4.Fabrication Procedure.rev 2

QUALITY PROCEDURE Doc No. POS-QP-01

Rev No. 2

Fabrication Page 1/13

Page 1/13

PROJECT NAME: AIN ARNAT - AIR COOLED CONDENSER

Controlled Copy

Uncontrolled Copy

POSCO E&C-VIET NAM Co., Ltd.

Address: Nhon Trach Industrial Zone

Dong Nai Province, Viet Nam

Tel No.: +84 (0) 613 560 869

Fax No.: +84 (0) 613 560 871

Website : http://www.poscoencvietnam.com

Prepared by Reviewed by Approved by

Name Ho Trong Phap Nguyen Anh Tuan

Signature

Date 17-Apr-2014 17-Apr-2014


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Contents 1.0 Revision History.

1.1 General

1.2 Application

1.3 Applicable code and standards

2.0 Material control

2.1 Material for fabrication

2.2 Receiving and ensuring of material

2.3 Mill certificates

3.0 Fabrications

3.1 Fabrication flow chart

3.2 Shop drawing

3.3 Steel measuring tape

3.4 Marking

3.5 Cutting and machining

3.6 Grooving

3.7 Drilling

3.8 Treatment of friction surfaces

3.9 Bending .

3.10 Straightening of distortion

3.11 Welding

3.12 Assembly

4.0 Painting and galvanizing

5.0 Packing

6.0 Attachment


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1.0 Revision History.

Rev. No Description of change Effective Date

0 Initial release Aug. 17, 2009

1 Change name of company July.18,2010

2 Revise to follow clients comment Apr.17,2014


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1.1 General

1.2 Application

This procedure covers fabrication for steel structure.

1.3 Applicable Code and Standards

AISC: American institute of steel construction

ASTM: American Society for Testing and material

ASME : Americal Society mechanical

AWS: American Welding Society

2.0 Material Control

2.1 Material for Fabrication

Plate: ASTM (A36),

Pipe: ASTM (A105, A106-B,A53-B)

2.2 Receiving and ensuring of material

Materials shall be stored on the sleeper or an adequate place not to be tied

to deformation, and shall be protected from corrosions, dusts, oils or other

foreign materials ingress.

Before commencement of manufacture, following shall be carried out:

- Appearance: Free any defects, such as scratching, strain or corrosion on

the surface of raw materials.

- Identification marking: Ensuring of material with stencil or stamp on raw

materials that the sort, size and quantity of these materials are

strictly in accordance with those on drawings and mill

certificates.

2.3 Mill certificates

All mill certificates furnished by supplier of material shall be submitted.

3.0 Fabrication

3.1 Fabrication Flow Chart

Refer. to the figure 3.1 attached herewith

3.2 Shop drawing

(1) Shop drawings shall be made accurately based on basic (design)


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drawing and specifications and shall be issued by client.

(2) Shop drawings shall serve as instructions for fabrication instead of the

design documents and the following details shall be contained as much

as possible in principle

j ) Steel framing plan, framing elevation, structural members schedule,

etc

ii ) Detailed shape, dimension, quantity, mark and materials

iii) Shape, dimension, joint detail, material specification, etc.

3.3 Steel measuring tape

(1) Steel measuring tape for fabrication shall be no.1 class of JIS B 7512

(steel measuring tape).

(2) Steel measuring tapes to be used in each process of shop fabrication

shall be checked for error against a standard steel measuring tape in the

custody.

(3) Tensile force at the time of above mentioned checking shall be 7-8kgf.

3.4 Marking

(1) Marking shall be made accurately and clearly on items to be required in

subsequent processes referring to ruler and template.

(2) Punch or drill marks shall not remain on the external surface of high

strength steel or mild steel to be bent as long as they are not removed by

cutting, punching or welding.

(3) Marking shall be made taking into consideration shrinkage, deformation

and finish allowance.

3.5 Cutting and machining

(1) Cutting of steel products shall be done by the most appropriate method

such as machine cutting, gas cutting or plasma cutting, taking into

account the shape and size of the steel product.

(2) In cutting steel products by gas, automatic gas cutting equipment shall be

used in principle.

(3) The precision of gas cutting plane at free edge of structural members

shall comply with the special notes. If not specified, the standards

indicated in table3.1 shall be applied.

Table3.1Roughness and notch depth

(4) Gas cut surfaces which do not meet the above requirements shall be

finished by grinding.

Roughness Below Rz200m

Notch depth Below 2mm


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(5) Cutting of weld bevel and the accuracy of machined surface shall comply

with the requirements in 3.6 "grooving"

(6) Thickness of steel plate to be sheared shall be not more than 13mm.

When slag or burr is generated on the cut surface, they shall be removed

by grinding.

(7) Where metal touch is specified in the design documents, the surfaces

shall be finished by such machine tools as facing machine or rotary

planer so that they fit accurately. The accuracy of the finished plane shall

comply with fig. 3.1.

(8) If a machine cutter (cold saw, etc,) which can secure the same accuracy

as by using cutting forming machine is used, the edges may remain as

cut.

