Repair WPS

Paul,

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

ACCP Level II VT, PT

ASNT TC-1A Level II MT, UTT 

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.

Tim,

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.

PWC

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

Kody,

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).

Now…

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.

PWC

It's a Work Lead... it doesn't ground anything

Hello Mr. Cameron,

I am writing this regards to an article you had wrote about grounding/grounds. I do have some

questions in regards to said article.

First of all do you have any references to the way grounds should be connected?

Secondly you mentioned in your article that grounding to a structure should not be used if at all possible. My question in regards to this: If OSHA regulations state that it is okay to ground to structures why say no to this?

The reason I am asking is that where I am employed we use the building structure for grounding purposes and we have people who are getting shocked while welding. The material is 6061, using pulse Mig and GTAW. The machines are grounded to the structure and from said structure to said welding fixture using a jumper. In a nutshell I'm trying to find references whether they be OSHA or from some other agency in regards to grounding.

Any help or information would be greatly appreciated.

Thank you,

Chris A.

Chris,

Yours is the perfect example of how the terms "ground" and "work piece lead" get used interchangeably. This leads to a dangerous situation.

On a common welding power source you will find a + stud and a - stud. To one of these you would attach a conduit leading to the electrode (ie: a wire feeder, a stinger, a Tig torch). To the other you would connect a conduit leading to a Work Lead Clamp. The polarity required would determine if the work lead runs from the + or - stud.

In the article you’re referencing I state, "…the work place lead does not ground anything." When installing welding equipment that statement is critical to remember.

OSHA will require that equipment be grounded to protect people from electric shock. The way equipment is grounded has nothing to do with the + or - stud on the front of the welding machine. This is accomplished through the permanent power connection supplying the machine (the plug). Or by a separate clamp and wire connecting the case or frame of the machine to ground (like the building). Sometimes both the plug and one of these wire connections is used. Again, they have nothing to do with the + or - stud on the machine.

ANSI Z49.1 - Safety in Welding and Cutting will require that the work table (positioner, fixture) also be grounded. This is accomplished with a conduit connected to the table or positioner, connecting it to a "driven rod" or often, the building. Again I clarify, this has nothing to with the + or - studs.

When we use the term "ground" we are talking about protection of people and equipment. You would be much better off referring to the leads coming off a welder as an electrode lead and a work lead, or a positive lead and a negative lead, but neither is ever considered a ground.

PWC

Paul W Cameron

You’re getting your “qualified” and “certified” all cobbled together…

Hi Paul,

As I was looking through the AWS website I found accredited test facilities listings. Then digging a little deeper I found AWS QC4-89 (standards for accreditation of test facilities). I was of the understanding that given the CWI endorsement, I could certify welders to the standards laid out in D1.1.

Am I to understand that as a school, accreditation is where we need to get to in order to send welders out the door with a certification? If not, what is the accreditation good for, besides marketing?
I thought that I had a pretty good handle on where I was going with this, but now I am second guessing myself.
Once again, thanks for any clarification and/or advice you can give.

Richard F.


Hey Rich,
You’re getting your “qualified” and “certified” all cobbled together…
You may have been a qualified Welding Inspector (meaning you have the skills needed) and once a 3rd party evaluated those skills you became a Certified Welding Inspector (to QC-1).
I may be a qualified Welder (meaning I have the skills needed) and once someone evaluated my skills against a standard and found that I met that standard I became a Certified Welder (to my employer or my trade union…)
The AWS runs a Certified Welder Program (Much like a Certified Inspector, Certified Educator or Certified Supervisor).  To run a program like that the AWS would need testing facilities around the country to do the testing.  The AWS wants to keep “tight wraps” on the program to maintain the programs integrity so they developed a program to certify a facility.  So there are guidelines your facility would need to meet to become an AWS Certified Test Facility.
You can still administer welder qualification tests without being an AWS Certified Test Facility, but those welders would be certified per AWS-D1.1, not AWS Certified Welders.  There is a difference.
A Welder takes a test at your facility or at his/her employer and those test results are not transferable employer to employer.  That Welders qualifications/certifications are the property/responsibility of the company.  A Welder who goes through the steps of becoming an AWS Certified Welder keeps that certification and that certification is portable.

There ya have it.
PWC

Pinholes and Purging

UPDATE:

In this original posting I talked about common solutions to Pin Holes.  My apologies for not picking up on this, but in his question Marv B. stated that prior to welding he “tried cleaning them [the components] with Brake Cleaner”.  Welding and Brake Cleaners can be a deadly combination.

There are many warnings on the “everyday” chemicals we use.  Often, I will simply assume that if it’s sold over the counter surely it must be safe.  But the SDS (Safety Data Sheet) for a can of brake cleaner may read, “Do not use this product near open flames, welding operations or excessive heat.  Vapors may decompose to harmful or fatal corrosive gasses such as hydrogen chloride and possibly phosgene.”  This can be debilitating or even deadly to the Welder or those around him/her.

