Use of PQR for GTAW+SMAW against WPS of SMAW

[goutam_freelance]

Our contractor has submitted WPS for SMAW but the PQR is GTAW+SMAW. He is insisting that as per cl. 200.4 of ASME Sec IX we can prepare multiple WPSs from one PQR. Material is carbon steel.
Is he justified ?

 

[david339933]

Yes, but the clause reference is wrong. QW-200.4 allows a multi-process WPS to be used individually. Multiple WPSs from a single PQR is covered in QW-200.2(f).

 

[goutam_freelance]

@david339933 But the bend test with GTAW+SMAW will give superior result compared to SMAW only. Can we consider them at par ?

 

[weldstan]

Yes you can. Writing multiple WPSs with a single multi process PQR is common place and permitted under ASME IX. Why do you necessarily believe that the GTAW deposited weld metal will be superior with regard to ductility? If the root and second passes were done with GTAW, the greatest weld metal dilution with the base metal will occur in that deposit and the carbon content and Carbon Equivalent of the deposited weld metal may well be greatest.

 

[goutam_freelance]

@weldstan I meant better quality welds are obtainable for GTAW like lower slag inclusion, porosity etc. Also as per QW 401 Sec IX, welding process is essential variable and as per 200.4 a) 1) the essential variables need to be applied for individual WPSs. Also QW 200.4 b) mentions separate PQR for root pass for GTAW, SMAW, GMAW, PAW and SAW and combinations thereof.

 

[david339933]

Again....200.4 is not the right paragraph....read 200.2(f). Why ask the question in the first place if you are not going to accept the answer?

Standard Designation: SC IX
Edition/Addenda: 2013
Para./Fig./Table No: QW-200.4(a)and QW-200.4(b
Subject Description: SC IX; QW-200.2(f). QW-200.4(a)and (b)
Date Issued: 11/26/2014
Record Number: 12-1784
Interpretation Number : IX-15-11
Question(s) and Reply(ies):
Background (1): A test coupon was welded on 8 mm material thickness with a combination of processes - GTAW for root and 4 mm weld metal deposit thickness, and SMAW for the remaining 4 mm thickness.

Question (1): Does QW-200.2(f) allow this PQR to support a WPS for welding with only the GTAW process?

Reply (1): Yes

 

[weldstan]

Ductility for both processes was demonstrated in the successful bend tests plus freedom from weld flaws which could have led to liner indications that would disqualify acceptance was also proved for both processes. And that is why the Code has accepted multiple process PQRs to be used for single and multiple process WPSs at least for the over 45 years that I have been working with AS<E IX.

 

[CWEng]

@gout- believe Weldstan and David. Both are correct. It is a very common practice and perfectly acceptable according to ASME Section IX. Both processes should have been represented in the test specimens, so it has all been proven out.

 

[goutam_freelance]

Thanks all for your valuable inputs. We have acceted the WPS/PQR with additional SMAW WPS/PQR for root pass as per QW 200.4 b). May be we are more stringent than ASME, but as client we have the right to be so.

 

[DekDee]

As the client you are perfectly entitled to go over and above the code requirements but (and this is a big but) you must state this requirement in the contract documents or project specifications so the contractor is aware of these requirements prior to commencement.
It seems you have received a PQR/WPS you were not happy with, come on here for justification of your unhappiness and then not been particularly happy with the responses.
If my assumptions are correct (and it was not noted in your project specs) the contractor would be perfectly justified in backcharging you for all additional costs related to the SMAW PQR/WPS,
Regards,
Shane

 

[david339933]

We have acceted the WPS/PQR with additional SMAW WPS/PQR for root pass as per QW 200.4 b).

Can you explain what you are doing a little more.