ms t4911

KNM Petrosab Engineering Sdn Bhd

METHOD STATEMENT FOR ERECTION AND

INSTALLATION OF FIXED ROOF STORAGE TANK

T-49-11 DIESEL OIL STORAGE TANK

0 19/10//2013 Hairol Zoll Edy Melchor Edy Melchor

Rev. Date Prepared By Checked By Approved By

METHOD STATEMENT FOR

ERECTION AND

INSTALLATION OF FIXED

ROOF STORAGE TANK

PROJECT. NO.

: K1202107

REVISION NO.

: 0

PAGE NO. : 1 of 12


REVISION HISTORY

SECTION PARA DESCRIPTION PREPARED BY


ERECTION AND


ROOF STORAGE TANK

PROJECT. NO.

: K1202107

REVISION NO.

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PAGE NO. : 2 of 12


TABLE OF CONTENTS

SECTION DESCRIPTION PAGE

1.0 SCOPE 4

2.0 APPLICABLE CODES, STANDARDS AND REFERENCES 4

3.0 DEFINITIONS 4

4.0 LIST OF EQUIPMENT 4

5.0 PREPARATORY WORKS 4

6.0 TANK ERECTION METHOD 6

6.1 ERECTION OF BOTTOM PLATES 6

6.2 ERECTION OF SHELL PLATES 7

6.3 INSTTALATION OF ROOF STRUCTURE 9

6.4 INSTALLATION OF ACCESSORIES &

TANK APPURTENANCES 10

6.5 ASSEMBLING OF STEEL STRUCTURES 10

& APPURTENANCES

7.0 WELDING SEQUENCE 11

8.0 INSPECTION 11

9.0 LEAKAGE TESTING 11

10.0 APPENDIX 12


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1 . 0 S C O P E

1.1 This procedure describes the sequence and methods to perform site erection and

fabrication of Fixed Roof Storage Tank for – Knock Down (KD) Tank for Sabah

Ammonia Urea (SAMUR) Project-

2.0 APPLICABLE CODES, STANDARDS AND REFERENCES

2.1 API 650 Welded Steel Tank for Oil Service (revision 11, 2010)

2.2 PTS 34.51.01.31: Standard Vertical Tanks - Selection, Design & Fabrication

2.3 PTS 64.51.01.31: Standard Vertical Tanks - Field Erection & Testing

2.4 PTS 20.156A: Standard Tanks, Volume 1 - Part 1

2.5 PTS 20.156B: Standard Tanks, Volume 1 - Part 2

2.6 Approved Drawings

2.7 BS 2654 cross reference with EN1491

3.0 DEFINITIONS

3.1 KNM PETROSAB : Contractor

3.2 Consortium : AIT

3.3 PCSB : OWNER

4.0 LIST OF EQUIPMENT

4.1 FCAW/ SMAW / SAW welding machines

4.2 Hand Grinder 4.3 Hot Air Blower

4.4 Spreader Bar

4.5 Webbing Sling 6meter, 3000kg

4.6 Webbing Sling 12m, 4000kg

4.7 Robin water pump

4.8 Portable electrode rod dryer

4.9 Mobile Crane 25 & 45 ton

4.10 Diesel water pump

4.11 Welding rectifier

4.12 Electric cut-off machine

4.13 Horizontal lifting clamp

4.14 Lifting clamp

4.15 Gauging machine

4.16 Vacuum 4.17 SLR-0365 G210 Screw Pin Chain Shackle '7/8' (6.5T)

4.18 Electrode Baking & Holding Ovens

4.19 Flux Oven

4.20 Wind girder

4.21 Welder Buggy

4.22 Panel Boards


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5.0 PREPARATORY WORKS

5.1 A 25 ton and 50 ton hydraulic Rough Terrain type crane will be positioned

around the tank foundation (100 ton and above crane only for erection of roof

structure assembly). If unfavourable soil conditions exist, pouring of gravel

materials or laying out of thick wooden planks or steel plates will used to support

the ground and crane stability.

5.2 Before using the crane for lining operations, the inspection will be carried out for

proper functioning and verify all the safety devices (e.g. overload protection) are

operating satisfactorily. Test certificate should be available for inspection.

5.3 Scaffoldings and welding buggy will be used to facilitate erection and welding

works. Proper permit will be secured prior to erection of scaffoldings and

welding buggy on site.

5.4 All the erection aids such as clamps, wedges, shims, spacer plates and other devices for aligning the welding joints will be provided on site including all lifting tackles.

5.5 AFC drawing checked and verified by KNMPESB shall be used.

5.6 Prior to erection, the centre slope shall be checked as per approved drawing. The

dimensions and elevations of the tank foundation as well as the correct

orientation for starting point shall be checked. Ensure that the foundation work

has been formally accepted by KNMPESB and AIT before proceeding with the

tank erection. A release note shall be obtained from civil discipline on the

handover of tank foundation.

