×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Inspection Opening

Inspection Opening

Inspection Opening

(OP)
As per ASME VIII div 1, UG-46 :

"All vessels 18 in. (450 mm) to 36 in. (900 mm), inclusive,
I.D. shall have a manhole or at least two handholes or two plugged, threaded inspection openings of not less than NPS 2 (DN 50)."

"(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."

For this vessel under above requirement, only one HH is available, while other nozzles are 2", and no threaded opening.
Since min HH size is 3"x2", the 2" instrument nozzles can't be used in placed of the second HH requirement.

However can the 2" non-threaded instrument nozzles be considered as meeting the requirement of 2" threaded inspection openings and therefore meeting ASME VIII requirement ?

Appreciate very much any advise.

RE: Inspection Opening


18" to 36" must have inspection openings of NPS 2
Flanged openings can be used if they satisfy f(7) - NPS 2

Your instrument nozzles are NPS 2, so therefore they satisfy f(7)(a). You must then check f(7)(b) and other clauses such as f(4)

RE: Inspection Opening

If the NPS 2 non-threaded nozzle is no longer than NPS 2 threaded nozzle. it´s OK . According to ASME B16:11 NPS 2
half-coupling is 43 mm long.
Regards
r6155

RE: Inspection Opening

r6155

Please explain where Sec VIII refers to length of inspection opening?

RE: Inspection Opening

1)@ david339933
I consider, in this pressure vessel, that NPS 2 threaded nozzle for instrument is half-coupling. Flange opening NPS 2 is longer than half-coupling, hence not has at least an equal view of the interior.

2)@ andrewleong
Is this pressure vessel subject to internal corrosion or having parts subject to erosion or mechanical abrasion? See UG-46(a)

Regards
r6155

RE: Inspection Opening

Interpretation: VIII-1-83-358
Subject: Section VIII, Division 1; UG-46(f), Attachments in Inspection Openings
Date Issued: May 20, 1985
File: BC85-124

Question: Would the requirements of UG-46(f)(2) be satisfied by providing two threaded
openings not less than 2 in. pipe size from which piping, instruments, or similar attachments can be removed, if the openings meet the requirements of UG-46(f)(7)(a) and (b)?

Reply: No. UG-46(f)(7) applies to flanged connections only

Regards
r6155

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources