Combination of PQR for WPS

Friend,

Frist you want to consider the combination of the process used for production.

What will be the thickness of the GTAW welding in the job & SMAW welding.

For GTAW process the material thickness will be 1.5 to 12mm

For SMAW process the material thickness will be 5mm to 30mm

I.e you cannot weld SMAW welding below 5mm & GTAW welding above 12mm.

You want to Qualify the WPS as per that.

Qualify thickness shall be 1.5 mm to 30mm.

Thanks

As per ASME IX, the weld deposit thickness shall qualify up to twice the thickness, therefore:

• PQR 1: GTAW, Weld deposit 6 mm → Base metal 12 mm thick.
• PQR 2: SMAW Weld deposit 15 mm → Base metal 30 mm thick.

• Combination of both PQR's 1 & 2: Weld deposit 21 mm → Base metal 42 mm thick.

Note: Combination means that both arc welding procedures are used for a test sample with 21 mm thickness.

See the attached PDF file for a test specimen with 14 mm thickness welded by a WPS & PQR with 3 mm SMAW & 11 mm SAW) used to qualify welding of a base metal thickness up to 28 mm thickness: WPSs_&_PQRs.

Dear All，

My interpretation as allowed by Standard will be the combination thickness should to the max of 30mm and within the WPS; TIG is qualified to weld from 1.5 ~ 6 and SMAW is 5 ~ 30mm but combination is 30mm. This is taking into consideration that the PQR has been prooven meeting the standard requirements and has granted with the extending qualifiication to 30mm within the essential variables. Similarly, the extending of qualification for combine processes are limited by various essential variables per process, including for thickness which is an essential and especially limited by CNV (impact testing) requirements and is related to thickness as well, and the results may vary by location of test. With these considerations, then we should be able in meeting the essential variables as set per different welding process within the code.

In addition for example, we can't take 3 x WPS with 3 different welding process, said 12.5mm each and combine it together and have the WPS qualified to 75mm (each qualified to 25mm). Therefore, for higher thickness qualification than 30mm in your case, you will need to conduct another PQR.

Thank you

Dear,

As per ASME combination of WPS require to qualify min.13 mm one process, If you are qualting your procedure GTAW in min 13mm thickness and SMAW 20mm your procedure will be quaalify to GTAW up to 26mm and smaw up to 40mm i.e you can weld up to 53mm in combination.

Regards

Israr Ahmed

Tata Projects Ltd.

+919930308261