UCS-56(a), Table UCS-56-1, ASME Sec. IX
UCS-56(a), Table UCS-56-1, ASME Sec. IX
(OP)
Hello to Everyone.
This query is with respect to the requirement of PWHT mentioned in Table UCS-56-1 & qualification of the PQR for the same
We are manufacturing a vessel with 20 mm thickness, SA 516 Gr. 70 (P No. 1) material. No special service requirements, no impact requirements. Hence as per table UCS-56-1 of ASME Sec. VIII Div. 1, PWHT is not required.
We have a qualified PQR of SA 516 Gr. 70 to SA 516 Gr. 70 material, 70 mm thickness, GTAW+SAW processes, tested without PWHT (i.e in as-welded condition).
A WPS was prepared for GTAW+SAW processes, to weld the joints of the above vessel. A note is added in the WPS stating that "THE TOTAL WELD METAL DEPOSITED USING THIS WPS SHALL BE 38 MM MAX" to comply with Table UCS-56-1 requirements.
The client has rejected this WPS stating that since PWHT is not required for the vessel, the PQR (without PWHT) can be qualified in 32 mm max thickness only. 70 mm thick PQR (without PWHT) cannot be accepted for these joints. Client has quoted the QG-100(b) clause of ASME Sec. IX "Whenever the referencing Code, standard, or specification imposes requirements different than those given in this Section, the requirements of the referencing Code, standard, or specification shall take precedence over the requirements of this Section".
I looked up for some interpretation related to this but couldnt find any. However, for P No. 3, interpretation for similar case exists (Interpretation No. Vlll-1-04-73, Record No. BC05-032) but dont know whether same can be applied to P No. 1.
Request all to throw some light on this.
Thanks & Regards
SD.
This query is with respect to the requirement of PWHT mentioned in Table UCS-56-1 & qualification of the PQR for the same
We are manufacturing a vessel with 20 mm thickness, SA 516 Gr. 70 (P No. 1) material. No special service requirements, no impact requirements. Hence as per table UCS-56-1 of ASME Sec. VIII Div. 1, PWHT is not required.
We have a qualified PQR of SA 516 Gr. 70 to SA 516 Gr. 70 material, 70 mm thickness, GTAW+SAW processes, tested without PWHT (i.e in as-welded condition).
A WPS was prepared for GTAW+SAW processes, to weld the joints of the above vessel. A note is added in the WPS stating that "THE TOTAL WELD METAL DEPOSITED USING THIS WPS SHALL BE 38 MM MAX" to comply with Table UCS-56-1 requirements.
The client has rejected this WPS stating that since PWHT is not required for the vessel, the PQR (without PWHT) can be qualified in 32 mm max thickness only. 70 mm thick PQR (without PWHT) cannot be accepted for these joints. Client has quoted the QG-100(b) clause of ASME Sec. IX "Whenever the referencing Code, standard, or specification imposes requirements different than those given in this Section, the requirements of the referencing Code, standard, or specification shall take precedence over the requirements of this Section".
I looked up for some interpretation related to this but couldnt find any. However, for P No. 3, interpretation for similar case exists (Interpretation No. Vlll-1-04-73, Record No. BC05-032) but dont know whether same can be applied to P No. 1.
Request all to throw some light on this.
Thanks & Regards
SD.





RE: UCS-56(a), Table UCS-56-1, ASME Sec. IX
RE: UCS-56(a), Table UCS-56-1, ASME Sec. IX
We intend to use GTAW+SAW process. The WPS includes the following ranges
Base metal thickness range : 5 mm to 200 mm
Total Deposited weld metal thickness : 38 mm max (using both processes together)
Preheat temperature : thickness < 32 mm - 30°C, thickness ≥ 32 mm - 100°C (70 mm thick PQR qualified with minimum preheat of 75°C)
The client's rejection is based on the ASME Sec. IX clause mentioned in the original post. Looking for any interpretation that can support our stand.
Thanks & Regards,
Sushil Dwivedi
RE: UCS-56(a), Table UCS-56-1, ASME Sec. IX
In the present context as PWHT is not required by the code, this PQR may be used up to 38 mm thk(both BM and deposited WM)with a minimal preheat of 200 Deg F. Metengr also guided you with similar recommendation.
As per your query there's no impact, however do not get caught if client insists on hardness restrictions.
Thanks.
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario,Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299
RE: UCS-56(a), Table UCS-56-1, ASME Sec. IX
nominal thickness : total weld metal deposited thickness 38 mm max
Preheat of 100°C min for thicknesses greater than or equal to 32 mm
Ironically the same PQR and same type of WPSs (WPSs are made project wise as per our QA system) have been accepted by authorized inspectors in the past and also by team leader during ASME U-Stamp renewal audits and till date no such rejection for this reason has been faced.
RE: UCS-56(a), Table UCS-56-1, ASME Sec. IX
As you stated, how do you satisfy dissimilar welds when one member is over 38mm thick? Both must be within the qualified thickness of QW-451.1 and may not require PWHT.
Just because the Code doesn't state that you are allowed to do something, doesn't mean it is prohibited.
This happened at an ASME tri-annual Audit recently and after a few phone calls by the auditor, it was put to bed and never mentioned again.