There are many manufacturers of cleaners, removers and degreasers used throughout our industry.  Most are safe when used as directed, so pay attention to the product labeling and review the products Safety Data Sheet (SDS).  Please use caution when determining how your weldment will be cleaned.  Only use approved cleaners to the manufacturer’s instruction.  Read the warnings and review the products SDS.  As my old boss used to say, “Somebody wants you home tonight.”

Thanks to Steve 'Brewdude' Garn who shares his experience on welding and brake cleaners at (http://www.brewracingframes.com/safety-alert-brake-cleaner--phosgene-gas.html).  I also want to give a special Thanks to the loyal readers that pointed my over-site. You come to us for good advice and I should pay attention to details when giving it.

PWC

**************************************
Hi Paul,
I was doing a search over the internet and came across your contact information.  If you don’t mind, can you help me with a problem?
I am machining a Bearing Housing made out of 1045.  I have to plug and weld some cross holes.  I am using 1018 for the plugs.  I am also using a tig welder to eliminate too large of a weld.  My problem is that I am getting pin holes in my weld.  Is it because I am not preheating the part.  or is it because I am welding 1018 to 1045?
We didn’t machine the parts dry so maybe there is a light film of coolant on the parts but I tried cleaning them and that didn’t seem to help.
If you could reply back that would be great or go ahead and give me a call.
Thanks!!!
Marv B.

Hey Marv,
The welding of the materials shouldn’t be a problem.
Let me ask, the machined port looks to be made up of 3 different drilling operations.  Are all 3 completed before the plug is welded in?
The reason I ask…
If the port to be plugged is drilled first (others drilled after welding) trying to weld a plug in the hole creates a condition I’ve dealt with most of my career.  When trying to seal weld the only opening in any cavity the air (or gases) in that cavity heat and expand. During that expansion a pin-hole will form at some location in the weld (just on solidification) to allow that expanding gas to escape.  Molten metal makes a poor seal 
Pipe-Welders see this same condition when finishing the root pass in a purged pipe.  If they don’t build an alternative location for the gas to escape the gas will blow through the final weld crater.
I also dealt with this condition on Flare Bevel Groove welds on a robotic application of a manufacturer where I served as Weld Engineer.  We were able to remedy that with a punched whole on the faying surface of the joint.
Not sure if this is your condition, but if you’re trying to seal the only opening, it sure could be.
Let me know.
PWC

Weld Inspection After Coating

Hi Paul,
I see your references on The Fabricator.com website and am wondering; how I can inspect/verify welds on painted product without being destructive?

Best regards,
Eric D.

Hey Eric,
On fabricated products coatings come in many types. galvanizing, paint, even the oxidizing of a weathering steel will have negative effects on the inspection of welded products.  For visual inspection (a form of nondestructive evaluation) any coating on the finished weld has the potential to mask or cover rejectable discontinuities such as size, cracks, undercut, overlap, porosity, etc…  Keep in mind, when we list defects by criticality, those that come to the surface generally top the list.  So there is risk in completing a visual inspection on any coated product.
That being said, as a CWI I’m often asked to do visual inspection on coated product.  I do, but I will ALWAYS note that the weldment viewed was coated and that coating limited the inspection.
As for other forms of NDE…
• Die penetrant (PT) would not be affective.  With die penetrants the discontinuity needs to come to the surface and the penetrent needs to enter the discontinuity through capillary action.  Any coatings would not allow that to happen.
• Magnetic particle testing (MT) does have the potential to reveal sub-surface discontinuities but that ability is limited and any coating will certainly affect its dependability.  MT will not work on your aluminum products, the material tested needs to be ferromagnetic.
• It’s not uncommon to do Ultrasonic testing (UT) on coated weldments.  I’ve performed UT on thousands of galvanized and painted products successfully.  Calibrations need to be adapted to allow for loss due to the coating, but those types of inspections are performed every day (at least in my world).
• Radiograph (RT) is another nondestructive method that would not be affected by most coatings.  In fact, RT would probably be the least affected.
So there ya’ go.  There are several nondestructive methods of NDE that can be performed on coated products, there are simply some adjustments that may be required due to the coating.  But your most affective form of nondestructive testing is visual inspection performed before, during and after welding and prior to any coating.

