Tuesday, September 29, 2015

WPS & PQR for Dummies

Hey Paul,
I'm reading up on the proper procedure and practices for developing a WPS and PQR, my question is, do you know of any resources that give a sort of 'WPS & PQR For Dummies'.
At current I'm reading through section 4 of D1.1, and taking notes as to what is required. The process we'll be qualifying is an in house change (bevel angle, and a slight change of amperage and travel speed.) that will be implemented into production.
From my limited perspective I'll be writing down the proposed values on the PQR, send it out for testing, if it comes back with a passing marks, I'll used that information to create a WPS.
However, on the PQR forms we have here, there is a line for "Governing WPS"...something about your seminar mentioning "Which comes first, WPS, or PQR" comes to mind, however I'm unable to to more than remember that idea.
Any help on the how-to is much appreciated! And also, do you have some sort of donation or fund in your name? I feel guilty asking for your assistance without some way to pay you back. If you've any ideas, let me know!
Thanks again!
Neil

Hey Neil,

WPS & PQR for Dummies… I like that.
You may find AWS-B2.1 helpful (https://pubs.aws.org/p/1245/b21b21m2014-specification-for-welding-procedure-and-performance-qualification).
Start by writing a “Preliminary WPS” (This could be considered a “Governing WPS”).  This isn’t a real, qualified WPS, it is simply a list of what you’d like your final WPS to look like.  Write each of the essential (and non-essential) variables, as you would like to see them.  Then work backwards to figure out what PQR(s) you’ll need to qualify them (notice, it could be several).
Starting with a Preliminary WPS helps keep you on track and keeps you from making the common mistake of finishing all your testing and concluding with an, “Oh Crap!... (insert problem here)”.  Problems like, “I should have used a Group II steel.” Or “I should have dropped the plate temperature to 50 degrees before starting the root pass (or fill pass).” Or “What was I thinking using a 4 in. pipe?” Or “I should have used a square groove.”  You get my drift.
Once you have a Preliminary WPS, break down each variable and ask yourself,  “What do I need to do to achieve that?”
Chances are your finished WPS will have greater ranges than your Preliminary because you’ll be working with real data.

As for your specific need (bevel angle, and a slight change of amperage and travel speed).  You may find that your original PQR already qualified the joint and parameters to within the ranges you are shooting for.  If so, you simply have to revise, or write an additional WPS.  If not, just go through the steps I laid out above.

This line kinda creeps me out, “I'll be writing down the proposed values on the PQR, send it out for testing, if it comes back with a passing marks, I'll used that information to create a WPS”.
That sounds a little, just-throw-it-over-the-wall-ish to me.  Let me break it down…
You’ll be:
• Writing down the proposed values
• Taking them to the Welder/Technician for feedback
• Observing, measuring and documenting as those proposed values are utilized
• Determining visual acceptance
• Sending the weldment out for NDE and destructive testing
• Reviewing the test results for compliance
• Using your collected data to develop a WPS
You have to be the one insuring every step was followed.  You’ll need to wear the welding helmet to insure technique was correct.  You’ll need to insure the final weldment met the acceptance criteria before NDE/Destructive testing.

And finally (and most important) yes, I have a GoQuenchMe campaign that runs continually.  You show up in my part of the country or I show up in yours and you have to buy the first round.  I believe in keeping it simple.

Cheers!
PWC

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