Is the WPS worthy?

[larry329]

Hello all. I have a question concerning a section 9 WPS. The WPS lists the parameters of the GTAW from P-8 group ALL to P-8 group ALL. The PQR supporting the WPS was tested using 304 base with 308 filler. The actual welding was done using 304L with 308L filler. The welding engineer is saying that the procedure can not be used for this welding. I am lost without section 9 code book. He says there is a change is essential variables, but both base and fillers appear to be in the same groups. Any help would be appreciated.

Thanks
Larry

 

[XL83NL]

I think he's not correct, but I dont have a copy of sec IX at hand to check.
Get yourself a legal copy of sec IX. If you work to sec IX, it is absolutely important to master the code AND have it at hand.
Furthermore, ask the welding engineer for a reference where he bases his remarks on.

 

[larry329]

Thanks XL. I'm mainly working to API 1104 with the exception being this hiccup. I'm trying to get my hands on the Section 9 without spending $400+. I've not talked with the engineer, but my chief is being the go between, between the project manager and the engineer. All I know is he has mentioned Article 2 of Section 9 and essential variables. We are having conference call in morning and I have no ammo. He is not saying the WPS was written incorrectly, just that it don't work for the base and filler metals.

Larry

 

[metengr]

Your WPS can be used for the P-No 8 base material and filler metal combination per the 2013 Edition of ASME Section IX.

 

[denlow60]

Larry329,

this is watt Section 9 said about metal.

QW-403.1 A change from a base metal listed under
one P‐Number in Table QW/QB-422 to a metal listed under
another P‐Number or to any other base metal. When
joints are made between two base metals that have different
P‐Numbers, a procedure qualification shall be made
for the applicable combination of P‐Numbers, even though
qualification tests have beenmade for each of the two base
metals welded to itself.

 

[larry329]

Thanks guys for your help. I can only believe that the WPS is perfectly acceptable to use. I was hoping someone would have a reason why it was not acceptable, maybe something I was over looking.

Thanks
Larry

 

[jwhit]

The only issue I can see is if the supplementary essentials come into play due to an impact requirement, which involves a change in filler classification. Other than that, I think you are good to go. The 308/308L filler metal is often dual certified to both classifications since there is no real difference other than maximum carbon.
I think I would restrict the procedure to Groups 1 & 2 since there is a change in A No.'s involved with Groups 3 & 4. That may actually be his complaint.

 

[weldstan]

The PQR supports the production welding. The WPS should be amended to specify the welding filler metal(s) to be used for the base metal grade(s) to be welded; as long as, impact testing is not required.

 

[GenB]

I know that books are expensive but without them we are blind. It hurts (my pocket)when I got power-piping latest edition... and forged fittings. just a few pages costs a lot. I got my money back in the first job.

 

[gtaw]

The engineer's concern may be that the WPS is not specific on what filler metal is to be used with various P8 base metals and combinations. I see WPSs written to Section IX that state 'All P8 Base Metals" for the acceptable base metals and then the WPS lists "All F6/A8" filler metals for acceptable filler metals and A numbers. That leaves it open for the welder to use filler metals that may not provide sufficient ferrite to prevent micro fissuring or that do not provide a good match for corrosion control.

It is pretty easy to write a WPS that "meets ASME Section IX" that are nearly useless for production or worse yet, can not be used for production.

ASME takes the position that the person writing the WPS knows what he/she is doing. Unfortunately, in some instances it is not the case. It is unfortunate that many engineers write the WPS for other engineers and forget the welder is the person that has to use it.

I usually develop a matrix of base metal combinations and the recommended filler metal to provide matching mechanical properties and mitigate the potential for corrosion. AWS D1.6 provides a table with just such information that can serve as a starting point.

Best regards - Al

 

[larry329]

Thanks for everyone's feedback. The ultimate conclusion was in the filler. The change in AWS filler classification from 308 to 308L, constituted a change in essential variables. I am definitely flying blind without the law book. It seems like a technicality that shouldn't hold things up. Lesson learned.

Weldstan wouldn't the PQR have to be re-qualified using the 308L? Impact test were actually performed with the PQR on the 308 filler.

