pWPS

WPAR

WAR

WPS

PRODUCTION

Preliminary

Approval of welding procedure

Welders approval

Welding Procedure Specification

Welding Procedure Specification

Required ApprovalsAvailable? Yes

Approved consumables

Experience

Standard procedure

Pre-production tests

TestweldingTesting

Reporting

pWPS

WPAR

WAR

WPS

PRODUCTION

Preliminary

Approval of welding procedure

Welders approval

Welding Procedure Specification

Welding Procedure Specification

Required ApprovalsAvailable? Yes

Approved consumables

Experience

Standard procedure

Pre-production tests

TestweldingTesting

Reporting

P. Loos 99

A weld cannot be checked to the full extent!

strength, ductility and corrosion resistance can only be checked by destructive techniques.

properties can only be guaranteed for the

actual product when manufactured to

exactly the same written procedure,

and carefully controlled.

EN 288

Why a WPSWhy a WPS

P. Loos 99 EN 288-3

Why a WPSWhy a WPS

The main objective of a WPS is to make awelding operation

reproducable

P. Loos 99 EN 288

Methods of approvalMethods of approval

welding procedure tests - EN 288 part 3 or 4

approved welding consumables - EN 288 part 5

previous welding experience - EN 288 part 6

standard welding procedure - EN 288 part 7

pre-production welding tests - EN 288 part 8

P. Loos 99 EN 288-3

Acceptance criteriaAcceptance criteria

EN 25817 level “B”

EN 25817 level “C” excess throat thickness

excess convexity excess weld metal

excessive penetration

P. Loos 99 EN 288-3

Acceptance criteriaAcceptance criteria

Strength according to parent metal

Impact requirements (temperature, energy)

according to the design requirements (and application standard)

P. Loos 99

EN 288 - ISO 9956EN 288 - ISO 9956Specification and approval of welding

procedures for metallic materials

Part 1 General rules for fusion welding

Part 2 Welding procedure specification for arc welding

Part 3 Welding proc. tests for the arc welding of steels Part 4 Welding proc. tests for the arc welding of aluminium and its alloys Part 5 Approval by using approved welding consumables for arc welding

Part 6 Approval related to previous experience

Part 7 Appr. by a stardard welding proc. for arc welding

Part 8 Approval by pre-production welding test

P. Loos 99 EN 288-3

Additional testsAdditional tests

Such tests may include:

longitudinal weld tensile test all weld metal bend test Charpy V-notch impact test yield strength or 0,2 % proof stress elongation chemical analysis micro examination delta ferrite determination in austenitic stainless steels

P. Loos 99 EN 288

Material groupsMaterial groups

The use of particular method of approval of a WPS is often a mandatory require-ment of an application standard.

In the absence of such a requirement the method of approval shall be agreed bet-ween the contracting parties at the enquiry or at the order stage.

P. Loos 5/99 EN 288

Approval of WPSApproval of WPS

Preliminary welding procedurespecification

( pWPS )

Approval on the pWPS by a methodacc. to EN 288 part 3/4, 5, 6, 7 or 8

Approved welding procedurespecification

( WPS )

P. Loos 99 EN 288-3

Welding Welding procedure tests tests

Tests shall be carried out in accordance

with this standard unless more severe

tests are specified by the relevant

application standard or contract

when these shall apply.

P. Loos 5/99 EN 288-3

Welding procedure testsWelding procedure tests

All new

welding procedure approvals

are to be in accordance with this

standard from the date of its issue

(first issue april 1992)

P. Loos 5/99 EN 288-3

Welders approval

The welder who undertakes the

welding procedure test satisfactory,

is approved for the appropriate

range of approval given in the

relevant part of EN 287

P. Loos 5/99 EN 288-3

Re - testing

If the test piece fails to comply with any of the requirements for visual examinaton or NDE, one further test piece shall be welded and subjected to the same examination. If this additional test piece does not comply with the relevant requirements, the pWPS shall be regarded as not capable of complying with the requirements of this standard without modification.

