PROJ 1051 FAB 001_2 Fabrication Procedure

8/19/2019 PROJ 1051 FAB 001_2 Fabrication Procedure

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PREPARED APPROVED

BY BYREV. DESCRIPTION DATE DATE

FABRICATION PROCEDURE

DOCUMENT TITLE :

PT. SANGGAR SARANA BAJA

JAKARTA - INDONESIA

FABRICATION PROCEDURE AT SHOP

23 Dec 2011


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PT. SANGGAR SARANA BAJA ______________________________________________________________________


DOC NO. : SSNP-GEN-MEC-VDR-005PROJ - 1051 - FAB - 001

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1. General

1.1. This procedure is applied to the shop fabrication of Storage Tank for SouthSumatra NGL Project to be constructed in Sungai Gerong and Prabumulih SouthSumatra Indonesia.

2. Related Documents

2.1 Applicable code and Standards1. API 650-11th Edition 2007: Welded Steel Tank for Oil Storage2. ASME Section IX: Qualification standard for welding and brazing procedure,

welders, brazes, and welding and brazing operators.3. ASME Section V: Nondestructive Examination.4. SSNP-GEN-MEC-SPC-0005 Spec. for Atmospheric Tank

2.2 Applicable Procedures1. Welding Procedure Specification (WPS) with PQR2. Inspection and Test Procedure3. NDE Procedure

3. Material Control

3.1. The materials receiving inspection shall be finished before starting thefabrication. Foreman shall check the inspection report received from QAdepartment.

3.2. Review of the material Identification Number with Mill Certificates and/ormaterial list shall be done before fabrication.

3.3. An adequate care shall be taken on during material handling and transportationto avoid damage and deformation, and especially for stainless steel, to avoidcarbon contamination.

3.4. Visual inspection shall be made to ensure no injurious defect such as sharpnotch, scratch, crack, lamination on the surface and cut edge of plate.

4. Fabrication Control

4.1. All fabrication works in shop shall be performed in accordance with the latestdocuments such as drawings, procedures and applicable specifications.

4.2. All materials to be used in this job shall comply with the material specificationsdescribed in the drawings.

4.3. The production welding shall be performed in accordance with the approvedwelding procedure specification (WPS) and by the qualified welders.


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5. Shop Fabrication

The fabrication shall be performed in accordance with approved drawings,applicable code and standards.

5.1 Marking1. Prior to marking, the material shall be checked for material specification,

overall dimension, thickness and identification mark.2. Marking shall be done direct on the material based on cutting plan, and

fabrication drawing. 3. Where the material is to be divided into two or more pieces, the ID mark

shall be transferred. The transfer of mark shall be made after layout butbefore cutting.

4. After marking the material, the dimension of marking, ID mark shall beinspected.

5. Color code shall be done on separated piece to classify the grade ofmaterial before cutting.

5.2 Marking method1. During shop fabrication, in case that the mill marking is unavoidably cut out

or the material is divided into two or more pieces, the original mill markingof such material shall be properly re-stamped on the each piece after

marking out the cutting line for cutting and before commencement ofcutting.

2. The coded marking which consist of Tank No., Shell Course No. and SerialNo. as shown below shall be stamped or painted on each shell and annularplates


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3. Coded marking shall be done with Low Stress Die Stamp or White ColorPaint as shown in the following table.

Note: Black paint for stainless steel

4. Coded Marking and Heat No. shall be circled with white color paint to findout the location of them easily.

5. The location of Coded Marking is as follows.

6. Coded Marking and Heat No. with traceability shall be recorded on the

cutting plan.

5.3 Cutting

1. Cutting of material and edge preparation shall be performed by thermalcutting, machining and grinding etc. to obtain the specified shape. Prior tocutting, the areas within 50mm of the cut shall be cleaned. The cut edge


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shall be lightly ground back to remove all oxided and heat affectedmaterials.

2. In thermal cutting, scale and oxide shall be thoroughly removed by grinding.The edge to be welded shall be uniform and smooth ground. In case ofstainless steel, iron contamination may initiate pitting attack during work, sosuitable precautions are necessary. The use of carbon steel wire brushesand tool including grinding disc are prohibited. Austenitic stainless steelbrushed and tools shall be used.

3. Stainless steel (if any) has to be covered by paper to avoid carboncontamination. The marking and color code shall be transferred.

5.4 Forming / Bending

Prior to bending, the surface of shell plate shall be cleaned by blower orbloom to prevent damage during bending. Thin plate may use without rolledcondition according to discretion of supervisor.