Thank
Larry

 

[gtaw]

A change in the filler metal classification is a supplemental essential variable. I am surprised the WPS is qualified with notch toughness requirements. Notch toughness usually applies to carbon and high strength low alloy steels. See if your application actually requires notch toughness testing.

Best regards - Al

 

[jwhit]

If there are no impacts involved the procedure should be good, filler classification is only a supplementary essential. Regardless, it is good practice to do a matrix of what filler metal is acceptable for what base metal. I do my P8 procedures that way and haven't had an issue.
In regards to impact testing, it isn't unusual for us to see an impact test requirement, primarily for CF3M/8M castings (316/316L) with testing at anything from room temp. (utterly ridiculous) to -320F. Many years ago, I did some impacts at -400F. Needless to say, I qualify my P8 procedures at -320F and include a notation stating that impacts only apply to the specifically qualified materials, ferrite controls for the filler metals are also included as part of the procedure. Some applications require ferrite of <5FN others are 6-12, while other times 5-20FN is required.

 

[larry329]

Al I am new to working this close with the PQR/WPSs. I was always given the correct procedure before welding started, but not on this job. I should have demanded it instead of asking politely, another lesson learned. My attack will be different from here on out. I looked at the F and A numbers on the fillers, they matched and the base metals both P8 group 1 you would think we was good to go.

My understanding was the PQR was developed for a NGL facility job in WY and due to the colder working temperature and the air temperature that the impacts had to be performed. From the meeting I also learned that the impacts were necessary on the current job that I am working. I'm a CWI, but far from a expert in metallurgy.

Corrosion is not a factor, so using 308 electrode instead of 308L sounds like a good solution if the welds had not already been made.

This is a great learning experience.

Thanks
Larry

 

[larry329]

Jwhit I'm with ya. Really -320?? My mistake not having the correct WPS or not understanding the supplemental essentials coming in to play with the imacts.

I haven't written a procedure, but will consider many of these factors when the time comes or if this one gets re-written.

Thanks
Larry

 

[weldstan]

If you had data indicating that the weld filler metal was dual certified, you would not need to requalify. If not, you will need to impact test qualify only test the deposited weld filler metal, assuming the 304/304L base metal is exempt from impact testing per the MDMT and governing Code. You may need multiple thickness qualifications depending on the thickness range of the materials to be welded.

 

[jwhit]

I would follow Weldstan's suggestion if you have to re-qualify to cover impact testing. Weld a plate for impacts only per the current procedure and test at the requisite temperature. Also, if you have the certs or at least lot numbers for the lots/heats of filler metal used and the composition is acceptable for dual certification, I would ask to your supplier to request a cert from the manufacturer referencing both 308 and 308L. Most of them will be happy to help you out. That should clear the problem for you without having to go through welding and testing.
Larry, don't feel too bad about not understanding how variables work. I've learned a lot of hard lessons because of lack of expert guidance and having the task thrown at me with a "you figure it out". It isn't an easy row to hoe. To make it even worse in my case, I end up having to justify every issue that comes up in regards to procedures to people who have never looked at a code book and have decided the rule doesn't apply to us anyway.

 

[weldstan]

The Code of Construction governs impact test requirements. If the MDMT is > -150 F, impact testing is not required under ASME B31.3. The WPS qualified with impact testing can be used for pipe/vessels under ASME VIII or ASME B31.3 where impact testing is not required.

 

[Hansac]

The original poster is having the same issue with me, except that both I and the other party in my case have access to ASME IX but we differ in the understanding of QW-423

I realized now the problem is this, quite a number, if not most, of so-called "welding engineer" or "welding specialist" or welding inspector (CSWIP 3.1 or 3.2) do not have a formal training in ASME Section IX.

CSWIP 3.1 does not teach ASME Code.

When I took my CSWIP 3.1 in 1999 and 3.2 in 2000, we used API 1104 as base code.

Therein lies this confusion.

Had these so-called experts in welding go to a reputable class in ASME, they would have been taught properly the correct understanding of QW-423.