Quality Assuarance

8/11/2019 Quality Assuarance

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Indian Institute of Welding ANBRefresher Course module 16

Quality Assurance ofWelded Structures


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Content

Concept of Quality Assurance & Quality Control

A Brief Discussion on ISO 3834

Inspection of Welds WPS,PQR & WPQ- A Brief Discussion

Comparison Between ASME Sec. IX and ISO 9606

Weld quality and defects

Limits of weld defects as per ISO 5817

Testing of Welds

Visual Testing

VT- its Criteria as per AWS D 1.1 and BS 5289


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Concept of QA & QCSome Definitions

Quality-The totality of features and characteristics of aproduct or service that bear on its ability to satisfy statedand implied needs.

Quality Management-That aspect of overall managementfunctions that determines and implement Quality System &Policy.

Quality System-The organisational structure,responsibilities, procedures, processes and resources for

implementing Quality Management. Quality Assurance-All those systematic actions

necessary to provide adequate confidence that a productor service will satisfy given requirement for quality.


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Concept of QA & QCSome Definitions

Quality Control-The operational techniques and activitiesthat are used to fulfill requirements for quality.

Quality Document-All necessary papers required to

produce Quality Product/Service duly approved byrespective authorities.

Quality Records-All necessary papers to demonstratethe achievement of required quality and the effectiveoperation of the quality system.

Quality Plan-A document setting out specific qualitypractices, resources and sequence of activities relevant toa particular product, service contract or project.


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QUALITY ASSURANCE

&QUALITY CONTROL OF

WELDING


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Quality

Fitness for purpose or use.

Conformance to specified requirements.

The totality of features & characteristicsof a product or service that bear on itsability to satisfy the stated and/or impliedneeds.

Degree to which a set of inherentcharacteristics fulfils requirements.


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Quality New definition

Meeting & anticipating customersrequirements, stated or implied.

At a given time& over a period of

time.At a price the customer can afford

and is willing to pay.Introducing new & better product s into

the market faster than competitor.Continuously bringing downthe cost of

manufacturing.


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Quality

Quality of a Product (or Service) isnot what you put in to it; it is whatthe Customer gets out of it.


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Quality

REQUIREMENTS :Need or expectation that is stated, generally

implied or obligatory.

GRADE :Category or rank given to different quality

requirements for products, processes, or systemshaving the same functional use .


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Quality

CUSTOMER SATISFACTION:

Customer

s perception of the degree to whichthe customer

s requirements have been

fulfilled. SYSTEM:

Set of interrelated or interacting elements.

MANAGEMENT SYSTEM:

System to establish policy and objectives and to achieve

those objectives. QUALITY MANAGEMENT SYSTEM:

Management system to direct and control an organizationwith regard to quality.


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Quality Assurance:The act of giving

confidence, the state of beingcertain or the act of makingcertain.

Quality assurance:The

planned and systematicactivities implemented in aquality system so that quality

requirements for a product orservice will be fulfilled.


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Quality

Control: An evaluation to

indicate needed corrective

responses; the act of guiding

a process in which

variability is attributable to aconstant system of chance

causes.

Quality control:The

observation techniques andactivities used to fulfill

requirements for quality.


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Quality - Customer focus

Organizations depend on theircustomers and therefore shall

1. Understand customer needs andexpectations Current & futureneeds

2. Meet customer requirements

3. Strive to enhance customersatisfaction


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Quality - Defect

Anything that

dissatisfies theCustomer (internalor external)


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Customer requirements are dynamic

Lower the Defects

1. Lower Cycle time (Delivery intime)

2. Lower Cost of production

3. Higher Customer Satisfaction4. Higher People Satisfaction

5. Higher Profits


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Two important questions:

1. Who are the customers?

2. What does it take to satisfy them?


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Quality - Sequence ofapproach

Inspection Call from shop or fabricator

Ensuring availability of Quality Plan,

Quality Control Procedures, Gauges(calibration) etc.

Verification of Purchase Orders

Verification of Dimensional Report w.r.t

Purchase Order, Approved Drawing


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Quality - Sequence ofapproach

Verification of raw material TCs

Performing - Visual Examinations

Ensuring - Job Identification detailsDimensional Check

Conducting LPI, MPI, RT / UT asapplicable.