1. The end portion of shell plate shall be formed to the required radius bymeans of pressing prior to rolling.

2. For rolling of plates to cylindrical shape, bending roller shall be used. Theroller shall have smooth surface and shall not flaw the material. Hammeringshall not be used in the process of bending or forming the materials.

3. During after forming of plate, the radius or curvature shall be checked bygauge plate.

5.5 Welding

1. Welding shall be carried out according to WPS and by qualified welders.WPS & PQR shall be approved before commencement of welding.

2. The groove face and weld surface shall be free from oil, dust, scale, waterand other foreign materials and keep dry before welding.

3. Welder shall wear protective equipment to prevent skin and eye fromforeign substances during welding.

4. Welding sequence and control, fixture and strong back should be

considered before starting welding in order to prevent distortion of work.5. The butt welding shall be slightly convex of uniform height, and have full

penetration. The butt joint shall be gouged or ground before welding forreverse side.

6. Temporary attachment shall be removed by grinding method.7. Visual inspection and NDE required.

5.6 Fabrication of component


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1) Shell PlateCutting for edge preparation shall be done with a flame planer, semi-automatic gas cutting machine or automatic beveling machine. Thermally-cut surface edges shall be grinded up to 2mm to remove notches andscale. The curvature of shell plate shall be performed by oil bandore andchecked by a curvature gage with the tank radius in accordance withdrawings, also the end parts of shell plate shall be carefully bended.

2) Annular PlateTrimming of outer curvature and beveling for both ends of annular plateshall be done with semi-automatic gas cutting machine. All damagescaused by gas cutting shall be smoothly finished by grinder.

3) Shell Stiffener & Top AngleThe materials shall be cut and beveled after bending to the indicatedradius, and back plate on beveled will be attached for site welding.

4) Shell Plate with Nozzle and ManholeShell opening shall be marked on the rolled shell plates and cut by semi-automatic gas cutting machine.

After tack welding of reinforcing plate to shell, the location of nozzle and manholes shallbe checked against the applicable drawings before cutting. Before commencement of

welding, the jigs shall be fixed on the opposite side of shell plates to prevent of weldingdistortion. After Completion of welding, NDE of welds and inspection shall be completed.

5) Roof StructureRafter and Girder shall be marked and cut with actual dimension in thedrawing and Rafter clips shall be welded on the exact location indicated inthe drawing. If the rafter and girder is assembled with bolt/nut, the holeshall be drilled by machine.

6) Roof PlateThe length and width of roof sketch plate shall be marked and cut carefullyin accordance with applicable drawings. In case of small diameter tanks,

the curvature of roof plate will be performed by roll bendor or pressingmachine.

5.7 Painting

Before delivery to site, all parts of the equipment shall be thoroughly cleaned of amill scale, rust, grease and other foreign materials and painted, if required, inaccordance with manufacturer’s practice and job requirement and all the document


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related to the painting will be submit. Painting work shall be accordance with the maker’sApplication Instructions and Painting Inspection Procedure.

1. Primer PaintingAll external surfaces of plates, piping, etc shall receive a primer paintingaccording to the applicable Painting Schedule.

2. Coal Tar Epoxy Coal tar epoxy paint only applied for the underside (direct touch to theBitumen of the foundation) of Annular Plate & Bottom Plate of the tank.

6. Dimensional Tolerance

6.1 Shell Plate

1. Prior to bending, Allowable tolerance of shell plate shall be as follows.

2. Curvature and distortion of shell plate shall be checked by means of atemplate, and allowable tolerance shall be as follows.


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3. The end of shell plate bended by roll bendor shall be inspected carefullywhether its curvature is avoided the over bending or the incompletebending.

4. The tolerance of bevel shall be in accordance with applicable drawing. If

the tolerances of bevel are not specified in the drawing, they shall be asfollows.


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6.2 Bottom Annular PlateAllowable tolerance of bottom annular plate is as follows.

6.3 Roof plateAllowable tolerance of roof plate is as follows.


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6.4 Shell stiffener & Top angle

1. Curvature shall be checked by means of a gage plate for the shell stiffener& top angle, or by placing a shell stiffener & top angle along the marked lineof tank radius on platform.

2. Curvature tolerance of shell stiffener is as follows:

6.5 Roof StructureAllowable tolerance of roof structure is as follows.


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6.6 Nozzle and Manhole attached to shell plateAllowable tolerance of Nozzle and Manhole attached to shell plate shall be asfollows.


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ATTACHMENT 1. Tank Fabrication Process Chart

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