5.7 Prior to erection the centreline of the tank will be marked on the foundation as well as the four points along the circumference at 0, 90, 180 and 270 degrees by AIT surveyor.

5.8 Elevation reference benchmark will be establish and set out on site. Plates and

structural materials intended for tank erection will be laid properly on the ground

with proper support and protection for not direct contact to the ground.

5.9 All the plate material shall be check for dimensional accuracy and reported in the

Applicable Inspection Report (Appendix I)


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5.10 Before tanks erection started, foundation shall be checked by the tank

builder with foundations contractor, and CLIENT to make sure that the

foundation are according to specification requirement. If there were some

obstacles on foundation to erecting of the tank, such foundation should be

repaired by foundation contractor. The foundation shall be marked on four

position (0°, 90°, 180° and 270°) and will be done by foundation contractor

or CLIENT. The item to be inspection of foundation are Dimension,

Flatness, Levelness and sump location.

6.0 TANK ERECTION METHOD

6.1 Erection of Bottom Plate

6.1.1 The bottom plate shall be arranged in accordance with Bottom

Plate Drawing and Orientation Drawing.

6.1.2 First Lay down, the sketches plate, start from centre through to

the four direction angle (0°, 90°, 180° & 270°).

6.1.3 The bottom centre plate shall be laid on the centre point

which had been marked by stretching piano wires crosswise

above the foundation. Centre bottom plates which will be

basis for laying other plates.

6.1.4 The arrangement of bottom plates shall be laid out from centre to

outward and tack-welded in surface to be straight as shown

attached figure. Tack welds shall be 1.18 inch long or more on

1ft - 7.68 inch pitch.

6.1.5 For three laps joint, after finished first layer welding, checked

welding line using Dye Penetrate Test or Vacuum Box Test

(Section V, article 6, of the ASME Code). Bottom plates shall be

assembled and tack-welded using special jigs for anti-distortion if

necessary. Weld sketches plates which shell plate will be laid

long of weld 7.87 inch (min.) from out to inward.

6.1.6 At the proper welding, the Vertical joints of 'V' blocks shall be

welded first. Lapped plates shall be in close contact during

welding. After the Vertical joints of 'V' blocks are welded, the

Horizontal joints 'H' blocks shall be made.


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6.1.7 Care shall be exercised during welding of bottom plates to

assure minimum distortion and uniform lapping with as

possible, plates shall be held in close construction at all lap

joint.

6.1.8 After completion of welding works of bottom, tested using

Vacuum Box and Soap suds to all welding line with a

vacuum of 5 to 7 psi.

6.2 Erection of Shell Plate

6.2.1 First Course The shell circle line for erection shall be drawn

on the bottom plates and punched equally by number of shell

plates.

6.2.2 When the assembling of the first ring have completed, the

vertical joints shall be tack-welded from inside to outside.

6.2.3 After completion of the tack-welded on the vertical joints, the

level of top edge and plumbness shall be inspected with an

instrument theodolite.

6.2.4 Check the item horizontal measuring position should be After

Temporary Assembling of 1st Course.

6.2.5 The first continuous welding shall be made from the outside

for vertical joints and back weld from inside. The Welding

from down to up .The strong back or key plates shall be

installed at right angle with the weld line to prevent plate

distortion during welding.

6.2.6 Prior to application of the first bead to the inside welding, the

strong back or key plates shall be removed and welded joints

shall be cleaned thoroughly in a manner that will leave the

exposed surface satisfactory for fusion the weld metal to be

added. This cleaning shall be made from inside by arc-air

gouging and/ or grinding to evenly and smoothly.


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6.2.7 Second Course, the scaffolding board shall be arranged with

lugs and brackets on both side of the first course. When the

traveling scaffolding is used the scaffolding shall be installed.

6.2.9 Vertical joints of the second course shall be assembled with

the match mark, which had stamped on the first course.

Vertical joints shall be matched accurately and retained in

position with spacers and stiffeners. Horizontal joints between

first and second course shall be matched to inside of each

plates and retained in position with spacers and stiffeners.

6.2.10 After completion of second course installed, start welding of

vertical joints of second course in the same manner as the first

course.

6.2.11 The welding of horizontal joints between first course and

second course shall be made the outside first, and being the

stiffeners removed. If there were some defect at first layer

which shall be hindrance to welding from inside, after that

the reverse side of horizontal joints shall be welded.

6.2.12 The fillet weld joint between shell plate and bottom plate shall

be welded after second or third course shell plate is assembled.

