking final profile and orientation marking
4 WEP preparation
5 Long seam set - up inspection & tack welding
6 Inspection of tack welding
7 Long seam welding face side
8 Long seam Grinding and welding C/B side
9 Long seam welding visual & PT inspection
10 Long seam welding UT & RT
11 Nozzle reference line marking
12 Final dimension inspection of nozzle
(B) Nozzle set up & fabrication on shell
13 WEP marking and preparation on nozzle
14 Development of Cutout on shell
15 Marking on Shell and cutout
16 WEP preparation on shell
17 Match the orientation marking of nozzle & shell
18 Nozzle Set Up & inspection
19 Tack welding and inspection
20 Circ.seam welding face side
21 C/B side Grinding and C/B side welding
22 Welding visual & PT inspection
23 Welding UT & RT
24 Final dimension inspection of nozzle
NOZZLE FABRICATION

 Nozzle Marking & Cutout on Shell/Cone/Head:
 Mark Orientation of Nozzle as per drawing.
 Mark Elevation of Nozzle as per drawing.
 Mark development of nozzle cutout on shell O/D w.r.to orientation & elevation
line.
 Make cutout by Gas cutting using Auto-cutting M/c
 Make WEP by either plasma-cutting & grinding or by machining.
 Carryout DP/MT of WEP & adjacent area to ensure defect free surface.
 Development For Nozzle :

 Nozzle Set-Up On Shell/Cone/Head :
 Mark Orientation lines on nozzle to take care of straddling as specified.
 Straddling of Bolt holes-3 types
 Off-Centre to orientation line
 On-Centre to orientation line
 Mark orientation lines on nozzle according to specification.
 Lift the Nozzle & match orientation line with Shell/cone/Head orientation line & elevation
line with the other center line of nozzle.
 Ensure level of nozzle in correct plane.
 Lock the nozzle by welding with shell.

SKIRT MANUFACTURING PROCESS
Sr.No. (A) Segment preparation
1 Plate receiving in shop
2 Plate marking and cutting
3 Squreness checking and edge preparation
4 Template making as per dimension
5 Plate rolling
6 Check the rolling diameter as per template
7 WEP making
(B) Segment set up and joining
8 Leveling segment on support stool
9 Segment set up and inspection
10 Tack welding of long seam and inspection
11 Re-rolling
12 Spider installation
13 Long seam welding face side
14 Long seam C/B grinding
15 Long seam welding C/B side
16 Long seam welding visual & PT inspection
17 Long seam welding UT & RT
18 Orientation marking on shell
19 Foundation ring install on shell & match the orientation marking
20 Tack welding of shell with foundation ring
21 Check all dimension as per drawing
22 Circ.seam welding of shell # flange
23 Final dimension inspection of skirt
24 Stress reliving process (heat treatment process)

SKIRT INSTALLATION PROCESS
Sr.No. Skirt # Dished End Joining (Horizontal)
1 Lug remove of skirt
2 Circ.seam WEP preparation on skirt
3 Orientation marking on skirt
4 Lifting the skirt
5 Skirt & dished end set up on saddle
6 Match & check the orientation marking of D'end # skirt
7 Tack welding & re-check orientation marking
11 Final dimension inspection D'end # skirt

HYDROSTATIC PRESSURE TEST PROCESS
Sr.No HPT Arrangement
1 Design the HPT arrangement drawing
2 Set up of HPT arrangement
3 Saddle arrangement
4 QC check all arrangement of HPT
5
Requirement material, tools & equipment
1) Thermocouple sheets/rubber sheet
2) Cover of the flanges
3) Pressure gauge as per requirement
4) Valve, nipple, spanner etc….
6 Arrange water tank as requirement
7 Arrange the water as per requirement
8 Arrange the water pump as per requirement of the pressure
9 Water fill up in the job& generate pressure
10 Holding time
11 DE pressuring the job as per steps

 Hydrostatic pressure test:
 Good planning is essential for completion of hydro test in minimum possible time.
 Gauges, transducer/ recorder , Sq. Bar, Hose pipes, Pump.
 Location, weight distribution, draining.
 Saddles, slope, venting
 Water- quantity, quality & temperature
 Torque tightening / tensioning units
 Flanges, bolts / studs
 Carry out tightening of Nozzle / Man way covers as per the required torque
 Use proper tightening unit to meet the requirement of PSI / Torque and follow the tightening sequence as per approved
procedure for bolts / stud.
 Start filling water after confirmation of all requirements (like venting, PPM of water, Clearance of Job for fill up) Ensure
that the nozzles (top) are open for air removal Let the water flow out of the top nozzles so that the air is removed.
 Close the nozzle & allow the water to flow from top and confirm absence of air bubbles.

 Start the pump for pressurizing the water inside the equipment. (Selection of pump depends on
the pressure and discharge of water from pump. Set the output pressure of pump such that it
should not exceed hydro test pressure for safer operation)
 Ensure that minimum two pressure gauges are attached
 The pressure gauges shall have an upper range of 2 times the test pressure but in no case less
than 1.5 times or more than 4 times the test pressure. The transducer shall have minimum
upper range of 1.25 times the test pressure. Only calibrated pressure gauge and transducer shall
be used. Validity of calibration shall be verified on the calibration sticker pasted on the
pressure indicators

 Tightening sequence:
1
2
3
4
6 7
8 5
 Increase the pressure as per the requirement given in drawing or the
approved procedure
 During pressurizing from design pressure to test pressure, no one shall
remain on the vessel or very near to bolted connections on the vessel
 Hold the test pressure for minimum 30 minutes or as specified by the
drawing / specification. The test pressure shall not get dropped during
the holding time. The vessel connections shall not be inspected closely
for any leakage at this stage
 Reduce the pressure to Design pressure. Check for any leakage in weld
joints and bolted joints.

 Sketch for hydrostatic pressure tests:

Shell fabrication.pptx

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Shell fabrication.pptx