Ask me the time and I build you a watch.
PWC

"Put your finger on it"

Hi, Paul.
I was seeking advice from you regarding D1.1  I'm a welding instructor at a steel mill in Northwest Ind.
We were sent 12 yrs ago to Hobart welding school for train the trainer class and to certify in all positions,limited & unlimited thickness plates w/backing. All SMAW, 7018 rod. (Did not like Hobart's 7018 rod). We believed that we are Qualified to qualify welders to weld anything structural in our mill. Does this sound correct or our we missing something?
Also the big question is, does D1.1 say you have to certify to weld structural or just qualify through the testing procedure to weld structure? A new instructor is saying we have to certify I do not believe this is what D1.1 says.
Any advice would be helpfull, Thank you for time.
Thanks, Pat

Hi Pat,
Hobart is a great school and the Train the Trainer program was a great idea.
If your company accepted the Hobart documentation as your Welder Qualifications (common) and your company maintained a Welder Continuity Log (see: http://www.thefabricator.com/article/arcwelding/arc-welding-101-d1-1-welder-documentation) and as long as there is no reason to question your ability, your Welder Qualifications will continue to be current.
Although the AWS Certified Welding Educator (CWE) program would require you to maintain your Welder Qualifications, being a CWE is not a code requirement for those of us who train and qualify our Welders, so anyone your company deems competent to do so can train and qualify your Welders.
As far as qualifying Welders to weld anything structural in your mill… you would need to determine what governing documents covers the welding requirements of your mill (D1.1, D1.3, D14.1…) and insure your Welders are being qualified to those requirements.  Those Welders would need to be qualified to a (or many) test procedure(s) and the test procedures would need to encompass all of the essential variables listed in the code(s) being used.  (I know… it’s enough to make your head spin)
Bottom Line: When someone comes to me with a code requirement that I don’t believe to be accurate, my first response is to ask them to “Put your finger on it”.  Equally important, when someone asks about a code provision I would never give an answer until I had ALL the required information and I was able to “Put my finger on it” as well.

PWC

Those damn CVN requirement...

Paul,
Do you mind my asking a quick question drawing from your expertise of AWS D1.1?
Table 4.6 of AWS D1.1-2010 is a list of supplementary essential variable changes that would require WPS requalification due to CVN (Charpy V-Notch) testing requirements.  Under base metal (item 2) it indicates:

“minimum thickness qualified is T or 5/8” whichever is less except if T is less than 1/4” then the minimum thickness qualified is 1/8”

I take this to mean that to qualify a PJP groove weld of a 3/16” plate a weld procedure would have to be qualified using 3/16” thick material  (“minimum T or 5/8” whichever is less”).  Do you agree?

I had been going off of the table 4.2 where a 1” plate would qualify for a range from 1/8” to unlimited thickness.  But that table is not intended for Charpy requirements.  So I may have been wrong with using table 4.2 when Charpy requirements exist. I can see the need to qualify the thinner materials when CVN is required due to the heat input changes due to the thickness changes.  But just want a second opinion.

Thanks,
Wes

Oh those damn CVN requirement...
I currently have 2 clients that I'm working with on this issue. Your assessment of the CVN Supplement is correct.
What we advised for our client to do was to machine the test plates to a nominal of 0.230" (because I also wanted to insure I was under 6mm to eliminate any code questions). We completed PQR's on 0.230", 0.3125" and 1.0" material, that covered our range.

Other things that bite ya for CVN requirements is...
"Multi vs Single Pass": Most PQR's that are typically run are multi pass.  These multi-pass PQR's would not qualify single pass welding.
-and-
"Max. Interpass Temp": If interpass tempuratures were to be measured under 125F the Maximum qualified interpass tempuature qualified would be under 225f. This would limit Preheat Catigory A and C Steels to 1-1/2" max. and Catigory B Steels to 2-1/2" max.

Good to hear from ya Wes.
PWC

GMAW Globular Transfer

Paul,
I work at a machine shop where I am employed as a qualified welder to AWS-D.1.1. I was wondering why it is that you can certify 75% argon and 25% CO2 when you are not allowed to use a short circuit transfer on materials over 3/16". I read your article every month and in order to obtain a spray transfer you need at least 83% Argon but yet I passed on a 1 inch test piece.

Thanks K. B.

Your question insinuates that if your shielding gas mixture is not Argon rich enough to obtain a Spray Transfer mode the only alternative is Short Circuit Transfer, that's just not the case.
When using a 75% Argon and 25% Co2 mix you would not be able to achieve a Spray Transfer, but achieving a Globular Transfer would be no problem. It is quite common to complete the test you discribed (Unlimited Thickness to D1.1) in the GMAW Globular Transfer mode for all positions (3G/4G) successfully.  This is a fairly typical test commonly given in todays construction industry.  I think you will find Globular Transfer a prefered transfer mode in industries that utilize a 75/25 mix.
As for Short Circuit, when I mentioned in an earlier article, the possibility of incomplete fusion being a concern on materials greater than 3/16th inch, I prefaced that by including, "... in certain positions and progressions...".  Completing an open root limited thickness Welder Qualification in the Vertical progression (Root Down/Fill & Cover Up) is a very common transfer mode used during testing.  In fact, a test of that nature, Root Pass with Short Circuit, Fill and Cover Pass in Globular, would successfully qualify a Welder in 2 processes (GMAW-S & GMAW) in a single test.
That would be a good Welder Qualification to have in your wallet.
PWC