Connecting Filler Metal(s) to a PQR/WPS

[JooeeyyB]

So I've been a CWI for a couple years, but haven't dabbled much on the technical sides of things. That being said, my question is how do you directly link a qualified PQR/WPS to a filler rod or more importantly multiple filler rods? I was told it goes hand and hand with section II, but either I'm missing an important step or just not getting it? Can anyone please elaborate on this for me or at least guide me in the right direct...

 

[metengr]

Not sure what you mean with linked. Each WPS/PQR should have one or more filler metals identified by an SFA or other designation.

 

[JooeeyyB]

They do have a SFA number, but do you have to use the exact filler metal noted on the WPS or can you venture away from that specified filler metal on the WPS as long as its still the same SFA number?

 

[metengr]

No. You should review ASME Section IX, Welding Procedure Qualification and essential variables - look at filler metal variables listed for each welding process. You identify filler metal on a PQR and WPS by F-No, A-No and SFA or AWS classification. A good example of multiple filler metals is a P-No 8 to P-No 8 WPS where you can qualify a range of austenitic stainless steel filler metals with one on a WPS with a supporting PQR.

 

[JooeeyyB]

Hmmm...ok. Thank you for the quick response.

 

[gtaw]

As noted, there are several essential variables associated with the filler metal. The PQR test assembly is welded with a particular filler metal that is assigned a F number. The resulting weld deposit will have a particular chemistry, which will fall into an A number grouping.

The WPS used for production can include any filler metal classification that has the same F number ( an essential variable) and provided the weld deposit chemistry falls into the same A number group (an other essential variable).

Now, the A number can be based on the A number as determined by the manufacture (when they qualified the filler metal) or on the actual deposit chemistry. Considering the F number for GTAW, FCAW, SAW, etc. for ferrous metals is grouped as F6, one must differentiate between the different filler metal classifications by the chemistry of the filler metal.

The filler metal specification will be the basic means of differentiating between the welding processes.

SFA 5.9 (F-6), ER316 (A-8) any filler metal classification meeting A-8 deposited chemistry is fair game.
SFA 5.18 (F-6), ER70S-3 (A-1) any filler metal classification meeting A-1 deposited chemistry is fair game.

However, while permissible by code, one would probably be more discriminate when selecting the filler metal to try to match the chemistry for improved corrosion resistance. If one was to weld a ASME SA240 type 304 with ER308, the chemistry is a better match than if one used ER316.

Best regards - Al

 

[pradipgoswami]

Hi Jooeeyy B,

Within the same SFA No or A No, client may insist on a specific make or batch of welding consumable depending on the criticality of the component being fabricated. Say in offshore fabrication of DSS/SDSSs components many clients are restrictive on brand and if required Batch No of welding consumables used. In many instances,the consumable(brand & batch)used for PQR should be used on the job.

In absence of such specific requirements SFA No and A.No requirements/Equivalence as per Sec-IX should be the deciding factor.

Thanks.


Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario,Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299

 

[JooeeyyB]

Sorry for the lag in response, but thank you guys for taking time to help better explain the issue I'm having. I will be putting my nose into section XI momentarily...Thanks again