wps - welding procedure specification - guide

7/21/2019 WPS - Welding Procedure Specification - GUIDE

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Welding Procedure Specifications

Welding Procedure Specification Example

A WPS is a document that describes how welding is to be carried out in

production. They are recommended for all welding operations and many

application codes and standards make them mandatory

What information should they include?

Sufficient details to enable any competent person to apply the information

and produce a weld of acceptable quality. The amount of detail and level of

controls specified on a WPS is dependant on the application and criticality

of the oint to be welded.

!or most applications the information required is generally similar to that

recorded on a Procedure "ualification #ecord $P"#% or Welding Procedure

Approval #ecord $WPA#%& e'cept that ranges are usually permitted on

thicknesses& diameters& welding current& materials& oint types etc.

(f a WPS is used in conunction with approved welding procedures then the

ranges stated should be in accordance with the approval ranges permitted by

the welding procedure.

)owever careful consideration should be given to the ranges specified toensure they are achievable& as the ranges given by welding procedure

standards do not always represent good welding practice. !or e'ample

welding positions permitted by the welding procedure standard may not be

achievable or practical for certain welding processes or consumables.

EN ISO 15609-1 (formall EN !"" Part !# European Standard $or

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Welding Procedure Specification%

*+ (S, -/01 2efines the contents of a Welding Procedure Specification

in the form of a list of information that should be recorded. !or some

applications it may be necessary to supplement or reduce the list. !or

e'ample only in the case of a procedure requiring heat input control wouldthere be a necessity to quote travel speed or run3out length for manual

processes.

&S'E I &merican )oiler and Pre%%ure *e%%el +ode

"W 40 5ists the variables for each welding process& all the variables stated

should be addressed. The range permitted by the WPS is dictated by the

P"# or P"#6s used to qualify it.

Typical (tems That Should 7e #ecorded ,n W.P.S83

+ommon to all Proce%%e% .

• Procedure number

• Process type

• 9onsumable Si:e& Type and full 9odification.

• 9onsumable 7aking #equirement if applicable

• Parent material grade and spec.

• Thickness range.

• Plate or Pipe& 2iameter range• Welding Position

• ;oint !it <p& Preparation& 9leaning& 2imensions etc.

• 7acking Strip& 7ack =ouging information.

• Pre3)eat $>in Temp and >ethod%

• (nterpass (f #equired $>a'imum Temperature recorded %

• Post Weld )eat Treatment. (f #equired $Time and Temp%

• Welding Technique $weaving&ma' run width etc.%

• Arc *nergy 5imits should be stated if impact tests are required or if

the material being welded is sensitive to heat input.

Specific ,o Welding Proce%%e% ''& ,I 'I

'& S.)

&/+



$+&W

Welding current yes yes yes yes

Type of Welding current A929

Polarityyes yes yes yes

Arc voltage (f Auto yes yes

Pulse parameters $Pulse time and peak @

backgound current%(f <sed (f <sed

Welding Speed (f >echanised yes yes yes

Wire configuration yes

Shielding gas $comp&flow rate% yes yes

Purge gas $comp @ flow rate% (f <sed (f <sed

Tungsten electode 2iameter and type. yes

+o::le diameter yes yes

Type of !lu' 9odification @ 7rand

+ameyes

+o::le Stand ,ff 2istance $2istance

from tip of no::le to workpiece%. yes

Setce%

A sketch of the oint configuration is required which should include the

basic dimensions of the weld preparation. Some indication of the runsequence is also beneficial& particularly if the correct sequence is essential

to ensure the properties of the weld are maintained.

Production Se2uence

Whilst this is good practice it is not a requirement of either AS>*

1 or *+4 Part 4B it could be issued as a separate "A procedure if

preferred.

Non 3e%tructi4e ,e%ting

A WPS is primarily concerned with welding not + 2 T& this activity should be covered by separate + 2 T procedures.

Welding Procedure Specification%



This is a simple instruction sheet giving details of how the weld is to be

performed& its purpose is to aid the planning and quality control of the

welding operation. *+ (S, -/01 $formerly *+4 Part 4% specifies the

contents of such a specification in the form of a list of items that should be

recorded& however only relevant information need be specified& for e'ampleonly in the case of a procedure requiring heat input control would there be a

necessity to quote travel speed or run out length for manual processes.