Confirming 1. LPI, MPI, RT / UT results.2. Heat Treatment details

3. Verification of HeatTreatment Charts and job correlation.


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Quality - Sequence of approach

Ensuring before External Inspection /Dispatch

Surface Protection-Painting(DFT)Work Order Details, Color Code

VCI Pellets, End Capping

Final Clearance by Third PartyInspection Agency / IBR


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Quality - Document

VerificationFirm / Product Approvals

WPS/PQR ,Welder Qualifications

Purchase OrderQuality Plan / Quality Control Procedure

Painting Schedule

Work Order, Drawings, Design Changes/ Non Conformances Report

Raw material / Pipes Test Certificate


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Quality - DocumentVerification

Lab Test Reports

NDE (LPI/MPI/RT/UT) Reports

Heat Treatment ReportsList of approved vendors for Electrodes /

Paints / NDE consumables

List of approved service agencies for Lab

Testing, NDT, Heat Treatment


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Quality - Prior to Fabrication Drawings &Specifications

Selection of WeldingProcess

Material Specification &Inspection

Inspection ofconsumables

Welding Procedures

Welding Equipments

Welder Qualifications

Testing Facilities


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Quality - During Fabrication

Inspection of preparedmaterial EdgePreparation, surfacecondition etc.

Assemblies Fit up, Rootgap, position, orientationetc.

Welding Consumables E 7018, E 7018-A1 etc.

Operators Qualification,Position, sequence etc.

WPS Conformance


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Quality - After Fabrication Visual Inspectiona) Surface Defects: BlowHoles, Porosity, UnfilledCrater, Un-fused welds

b) Surface Cracksc) Damaged to parentmetal:

Undercut, Burning,

Overheating

d) Profile Defects:- Overlap,

Excess penetration,

Incomplete penetration


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Quality - After Fabricatione) Incorrect Finish:-

Ripple Mark

Weaving Faults

Chipping & Peening marks

Spatter

Inspection of WeldDimensions Fillet, Throatsize.

Mech.Testing:- Test Coupons,Results.

NDE


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Quality

Quality is better definedas

Error free or Defectfree performance.

Do the right things

right the first time andevery time.


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Welding Defects

Small imperfections which affects theproperty of the weld metal are called

discontinuities

When the discontinuty is large and affectthe function of the joint is termed as defect.


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Defects

A. External defectsB. Internal defects

C. Both internal&external defects

External defects


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External defects

1. Undercut

2. Cracks

3. Blowhole and porosity

4. Slag inclusions

5. Edge of the plate melted off6. Excessive convexity/oversized

weld/ Excessive Reinforcement

7. Excessive Concavity/InsufficientThroat thickness/ Insufficient fill


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Contd

1. Incomplete Root penetration /Lackof penetration

2. Excessive Root penetration3. Overlap

4. Mismatch

5. Uneven/Irregular bead appearance

6. Spatters


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Internal defects

1. Cracks

2. Blowhole and porosity

3. Slag Inclusions4. Lack of fusion

5. Lack of Root penetration

6. Internal stresses or locked-upstresses (or) Restrained joint


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Both External And InternalDefects

1. Blowhole

2. Slag inclusions

3. Lack of penetration (fillet weld)4. Cracks

5. porosity


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Dimensional defects

Distortion

Incorrect Joint Penetration

Incorrect Weld Size

Incorrect Weld Profile


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Structural discontinuties

Porosity

Slag Inclusion

Under cut

Incomplete fusion

Incomplete penetration

CrackSurface defects


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Faulty weld size and profile

BUTT JOINT

Lack of Reinforcement

Excessive Reinforcement

Irregular ProfileFILLET WELD

Insufficient Throat

Insufficient Leg Length

Excessive Convexity(or)Concavity

Unequal Leg Lengths

Irregular Weld Face


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Crack

Discontinuty caused by the tearing ofthe metal

Hot crack

Cold crack

Crater crack


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Porosity

Group of gas pores in a weld due toentrapment of gas during solidificationis termed as porosity.

Porosity: small spherical cavitieseither clustered locally (or)scattered

Blow hole: single large cavity

piping (or)warm holes: Elongated (or)tubular gas cavities


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Reason

Contamination of the base metal

Moisture in the electrode

Improper arc length

Excessive current

High travel speed


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Slag inclusion

Entrapment of slag or Non- Metallicinclusion

incomplete deslagging of a previouspass.

Excessive weaving. (slag solidity atthe sides of the bead)

Improper travel speed

Excessive amount of slag ahead of thearc.


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Remedies

Proper cleaning of slag

Restrict the width of theweaving(width of slag immediatelybehind the weld puddle remainsmolten.


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Weld spatter

At the conclusion of a weld smallparticles (or) globular of metal may

sometime be observed scatteredaround the vicinity of the weld.thisis known as spatter.

Reason

Arc blow:(making the Arcuncontrollable)

1. Too long an arc


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Under cut

Continues or discontinues groove atthe toes of the weld pass and islocated on the base metal.

Excessive current

High travel speed

Improper electrode angle.

Improper electrode size


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Incomplete Penetration

Failure of weld metal to reach and fuse theroot of the joint.

