Heat Input Qualifications D1.5 2015 clarification

Date 07-28-2016 12:04

Hey All,

I'm looking to get a general consensus on interpretation of D1.5:2015 Section 5.12, namely the first sentence of the bottom paragraph regarding Average calculation vs per pass Heat Input.

"The heat input for any individual weld pass in a qualification test, except the root and cap passes, shall be within +/- 10% of the average heat input of all passes in the test."

This is the one causing the most disagreement between myself and our QE (Quality Engineer/Boss) and the QC at our other plant.

My understanding of this is: The 10% +/- is against the full average of all passes.
QE and other QC look at it as: The 10% +/- is against the average, excluding the root and covers (the average used for the WPS).
All of us agree that only the non-root/cover passes are to be within the 10% +/- limit.

Basically, to me it looks like you need to keep two Heat Input Averages, one with all passes (to be used for the 10% +/- verification), and the second one being all non-root/cover passes (to be used for the min/max on the WPS).

Thanks,

By pipewelder_1999 (****)

Date 07-28-2016 12:23

I interpret the average to be calculated without the values for the root and cap passes because of the statement ..." The average heat input for the test shall be calculated using the calculated heat input value for all passes exempting the root and cap passes...."

I can however say this code has been an adventure to get to know in the past few weeks.

By Steelslinger (**)

Date 07-28-2016 15:09 Edited 07-28-2016 15:15

But the rest of that sentence becomes, in my mind, the qualifier, "...and that average shall be the WPS Heat Input."

And I think this is what is causing the confusion. Because if you look at the first sentence, the one in question, it specifically states, "...shall be within +/- 10% of the average heat input of all passes in the test." It doesn't state "the test average", plus it comes well before the other sentence in the paragraph. To me that is calling out for two different averages to be used for two different purposes.

I tend not to read past what is written and take a fairly literal interpretation. It's a huge rewording from 2010 version.

By MBSims

Date 07-30-2016 00:04

I read it the way it is written. The heat input of any individual pass must be within 10% of the average of ALL passes. This requirement does not apply to the root and cap passes.