PQR thickness range Vs WPS thinkness range

[bigmcsparron]

we have a PQR for duplex carried out on 6.5mm thick pipe this according to the PQR thickness range says qualified fro 1.5mm to 13mm , we have run some WPS's using this procedure on 13mm thickness pipe, on the WPS it states max thickness welder is qualified for Is 26mm 2xt, my question is which is correct? can the welder still weld up to 26mm thick pipe even though the PQR says a maximum of 13mm

 

[gtaw]

The PQR should list the thickness of the base metal used. If the welding standard used is ASME Section IX, then the thickness of the weld deposited with each F number and process should be recorded in addition to the thickness of the base metal. In any event, the range qualified is not listed on or by the PQR.

Someone doesn't understand how to properly document the PQR and WPS.

Best regards - Al

 

[bigmcsparron]

hi al, the PQR.WPS and welder quals are produced by TWI software, everything is recorded correctly, the software then produces the WPS on the information on the PQR.
what I am saying it that the WPS then shows a minimum of 1.5mm and a maximum of 13mm thickness range qualified . if I then test a welder out on 13mm thickness pipe the welder qualification then states the welder can weld up to 26mm thickness, is this correct ? can the welder weld up to 26mm on the same PQR and WPS?

 

[DekDee]

bigmcsparron,
No, the welders must follow a qualified WPS and your qualified WPS is only valid to 13 mm.
Regards,
DD

 

[weldtek]

It sounds as though you're confusing the requirements for procedure qualification with those for welder qualifications. Software packages designed for generating welding related documents are not a replacement for the Code. If you don't already have one, get a copy of applicable code book and refer to it.

 

[holdpt]

Based on your 2nd entry on this topic, the welder is qualified to weld up to 26mm because you tested on 13mm, but he cannot weld on a thickness for which you do not have a WPS. Therefore, your WPS is limited to 13mm and in effect the welder is also until you produce a WPS that is supported for thicker material.

 

[SectionIX]

The qualified range of the WPS is based on the thickness of the test coupon(s) and is independant of the welder qualification range, and vice versa.


To take this further:

A WPS qualified on 13mm thicknesses cannot be used outside the qualification range (5mm to 26 mm per ASME Section IX QW 451.1) just because the welder may be qualified to weld thicker materials. To make this even more confusing, lol, the qualiied WPS thickness range could actually be 13mm to 26mm if supplemental essential variables apply (See ASME Section IX QW 403.6).

As a final comment, if a single welder is qualified on material 13mm and over, with a minimum of three layers, he/she effectively has no thickness limitation. See ASME Section IX QW-452.1(b.

 

[bigmcsparron]

HI SECTIONIX, now I am confused, are you saying that if the welder is tested out on 13mm thickness and uses more then three layers of weld then he can weld all thicknesses even thought the wps states a max of 13mm? have got this right?

 

[gtaw]

He is qualified for any number of WPSs. He is not limited to the one WPS used to weld the performance test coupon. If the welder is qualified for unlimited thickness, he is limited by the range of the WPS used for production. If that WPS (different for the WPS you noted) is qualified for 75 mm, he can weld to the maximum thickness qualified by the "new" WPS.

Best regards - Al

 

[SectionIX]

bigmcsparron,

The bottom line is this: The welder needs to be qualified to use the WPS, and the WPS thickness range will not change based solely on the welders qualification.

The WPS thickness does not change just because the welder may be qualified to weld materials thicker than allowed by the WPS. The only way for a WPS thickness range to change would be:

1. Additional test coupon(s) are made, destructively tested, and meet ASME IX requirements to extend the qualified thckness range.

2. The Company elects to restrict, or lower the qualified thickness range on the WPS. I've observed companies that had welding procedures that were qualified up to 50 mm restrict their use to 25mm. While not the best practice, you can make the WPS more restrictive if you so choose.

 

[mrvas]

can any one clarify my doubt?


AS PER ASME Section IX QW-452.1(b) for performance 13mm and over, with a minimum of three layers, no thickness limitation......but i have doubt in this .what is that three layer ?if it is root,fill,cap. then why we are exclude that cap and excess root penetration for thickness qualification?


QW 452.1
GENERAL NOTE: The “Thickness of Weld Metal” is the total weld metal thickness deposited by all welders and all
processes in the test coupon exclusive of the weld reinforcement.

by
ap