Reason :

Less bevel angle High welding speed

Low current

Large dia electrode

Insufficient Root gap Improper Electrode angle


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Controlling factors

1. Proper travel speed

2. proper parameters

a.current

b.voltage

c.flow rate

3.proper edge preparation

a.Angle

b.Root gap


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Contd

4.suitable diameter of electrode

5.Base metal preparation

6.Baking of electrode


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Documentation

Manual- Strategic Type,

Top Management Function

Procedure- Tactical Type,

Departmental Function

Work Instruction-

Operational Type,

Supervisory Function

Records- Specific Type,Related to all Function


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QUALITY PLAN FOR MANUFACTURING / INSPECTION ACTIVITY

Importance Type Test Type Agency Column

MA = Major P = Test / Inspection to be performed 1= Customer

CR = Critical W = Test / Inspection to be Witnessed 2 = Organization

MI = Minor V = Verification of Documents/Test Records 3 = Consultant / Inspection Agency

S

l

.

N

o

Item

Description. /

Operation

Characteristics

Checked

Categor

y

Type

Method of

Check

Extend

of

Check

Reference

Document

Acceptance

Norms

Format

of report

Agency

RemarksP W V

1

.

RAW

MATERIALS

Plate

Rounds

Chemical &

Physical

Properties

Internal Flaws

Chemical

Properties only

M A

M A

M A

Verification

U. T.

Verification

1 / Heat

100%

100%

Order /

Specification

Order /

Specification

Drawing

Drg.Spec.

Drg. Spec.

Drg. Spec.

MTC Lab

Report

Lab

Report

Lab

Report

2

2

2

1

3

1

3

1

3

UT for Plates >12 mm thick

2

.FORGINGS

Chemical

Properties

Dimensions

M I

M A

Verification

Measure

ment

1 Heat

Size

Order

/Spe

cificatio

n

Drawing

Drawing

Drg.Spec.

Detail Drg.

Lab

Report

I. R.

2

2

1

3

1

3

3

.

FABRI

CATED

ITEMS

Fit up

Welding Quality

N D T

Dimensions

M A

M I

C R

M A

Visual

Visual

Dimension

UT, RT,

MPT LDP

Visual

Measure

ment

100%100%

Order /

Spe

cificatio

n

100%

Drg. Spec.

Drg. Spec.

Drg. Spec.

Drg. Spec.

Drg.Spec.

Drg.Spec.

Drg.Spec.

Detail Drg.

I. R.

I. R.

UT

Report

I.R.

2

2

2

2

1

3

1

3

1

3

1

3

4

.PAINTING Paint Thickness

M A

M I

Visual

Film

Thickness

100%

Sample

Drg. Spec.

Drg. /

Specification

.

Drg.Spec.

Drg.Spec.

Painting

Certificat

e

Painting

Certificat

e

2

2

1

1

3


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Quality Standards

Basic StandardsSpecifying general requirements with basic significance eg.QualityManagement Systems, drawings & tolerances

ISO 9000 ff, EN 4500 ff, ISO 17000 series

Special Basic StandardsSpecifying matters for several applications eg. Test procedures,welding requirements, materials

ISO 3834

Special StandardsProduct or application standards eg. Pressure vessels, piping,railway cars

ISO 16528, EN 1090, ISO/DIS 10721, EN 15085,


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Quality Management in Welding

Basic Standard for QMSISO 9001 -2000

ManufacturingISO 3834, EN 1011, ISO 5817

PersonnelISO 9606, EN 287, ISO 14731, ISO 14732

ProceduresISO 15607 15614

Testing and Inspection PersonnelISO 9712, EN 1289

Materials and Calculation & Design


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Application of ISO 3834

Certification of companies in accordance

with ISO 3834 Parts 2, 3 or 4

Certification of personnel in accordance

with ISO 14731


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ISO 14731 Requirements forWelding Co-ordination Personnel

Welding Co-ordination :

- Manufacturing operations for all welding and welding relatedactivities

- The sole responsibility of the manufacturer

- May be sub-contracted- May be carried out by more than one person

Welding Co-ordinator

- Responsible and competent person

- Specified tasks and responsibilities

- Qualified for each task

Welding Inspection

- Is part of welding co-ordination


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Wh t i ISO 3834?


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What is ISO 3834?

It is an international standard created by

weldingprofessionals

ISO 9001 provides the requirements for aquality management system; it does not

establish requirements for products.ISO 3834 on the other hand, does provide the

quality requirements for a welded product


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It encourages a proactive process orientatedapproach to managing and controlling

welding product quality in a workshop oron site

It is also a Factory Control System to controlactivities for the manufacture of the product


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2. Why adopt ISO 3834 when we haveISO 9001?

ISO 9001 is a comprehensive standard that lays

down quality management system requirements for

any organisation

ISO 9001 however, does not prescribe specific

details forspecial processes.Welding is regarded as aspecial process.

ISO 3834 was developed to identify all factors that

could affect the quality of welded product and which

need to be controlled at all stages, before, during and

after welding.


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4. What are the benefits of using theISO 3834 Standard for the manufacturer?

