I have a PQR for butt weld. Base metal PNo.1 thk T= 40 mm, weld metal thk. t=40 mm. Preheat 100 °C. No PWHT.
May I use it to qualify WPS for Sect. VIII Div.1 pr. vessel T= 38 mm, t= 38 mm. Pre heat 100 °C No PWHT.
Note that the PQR itself is not acceptable to UCS-56 where butt weld thk t>38 mm requires PWHT.
Mauro

Good morning Mauro,
I am not sure if this is a trick question as it is an ASME VIII question posted in the ASME IX section ?
I am much more familiar with my piping codes but will try and respond.
UCS 56 Note 2(a) states PWHT is only mandatory for over 38 mm nominal thickness.
UCS 56 Note 2 (b) for nominal thicknesses between 32 and 38 mm your preheat must be 93 degrees C minimum.

Based on that your WPS would be acceptable.
Have I missed something ?
Regards,
BB

Mauro & Ballbearing

I request both of you to go through my opinion. First of all, performing PQR for T=40 & t=40 without PWHT itself is not advisable. The reason is that this will allow to weld unlimited thk without PWHT if you follow Section IX.

Secondly, when t=38, t=38 then why to use PQR whete T=40 & t=40? We can very well use PQR T=20, t=20 and follow preheating as 95 deg C. Lests understand that PQR MUST meet the requirement of Construction Code and not Section IX which is reference code to prepare PQR and WPS.

I will only say that using PQR T=40, t=40 without PWHT for T=38, t=38 is good example to explain how to take benefit of Code allowable limits.

So in my opinion, if Designer says in his data as PWHT YES then lets follow it. Designer is the person who will make sure that everything meets the requirement of Construction Code.

svghate,
Mauro did not say he was qualifying a 40 mm plate to enable him to weld on a 38mm plate without PWHT.
Of course a 20 mm plate would be an acceptable alternative but he already has a PQR he has previously qualified on 40 mm plate without PWHT.
Your reference to unlimited thickness as per ASME IX is irrelevant because the construction code overrules ASME IX and Mauro has informed us it is ASME VIII,
I am still waiting for Mauros response to find out if it is a loaded question.
Regards,
BB

Yes, a QCM with little experience of tht Code, made PQR using T=40 mm. It would have been so easy to weld (t) 38 mm only and, since 100 °C preheat was applied would have been in accordance with Sect. VIII.
The PQR is written, the mechanical tests report thk 40 mm, there is no chance to change anything now.
My opinion is that it can be accepted to support a WPS for t=38 mm. to be used for Sect.VIII Div. p.v. because the PQR was made in accordance with Sect. IX, which does not mandate for PWHT, but only records whether it is made or not. I would have been more happy if the PQR respected Sect. VIII. of course.
I would like to have opinion on this and not suggestions for alternate PQR.
mauro
mauro

I think there's no problem- it does not violate anything. Sure, it's awkward, but they can always say it's to confuse the enemy
Konrad

_________________
Konrad Anikiel