Hello All,

New to this site, I've got some questions regarding specific interpretations in ASME Section IX in regards to applications for welder testing.

I want to know if I can substitute a filler for a WPQ test so long as F-number stays the same.

Specifically I have a WPS for P-5B to P-5B using ER80S-B6 and E8018-B6 fillers.

I know that I can sub base material to P1 for the WPQ test but can I sub filler metal to ER70S-6 and E7018?

I know that these fillers are both F6 and F4 but they're distinctly different chemical compositions and normally you couldn't substitute them on a WPS as it would be an essential variable change (A No's aren't the same) but there's no clear indication that this is not possible.

My interpretation is that it would not be a valid test to substitute the filler metal even though it's the same F-number as you're no longer following the WPS in it's entirety (minus the allowable deviations set out in the code) since there's no clause that distinctly states filler substitution the same way it states for base metal substitution.

If anyone can share their opinion and interpretation regarding this scenario I would greatly appreciate the input.