Less rework Jobs completed on time Local and international recognition as a competent organisation

Meet the welding-related requirements of ISO 9001 More efficient coordination of welding activities More pro-active and responsible workforce Increased opportunities and capability to bid on jobs Cost savings more efficient technology

Reduced surveillance audits and inspections bypurchasers with significant savings


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5. What are the benefits of using theISO 3834 Standard for the individualemployees?

Helps to do the job more satisfactorily

Greater job security

Higher regard by other people Professional recognition

Satisfied employer and customer

More rewarding job position Develops team spirit

6 H i t t ldi


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6. How important are weldingpersonnel?

A key feature of ISO 3834 is the requirement toensure that people with welding responsibilities arecompetent to discharge those responsibilities

This is achieved by incorporation of anotherstandard, namely, ISO 14731Welding coordinationTasks and responsibilities

The specifying of minium requirements for personneldealing with welding coordination and weldinginspection personnel


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7. What is the definition of amanufacturer?

ISO 3834 defines a manufacturer as a person or

organization responsible for the welding production.

The Standard uses this term to describe any such

organisation, including manufacturing organisationssupplying welding services, either for new products or

for repair and maintenance, as well as other

organisations where the application of the

requirements of ISO 3834 are relevant

A manufacturer may be involved in manufacture,

fabrication, construction, repair or maintenance.


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8. What are the types of manufacturingorganisation thatISO 3834 can be applied to?

Fabrication companies

Construction companies - on-site work

Repair and maintenance contractors

Manufacturers of products

Welding workshops on sites under the same

technical and quality management

Owners of plant with their own workshop(s)


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9. What are the types of other organisation thatISO 3834 can be applied to?

Those which, though not creating welded productthemselves, are specifying or requiring such work fromothers and are thus involved in weld design, contractdevelopment, and review of technical requirements andcompetencies of subcontractors namely

Asset owners without own workshops, both privateand government Project management companies Design companies

Consultants Government agencies


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10. How many parts does ISO 3834 have?

ISO 3834: 2005Quality requirements for fusion welding ofmetallic materialsconsists of 6 parts:

ISO 3834-1:2005, Criteria for the selection of theappropriate level of quality requirements

ISO 3834-2:2005, Comprehensive quality requirements

ISO 3834-3:2005, Standard quality requirements

ISO 3834-4:2005, Elementary quality requirements

ISO 3834-5:2005, Applicable documentation (not full title)

ISO/TR 3834-6:2007, Guidelines on implementing ISO

3834


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11. How does ISO 3834 link in with ISO 9001?

ISO 3834 does not replace ISO 9001 as a qualitymanagement system however it contains manyattributes that will be important for a weldingmanufacturer, in both workshops and at fieldinstallation sites, seeking ISO 9001 certification

Elements of ISO 9001 should be considered whenimplementing ISO 3834 quality requirements andseeking ISO 3834 certification

The specific complementary elements of ISO 9001are detailed in ISO 3834

WTIA TGN-3834-06 2007 gives more detailedinformation


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12. Describe how the flexibility of ISO 3834can be applied?

ISO 3834 describes the following four situations where ISO3834 can control welding: Case 1: To provide specific requirements in specificationswhich require the manufacturer to have a qualitymanagement system in accordance with ISO 9001:2000

Case 2: To provide specific requirements in specificationswhich require the manufacturer to have a qualitymanagement system other than ISO 9001:2000

Case 3: To provide specific guidance for a manufacturer

developing a quality management system for fusion welding.

Case 4: To provide detailed requirements for specifications,regulations or product standards that require control ofFusion welding activites

13 What are the implications to satisfy Case 1: To provide specific


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13. What are the implications to satisfy Case 1: To provide specificrequirements in specifications which require the manufacturer tohave a quality management system in accordance withISO 9001:2000

For the purchaser - it implies that they want themanufacturer

to have a quality management system in accordance with ISO9001 and want to ensure that the supplier manages the quality

of the product. To achieve this the purchaser must detail therequirements contained in ISO 3834 into the weldingspecification. For the Manufacturer - it implies that their quality

management system must comply with ISO 9001 and thatthey need to meetthe requirements of ISO 3834. . It is

recommended that the supplier incorporates therequirements of ISO 3834 into theirISO 9001 quality management system using it as abolt on

14 What are the implications to satisfy satisfy Case 2: To provide


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14. What are the implications to satisfy satisfy Case 2: To providespecific requirements in specifications which require themanufacturer to have a quality management system other thanISO 9001:2000

For the purchaser - it implies that they want the manufacturerto have a quality management system but not necessarily inaccordance with ISO 9001. Additionally the purchaser wants toensure that the manufacturer manages the quality of theproduct. To achieve this the purchaser must detail therequirements contained in ISO 3834 into the weldingspecification or contract documents.

