Weld corrosion testing on an ASME cladded pressure vessel. (UCL-32)

[Duke]

Hi all,

We have manufactured a glycol contactor vessel using carbon steel plate with 316SS internal cladding (3 mm).

DNV-GL, the vessel 3rd party inspector, is asking for a weld corrosion testing.

The project specification/data sheets does not request any weld corrosion testing.

DNV-GL interprets the UCL-32 (Weld Metal Composition) of ASME VIII div. 1 as a corrosion testing requirement.

UCL-32 states the following :

Welds that are exposed to the corrosive action of the contents of the vessel should have a resistance to corrosion that is not substantially less than that of the corrosion resistant integral or weld metal overlay cladding or lining. The use of filler metal that will deposit weld metal with practically the same composition as the material joined is recommended. Weld metal of different composition may be used provided it has better mechanical properties in the opinion of the manufacturer, and the user is satisfied that its resistance to corrosion is satisfactory for the intended service. The columbium content of columbium-stabilized austenitic stainless steel weld metal shall not exceed 1.00%, except when a higher columbium content is permitted in the material being welded.

As you see, there is no mention of any corrosion test requirement in this article and the client confirmed that he does not require any weld corrosion testing.

In the same meeting, DNV-GL confirmed that he will not accept the contactor vessel.

I would like to have your interpretation and experience regarding weld corrosion testing of cladded ASME vessels.

Thank you.