Pipeline Radiography

It depends on the thickness of the pipeline.

x-ray can be easy operation and safety.

but your description is more detail and suit to learner.

I'm not aware what's preferable for Shell.

Gamma probing is much more "dipper" vs XRay one. However there's a lot of safety/security headache when any Gamma instrument is applying, maintaining and then utilizing. I suppose it depends upon particular needs and particular country's regulation conditions what kind of above mentioned instruments is to be considered as preferable.

There are both advantages and disadvantages of both from user point of view. However the quality of radiographs and detectability will be same for both of them.

The pipeline being usually thin in crossection (less than 2.5") X ray is perfectly ok however the problems are in handlability of the equipment.

The Radio isotopes are much easoer to handle. But the isotopes (Ir or Se) has its own precautions to be taken while handling and the necessary strict guidelines are to be followed.

There is as I know no preference are put by the inspection agency as far as the type of the ray for this type of pipelines, better to check back with them.

In case of bulk production why don't you look into the digital imaging with X ray ?

check this site

www.ndt.net/article/mendt2007/papers/light1.pdf

These may have some initial cost but will balance out in long run. You may search out and find suppliers with required IQI