For the Manufacturer - it implies that they must have a qualitymanagement system and meet the requirements of ISO 3834. Itis recommended that the manufacturer adopts ISO 3834 and

incorporate some elements from ISO 9001 to satisfy this requirement

15. What are the implications to satisfy Case 3:To provide specific


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p y p pguidance for a manufacturer developing a quality managementsystem for fusion welding.

For the purchaser - it implies increased confidence in theirsupplier for its recognition of the importance of controlling thequality of the welded product

For the Manufacturer - it implies that they recognise theimportance of managing the quality of the product that theyproduce. To achieve this they need to use ISO 3834 as a set ofguidelines to identify the key areas that need to be controlled.

In addition it lists the elements of ISO 9001 that need to beconsidered when developing a quality management system


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16. What are the implications to satisfy Case 4:To provide detailedrequirements for specifications, regulations or product standardsthat require control of fusion welding activities

For the purchaser and the Manufacturer - it impliesthat there is an industry-wide recognition of thebenefits that ISO 3834 has on the quality of weldedproducts.

This ISO 3834 Standard will be specified inspecifications, regulations and product standardsacross all industry sectors such as pressureequipment, mining, building and construction,pipelines, railway etc. Therefore why not takeAdvantage of these benefits now.


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17. What are the main weldingrequirements covered in ISO 3834 ?

Review of requirements Technical review Subcontracting Welding personnelWelders and welding operators, Welding coordination

personnel Inspection & testing personnelWelding Inspection personnel; Non-destructive

testing personnel EquipmentProduction and testing equipment; Description of

equipment; Suitability of equipment; Newequipment; Equipment maintenance


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Welding and related activities

Production planning; Welding procedure

specifications (WPS); Qualification of the welding

procedures; Work instructions; Procedures for

preparation and control of documents Welding Consumables

Batch testing; Storage and handling

Storage of parent materials

Post-weld heat treatment


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Inspection and testing

Inspection & testing before welding; Inspection &

testing during welding; Inspection & testing after

welding; Inspection & test status

Non-conformance and corrective actions Calibration and validation of measuring,

inspection and testing equipment

Identification & traceability

Quality records

Quality requirements as per


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Quality requirements as perISO 3834

Selection of Welding Quality


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Selection of Welding QualityRequirement as per ISO:3834

Contract Welding Requirement Quality Requirement

When quality system

conforming to ISO

9001 is required

When quality system

conforming to ISO

9001 is notrequired

Comprehensive quality requirement Use ISO 3834-2 Use ISO 3834-2

Standard quality requirement Use ISO 3834-2 Use ISO 3834-3

Elementary quality requirement Use ISO 3834-2 Use ISO 3834-4

Comparison of Welding quality


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requirements with regard to ISO 3834-2,3834-3 And 3834-4

Elements ISO 3834-2 ISO 3834-3 ISO 3834-4

Contract review Full documented

review

Less extensive review Establish that capability and information is

available

Design review Design for welding to be confirmed

Subcontractor Treat like a main fabricator Shall comply with all requirement

Welders, Operators Approved in accordance with ISO 9606

Welding coordination Welding coordination personnel with appropriate

technical knowledge

Not required but personal responsibility of

manufacturer

Inspection personnel Sufficient and competent personnel to be available Sufficient and competent third parties

access are needed

Production equipment Required to prepare, cut, weld, transport, lift, together

with safety equipment and protective clothes

No specific requirement

Equipment maintenance Shall be carry out,

maintenance

plan

necessary

No specific requirements,

shall be adequate

No requirement

Production plan Necessary Restricted plan necessary No requirement

Welding procedure

specification (WPS)

Instruction to made available to welder No requirement

Welding procedure approval In accordance with the appropriate part of ISO

9956,approved as application standard or

contract demands

No specific requirement

Comparison of Welding qualityi t ith d t ISO 3834 2


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requirements with regards to ISO 3834-2,3834-3 And 3834-4

Elements ISO 3834-2 ISO 3834-3 ISO 3834-4

Work instructions Welding procedure specification (WPS) or dedicated

work instructions to be available

No requirement

Documentation Necessary Not specified No requirement

Batch testing of

consumables

Necessary Not specified No requirement

Storage and handling of

welding consumables

According to suppliers recommended minimum

Storage of parent

materials

Protection required from influences by the

environment, identifications to be maintained

No requirement

Post-weld heat treatment Specification and complete

record necessary

Confirmation to

specification

necessary

No requirement

Inspection before, during

and after welding

As required for specified operations Responsibilities as specified in

contract

Non-conformances Procedures shall be available

Calibration Procedures shall be

available

Not specified

Identification Required when appropriate Required when

necessary

Not specified

Traceability Not specified

Quality records Shall be available to meet the rules for product liability As required by contract

Retained for 5 years minimum

I ti f W ld


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Inspection of Welds

Definition of Inspection as per ISO Std.

Inspection is that quality control action bymeans of examination, observation or

measurement to determine the conformance of

material parts, components, system,structures

as well as processes and procedures withpredetermined quality requirements.