(9) For scallop formation, a machining tool or a manual gas cutting machine

equipped with attachment shall be used. Forming accuracy shall comply

with table 3.1 if the accuracy prescribed in table 3.1 cannot be secured,

finishing shall be made by grinding.

Figure 3.1 Accuracy of Finished Plane

3.6 Grooving

(1) Tolerance for roughness and notch depth of grooving shall comply with

table 3.2.

Table 3.2 tolerance for roughness and notch depth of groove

Roughness Not more than Rz200m

Notch depth Not more than 2mm

(2) If the roughness and notch depth exceed the prescribed tolerance, the

surface shall be corrected by appropriate such as weld reinforcing or

grinding

3.7 Drilling


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(1) Holes for high strength bolts shall be drilled. If the joint zones undergo

blasting, drilling shall be done prior to blasting.

(2) Drilling shall be done in principle for holes for bolts, anchor bolts and

reinforcing bars. Punching may be done. When slag or burr occurs in the

hole, they shall be corrected by grinding.

(3) Gas cutting may be done for holes, not less than 31mm in diameter. Gas

cutting holes shall be not more than Rz200m, and accuracy of hole

diameter shall be within 2mm.

(4) The hole diameters for the high strength bolts, ordinary bolts and anchor

bolts shall comply with diameter on the drawing.

(5) Hole surfaces shall be at right angle to the member surface, and in the

designated positions. Burrs, slag or chips around holes shall be

completely removed after drilling.

3.8 Treatment of friction surfaces

3.8.1 Treatment of friction surfaces

Methods of treating friction surfaces for high strength bolted connection to

secure a slip coefficient not less than 0.45 shall be either spontaneous rust

generation or blasting as specified hereunder special treatments of friction

surfaces other than the methods specified hereunder shall comply with the

special notes.

(1) Spontaneous rust generation

Friction surfaces shall be treated by removing mill scales with disc grinder

to an extent of more than twice the outside diameter of the washer, and be

kept to the open air in which red rust is spontaneously generated.

(2) Blasting

Friction surfaces shall be shot or grit blasted. Friction surface with

roughness of not less than 50s shall be secured and red rust generation is

not necessary.

3.8.2 Remarks for treatment of friction surfaces

(1) Floating rust, dust, oil, paint, varnish and welding spatter on friction

surfaces and parts of surfaces which are to be in contact with washers

shall be removed.

(2) There shall be no clamping flaws or irregularities on the friction surfaces

and parts of surfaces.

(3) Mill scales may remain on friction surface in cases where light gauge

steel of thickness less than 600mm is used and a design slip coefficient

of 0.45/2 (approximately = 0.23) is adopted. Floating mill scales shall be

removed.


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3.8.3 Slip test

(1) When test for confirmation of slip coefficient is made, the time and

method of the tests shall comply with the special notes.

3.9 Bending

(1) Bending shall be carried out at room temperature or by heating. Bending

by heating shall be done in red heated condition, and shall not be done in

the range of blue brittleness(200-400oC)

In this case, temperature shall comply with para. 3.10 Straightening of distortion."

(2) The inside radius of bending at room temperature shall be not less than

twice the plate thickness, as shown in figure 3.2

3.10 Straightening of distortion

(1) Distortion generated during fabrication shall be straightened at room

temperatures or by heating (Refer to Correction distortion Doc No :

POS-QP-001) to the extent that avoids impairing quality, if the specified

accuracy of the product is not secured.

Figure 3.2 Inside radius of bending

(2) In straightening distortion by heating, a press or a roller shall be used.

(3) The temperatures at which distortion is straightened by heating shall by

in accordance with the following standards:

Maximum temperature shall not exceeds:

600oC for quenched and tempered steel

650oC for other steel

3.11 Welding

3.11.1 General

Posco e&c Viet Nam shall submit the following documents to be used in welding of the works which are subject to clients approval.

Welding procedure specification (WPS)

List of qualified welders and welding operators


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3.11.2 Welding material

(1) All welding materials shall be stored and handled with care and in

accordance with the manufacture's recommendations.

(2) Covered electrodes shall be stored in the drying place and shall be dried

in the drying oven before use in accordance with the conditions shown

manufactures recommendations

3.11.3 Welding procedure qualification

The Design Team shall specify the requirements for weld joints.

The Production Team shall then establish Welding Procedure including

welding material control to meet such weld joints requirements.

Quality Team shall certify or authorize Welding Procedure Qualification Test

Records according to requirements of the applicable code.

Test records shall be reviewed by the Quality Assurance section and then

submitted to the client for reference.

Following information are to be included.

Procedure reference number

Specification or type of material to be joined

Range of materials thickness

Welding process

Size and brand name of consumables

Deposition sequence

3.11.4 Welder's qualification.

All welders and welding operators engaged in welding of the works shall be qualified in accordance with applicable standard. Qualified welders can be engaged in production welding of the works.

