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Up Topic Welding Industry / General Welding Discussion / Pre- qualified wps
- - By gm hdec Date 04-12-2017 04:40
Can we use prequalified WPS for production welding?
Parent - - By Lawrence (*****) Date 04-12-2017 11:09
Hi GM

Prequalified WPS's are designed for exactly that!   Production :)

Having said that, The term "prequalified" usually lends itself to one of the AWS "D" Codes... Such as D1.1, or D.16.   Some specifications and codes allow the use of prequalified WPS's and some don't.

Even when Prequalified WPS's are allowed, they must be written by an expert that can be sure that the parameters, joint configurations, shield gasses if any, and other essential variables are within the scope of the code, and the production work.

Tell us more about your project and you may be able to get more clear guidance.
Parent - By gm hdec Date 04-12-2017 12:10
Thank you, Lawrence
Attachment: AWS-WPS-015pdf.pdf (302k)
Parent - - By welderbrent (*****) Date 04-12-2017 13:27
The answer is 'YES',  IF you are working to a code that allows and provides for such usage.  You can't go to D1.1 and develop a Prequalified WPS for use to D1.4 on rebar.  D1.4 only allows for ONE prequalified joint, fillet weld around the end of a rebar stood up on a plate, W shape, etc.

It would really help if you would at least tell us which code you are working to and if possible a slight description of what it is you are trying to accomplish. 

Of course, the more information you can get us the better: welding process, applicable code, welding position, base metal classification, filler metal classification, joint configuration, etc. 

He Is In Control, Have a Great Day,  Brent
Parent - - By gm hdec Date 04-13-2017 10:22
Thank you
Parent - By 803056 (*****) Date 04-16-2017 13:35 Edited 04-16-2017 13:39
Just a couple of observations:

DCRP is no longer considered standard terminology. DCEP or DCEP is the preferred designations for polarity used with direct current.

Post Weld Heat Treatment - yes or no, leaving a blank or "_" doesn't provide the information required.

Inclusion of the table showing matching filler metals should be limited to the filler metals listed by the WPS. Inclusion of filler metals used with other processes is misleading and confusing. In short, eliminate the table listing matching filler metals. You have already limited the welder to E7016 and E7018.

The preheat table you included is for welding with electrodes that are not considered low hydrogen. Both E7016 and E7018 are low hydrogen provided they are stored properly. If they are not stored properly to maintain their low hydrogen characteristics, they are not in compliance with D1.1 regarding prequalification and the WPS needs to be qualified by testing in accordance with Clause 4.

Your joint details do not include prequalified fillets or skewed T-joints.

You could include more specific detail regarding when backing and back gouging must be used, e.g., "CJP groove welds welded from one side are required to utilize backing. CJP and PJP groove welds welded from one or both sides do not require a separate backing. CJP groove welds welded from both sides shall be back gouged to sound metal before welding the second side. Back gouges shall comply with the geometry of a prequalified J or U-groove."  

You didn't fall into the trap of trying to conform your WPS to a single page format. Good job.

Happy Easter - Al

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Up Topic Welding Industry / General Welding Discussion / Pre- qualified wps

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