Nine Essential Variables of


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Nine Essential Variables ofWelding

1) Joints

2) Base metal

3) Filler metal

4) Position 5) Pre-heat

6) PWHT

7) Shielding Gas

8) Electrical Characteristics 9) Technique


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WPS,PQR and WPQ

WPS

PQR

WPQ

Welding Procedure Specification is a writtendocument to provide direction for makingproduction weld to the code requirement.

Procedure Qualification Record is a record ofthe welding data used to weld a test coupon. Itis also contains the test results of the testspecimen.

Welding Performance Record determines theability of the welder/welding operator to achievethe minimum requirement specified for anacceptable weldment.


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ASME Code

ASME code widely used in India

WPS Format - QW 482

PQR Format - QW 483

WPQ Format

QW 484

WPS Format as per


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WPS Format as perASME Section IX

QW-482 Front side

Inspection During Welding


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Inspection During Welding

1) Welding Process Parameter

2) Inter pass Temperature

3) Filler metal/Electrode condition

4) Inter pass cleaning

5) Distortion

6) Flux /Shielding gas flow


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Inspection After Welding

1) Dimensional accuracy

2) Appearance of the weld

3) Post Weld Heat Treatment (if any) 4) Evaluation of internal and surface defects

with or without the aid of Destructive/Non-destructive testing.

Comparison Between ASME Sec IX


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Comparison Between ASME Sec. IXand ISO 9606- Scope

As per ASME Sec. IX

The rules in this section

apply to the preparation of

WPS, PQR and qualificationof welders and welding

operators for all types of

manual and machine

welding permitted in this

section.

As per ISO 9606-1:1994

This part of ISO 9606specifies requirements,ranges of approval, testconditions, acceptancerequirements andcertification for approvaltesting of welderperformance for the weldingof steels.

Comparison Between ASME Sec. IX


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Comparison Between ASME Sec. IXand ISO 9606- Reference

As per ASME Sec. IX

ASME Sec.VIII and ASME

B 31

As per ISO 9606-1:1994

ISO 857,1106-1,1106-2,

1106-3, 2560, 3452, 3580,

3581, 4063, 5173, 5817,6520,6949, 9956-2 and

9956-3



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pand ISO 9606- Definition

As per ASME Sec. IX

As per QW- 492

As per ISO 9606-1:1994

1) Welder

a) Manual &

b) Welding operator2) Examiner Or Test Body

3) WPS

4) Range of Approval

5) Test Piece

6) Test Specimen7) Test



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pand ISO 9606- Variables

As per ASME Sec. IX

Joints ( QW-402)

Base Metal ( QW-403)

Filler Metal ( QW-404)

Position ( QW-405) Preheat (QW-406)

Postweld Heat Treatment (QW-407)

Gas ( QW-408)

Electrical Characteristics ( QW-409)

Technique (QW-410)

Note- Varies with different welding

processes

As per ISO 9606-1:1994

Welding Processes

Joint Type

Material Group

Filler metal, Shielded gasand flux

Dimensions

Welding position



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pand ISO 9606- Material Grouping

As per ASME Sec. IX

Steel & Steel alloys

Aluminium & Al. base alloys

Copper & Cu. base alloys

Nickel & Ni. base alloys Titanium & Ti. base alloys

Zirconium & Zr. base alloys

As per ISO 9606-1:1994

Low-carbon unalloyed steelsand/or low alloyed steels (W01)

Cr-Mo and/or Cr Mo V creep

resistant steels (W02) Fine grained structural steels

normalised,quenched andtempered as well asthermomechanically treated steelsand nickel steel with Ni content 2%to 5%

Ferritic or martensitic stainlesssteels with Cr content 12% to 20%.

Stainless ferritic-austenitic andstainless Cr-Ni steels.


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and ISO 9606- Position-Pipe-Fillet

As per

ASME

Sec IX

As per

ISO9606



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and ISO 9606- Position-Pipe-Butt

As per

ASME

Sec IX

As per

ISO9606



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and ISO 9606- Type of Test

As per ASME Sec. IX

A) For Butt Weld

i) Transverse side bend,ii) Transverse Face Bend

iii) Transverse Root Bend

B) For Fillet Weld

i) Fracture Test

ii) Macro Examination

C) Visual

D) Radiographic Examination

As per ISO 9606-1:1994

Visual

Radiography

Bend

Fracture

MPI or LPT

Macro (Without Polishing)

Comparison Between ASME Sec. IX and ISO 9606-E i R l f Q lifi ti


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Expiry or Renewal of Qualification

As per ASME Sec. IX

When the welder has not weldedwith a process during a period of 6months or more, his qualificationsfor that process shall expire;unless, within the six months periodto his expiration of qualification

a) A welder has welded using a manualor semiautomatic welding which willmaintain his qualification for manualand semiautomatic welding withthat process.

b) A welding operator has weldedusing a machine or automaticwelding which will maintain his

qualification for machine andautomatic welding with thatprocess.

