Auto UT / TOFD

[BY11]

Is it possible to do TOFD on Cir Seam joint involving shell and head.

Shell material : CS
Shell Thickness : 200 mm
Head Material : CS
Head Thickness : 100 mm
Joint with 1:4 Taper

And what should be the qualification block thickness ( is it based on head or shell thick )

Planned to do TOFD before the WOL and after WOL with inconel 825

looking forward to members valuable feedback and time,

Regards,

BY11

 

[weldstan]

Cannot recommend TOFD or 825 overlay. I assume that O.L. is actually Alloy 625.

 

[BY11]

Can you please share your reasons for not recommending the TOFD and 825 OL & Why do you think it is 625 instead.

 

[weldstan]

If you wish to see cracked overlays, do use 825, which is highly crack prone.
The dissimilar thickness and shell head geometry make TOFD very difficult. If I were the Purchaser, I would not permit its use.

 

[sharmass]

BY11
Understand that the clad is only for corrosion and not contributing to design thickness.
You can use TOFD on clad. Make sure the calibration and qualification blocks both are cladded
Try using TOFD and Phased Array combination
You must cover entire volume of the weld and prove it through demonstration
Because of the taper you may have to scan from inside and outside both to cover the entire volume.
You must talk to your Level III (experienced in TOFD) about scan plan