3.11.5 Welding preparation

All welding edge shall be fully cleaned by wire brush of equal. The surfaces

for welding shall be dry and free any scale, rust, oil, or other foreign

materials.

All welding electrodes, wires and fluxes shall be stored in a clean

place and protected. All welding consumables shall be property

identified and shall retain their identification up to the time of use.

- Tack welds shall be subject to the same quality requirements as the

final welds except that;

(1) Preheat is not mandatory for signal pass tack welds which are remelted

and incorporated into continuous submerged arc welds.


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(2) Discontinuities such as undercut, unfilled craters and porosity need not

be removed before the final submerged arc welding.

Tack welds to be incorporated into the final weld shall be made with

electrodes meeting the requirements of the final welds and shall be

cleaned thoroughly. Multiple-Pass task welds shall have cascaded ends.

Tack welds not incorporated into final welds shall be removed, except that

for buildings they need not be removed unless by the engineer.

Pre-heating shall be carried out by electric resistance or induction

equipment or by specially shaped gas burners.

Temperature shall be checked by temperature indication crayons or

equal at a distance of about 50mm from the welding point to ensure the

homogeneity of specified temperature at whole part from weld line to

100mm apart.

- The standard edge preparation for the steel structure work shall be

made in accordance with shop drawing.

3.11.6 Welding

After welding, all slag, excess reinforcement and surface irregularities shall

be removed.

Cleaning may be carried out by hand or power tools. Flame gouging is

prohibited.

Harmful defects (cracks, undercuts, overlaps, arc strikes, etc.) in welds shall

not be accepted.

The welding materials shall give a satisfactory deposited metal which

has mechanical properties superior to that of the base metal.

Table 3.6 Drying of welding material

Division Drying condition

Temperature (oC) BakingTime (Hour)

Low hydrogen Type

Electrode, AWS A5.1 260 - 430 2

Other Type Electrode,

AWS A5.4 150-200 0.5-1

3.11.7 Tack welding


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(1) Tack welding shall be shielded arc welding or flux cored arc welding

process.

(2) Welders for tack welding shall be properly qualified.

(3) The selection and storage of welding materials for tack welding shall

comply with item 3.11.2 "welding materials. If Shielded metal arc Welding

is used for tack welding, welding material with low hydrogen content shall

be used.

(4) In tack welding, beads having required length and leg length shall be

deposited. at required intervals, in order to keep the shape during the

assembly, transportation and finish welding work, and furthermore in order

to avoid cracking of tack welding.

The minimum length of a bead for tack welding shall comply with table 3.5.

Table 3.5 Length of bead for tack welding (unit: mm)

Material (t) Minimum Length of Bead for Tack Welding Pitch

Manual, Semi Auto Auto

300-400 Mild steel 40 50

High strength Steel 50 70

(5) Tack welding quality shall be same as that of the final welding. Tack

welding shall not be done in grooves. If tack welding of the inside of

grooves is inevitable, it shall be done so as to secure the required quality

of finish welding

3.12 Assembly

3.12.1 General

(1) The method and order of assembly and the order of welding will greatly

affect on the accuracy and quality of products. Therefore, they shall be

fully examined at the stage of making the outline for fabrication or prior to

that stage

(2) First article shall be pre assembled at shop.

3.12.2 Preparation for assembly

(1) Structural members shall be checked beforehand for member codes,

material quality and quantity as well as for damages/stains, corrosion

and harmful directs. If there are any abnormalities, members shall be

replaced or repaired.

(2) Any distortions such as bending or warping of members, shall be


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straightened before assembly to achieve the prescribed product

accuracy.

3.12.3 Assembling work

(1) Assembling shall be done using surface Plates or jigs suitable for the

work so as to keep accurately the positions and angles of structural

members to be assembled.

(2) Backing strips and end tabs shall be provided at the prescribed intervals,

so that the space between base metal and such members are

eliminated.

(3) Presence of surface gap between each members and groove shape in

butt weld joints shall be checked and repaired if any inadequacies are

found,

4.0 Painting and Galvanizing

Painting or galvanizing for steel components required on the shop drawings

shall be performed in accordance with the Painting procedure, or

Galvanizing procedure.

5.0 Packing

All materials and steel components shall be adequately anchored, braced

and packed in accordance with the Packing procedure.

6.0 Attachment

6.1 Fabrication flow chart


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DRAWING; SPECIFICATION

PREPARING PROCEDURE SHOP DRAWING MATERIAL PROCUREMENT

REVIEW ANDAPPROVAL

REVIEW ANDAPPROVAL

INSPECTION

MARKING, CUTTING, DRILLING

INSPECTION

FIT-UP

INSPECTION

WELDING

INSPECTION

BLASTING AND PAINTING

INSPECTION

PACKING

INSPECTION

DELIVERY

No

Yes

No

No

No

No

No

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

OR GALVANIZING

Attachment 6.1 Fabrication flow chart

4.Fabrication Procedure.rev 2

Documents

fabrication page

material materials

fabrication plate

material control

fabrication flow chart

material asme

material specification

supplier of material