6.2.13 Third and Upper Course, third and upper course shall be

assembled in the same manner as the second course. The

temporary assembling of each course shall be completed in the

day, and the maximum allowable numbers of shell course

to be assembled temporarily shall be 3 (three) courses in case

of the plate used 8 (eight) feet width and 4 (four) courses in

case of the plates used 6 (six) feet width.

6.2.14 The vertical joints of third course shall be welded before

the welding of horizontal joints between second and third

course. Owing to circumstances of erection schedule,

welding of vertical joints of 2 (two) or 3 (three) courses

may be proceeded prior to welding of horizontal joints.

6.2.15 Assembling and welding of other upper courses shall be made

as the same manner as stated before. In principle, shell plates

which is higher than 5th courses shall be assembled and

welded one by one course.If there were some undesirable

phenomenon like a settlement of foundation during the shell

assembling and welding, the level should be measured.


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6.2.16 Provision for Wind Load, whenever the strong winds is foreknow

to blow during temporary assembling, following provisions

shall be made.

6.2.17 When the typhoon is anticipated to approaching during the

assembling of the shell plates higher than 4th course, the

plates higher than 4th course to be assembled temporarily shall

be taken down to the ground.

6.2.18 If the shell plate have been assembled up to 4th course, the

channel stiffener ring shall be installed by clamping on the top

periphery. The plate shall also be tied to supports on grounds by

wire ropes.

6.2.19 Top Angle, top angle shall be assembled and tack-welded after

the welding of vertical joints of the shell finally and grind

smoothly of vertical weld to pass through top angle. The

horizontal joints between top angle and shell shall be welded

finally.

6.3 INSTALLATION ROOF STRUCTURE

6.3.1 Installation of Cone Roof Installation of Rafter Lug: Mark the

position of rafter lug on internal surface of top course

shell plate and then welded there to.

6.3.2 Roof Plates, roof plates shall be installed in accordance with

drawing after all roof structure bolted and welded

completely.

6.3.3 Roof plates shall be laid out and tack-welded using special

jigs for anti- distortion if necessary. Tack-welds shall be

made not less than 1 inch long on 20 inch center.

6.3.4 At the continuous welding, transverse joints shall be welded

first. The welding shall be started at the center of plate

width and proceeded outwards symmetrically. When all

transverse joints are welded, welding of the longitudinal

joints shall be made from center to outward in a same

manner as the transverse joints, circumferential joints

between roof plates and top angle shall be welded finally.


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ROOF STORAGE TANK

PROJECT. NO.

: K1202107

REVISION NO.

: 0

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6.4 INSTALLATION OF ACCESSORIES & TANK APPURTENANCES

Each tank accessories and appurtenances shall be assembled and

installed in accordance with the applicable construction drawings which it

have an Approval for Construction status.

6.4.1 Nozzles & Manhole

Lay out position of Nozzles/Manhole on the shell plate and

roof plate. Check orientation, elevation and radius/diameter every nozzles. After

approved by inspector, cut the marked area and set up reinforcing plate for each

nozzles Fit up Nozzles and use temporary support for neck nozzles and also

check projection flange from shell plate. Weld joint neck nozzles to shell from

inside and outside tank and weld reinforcing plate to shell plate

6.4.2 Roof Handrail

Lay out position of all post handrail at around top roof plate,

set up and weld each post handrail to roof plate, set up and weld pipe handrail

(already bended) on the top post handrail. Set up and weld pipe handrail as middle

handrail on the middle of the post handrail. Set up and weld flat bar as bottom

handrail with distance 100 mm from roof plate on the bottom post handrail.

6.5 ASSEMBLING OF STEEL STRUCTURES AND APPURTENANCES

6.5.1 All appurtenances will be assembled and installed in accordanc with

AFC drawing within tolerance specified in PTS 64.51.01.31 (Standard

Vertical Tanks — Field Erection & Testing).

6.5.2 The shell manhole opening will be made after adjustment of the level,

verticality and roundness are completed, prior to the installation of 2nd

course shell plates.

6.5.3 Cutting of holes for nozzles will be made upon completion of the welding of bottom to shell plate and upon approval by AIT representative after

inspection.

6.5.4 When welding the manhole and nozzles, the shell plate will be

reinforced with strong back to avoid possible distortion and

deformation.


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7.0 WELDING SEQUENCE

7.1 Welding sequence of bottom plates, shell plates and roof plates shall be as per AFC

drawings.

8.0 INSPECTION

8.1 Inspection shall be carried as per Inspection and Test Plan and other applicable

Procedures.

9.0 LEAK TEST

9.1 Leak test shall be carried out as per approved Hydrotest Procedure

(KPE1011020- Q-P-006).


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APPENDIX I (APPLICABLE INSPECTION FORMS)


APPENDIX II (SKETCHES ATTACHMENT)


APPENDIX III (STRUCTURAL CACULATION FOR GONDOLA CAGE)

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