P. Loos 5/99 EN 288-3

Re - testing

If any test specimen fails to comply with the relevant requirements only due to geometric weld imperfections, two further test speci-mens shall be obtained for each one that failed.

These can be taken from the same test piece if there is sufficient material available or from a news test piece, and shall be subjected to thesame test.

P. Loos 5/99 EN 288-3

Re - testing

If either of these additional test specimens

does not comply with the relevant require-

ments, the pWPS shall be regarded as

not capable of complying with the require-

ments of this standard without modification.

P. Loos 5/99 EN 288-3

Range of approval

An approval of a WPS obtained by a

manufacturer is valid for welding in

workshops or sites under the same

technical and quality control of

that manufacturer.

P. Loos 99 EN 288-5

Essential variables

Process: 111; 114; 131; 135; 136; 137; 141

Material: group 1, 9 (EN 288-3)

group 21, 22a, 22b (EN 288-4)

Parent metal thickness: 3 - 40 mm

Size of fillet weld: 3 mm

Pipe diameter: > 25 mm

P. Loos 99 EN 288-5

Approved welding consumables

Some material do not deteriorate significantlyin the heat affected zones, provided heatinputs are kept within specified limits.

For such materials, a pWPS shall be con-sidered approved on the condition that thewelding consumables are approved and thatall essential variables are within the rangefor which the approval is valid

P. Loos 99 EN 288-6

Previous experience

A manufacturer may have a pWPS appro-

ved by referring to previous experience on

condition that he can prove by appropi-

ate documentation of an independant

nature that he has previously satisfactorily

welded the type of joint and materials in

question

P. Loos 99 EN 288-6

Previous experiencePrevious experience shall involve:

Satisfactory documentation of tests (e.g. non- destructive, destructive, leak or pressure tests) in all cases.

AND A summary of welding manufacturing of at least one year during an appropriate period (5 years)

ORSuitability of welds in service for an appropri-

ate period (5 years)

P. Loos 99 EN 288-7

Standard welding procedure

A standard welding procedure shall beissued as a specification in the format ofa WPS or WPAR based on an approvalto the relevant part of EN 288 for weldingprocedure testing.

Application of a standard welding proce-dure is also subject to be satisfied bythe user.

P. Loos 99 EN 288-7

Essential variables

Process: 111; 114; 131; 135; 136; 137; 141

Material: group 1, 9 (EN 288-3)

group 21, 22a, 22b (EN 288-4)

Parent metal thickness: 3 - 40 mm

Size of fillet weld: 3 mm

Pipe diameter: > 25 mm

P. Loos 99 EN 288-7

Standard welding procedure

The use of a standard weldingprocedure requires welding coordi-nation in accordance with EN 719.

The user has to fullfill quality requi-rements in accordance with the ap-propriate part of EN 729.

P. Loos 99 EN 288-8

Pre - production welding tests

At least the following tests are to be performed:

a) visual inspection (100 %)

b) surface crack detection

c) hardness tests (for Re 275 N/mm²)

d) macrographic examination

P. Loos 99 EN 288-8

Pre - production welding tests

Pre-production welding test are used where theshape and dimension of standardized test pie-ces do not adequately represent the joint to bewelded.

One or more special test pieces shall be madeto simulate the production joint in all essentialfeatures e.g. dimensions, restraint, heat sinkeffects.

P. Loos 99 EN 288-2

Content of a WPs

preparation of the components to be welded

assembling of components for welding

welding process

post work of the welded connections(e.g.grinding)

heat treatment (during fabrication/finalizing)

P. Loos 99 EN 288-3

Material groups

a procedure test with one steel of a group co-vers the lower alloyed steels of the samegroup or the steels with equal or lower speci-fied yield strength of this groupas long as the welding consumables used forthe test can also be used for the steels of thisgroup

group 2 covers group 1

P. Loos 99 EN 288-3

WPAR

Welding Procedure Approval Record

(WPAR)

The welding procedure approval record WPAR)is a statement of results of assessing each testpiece including re-tests.It shall be signed by the examiner or test body

P. Loos 99 AD HP 2/1

Pressure vesselThe welding procedure tests for pressure vesselsare detailed in the AD-Merkblatt HP 2/1.

