QW-304

[Fizza453]

Does QW-304 prohibit the use of only Radiographic Examination for the performance qualification when using GMAW short circuiting mode?
If we read word by word, it looks QW-304 intends to prohibit RT only and does allow UT for performance qualification using GMAW short circuiting mode.



Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN

 

[SectionIX]

Agreed. RT for GMAW-S welder qualification is specifically prohibited.

For GMAW, we generally destrictively test because, frankly, its easier. Plus, QW 191 adds a coupon thickness minimum of 1/2" which may be greater, in many cases, than the standard thicknesses used for testing.


From ASME IX:
QW-191.2.1 Method
(a) The ultrasonic examination in QW-142 for welders
and in QW-143 for welding operators may be conducted
on test welds in material 1?2 in. (13 mm) thick or greater.

 

[Fizza453]

Section IX,

Taking consideration of QW-191.2.1 limitations, So I conclude UT can be used for performance qualification for GMAW Short Circuiting Mode. Correct?

Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN

 

[metengr]

Here is what the 2010 Section IX QW304 states....

Alternatively,welders may be qualified by volumetric NDE per QW-191 when making a groove weld using SMAW, SAW, GTAW,
PAW, and GMAW(except short-circuiting mode for radiographic
examination) or a combination of these processes,...

Yes, UT must be used for welder qualification in lieu of RT or by mechanical test. The reason is short circuit GMAW increases the potential for LOF defects and they can be missed with RT versus UT.

 

[Fizza453]

May TOFD be used to satisfy the requirements of QW-191 instead of manual UT?


Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN

 

[Duwe6]

No TOFD, unless you can prove 100% coverage, and we know TOFD doesn't really examine the weld cap. It is supurb for the bottom 4/5 of any weld. But it won't really examine the cap.