A weld procedure specification may cover a range of thicknesses& diameters

and materials& but the range must be specified and be compatible with the

rest of the parameters on the document. ( suggest that you produce a new

WPS for each type of oint and keep to the ranges of thickness and

diameters specified in the welding procedure standard.

Welding Procedure%

Welding procedures are required when it is necessary to demonstrate that

your company has the ability to produce welds possessing the correct

mechanical and metallurgical properties.

A welding procedure must qualified in accordance with the requirements of

an appropriate welding procedure standard such as *+ (S, -/-C Part - as

follows83

-. Produce a welding procedure specification as stated above.

4. Weld a test piece in accordance with the requirements of your

specification. The oint set up& welding and visual e'amination of the

completed weld should be witnessed by an (nspection 7ody. The

details of the test such as the welding current& pre3heat etc.& must be

recorded during the test.

D. ,nce the welding is complete the test piece must be subect to

destructive and non destructive e'amination such as radiography and



mechanical tests as defined by the welding procedure standard. This

work can be carried out in any laboratory but the (nspection 7ody

may require to witness the tests and view any radiographs.

C. (f the test is successful you or the test body complete the appropriate

documents which the test bodies surveyor signs and endorses. The

necessary documents are as follows83

E1 Welding Procedure &ppro4al ,e%t +ertificate

This is the front sheet and only gives details of what the procedure

can be used for. i.e. its range of approval.

E! 3etail% Of Weld ,e%t

This gives details of what actually took place during the test weld it is

similar to a WPS but should not include ranges of welding

parameters.

E ,e%t /e%ult%

2etails of +2T and >echanical testing #esults

E Welder &ppro4al ,e%t +ertificate7

This is the welder approval part of the qualification.

Note The *-& *4& *D& *C designations are used by some (nspection

Authorities to refer to the individual forms. *'amples of these forms are

given in anne'es of *+ (S, -/-C and *+4E.

!orms *-& *4& *D may be referred to as the WPA# $Welding Procedure

Approval #ecord% or WP"# $Weld Procedure "ualification #ecord%.

(n general a new welding procedure must be qualified for each of the

following changes subect to the individual requirements of the appropriate

standard used83

• 9hange in parent material type.

• 9hange of welding process

• The diameter range for pipe given by the welding standard is

e'ceeded. Typically 0.'2 to 4'2.



• The thickness range is e'ceeded. Typically 0.'t to 4't.

• Any other change required by the welding standard.

Welder &ppro4al ,nce the procedure is approved it is necessary to demonstrate that all your

welders working to it have the required knowledge and skill to put down a

clean sound weld. (f the welder has satisfactorily completed the procedure

test then he is automatically approved but each additional welder must be

approved by completing an approval test to an appropriate standard such as

*+ 4E part - as follows83

9omplete a weld test as stated in 4% above. The test should simulate

production conditions and the welding position should be the

position that the production welds are to be made in or one moresevere

!or ma'imum positional approval a pipe inclined at C degrees

$referred to as the /= position% approves all positions e'cept vertical

down.

Test the completed weld in accordance with the relevant standard to

ensure that the weld is clean and fully fused.

!or a butt weld this is normally a visual e'amination followed by

radiography.

,nce the test is completed the *C form has to be completed by you or

the test body and signed by the test bodies surveyor.

+ote The above changes that require a new welding procedure may

also apply to the welders approval& refer to the standard for precise

details.

&S'E 9

AS>* 1 as far as the pressurised systems regulations are concerned can be

considered as equivalent to *+ (S, -/-C3- *+ 4E. )owever it may not be contractually acceptable. The advantage in using AS>* is that generally

fewer procedure tests are required particularly when welding pipework.

Welder &ppro4al Witout & procedure

7S CE4 is for the qualification of welders where a weld procedure is not

required either by the application standard that governs the quality of



production welds or by contractual agreement. Typically applied per

7S41E- for welding of boiler pipework less than -E bar g and 400F9.

7asically the same rules mentioned above for the welder approval apply.

&cceptance Standard%

(n general welds must show a neat workman like appearance. The root must

be fully fused along the entire length of the weld& the profile of the cap

should blend in smoothly with the parent material and the weld should be

significantly free from imperfections. #eference should be made to the

acceptance standard for precise details.

