Questions on welding procedure qualification with impact test requirem
Questions on welding procedure qualification with impact test requirem
(OP)
Hi all,
I am reviewing one WPS which is supported by 3 PQR's and was confused by the vendor's documents. Impact test is required for the Welding Procedure qualification (Design temperature of vessel is -46 DegC).
WPS (SMAW):
Base metal: P1 Gr.1/2 to P1 Gr.1/2
Base metal Thickness range: 3/16" – 2"
PQR-1 (SMAW):
Base metal: P1 Gr.1 to P1 Gr. 1
Test coupon thickness: 1"
Tensile test, bend test, but no impact test
PQR-2 (SMAW):
Base metal: P1 Gr.2 to P1 Gr.2
Test coupon thickness: 0.24"
Impact test, but no tensile test and bend test
PQR-3 (SMAW):
Base metal: P1 Gr.1 to P1 Gr.1
Test coupon thickness: 0.24"
Impact test, but no tensile test and bend test
My question:
(1) Can these PQR's support Gr1/2 to Gr1/2 welding at the specified thickness range? To my understanding, Gr.1/2 are only qualified by the thickness from 3/16-0.48" by PQR-2 & 3.
(2) Can we use the combination of PQR-1 (No impact test), PQR-2 & 3 (No tensile and bend) to support the WPS, assume the other parameters are ok.
Please help me.
Thanks.
I am reviewing one WPS which is supported by 3 PQR's and was confused by the vendor's documents. Impact test is required for the Welding Procedure qualification (Design temperature of vessel is -46 DegC).
WPS (SMAW):
Base metal: P1 Gr.1/2 to P1 Gr.1/2
Base metal Thickness range: 3/16" – 2"
PQR-1 (SMAW):
Base metal: P1 Gr.1 to P1 Gr. 1
Test coupon thickness: 1"
Tensile test, bend test, but no impact test
PQR-2 (SMAW):
Base metal: P1 Gr.2 to P1 Gr.2
Test coupon thickness: 0.24"
Impact test, but no tensile test and bend test
PQR-3 (SMAW):
Base metal: P1 Gr.1 to P1 Gr.1
Test coupon thickness: 0.24"
Impact test, but no tensile test and bend test
My question:
(1) Can these PQR's support Gr1/2 to Gr1/2 welding at the specified thickness range? To my understanding, Gr.1/2 are only qualified by the thickness from 3/16-0.48" by PQR-2 & 3.
(2) Can we use the combination of PQR-1 (No impact test), PQR-2 & 3 (No tensile and bend) to support the WPS, assume the other parameters are ok.
Please help me.
Thanks.





RE: Questions on welding procedure qualification with impact test requirem
(1) impact qalification for Groups 1 and 2 for P-No 1 base material from 3/16" to 2T.
(2) Yes, for the WPS.
RE: Questions on welding procedure qualification with impact test requirem
RE: Questions on welding procedure qualification with impact test requirem
RE: Questions on welding procedure qualification with impact test requirem
Response to (1): Normaly, if impact test required, thickness range by PQR-1 is 5/8"-2" (3/16"-2" without impact requirement); Thickness range by PQR-2/3: 0.12"-0.48";
If we conbine these PQR's, then the qualified range is 3/16"-0.48". Thickness range from 0.48"-2" is not qualified because no impact results in PQR-1, If I am wrong, please correct me.
Response to (2) Similar to question 1, PQR-1 has tensile and bend test, but no impact test. How can it support the WPS with impact test requirement from thickness range 0.48"-2".
Thanks again.
RE: Questions on welding procedure qualification with impact test requirem
RE: Questions on welding procedure qualification with impact test requirem
Thanks for you response.
The fabrication code is ASME VIII. The welding procedure qualification shall be in accordance with ASME IX. What I mentioned in this thread is based on ASME IX.
RE: Questions on welding procedure qualification with impact test requirem
Ok, I see that you have reviewed Section IX. I went back and double checked your PQR variables. Since 0.24" is less than 1/4", QW-403.6 requires the minimum qualification thickness as 1/2T (coupon thickness), 0.12" minimum. Are you sure this thickness is 0.24" or is it close 0.250" to simplify this process?
Anyway, using Table QW-451, the minimum thickness for qualification based on a coupon thickness of 1" is 3/16" for bends and tensile testing.
A WPS that is supported by multiple PQR's must have essential and supplementary essential variables within stated ranges (see Article II). In this case, the 3/16" min would be required for this WPS qualified for impact because your PQR that is for bends and tensile has this as a minimum range (despite the impact qualification allowing a minimum base metal thickness of 0.12").
So, as I stated above the minimum base metal thickness is 3/16" for impact IF multiple PQR's are used for this WPS.
RE: Questions on welding procedure qualification with impact test requirem
Thanks for your time.
It looks like the thickness of 0.24" is used to simplify the process.
Actually I understand why the vendor speicfy 3/16" as the minimum, just like you mentioned above.
My concern is the maximum thickness range. Impact test is performed only on PQR-2/3, which support the thickness range from 3/16" to 0.48". Thickness range 0.48"-2" is only supported by bend test and tensile test, but not impact test.
RE: Questions on welding procedure qualification with impact test requirem
RE: Questions on welding procedure qualification with impact test requirem
QW-401.3 (the second paragraph of this section) indicates that additional test coupon should use the same procedure and same essential variable. It means that the addition test coupon thickness is the same as the orginal test coupon thickness.
Probably this is the reason why the forth paragraph of QW-401.3 mentions that no limit the maximum thickness is applied.
If I am wrong, please correct me.
RE: Questions on welding procedure qualification with impact test requirem
RE: Questions on welding procedure qualification with impact test requirem
You are right that the same essential variables need to be used. Since the first WPS qualifies 3/16" to 2", and the other PQRs are .24", they are within the essential variable range as the first PQR. Since QW-403.6 doesn't affect the maximum thickness, the .48" limit that would be imposed had the .24" PQRs been the only ones does not apply, and the procedure should be qualified for impacts from 3/16" to 2".