I need some explanation of NB-4360. Is this article about some special seal type tube to tube sheet joint?

HELP ! ! !

I need some explanation of NB-4360. Is this article about some special seal type tube to tube sheet joint?

abc123

By definition, is NB-4361(a) requirement applies the special seal type tube to tubesheet joint?

Is the tube to tubesheet joint falls on the category of specially design welded seal?

In my opinion, the answer is No.

leem

There is a h.e. design where the channel is closed by bolted flange which ensures normal strength and tightness. Hydrostatic test is made in this conditions. The perfect seal is further ensured by a ligth metal sleeve welded to the outside of the raised face of the two flanges. Sleeve is made of two rings each welded to the flange before h.test. After hydrotest the two rings are welded together becoming a sleeve, tight. I presume it is the case.
Mauro