(ts a good idear to ensure that you can achieve the appropriate standard

before you call in an (nspection 7ody. Penetration defects and lack of

fusion can often be easily detected by sectioning welds and bending them.

Welder Performance Qualification (WPQ)

'aterial%

The purpose of this test is to determine the welders ability to deposit a

sound weld therefore the base material is not considered as critical as it is in

the P"#. )ence a performance test on any material in P groups - to --

approves all those groups and sub groups& also PDC and PCG $PC03PC1%.

Providing a compatible consumable e'ists with the same ! number used in

the qualification test. $"WC4D.-%

+ote a single sided weld is classed as a weld without backing and a double

sided weld or weld with sealing run is classed as a weld with backing

+on%uma8le%

The ! number cannot be changed without re qualification of the welder

e'cept that for performance qualification only using S>AW $>>A% !

numbers up to and including C approve all lesser ! numbers for double

sided or welds with backing onl. ,ne 9onsumable from !C- To !C

approves any of these consumables& e'cept SAW. #ef. W0711.

+ote HAH numbers do not apply to welder approval tests.

*aria8le%

!or each welding process there is a list of essential variables in "WD4 to



"WDE and "WD/0 for welding operators& these are not necessarily the

same as the ones for the P"#. *ssential variables cannot be changed.

*'planations of all these variables is given in section (I of the code.

3iameter and ,icne%% /ange%

2iameter limits for all circular welds including groove welds& branch welds

and fillet welds is given in "WC4.D. there are no upper limits on diameters

approved and pipe covers plate

+ote for branch welds the diameter considered for the above limits is the

one containing the weld preparation.

Thickness limits& groove welds.

The thickness limit only applies to the deposited weld metal thickness not

the plate thickness and any groove weld approves all fillet weld si:es. !or t greater than -4.mm there is no restriction on the si:e that can be

welded $Providing the test weld deposit contains at least D layers of weld%.

Thickness limits& fillet welds.

A test on plate greater than D-/J approves all base metal thicknesses and

fillet weld si:es ref. "WC4.. $+ote the above diameter limits apply unless

the fillet weld is qualified by a groove weld%

:oint +onfiguration ;oint geometry& a double I $or <% is considered the same as a oint with

backing and does not qualify a single I $or <% without backing& but a single

full penetration oint without backing qualifies all oint configurations.

&ppro4al /ange

*'tent of approval is very well e'plained in "WC/-.1. Take particular note

of welding positions which are also e'plained in "WC/-& for e'ample to

qualify a fillet weld in the normal hori:ontal3vertical position with a groove

weld& the groove weld must be qualified in at least the 4= position. The

welding positions defined in "WC/-.-.@ "WC/-.4 should be referred to inthe WPS. The position designations8 -= &4= &D= &C= &= &/= $=roove

Welds% and -! &4! &D! &C! $!illet Welds% are test positions

Period of *alidit;/ene<al of ualification% (W !!7!#



Providing the welder uses the process for which he is qualified and there is

no reason to question his ability then his qualification lasts indefinitely.

(f the welder does not use the welding process for which he is qualified for

a period of / months or more then he must perform a new test in pipe or plate& any parent material& thickness and position& if successful all the

welder approvals for that welding process are renewed in one test.

,e%ting /e2uirement%

Test requirements for groove welds "WC4 consists of either83

• ,ne face bend and one root bend e'cept for welding positions 5 =

6 which require 8end% (#ef "WC4.- +ote C%. (f the plate

e'ceeds DJ side bends may be used. See "W C// for precise

details and e'ceptions.

Note>- )end ,e%t% can in mo%t ca%e% 8e replaced 8 /adiograp

?See )elo<@7

• /adiograp is optional and must be supplemented by bend tests

when using =>AW $>(=>A=% with dip transfer $Short 9ircuiting

Arc% or when welding some special materials. #ef. "WD0C.

Note>- .ltra%onic Examination in lieu of /adiograp i% not

permitted

Test requirements for fillet welds in plate ref. "WC4.83

• ,ne macro section $"W -C% and ,ne fracture test $"W-4%.

