UG-46(7)(b) interpretation

[gwalkerb]

We've been having some issues recently with AIs not accepting our inspection openings. We're currently trying to figure out what the requirements are from code as referenced in this section:

(7) Flanged and/or threaded connections from which
piping, instruments, or similar attachments can be removed
may be used in place of the required inspection openings
provided that:
(a) the connections are at least equal to the size of
the required openings; and
(b) the connections are sized and located to afford
at least an equal view of the interior as the required inspection
openings.

Clause (b) is what's giving us some issues. For example, on a vessel with ID between 18" & 36", a 2" threadolet is an acceptable inspection opening. Often, however, we have customers who disallow threaded connections in vessels. Up until now we've been using RFLWNs as our non-threaded inspection openings (in this case a 2-1/2" RFLWN). This hasn't been a problem until recently, we've been having vessels rejected because although the 2-1/2" RFLWN has an opening greater than the 2" TOL (2.5" vs 2.375"), via clause (b) the projection of the nozzle from the vessel creates a problem with providing an 'equal view of the interior'. We did a quick mockup and found that to provide an equivalent view of the interior of the vessel, we would require an 8" RFLWN nozzle. This seems a little excessive, and we would have problems fitting in such a large nozzle just for the purposes of inspection. Has anyone else had any experience with this issue? We were also considering using studding outlets, but cost-wise those aren't a great choice either.

 

[jtseng123]

How does submarine look beyond the ocean surface ? Buy several of those for your customer.

 

[nickelkid]

Studded outlets are how I have known this issue to be addressed in the past. Although I believe jtseng123's suggestion is more of a norm today. As you have noted, it comes down to cost.

 

[gwalkerb]

The problem was with our ABSA inspector. We explained to him the marvels of modern technology including mirrors, boroscopes, etc, but he said he has to follow the letter of the code rather than it's intention. Which seems like BS, but unfortunately he has the power. It looks like we might have been able to come to an agreement with him and will only have to slightly increase the size of our inspection openings, and use studding outlets in some circumstances. Honestly, that's a section of code that could use an update.