Multi Process Welding ProceduresQW200.4 and QW451.1





Base Metal approval range for the above welded joint is 4.76mm To 52mm Ref QW451.1


If the joint is made of more than one welding process then the maximum deposited thickness each process in the above example is (2 x Deposited Weld Metal t) :-†† GTAW 12mm†† and SMAW 52mm (This is because t = T for this process as t > 19.1mm QW451.1)


If the SMAW deposit in the above qualification was less than 19.1mm, assume 18mm and GTAW 8mm then to weld a joint 52mm thick with 8mm GTAW and 44mm SMAW is not permitted as maximum SMAW deposit would be 36mm


You can delete the SMAW and qualify an all GTAW weld4.76mm To 12mm thick or delete the GTAW and weld SMAW 4.76mm to 52mm thick, providing all the essential, non essential and supplementary variables are applied to the WPS.(Note the procedure allows the SMAW to be used as a root run but not the welder qualification.)


When tested the deposited weld metal of each process must be included in the tension and bend test specimens and impacts where applicable.Note it is acceptable for the impact test for the GTAW to contain some SMAW in the test specimen.


PICK and MIXQW200.4 b[Note restrictions in QW451.1 notes (1)]

This applies to test coupons 13mm and thicker and welding processes SMAW, SAW, GTAW, GMAW.A WPS consisting of several processes can be created from different PQRís, but the maximum thickness of base metal covered by this WPS canít exceed 2 x the thickness of the thinnest test coupon used for each PQR and each process canít exceed 2 x its deposited thickness.This applies even if all the processes used for that coupon are not required in this WPS.However the base metal thickness of the PQR used for the root does not have to be considered if the WPS is single sided QW200.4 b


Note test coupons 38mm and above approve deposited weld metal and also base metal thickness up to 200mm max QW451.1.(QW403.7 Processe GTAW,SMAW,GMAW,SAW)





Can the proposed PQR be made from the above example + PQR 2 + PQR 3.


Consider individual deposited thickness 2 x t

GTAW 12mm > 6mm.SMAW 60mm > 39mm.GMAW 66mm > 20mmAll OK


Consider Plate thickness 2 x T

SMAW 60mm <65mm Fail.GMAW 66mm > 65mm OK.†† GTAW not considered.

SMAW procedure canít be used for proposed PQR



If you want to weld a 30mm plate and your welder qualifications only go up to 15mm use two welders.You canít use one welder with two different qualifications for the same process

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