QN 1: I qualified a PQR using 3.2/4.0mm electrode. But I want to use 4.8mm electrode in WPS how can I derive the parameters like Amps/Volts/Travel speed-PQR qualified with impact test.

Response: Assuming you are talking about SMAW Process, see what manufacturer's recommendations are for Amps / Volts. Use your Heat input formula: A*V*60/TS to see where the numbers come in regarding travel. You might have to play with it a bit. These are not "Code Rules" but rather on way to derive where the numbers will come in.

QN 2: Any suggestions how to set the ranges in WPS? (PQR actual values for example Amps 110-160 volts 18-28 travel speed 72- 110 mm/sec) is there any tolerances for this parameters applicable as per section IX. (like +/- 10% etc)

Response: Again no code rules, assuming SMAW (provided heat input isnt exceeded) and provided your not doing Hardfacing or Corrosion Resistant overlays, which would impose + / - 10% (QW-409.22). Always check the manufacturers recommended parameters and / or SFA listings.

Neither of the above responses are "Code" type responses but good practice.

Max. heat input of your WPS shall be not higher than min. heat. input of your PQR. You only may increase speed, I presume, but you better don't use rod dia. higher than the smaller of the one used in PQR. Think about this when you will make next PQR with impact testing.
Mauro

MR GONZAGA,

If the heat input is 1.5 - 2.8 KJ/MM in PQR test run, why I don't i use the max heat input in the wps as 2.8 KJ/MM. And electrode size is not an essential variable. If i can limit the heat input in production can I use the higher size electrode?

Mauro;

"Max. heat input of your WPS shall be not higher than min. heat. input of your PQR. You only may increase speed, I presume, but you better don't use rod dia. higher than the smaller of the one used in PQR. Think about this when you will make next PQR with impact testing."

Is it a typo when you say not higher than min. heat?

If not, can you please explain?

As I read the SEV's, I don't see rod diameter as a variable, unless exceeding 1/4" or 6 mm? Depending on the heat input qualified, it seems to me it may be possible to increase rod size.

I do not aunderstand this. If the actual heat input values are 1.8 to 2.4 KJ/MM? can I use Max heat input values as 2.4 KJ/MM in WPS or not?

H.I. in WPS shall not be higher than the lower H.I. in PQR.
H.I. is a supplementary variable (valid when impact testing is concerned) see QW-499.1. It is conservative not to exceed the minimum because you may weld your test coupon with 10 weld beads having H.I. of e.g. 70 KJ/mm and 2 cap weld beads having 100 KJ/mm. You will not allowed to perform your production weld with an H.I. of 100.
Or, if you prefer, if the impact test specimens have been taken in the lower H.I. area with a satisfactory result, this does not guarantee that the same satisfacctory result may be obtained in the higher H.I. area.
The diameter of the rod is not essential nor supplementa variable, but, at a larger diameter corresponds higher current and therefore higher H.I.
I know you can increase speed but usually in SMAW process it is not possible to increase speed so much to maintain same H.I.
mauro

Mauro;

Your interpretation of not permitting a heat input on the WPS as the LOWEST input recorded from the PQR is new to me, and I do not agree with it.
QW-409.1 is not as restrictive as your interpretation, at least in my opinion.

Like all of us, when performing PQR with impacts required, I record each and every "segment" of weld deposit. I then evaluate the highest, lowest and determine mid-range. The Mid-range is where I normally try to establish my parameters but I do list both the lowest and the highest range on my WPS.

If I wish to amend my WPS to use a larger diameter rod (not to exceed 1/4" or 6 mm), I then look to my recorded variables to see if it is possible to use the larger rod within the heat inputs.

I'd like to have other opinions if you think this is incorrect application of code?

Do you mean that you record sections of weld and relevant parameters (H.I.) and than make impact in these sections? And that, if impact value in any of the sections is not acceptable, then you will not use those parameters in your production WPS? Then I agree. But I don't believe you will do so. Otherwise, believe me, my interpretation is the correct one and it is better you follow it in your Code work, if your Company has a Certificate of authorization.
Good luck, Mauro

Mauro

I do record sections of weld and relevant parameters (H.I.) and than make impact on the ENTIRE coupon(s), as required by constructing code. If impact values are found not acceptable, then I will not use those parameters in my production WPS. This is true.

On my WPS, I record the highest and lowest H.I. values from the PQR(s), after assuring that none of the parameters listed (amps, volts, travel) will permit the HIGHEST value to be exceeded.

I worked for many years as the Principle Welding Engineer for several Certificate Holders and have never had any AI or ANI or Customer question these practices, so if we still disagree, then so be it. I am now working under auspices of ASME B31.3 and find it a welcome change.

Your explanation sounds reasonable. It deserves consideration. Consider the supplementary variable as an essential like e.g. welding method. Code (Sect.IX) requires all welding methods be represented in the test coupons (not necessarily a test per method). Your test coupons, as I understand, do it, because in the same coupon there are lower and higher H.I. I am open to discussion and other's point of view. I will present to the ASME Team Leader at the next Joint Review. I will write again on this forum when I will have a more definitive interpretation. Mauro.

Mauro, one of my dearest friends has been a senior officer of ASME IX for many years so I'm very fortunate in that whenever I need an opinion on something about ASME, I can send him an e-mail.