Figure 5-6 S-N nozzle note

[IFRs]

This question is regarding weld spacing to an S-N nozzle.

The S-N note is: "Non-Reinforced Opening (manhole or nozzle inserted into the shell per the alternate neck detail of Figure 5-7B).

I guess I'm confused (not an unusal event).

The note says "non-reinforced" but then refers to a weld detail which shows reinforcing: (T+t) thickened shell plate.

What does API mean by "non-reinforced" in this particular case?

 

[JoeTank]

API has some really bad wording here. Just because a nozzle doesn't have a separate repad does not mean it is not reinforced. The "non-reinforced" wording is not helpful.

Joe Tank

 

[IFRs]

I mean no disrespect but do you have any history, documentation or backup for this interpretation? IE that for this S-N note where API says "non-reinforced" they mean "has no separate reinforcing plate"? Has API answered this question before?

 

[JoeTank]

IFRs,
Sorry. I have no specific backup other than common usage within the inductry. But, I believe that the S-N note has been changed or modified within last five years or so to the current wording.

Joe Tank

 

[IFRs]

Update:

API has addressed this issue and a ballot item was approved for publication in a yet to be published Addendum #1 of API 650 11th edition. The new wording of the S-N note reflects the intent of "S-N" to mean self-reinforced or reinforced without a separate re-pad, inlcuding small nozzles and couplings that do not need a re-pad and manways or nozzles installed in a thickened insert plate.

 

[JoeTank]

IFRs,
Thanks for the update. Does that mean I wasn't wrong?
Joe

Joe Tank

 

[IFRs]

Joe -
You are seldom if ever wrong. In this case, your virtue is intact.