ASME Sec IX QW-288.3(e) Rods Diameter

[The Azar]

Hello,

I would like to ask if anyone has information about ASME Sec. IX regarding PQR essential variables as per QW-288.3(e)for Tube to Tubesheet heat exchanger weld:
QW-288.3 Gas Tungsten Arc, Plasma Arc, and Gas Metal Arc Welding:
(e) For GTAW or PAW, a change in the nominal diameter of the filler metal or electrode.

Well it is clear enough that the diameter of the filler metal is an essential variable; however, I just need to confirm if this essential variable is a must to be applied in production weld exactly as per PQR layer arrangement, e.g. if PQR root pass filler metal dia was 1.2mm, hotpass dia used 1.6 mm, third layer 2.0 mm, can I use in production weld 1.6 mm dia for root layer and 2.0 mm for balance instead? knowing that PQR already used these sizes with different layers.
ps, I've posted this thread in structural engineers-welding.

Thank you in advance.

AZAR

 

[SectionIX]

QW-288.3(e)is not specific to weld pass. As long as your PQR was qualified using, in your case, 1.2mm, 1.6mm and 2.0mm diameter filler metal, there is no restriction for use in any specific pass during production welding.

 

[The Azar]

Thank you SextionIX, actually I agree with your post; however, do you think that there is any supporting interpretation for this issue? I believe that other may also consider changing the diameter from PQR layer/pass in production weld is essential as it is not clearly mentioned in the Code; for example, some may claim that root pass shall be made with the same diameter filler metal used in PQR to assure minimum leak-path distance as the tube to tubesheet joint configuration is also essential.

Cheers,

AZAR

 

[SectionIX]

The Azar,

I looked through ASME interpretations before my initial reply. There were no relevant interpretations for this matter.

Common sense always needs to be applied to any welding situation, and it is your responsibility to make sure this happens.If you remain concerned, have several PQR's made with different filler metal diameters for each of the various passes.

ASME IX QW-288.3(e) reads as follows: "For GTAW or PAW, a change in the nominal diameter of the filler metal or electrode". I imagine if the ASME IX Committee felt this required additional consideration, this variable would have been stated differently.

 

[The Azar]

SectionIX,

Thank you for your replies; its really appreceiated.