Hi

I found a few WPS with the base metal thickness are qualified based upon the table 323.3.1 of ASME B31.3, as T/2 to T+6.

But I believe this table is applicable for impact testing in fabrication and assembly, and not at all for qualification of WPS.

I interpret it as below.

For each WPS we need an impact test from production test coupon (PTC)[Not exactly a PTC, since it asks for impact test of a production weld joint itself to be impact tested]. Also for each consumables. And table A-5 defines the thickness and number of these PTC test coupon.

For example,

Consider we have a WPS, with PWHT, qualified in base metal thickness range of 16mm to 60mm, with impact, with same filler material.

Imagine we need to use this WPS on 3 different thicknesses 16mm, 20mm and 50mm.

As per A-5 (a) if we do an impact test on a PTC extracted from 20mm thick joint of fabrication, no need of an impact on 16mm thick joint of fabrication, since it qualifies 10mm to 26mm. But it doesn’t qualify the 50mm joint as its PTC qualifies 25mm to 56mm. Hence we require two PTC’s impact tested, in this case.

Hence I still believe the base metal qualified for WPS has to be as per ASME Sec IX QW 403.6, and considering the qualified thickness as T/2 to T+6 is wrong for a WPS.

But again, I found a code case, interpretation 25-29, below

Interpretation 25-29

Subject: Table 323.3.1, Welding Procedures With Impact Tests (B31.3-2012)
Date Issued: April 28, 2015
File: 15-586
Question: The requirements for qualification of a welding procedure with impact tests given
in Table 323.3.1 are different from the requirements of ASME Section IX, QW-403.6. Moreover,
QG-100(b) of Section IX states that the rules of the construction code take precedence over the
rules of Section IX. Does the Code require Table 323.3.1 be applied when qualifying a welding
procedure with impact tests?

Reply: Yes.

It would be grateful if I can get a clear picture in this matter.