PQR Help!

By Todd Bitter (*)

Date 08-22-2002 20:59

Sorry, D1.5

By kpauley (*)

Date 08-22-2002 21:50

I believe all that's required is the classification and specification. If it conforms to these who cares who made it. I would want conformity reports though.

By DGXL

Date 08-22-2002 23:58

Table 5.3 of the AWS D1.5:2002 does not delineate a change in the electrodes' manufacturer as an essential variable for FCAW or any other process.

BUT, it is not uncommon for project specifications to require (re)qualification if an electrode manufacturer is changed. Check your specs.

It is becoming common place to requalify for structual applications despite the compliance to the same electrode specification and classification.

By Todd Bitter (*)

Date 08-23-2002 15:48

Thanks alot for the support. I am dealing with the MNDOT and they are telling me that if it was D1.1, I would not have to re-qualify but, sence it is D1.5 I would. The job spec does not address this. Thanks again for the support..Todd

By chall

Date 08-23-2002 17:55

Todd, We deal with a number of State DOT groups on the East Coast, at our fab shop (CHGuilford is the QC Manager). He is out this afternoon, but perhaps he will comment on this later. From what you describe, it is very likely a State imposed rule. For NYDOT we have had to qualify an significant number of PQRs for things already qulaified IAW D1.5. In one instance, the all weld metal tensile value was too high and they sent us back to the booth. If the spec is simply D1.5, have him show you what he is refering to. Charles Hall

By DGXL

Date 08-23-2002 23:07

Todd:
Did you ask MNDOT to site their qualifier for this requirement? In other words, is this a verbal requirement or a contractual requirement?

By bspeirs (*)

Date 08-25-2002 03:28

Maybe not relevant here, but NACE also has a requirement for qualifying welds by manufacturer and wire type/brand if it is to be used in H2S service - I think it is NACE Mr-0472. There can be a large difference in weld hardness (sour cracking susceptibility) with FCAW. EWI also has some literature/tests on this variance.

We would get a qualification done if there was a switch from ESAB 'Ultra' (E71T-1) to ESAB 7100LC (also same E71T-1 spec)

By Todd Bitter (*)

Date 08-26-2002 14:17

DGXL
I believe he was looking at the WPS requirments and not the PQR. I am working as a outside inspector so I am giving the fabricator a chance to work this out. As of this time we wrote a new WPS for the different mfg. of the wire and work is in progress. Thanks to all for the support....If I fined out anything different I will let you all know....Todd

By CHGuilford (****)

Date 08-26-2002 17:56

Take a look at D1.5 Table 5.1 and the commentary to it. Those combined with other sections like 5.12 indicate that if you change electrode manufacturers the WPS needs to be qualified (PQR). At least for FCAW wire and SAW fluxes. Apparently, solid electrodes such as for SMAW, GMAW, and SAW don't need requalification as long as they comply with the classification. See the Gen'l Notes for Table 5.3

As Charles Hall mentioned, we have run several PQRs for NYSDOT because of variations in the required AWMT results. They have a maximum yield requirement that we had problems attaining with our usual consumables. Ours was consistently too high. We tried several other wires of different manufacture of E71T-1 and found varied results in CVNs, yields, and tensiles. Shielding gases (100% CO2 and 75%Argon/ 25% CO2) also gave markedly different results.

So from what I have experienced, and depending on what you are welding, there may be good reason to run a PQR anyway.

Have fun,
CHGuilford

By BankerQC (*)

Date 08-26-2002 19:12

Also be advised that some DOT's also have lists of qualified electrodes that must be adhered to if the mfg'r does not want to run the PQRs.
Also seems that i read a post here several months ago regarding this and advising the use of the aws spec. and classification instead of the electrode makers trade name.

By Todd Bitter (*)

Date 08-26-2002 19:39

Just got off the phone with David McQuaid, Chair/AWS D1. It is required to run a new PQR due to the fact that fluxes are so much different from mfg. to mfg.. CHGuilford reply was basicly what David stated.....Todd

By DGXL

Date 08-27-2002 00:56

Good catch CHG. I see I am becoming a creature of habit. This is dangerous for inspectors, relying on information we thought to be accurate in the past. This info has been right under my nose. RATZ.

Over here in the west, CalDOT started enforcing the code after the Northridge earthquake. I've been asking their representatives for the last 6 years where the bridge code specified this requirement, and none of them knew where it was in the code book, only that it was a requirement.

We ran some tests 2 years ago with various FCAW-S electrodes and found many interesting results:

> Not all FCAW electrodes combine with each other. This includes electrodes within the same classification.
> Not all FCAW-S electrodes combine with SMAW electrodes (and vice-versa).
> Some electrodes required substantially more skill to run, while others were very user friendly.
> Many structural engineers here in the west (seismic zones 3 & 4) also have this requirement in their specifications, but aren't sure why they require it (?).
> Some engineers have become so confused about what electrodes can be used for bridges or cyclycally (and static!) loaded structures, they prohibit the use of FCAW period!

Glad I don't do much of this type of work any more...

By CHGuilford (****)

Date 08-27-2002 13:25

DXGL,
Glad to have been able to give a good answer. Actually, it took me a while to find the Table 5.1. Whenever we run PQRs, Section 5 is very clear in my mind. But as soon as we finish up, it all turns to mud so I have to research the info all over again. Funny how it works that way.

As you noted, many engineers prohibit FCAW because of the wide variations and lack of confidence. I would hope instead of restricting FCAW that they would allow filler metals that are tested and proven.

CHGuilford