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Welder Performance Qualification (WPQ)

MaterialsThe 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 PQR. Hence aperformance test on any material in P groups 1 to 11 approves all those groups and

sub groups, also P34 and P4X (P40-P49). Providing a compatible consumable exists

with the same F number used in the qualification test. (QW423.1)

Note 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

ConsumablesThe F number cannot be changed without re qualification of the welder except that for

performance qualification only using SMAW (MMA) F numbers up to and including4 approve all lesser F numbers for double sided or welds with backing only. One

Consumable from F41 To F45 approves any of these consumables, except SAW. Ref.

QW404.11.

Note 'A' numbers do not apply to welder approval tests.

VariablesFor each welding process there is a list of essential variables in QW352 to QW357

and QW360 for welding operators, these are not necessarily the same as the ones for

the PQR. Essential variables cannot be changed. Explanations of all these variables isgiven in section IV of the code.

Diameter and Thickness RangesDiameter limits for all circular welds including groove welds, branch welds and fillet

welds is given in QW452.3. there are no upper limits on diameters approved and pipe

covers plate

Note 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 sizes.

For t greater than 12.5mm there is no restriction on the size that can be welded

(Providing the test weld deposit contains at least 3 layers of weld).

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Thickness limits, fillet welds.

A test on plate greater than 3/16" approves all base metal thicknesses and fillet weld

sizes ref. QW452.5. (Note the above diameter limits apply unless the fillet weld is

qualified by a groove weld)

Joint ConfigurationJoint geometry, a double V (or U) is considered the same as a joint with backing and

does not qualify a single V (or U) without backing, but a single full penetration joint

without backing qualifies all joint configurations.

Approval RangeExtent of approval is very well explained in QW461.9. Take particular note of

welding positions which are also explained in QW461, for example to qualify a fillet

weld in the normal horizontal-vertical position with a groove weld, the groove weld

must be qualified in at least the 2G position. The welding positions defined in

QW461.1.& QW461.2 should be referred to in the WPS. The position designations:1G ,2G ,3G ,4G ,5G ,6G (Groove Welds) and 1F ,2F ,3F ,4F (Fillet Welds) are test

positions

Period of Validity/Renewal of Qualifications (QW 322.2)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.

If the welder does not use the welding process for which he is qualified for a period of

6 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 weldingprocess are renewed in one test.

Testing RequirementsTest requirements for groove welds QW452 consists of either:-

One face bend and one root bend except for welding positions 5G & 6G whichrequire 4 bends (Ref QW452.1 Note 4). If the plate exceeds 3/8" side bends

may be used. See QW 466 for precise details and exceptions.

Note:- Bend Tests can in most cases be replaced by Radiography {See

Below}.

Radiography is optional and must be supplemented by bend tests when usingGMAW (MIG/MAG) with dip transfer (Short Circuiting Arc) or when welding

some special materials. Ref. QW304.

Note:- Ultrasonic Examination in lieu of Radiography is not permitted

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Test requirements for fillet welds in plate ref. QW452.5:-

One macro section (QW 184) and One fracture test (QW182).The location where each specimen has to be taken is defined in QW463

Radiography Ref QW 191

A length of at least 6" must be examined for plate or the entire circumferencefor pipe.

If the pipe circumference is less than 6" then more samples must be welded upto a maximum of 4. Ref QW 302.2.

Visual Examination Ref QW 302.2 & QW 190Performance test coupons must show complete joint penetration with full fusion of the

weld metal and base metal.

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

the welder must always work within the extent of approval of any properly qualified

W.P.S. and his W.P.Q.

The welder who qualifies the P.Q.R. is automatically approved within the limits

specified in QW304, QW305 and QW303. Ref QW301.2.

Specialist Processes

Such as corrosion resistant overlay or hard facing are covered in QW 453.Procedure variables are defined with all procedure variables in QW252 and in QW380

for welder approval.

Min base thickness approved = size welded or 1", QW 453

Min Deposit Size Approved:- Point Where Chemical analysis taken No upper limit

QW402.16 (462.5a) Welding Positions QW405.4 Performance Qualification approves

all deposit thickness No min.QW381