There shall be no specific reason toquestion the welders skill andknowledge

As per ISO 9606-1:1994 A welders approval shall remain valid

for a period of 2 years providing thatthe relevant certificate is signed at six-months intervals by employer/co-ordinator and that all followingconditions at fulfilled

a) The welder shall be engaged withreasonable continuity on welding workwithin the current range of approval.

An interruption for a period no longerthan 6 months is permitted.

b) The welders work shall be inaccordance with the technicalconditions under which the approvaltest is carried out.

There shall be no specific reason toquestion the welders skill andknowledge

Weld Quality


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Weld Quality

Discontinuity

An interruption of the typical structure of a material, such as a

lack of homogeneity in its mechanical, metallurgical, or physical

characteristics.

A discontinuity is not necessarily a defect but all defects are

discontinuities.

Defect

A defect is a rejectable discontinuity, which occurs in an amountgreat enough to render a particular object or structure unsuitable

for its intended service based on criteria in the applicable code.

Classification of Defects


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Classification of Defects

Planar defects / Two dimensional defects --

E.g. cracks, lack of fusion, lack of penetration, are

crtical in nature and are not tolerated to any extent.

Voluminar defects / Three dimensional defects--E.g. slag inclusion, cavities, porosities, etc are

tolerated to a certain extent depending on the

product class and applicable code.

Geometric defects-- E.g. excess reinforcement,

underfill, root suckback, distortion are also permitted

to a certain extent.

Misalignment (hi lo)


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Misalignment (hi-lo)

Definition:Amount a joint is outof alignment at the root

Cause:Carelessness. Also due to joining differentthicknesses (transition thickness)

Prevention:Good Workmanship.

Repair:Grinding. Careful on surface finish and

direction of grind marks.

Undercut


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Undercut

Definition:A groove cut at the toe

of the weld and left unfilled.

Cause: High amperage, electrode

angle, long arc length, rust.

Prevention:Set machine on scrap metal. Clean metal before

welding.

Repair:Weld with smaller electrode, sometimes must be low

hydrogen with preheat. Sometimes must gouge first.

U d t


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Undercut

Insufficient Fill on the Root Side


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(Suck back)

Definition: The weld surface is below the adjacent

surfaces of the base metal at the weld root.

Cause: Typically improper joint preparation orexcessive weld pool heat.

Repair: Back weld to fill. May require removal of weld

section by grinding for access to the joint root.

S k b k


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Suck back


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Concavity


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Concavity

Convexity


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Convexity

Reinforcement


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Excessive

Insufficient

Improper contour

Face Reinforcement

Root Reinforcement

The amount of a groove weld which extends

beyond the surface of the plate

Excessive Reinforcement


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cess e e o ce e t

Definition: Specifically defined by the standard.Typically, Reinforcement should be flush to1/16(pipe) or flush to 1/8(plate or structural

shapes). Cause: Travel speed too slow, amperage too low

Prevention: Set amperage and travel speed on scrapplate.

Repair: Remove excessive reinforcement and featherthe weld toes to a smooth transition to the base plate.

Excessive reinforcement


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Excessive reinforcement

Insufficient Reinforcement


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Definition: Specifically defined by the standard. Typically,Underfill may be up to 5% of metal thickness, not to exceed

1/32as long as the thickness is made up in the opposite

reinforcement. Not applied to fillet welds.

Cause: On root reinforcement - Too little filler metal will causethinning of the filler metal. In OH position, too hot or too wide

will cause drooping of the open root puddle.

Prevention: Use proper welding technique. Use backing or

consumable inserts. Use back weld or backing.

Repair: Possibly simply increase the face reinforcement. If back

welding is not possible, must remove and reweld.

Insufficient reinforcement


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Insufficient reinforcement

Burn-through


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Burn through

Definition: When an undesirable open hole has beencompletely melted through the base metal. The hole may or

may not be left open.

Cause: Excessive heat input.

Prevention: Reduce heat input by increasing travel speed, use

of a heat sink, or by reducing welding parameters.

Repair: Will be defined by standards. Filling may suffice.

Otherwise, removal and re welding may be required.

Burn-through


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g

Lack Of Penetration
http://localhost/var/www/apps/conversion/tmp/radiograph/burn_throughs.jpg


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Lack Of Penetration

Definition: When the weld metal does not extend to the required

depth into the joint root

Cause: Low amperage, low preheat, tight root opening, fast

travel speed, short arc length.

Prevention: Correct the contributing factor(s).

Repair: Back gouge and back weld or remove and reweld.

Lack Of Penetration


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Lack Of Penetration

Incomplete Fusion


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Incomplete Fusion

Definition: Where weld metal does not form a cohesive bond

with the base metal.

