Weld NDT of tapered fitting 2

[Engjacob]

Hi

I have been informed from our NDT staff that they cannot make radiography on pipe to fitting (Tee, reducers ect.) weld, if the fitting has tapered transition due to different thickness.
The explanation is that it is not possible to see root faults due to shadows.
This seem strange as both PED and ASME seem to approve tapered solution, but how can this be so if it is not possible to make NDT of the weld?

See attached picture of weld.

Hope some NDT expert can enlighten me Thank you.

Br
Jacob

 

[remetaper]

Need to know 1) geometry and dimension of pipe ( outside diameter and thickness) (2) steel grade of tube (3) autogenous welding or by filler?.
All these info are indispensable in order to understand which kind of NDT methode could be applied.

 

[Engjacob]

Dimensioner is from OD33,7mm to OD356mm thickness from 2mm to 15mm.
Material is carbon Steel, p235gh or A516 gr60
With filler.

 

[Dhurjati Sen]

Dear Engjacob,

I have seen dozens of such radiographs. Of course, the taper would partially hide the root defects. Ask the NDT guys to take two shots for each pipe section, both with DWSI technique, one the usual and the other with the source placed a little away from the tapered side.

Regards.

DHURJATI SEN

https://www.nace.org/people/dhurjatisen

 

[Engjacob]

Hi Dhurjati

Thank you for your feedback. Greatly appreciated.

 

[DekDee]

Please do not listen to your NDT staff.
It is not a problem at all and I have personally shot hundreds of tapered fittings.
The root of the weld is the most critical and that is the same thickness on both sides.
As you move out from the root the thickness increases slightly but it is gradual and the area of interest is still clearly visible.
Best suggestion I can give is have them radiograph a joint of certain thickness and then RT a joint of same thickness with a taper.
See for yourself.
Remember, density and sensitivity are all that matter and if one side of the joint is dark and the other is light but they fall within required parameters then everything is fine,
Regards,
Shane