Welding and testing must be witnessed by theauthorised Inspector.

The results of the procedure qualification testingshall be available prior to the production.

The qualification is based on

EN 288-3 EN 288-4

P. Loos 99 AD HP 2/1

Pressure vessel

Additional requirements are given for:

material groups

welding positions

amount of testing

approval requirements for testing

P. Loos 99 AD HP 5/2

Production testsThe number of the test pieces and the type of de-structive and non-destructive testing depends on:

type of joint (round seam, long seam)

design stress level of the welded joint

(85 %, 100 %)

the base material

number of shell rings

post heat treatment (U, W)

thickness of base material

P. Loos 99 EN 288

SummaryQ u a l i t ä t s k o n t r o l l e w ä h r e n d d e rF e r t i g u n g I u n d I I

S F I - 3 / 4 . 4 - 4 . 5S e i t e 1

W h i c h p o s s i b i l i t i e s o f a p p r o v a l o f w e l d i n g p r o c e d u r e s a r e a v a i l a b l e ?

W h a t a r e t h e l i m i t s o f t h e s e p o s s i b i l i t i e s ?

W h i c h i m p o r t a n t e s s e n t i a l v a r i a b l e s a r e i n c l u d e d i n t h e W P S ?

W h a t t y p e o f t e s t p i e c e s a r e s t a n d a r d t y p e s a c c o r d i n g t o E N 2 8 8 - 3 ?

W h i c h t e s t s ( n o n d e s t r u c t i v e o r d e s t r u c t i v e ) a r e n e c e s s a r y f o r E N 2 8 8 - 3 ?

P. Loos 99 EN 288

SummaryQ u a l i t ä t s k o n t r o l l e w ä h r e n d d e rF e r t i g u n g I u n d I I

S F I - 3 / 4 . 4 - 4 . 5S e i t e 1

W h a t a r e t h e a c c e p t a n c e c r i t e r i a f o r t h e w e l d e d j o i n t o f t h e p r o d u c t i o n t e s t ?

W h a t e a s e g i v e s t h e g r o u p i n g s y s t e m f o rs t e e l a c c o r d i n g t o E N 2 8 8 - 3 ?

W h a t a r e t h e r a n g e s o f a p p r o v a l f o r t h i c k -n e s s a n d d i a m e t e r ?

W h i c h c h a n g e s t o E N 2 8 8 - 3 a r e m a d e i n t h e G e r m a n s t a n d a r d s a n d r e g u l a t i o n s ?

W h a t i s t h e s e n s e o f a p r o d u c t i o n t e s t ?

P. Loos 99

Production tests

The requirements ofproduction tests in the field of

steel structuresare given in guideline

DVS 1702.

For aluminium and aluminiumalloys the DIBt guideline is

applicable

P. Loos 99

Steel structuresBased on the requirements of DIN 18 800 Teil 7,welding procedure tests for steel structures arerequired if:

a) fully mechanized processes are used

b) fine grain steels with a yield strenght (Re) > 360 N/mm2 are used

Welding and testing has to be performed under thewitness of a representative of the accredeted inspec-tion authoraty for the comprehensive form of verifica-tion.

P. Loos 99

Steel structuresFor the fully mechanized processes and for

fine grain steels with (Re) > 360 N/mm2 ,the

requirements of EN 288-3 are applicable.

Exceptions:

Fillet welds are not covered by butt welds.

Welding and testing of fillet welds has to be do-ne in accordance with Guideline DVS 1702(cruziform test).

P. Loos 99

Aluminium structures

Welding procedure tests for aluminiumstructures must be performed in accor-dance with the guideline of the GermanInstitute of Structural Engineering (DIBt)

For butt welds the guideline is based onEN 288-4