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Up Topic American Welding Society Services / Certifications / Part B Confusing Question
- - By Maks Date 12-05-2016 02:32
Hello,
I've been working on practice questions for the new Part B.
Given: In WPS: Amp range:180-350A and WFS:150-300. In the PQR: Amps: 165-225A, WFS: 250-260.
Question: Is requalification required?
My answer is "yes". Because assuming the same voltage, the higher end of the amperage per WPS will cause an increase in heat input.
Heat Input per WPS: 25*350*60/300=1750J/inch.
Heat Input per PQR: 25*225*60/260=1298 J/inch
The potential HI per WPS is significantly higher than the one in PQR. The HI is a variable in Table 8.
Correct answer per Answer Key is "No. The AMPs and WFS are not variables in Table 8"
Which answer is correct?
Please advise.
Thanks
Parent - By pipewelder_1999 (****) Date 12-05-2016 11:35
One thing to understand regarding heat input is that it is controlled during welding and the value is listed on the WPS. Because ranges for Amps/Volts/Travel speed may allow for settings that exceed the max heat input.

However your formula should be
Heat Input (Joules per minute) = (Volts x Amps x 60) / Travel Speed (IPM)

You are using the Wire Feed Speed which has nothing to do with calculating heat input.

Regardless, I may very well have a WPS in which heat input is required to be controlled yet the right "mix" of variables within the ranges allowed could result in not meeting the requirements. As the welder and inspector, I would need to verify that the ranges used DURING PRODUCTION are within the heat input requirements of the WPS.

I am not familiar with the specifications related to the new part B so their may be some other limiting factor to consider but your travel speed value is outta whack regardless.

Hope this helps.

Have a great day.

Gerald Austin
Weldingdata.com
Greeneville, Tn
423-914-1481
Parent - - By welderbrent (*****) Date 12-05-2016 17:09
Why are you 'ASSUMING' anything?  Never assume anything especially on the exam. 

Next, why are you looking at heat input?  Where pray tell did they make that part of the consideration? 

NEVER EVER make more of the test than what is there.  Use only the information provided to you.

Obviously, WFS is in the allowable zone. 

Amps is way outside the PQR... BUT, according to what you posted, Table 8 in Part B does not include Amps nor WPS as variables.  SSOO, the simple answer is 'NO' , requalification is not required. 

He Is In Control, Have a Great Day,  Brent
Parent - - By 803056 (*****) Date 12-05-2016 19:25
First, your question makes no sense. "Is requalification necessary?"

Are you asking whether the WPS needs to be requalified or does the welder have to be requalified? Two totally different questions requiring different considerations.

Be sure to determine whether the question is dealing with procedure qualification or welder qualifications. That will determine what variables are considered to be essential variables. the essential variables, if changed or if changed beyond permitted ranges will require requalification of the WPS or the welder.

Next, you need to look at the answers provided to give you a little direction. You can use the process of elimination to discount at least two if not three of the five responses provided.

Good luck - Al
Parent - - By jwright650 (*****) Date 12-05-2016 20:21
"Be sure to determine whether the question is dealing with procedure qualification or welder qualifications. That will determine what variables are considered to be essential variables. the essential variables, if changed or if changed beyond permitted ranges will require requalification of the WPS or the welder."-Al

The exam writers love to try to trip you up with WPS vs Welder qualifications and which set of essential variables are to be used for various things. I have run into that very thing when discussing different views of opinions in the field among inspectors. It shouldn't be so, but I have discussed/argued with very seasoned CWIs over these same types of issues.

ie. Welder qualified on 3G & 4G 1"coupon with E7018 with an A/C machine and the proper WPS back at the office. A CWI (with a "79" in his certification number) on a job threw out the welder's certs. and told him not to weld on the job until he was recertified on a D/C machine. I tried my best to lead the seasoned CWI by the hand and show him the path through the code and read out the essential variables regarding the welder, but he refused to listen and said that guy will not weld on his job.
Parent - - By 803056 (*****) Date 12-05-2016 20:52
Interesting on two counts. First it is the Engineer's responsibility to either accept or reject the welder qualifications. A review of D1.1 will reveal the verification inspector has little or no responsibility to review, accept or reject a welder's qualifications.

Then, remember, one only needs to score 72% correct to pass the CWI examinations, To say one mastered the subject matter with a score of 72% is a stretch to say the least. Just image the mistakes he's made over the last 30 plus years. Clearly he isn't the brightest light in the bunch.

From what I can tell, his only authority under the auspices of D1.1 is to request a requalification test if the welder is producing unacceptable welds.

I would requalify the welder and send an invoice to his employer because he is overstepping his authority under D1.1.

Now, if the verification inspector is given or assigned additional responsibilities by the project specifications, I would concede.

Al
Parent - - By jwright650 (*****) Date 12-06-2016 18:37
I came to the conclusion, after lots of wasted breath, that this guy made up his own rules as he went. Everything about the welder was in perfect order according to AWS D1.1. I lost no sleep over it,  however it was frustrating dealing with that situation.
Parent - By 803056 (*****) Date 12-07-2016 02:18
It is the 10-80-10 rule at work once again.

Al
- By Maks Date 12-07-2016 04:47
Thank you all for your input. Each of your answers helped in understanding the question.
The question was regarding possible requalification of the WPS, not a welder, but it was a good point to remember.
And yes, I did confuse wire feed with travel speed in calculating the heat input. Even if travel speed were given, I still shouldn't have assumed any heat input, because the heat input itself is a controlled variable in WPS.
Thanks
Maks
Up Topic American Welding Society Services / Certifications / Part B Confusing Question

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