Are you working to a CODE? If you are strictly working to ASME Sec VIII D1 for a pressure vessel, then Refer to Fig UW-3 and UW-12. If you have a slip-on flange it is a Cat C and RT is not applicable (not required) even if the whole vessel calls out for a degree of examination. If you need to do RT (customer or service driven) then UT can probably be substituted, but you need to look at your situation if a slip-on would even be allowed.
Slip-on flange should not require RT or UT because of the geometry being unfavourable to both. Surface crack detection (MPI for carbon steel, penetrant for stainless) shouls suffice.
If RT is not possible on a weld, you might want to check if TOFD (Time-of-Flight Diffraction) can help. This is a type of ultrasonic testing, but you can visualize the defects and also "around the corner".
OSIRIS7,
It is still a fillet weld (or two of them)- TOFD or manual UT is still pretty much useless on a fillet weld.
What are you actually looking for in your UT scan ?
Weldstan described it perfectly !
Regards,
DD
OSIRIS7,
Whereas slip on flanges are used in low pressure applications and the fillet welds are likely small, TOFD will not provide any valuable information.
