UT as NDT for Welded Joints
Rajesh
May I know if what is the preffered practice of NDT for Welded joints,
particularly when flanges are made in segments & then welded.
As I understand ASME does not allow UT
But AD- Merckblatt recommeds UT.
Please comment.
Regards
Rajesh Bhavsar
Singh Rishi Raj (Tasnee Site)
Please let us know more details.
In AD , NDT requirements are based on metal.
Specific details will help us .
Best Regards,
Rishi Raj Singh
Bathula Raghuram (Mumbai - PIPING)
It is designer's choice (what is end use, is it for skirt base or any part of the item which is subjected to stress due to pressure?); AD has a choice of choosing between D or US for butt welds under stress (LN)
In ASME Design “E” is selected based on RT; other wise it is quite normal to use UT for skirt base flange made of segments from plate, otherwise I have not come across any body flange made from plate in segment, instead of forging.
However TOFD can be and is used as a substitution of RT. It is superior in that it can fully characterize and size defects that are found. It is permitted as a substitute for RT in the ASME Boiler and Pressure Vessel Code via Code Case 2235.However, the use of TOFD requires substantial skill and experience.
Note: RT is superior for what it does. TOFD is a new toy to play!