Cause: Low amperage, steep electrode angles, fast travel

speed, short arc gap, lack of preheat, electrode too small,

unclean base metal.

Prevention: Eliminate the potential causes.

Repair: remove and reweld, being careful to

completely remove the defective area. This is

sometimes extremely difficult to find.

Incomplete Fusion


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Incomplete Fusion

Arc Strike


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Definition: Arc strikes result when the arc is initiated on the

base metal surface away from the weld joint either

intentionally or accidentally

Cause: Carelessness of welder Prevention: In difficult areas, adjacent areas can be protected

using fire blankets.

Repair: Where applicable, arc strikes must be grinded smooth

and tested for cracks. If found, they must be remove andrepaired using a qualified repair procedure and inspected as

any other weld.

Slag Inclusion


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Definition: Slag entrapped within the weld

Cause: Low amperage, improper technique, Trying to weld in

an area that is too tight. Improper wire brushing / cleaning

between passes.

Prevention: Increase amperage or preheat, grind out tight areas

to gain access to bottom of joint.

Repair: Remove by grinding. Reweld.

Slag Inclusion

Slag inclusion


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ag u o

Tungsten Inclusion


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Definition: A tungsten particle embedded in a weld. (Typically

GTAW only)

Cause: Tungsten electrode too small, amperage too high,

electrode dipped into the weld pool or touched with the fill rod.

Prevention: Thoriated or Zirconiated tungsten electrodes are

used in place of pure tungsten electrodes.

Repair: Grind out and reweld

g

Tungsten inclusion


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g

Spatter
http://localhost/var/www/apps/conversion/tmp/radiograph/tungsten_inclusions.jpg


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Spatte

Definition: Small particles of weld metal expelled from the

welding operation which adhere to the base metal surface.

Cause: Long arc length, severe electrode angles, highamperages.

Prevention: Correct the cause.

Repair: Remove by grinding or sanding.

Spatter


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Spatter
http://www.weldreality.com/co2-bad-weld.jpg


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Cracks


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Cracks

Cracks


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Cracks

Laminations


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Laminations

Base Metal Discontinuity

May require repair prior to welding

Formed during the milling process

Porosity - Types


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Porosity is gas pores found in the solidified

weld bead.

Single Pore

Uniformly Scattered

Cluster

Linear

Porosity


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Porosity

Clustered Porosity


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Clustered Porosity

Testing


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g

It is defined as the physical performance of

operations to determine quantitative

measure of certain properties of a process It aim to determine quantity i.e. to

discover facts regardless of the implication

of the result.


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Defects and their Limits as per ISO 5817 -2003


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Defects and their Limits as per ISO 5817 -2003 contd.


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Surface Cracks- Detectable by VT


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Surface Irregularities-Detectable by VT


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Contour Defects- Detectable by VT


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Root Defects- Detectable by VT


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Visual Inspection Acceptance Criteria as per AWS D 1.1


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Discontinuity Category&Inspection Criteria

Static Loaded(Nontubular)

Dynamic Loaded(Nontubular)

All Loads(Tubular)

Underrun-In fillet weld upto 1.6 mm

subject to it does not exceed 10% of theweld length. No underun is permitted for

web-to-flange welds of girder

Applicable Applicable Applicable

Undercut-Upto 1 in. not to exceed 1mm.

For an accumulated length of 2inch in any

12 inch for material above 1in. Undercut

above 1.6mm not allowed.

Applicable Not-Applicable Not-Applicable

Porosity-No porosity in the butt weld

traverse to tensile strength. In other butt

welds and for fillet weld the size of

1mmin linear inch of weld and shall notexceed 19 mm in 12 in length of weld

Applicable Not-Applicable Not-Applicable

Porosity-In fillet weld the frequency of

porosity shall not exceed one in 100mm

of weld length and the maximum diameter

shall not to exceed 2mm.

Not-Applicable Applicable Applicable

Visual Inspection Acceptance Criteria


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Discontinuity Category&Inspection Criteria

Static Loaded(Nontubular)

Dynamic Loaded(Nontubular)

All Loads(Tubular)

Crack- The weld shall have no crack Applicable Applicable Applicable

Weld/Base-Metal Fusion-Through fusion shallexist between weld metal to weld metal and

base metal


Crater- All crater shall be filled up to the full

cross section except for the ends of the

intermittent fillet welds outside the effective

length


Weld Profiles-Weld profiles shall be inconformance to 5.24


Time of Inspection- Immediately after the

completed weld reaches the ambient temp.For

ASTM A514,A517,A709 not less than 48 Hrs.


Visual Inspection Acceptance Limit-Piping


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As per BS 5289

Acknowledgements


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Acknowledgements

We gratefully acknowledge the contributions of

the following faculty members for developing

this module

Mr.A.K.Bose

Mr.N.Sadasivan

R.Banerjee


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Thank You

Quality Assuarance

Documents

Transcript of Quality Assuarance