Saturday, December 13, 2014

Repair WPS

When codes refer to a company having a "repair WPS", are they saying that a different test needs to be qualified other than the procedures that have already been qualified?
If this is the case, would you record the NDE, hold points, etc. that are required in the WPS? Sort of like, these are the steps and sequence of events that are required to take place.
Timothy C. CWI, CWE

P.S, Thanks for the time you've taken over the years to let us ask, argue, talk through, and debate all the issues we come across. It only makes us better at what we do.

And all this time I thought I was the only one that would get up at 6am on a Saturday with welding on the brain (I happened to be calibrating my UT scope when I got your email).
Let me concentrate on your first question as it would relate to AWS D1.1 (because you are right, the Bridge Code is more specific).
D1.1 requires a repair WPS, why would they state that? 
In most manufacturing environments we would have specific WPS’s for specific joint configurations, materials, positions welded… Let’s imagine the company "PWC Weld-All" had WPS's for all position, unlimited thickness, Base Metal Group 1 & 2 for Lap, T- (fillets & grooves), V-, Bevel and Square Groove Joints.  Your first impression would be that PWC has his shit together, right?  Now let's say PWC hired his brother (because his Mom made him) to punch bolt holes in steel with an Iron Worker.  Who could mess that up?  Well, his brother did and now you’ve got four 1- inch holes in the web of a S24x100 I-Beam.  The customer insists they be filled.  Which WPS will cover this repair?  Since the joint configuration now is a hole in a plate none of the existing WPS's will apply.  A new WPS will need to be developed which may or may not require testing (dependent on code requirements).
Here's another scenario… The base plate of a light pole tower is welded using FCAW-G.  While being erected the customers inspector finds unacceptable porosity and requires a repair.  That repair could be made using the same procedure used to manufacture the tower, but it wouldn’t be practical to use FCAW-G, in the field.  A procedure would need to be written (and possibly qualified) to complete this repair using another process (FCAW-S or SMAW). 
One last scenario… A crack in a weld is discovered in a Bevel-Groove.  The engineer determines it can be repaired.  This can typically be done using the original WPS.  While excavating you find this crack extends into base material.  Now your joint configuration will probably be outside the tolerances of your WPS, so another WPS will need to be written (and possibly qualified).
Often times the PQR's you've previously completed will cover the repair WPS, but you still need to write the new WPS. 
As the engineer I have written many repair WPS's.  When I do I will put language in there that is not typically found in a production WPS.  Things like, “Drill a X/X diameter hole at each tip of the crack to reduce the chances of growth.”  or, “Once  discontinuity is removed PT to insure its complete removal.” or, “MT each weld layer to insure soundness.” or “Never let my brother touch that machine again.”
So your repair WPS isn't anything different then any other WPS, you just want to insure that you've covered all your bases in regard to material, joint configuration, position before moving forward with the repair.

Ask me the time and I build you a watch.  Sorry about that.


Tuesday, December 9, 2014

Maybe B2.1 is the better choice...

 Hey Paul,
 It’s Kody P.  I was in your Minneapolis seminar, I was wondering if you would be willing to get me pointed the right direction for a PQR/WPS testing of pipe/tube to plate for fillets and PJP groves in AWS-D1.1?
The pipe/ tube is “unlisted” material of the following specs: A519 1026, A519 1026cw, A519 1026hr, A513 1026, A513 1026cw, (min yield is 35ksi – 70ksi grade dependent).  All are not pre-qualified or listed and the rings will be A36 or some grade of A514.  Size ranges from 2” OD tube 3/16 wall with 1/8” fillet and bevel to 20” + OD 2” wall with up to 1 ¼” fillet / bevel.  Plate ranges from 3/8” to 2”+
I know I need to do macro etches but I am a little confused as to how to get the tensile specimens /side bends for the sizes we are working with.
As of right now my thoughts are to purchase some large od tube/pipe and use that to cut coupons from to do 1G test plates to prove the process, Then do the fillets/PJP etches. If both are successful I could use both PQR’s to make a WPS and repeat for all combos. But then at that point should I use AWS-Fig. 4.10/4.11 or 4.23 for the 1G test set up?
Any thoughts or advice would be appreciated
Thank you
Kody P. Lead Inspector

It’s amazing what you run into, isn’t it?  My first WPS experience as a “green” CWI was insuring the company I worked for met all the requirements to weld carbon and stainless to ASME.  Something I had zero experience with.  (I learned a lot… one mistake at a time)
First thing I would do if I were you would be to group the A519 grades and the A513 grades (what do I mean by that?).  Just find some A519 Grade 1026 and some A513 Grade 1026 (forget about those additional designators, they don’t amount to enough to matter.).
Next: Get yourself a copy of AWS-B2.1 Specification for Procedure and Performance Qualification.  In it you’ll find that the AWS groups your A519 into Group 2 and your A513 into Group 1 (or visa-versa, I don’t remember which).
This group of PQR's could get extremely complicated if you qualify to D1.1, so don’t.  Qualify to AWS B2.1 and just state that on your documentation.  Qualifying to B2.1 can be as simple as making the weldment just as you do in production and then cutting and etching the welds to insure you meet the size and soundness requirements.  You may have to do one for each pipe size (or significant change in part size) but that is a whole lot easier and can be done in pretty short order.
I have a lot of experience in writing WPS's for “Unlisted” steels and take it from me, meeting D1.1 with materials that aren’t the same shape (ones a tube and ones a plate) sucks.  I would never advise it.
Sounds to me like you are the perfect example of why the AWS came up with B2.1
That's my advice and I'm only 1/2 a beer into giving it, so it should still be good.
Let me know what you decide.