The location where each specimen has to be taken is defined in "WC/D

/adiograp /ef W 191

• A length of at least /J must be e'amined for plate or the entire

circumference for pipe.

• (f the pipe circumference is less than /J then more samples must be

welded up to a ma'imum of C. #ef "W D04.4.

*i%ual Examination /ef W 0!7! = W 190



Performance test coupons must show complete oint penetration with full

fusion of the weld metal and base metal.

The welder performance test must follow a properly qualified W.P.S. ,nce

qualified the welder must always work within the e'tent of approval of any

properly qualified W.P.S. and his W.P.".

The welder who qualifies the P.".#. is automatically approved within the

limits specified in "WD0C& "WD0 and "WD0D. #ef "WD0-.4.

Speciali%t Proce%%e%

Such as corrosion resistant overlay or hard facing are covered in "W CD.

Procedure variables are defined with all procedure variables in "W44 and

in "WD0 for welder approval.

>in base thickness approved K si:e welded or -J& "W CD

>in 2eposit Si:e Approved83 Point Where 9hemical analysis taken +o

upper limit "WC04.-/ $C/4.a% Welding Positions "WC0.C Performance

"ualification approves all deposit thickness6 +o min."WD-

ASME Definitions, Consumables, Welding

Positions AS>* P >aterial +umbers *'plained

AS>* has adopted their own designation for welding processes& which are

very different from the (S, definitions adopted by *+4C0/D.

3e%ignation 3e%cription

,!W ,'yfuel =as Welding

S>AW Shielded >etal Arc Welding $>>A%

SAW Submerged Arc Welding

=>AW =as >etal Arc Welding $>(=>A=%

!9AW !lu' 9ored Wire

=TAW =as Tungsten Arc Welding $T(=%

PAW Plasma Arc Welding

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Straight polarity K *lectrode 3ve

#everse polarity K *lectrode Lve

&S'E $ Num8er%

!

+umber =eneral 2escription

- )eavy rutile coated iron powder electrodes 83 A.- 8 *E04C

4 >ost #utile consumables such as 83 A.- 8 */0-D

D 9ellulosic electrodes such as 83 A.- 8 */0--

C 7asic coated electrodes such as 8 A.- 8 *E0-/ and *E0-

)igh alloy austenitic stainless steel and duple' 83 A.C 8 *D-/53-/

/ Any steel solid or cored wire $with flu' or metal%

4G Aluminium and its alloys

DG 9opper and its alloys

CG +ickel alloys

G Titanium

/G Mirconium

EG )ard !acing ,verlay

+ote83 G represents any number 0 to 1

&S'E & Num8er%

These refer to the chemical analysis of the deposited weld and not the

parent material. They only apply to welding procedures in steel materials.

A- Plain unalloyed carbon manganese steels.

A4 to AC 5ow alloy steels containing >oly and 9hrome >oly

A Austenitic stainless steels such as type D-/.

&S'E Welding Po%ition% rapic /epre%entation

+ote the welding progression& $vertically upwards or downwards%& must

always be stated and it is an essential variable for both procedures and

performance qualifications.

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Welding Positions !or =roove welds83

Welding Po%ition ,e%t Po%ition ISO and EN

!lat -= PA

)ori:ontal 4= P9

Iertical <pwards Progression D= P!

Iertical 2ownwards Progression D= P=

,verhead C= P*

Pipe !i'ed )ori:ontal = P!

Pipe !i'ed N C degrees <pwards /= )50C

Pipe !i'ed N C degrees

2ownwards/= ;50C

Welding Positions !or !illet welds83

Welding Po%ition ,e%t Po%ition ISO and EN

!lat $Weld flat oint at C degrees% -! PA

)ori:ontal 4! P7

)ori:ontal #otated 4!# P7

Iertical <pwards Progression D! P!

Iertical 2ownwards Progression D! P=

,verhead C! P2

Pipe !i'ed )ori:ontal ! P!

Welding Po%ition% W171 and W617!

7asically there are three inclinations involved.

• !lat& which includes from 0 to - degrees inclination

• - 3 0 degrees inclination

• Iertical& 0 3 10 degrees

!or each of these inclinations the weld can be rotated from the flat position

to )ori:ontal to overhead.

wps - welding procedure specification - guide

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