QW-406 PREHEAT 3

[deepu78]

QW-406 PREHEAT ASME IX
QW-406.1 states A decrease of more than 100°F (55°C) in the preheat temperature qualified. The minimum temperature for welding shall be specified in the WPS.
What does the "decrease of more than 100°F (55°C)" mean?
ASME IX Table QW-253 this is an essential variable.

Does it mean pre heat of > 100 deg F or 50 Deg C from PQR pre heat temp needs new PQR
DV

 

[r6155]

Read again, ASME is very clear.

Regards

 

[david339933]

If your PQR was done with 200F preheat, you can write a WPS with 100F as min. preheat without requalification.

 

[r6155]

It's the other way around.

1) write a WPS (preheat 200 F)
2) do a PQR (preheat 200 F with small tolerances)
3) during production welds a preheat change to 100°F can be performed without requalification of WPS (and corresponding PQR)

Regards

 

[DekDee]

r6155,

Read again, ASME is very clear.

I think maybe you need to read again.
You are incorrect.
David is correct.
A WPS must be complied with - if the WPS states 200 F minimum preheat then that is the minimum preheat - end of story.
QW 406.1 is based on the relationship between the PQR and the WPS.
QW 406.1 is not based on the relationship between the WPS and what the worker on the shop floor feels like doing.
PQR qualified at 200 F minimum preheat allows you to write a WPS with 100 F minimum preheat without requalification of the PQR.

Interpretation: IX-83-165
Subject: Section IX, QW-406.1
Date Issued: May 14, 1985
File: BC85-O24
Question (1 1: A PQR is generated that lists 400°F as the preheat temperature. Per QW-406.1, can
the WPS require a minimum preheat temperature of 300°F?
Reply (1 1: Yes.

Cheers,
Shane

 

[r6155]

Ummmmm!!
First of all you need the WPS, then you need to do PQR that confirm all information in the WPS. Not vice versa.
An example see QW-540 Stanadard WPS Specification
QW-540 PRODUCTION USE OF SWPS
As with any WPS, welding that is done following an
SWPS shall be done in strict accordance with the
SWPS. In addition, the following requirements apply to
the use of SWPSs:
(a) The organization may not deviate from the welding
conditions specified on the SWPS.
(b) SWPSs may not be supplemented with PQRs or
revised in any manner except for reference to the applicable Code Section or other fabrication documents as
provided by QW-511

Regards

 

[david339933]

There is no Code requirement for a so called Pre-WPS. Not sure what SWPS has to do with any of this.

 

[r6155]

If you're not sure, it's bad news, I'm very sorry.
I am sure.
Everything is related, you should even be sure with ASME V, ASME VIII, B31.3......etc, etc.

Regards

 

[DekDee]

r6155,
What on earth are you smoking ?
The discussion is about QW 406.1
Has absolutely zero, zilch, nil, nada, nothing to do with Standard Welding Procedure Specifications.

 

[DekDee]

r6155,
It seems you do not even understand the clauses you are quoting.

First of all you need the WPS, then you need to do PQR that confirm all information in the WPS. Not vice versa.

QW-510 ADOPTION OF SWPSS
(d) The organization shall weld and test one groove
weld test coupon following that SWPS
(e) The coupon shall be visually examined in accordance
with QW-302.4 and mechanically tested in accordance
with QW-302.1 or volumetrically examined in
accordance with QW-302.2.

QW 300 is Welder Performance.

There is no PQR required or applicable for your SWPS

 

[r6155]

Ummmm
I say QW-540 PRODUCTION USE OF SWPS, no QW-510

Regards

 

[david339933]

What are you smoking is right?!? Nobody mentioned SWPSs, only you. As soon as the OP states PQR, SWPSs are out the window, they cannot be supplemented with PQRs.
You may be SURE of yourself, but you are off topic.

 

[r6155]

Perhaps you have never performed or witnessed a step-by-step PQR in the workshop.
Sorry.

Regards

 

[david339933]

I have witnessed many PQRs, however, the Code is clear. SWPSs cannot be supplemented with a PQR. You also have to follow the SWPS as written, there is no reduction in preheat. You say, everything is related......not SWPSs and WPSs. Instead of admitting your mistake, you grab onto SWPSs as a way to save face. SWPSs are irrelevant to this thread.

 

[r6155]

You say that you first do the PQR and then complete the WPS.
That's what's wrong.

Regards

 

[SJones]

@r6155 are you pointing out the need for a pWPS?

https://www.twi-global.com/technical-knowledge/job-knowledge/welding-procedure-039

The pWPS can be subjected to amendment based on the specific data from the test welding.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[r6155]

Thank you SJones.
Yes, good article from TWI
This is similar to ASME IX ARTICLE V STANDARD WELDING PROCEDURE SPECIFICATIONS (SWPSS)QW-500 to QW-540.

Regards

 

[DekDee]

r6155
Now we are getting even more off topic.
pWPS's are applicable for BS/EN/ISO applications.
They are not applicable for ASME IX applications which is clearly what the post is about.

I fail to see how they can be similar if one is a preliminary WPS (pre-PQR) and one is a WPS based on a qualified PQR.

STANDARD WELDING PROCEDURE SPECIFICATIONS (SWPS)
(Excerpt from AWS B2.1/B2.1M:2021)
All SWPSs are supported by procedure qualification records (PQRs) which meet the rules of AWS B2.1 and which in addition are intended to meet the rules of the major codes which govern the intended applications such as .....Section IX.....
The data to support a Standard Welding Procedure Specification are derived from procedure qualification records (PQRs) generated by the B2G Subcommittee on Procedure Qualification Records and PQRs received from industry and government agencies. For all committee generated PQRs, the welding, testing, and evaluation are performed under the direct supervision of the B2G Subcommittee.
The purpose of this policy is to restrict the WPS to a high probability of successful application by all users. In judging the extent of such restriction, the Committee is guided by the number and scope of the supporting PQRs, including the specific material, thickness and value for each welding variable used for the development of the PQR, and by known fabrication experience. The minimum number of supporting PQRs required by the Committee is two but is usually in the range of two to fifty, the specific minimum number being a Committee decision for each WPS. It is the intent of the AWS B2 Committee to have SWPSs only for commonly welded materials and common manual and semiautomatic welding processes.

(Note: PQRs are not available to the purchaser of the SWPSs. The PQRs are deleted after validation)

SWPS's are created by an AWS committee utilising multiple PQR's - your comment that a WPS comes before a PQR is ridiculous.

 

[SJones]

@DD - pWPS is applicable to ASME IX if the end user makes it so. There has to be something to make test welds with.

https://www.iogp.org/bookstore/product/s-705-welding-of-pressure-containing-equipment-and-piping/

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[DekDee]

SJones,
Totally understand but pWPS has zero, zilch, nada, nothing to do with what the conversation is about.
ASME IX QW 406.1
All you have done is made R6155 think he has support in his hare-brained assertions.

Lets clear this up once and for all.
If working to BS/EN/ISO or Client requirement - pWPS then PQR then WPS.
If working to ASME IX - PQR then WPS

You say that you first do the PQR and then complete the WPS.
That's what's wrong.