×
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

ASME Sect. 8 Div.1 thread-o-let and 1/2" pipe wall

ASME Sect. 8 Div.1 thread-o-let and 1/2" pipe wall

ASME Sect. 8 Div.1 thread-o-let and 1/2" pipe wall

(OP)
Question:

I am doing a demonstration vessel with 8" sch 80 pipe (1/2" wall), a 8" pipe cap and flange at opposite ends.  I intend on putting a thread-o-let on the side of the vessel.

I have all my materials on hand and now I see in my design calc's that UW-16 (3)(a)(1) is limiting me to 3/8" maximum vessel wall.

I can't find where any additional calc's can be done to make this work. Can someone point me in the right direction? Or am I just plain hosed?

roadapple

RE: ASME Sect. 8 Div.1 thread-o-let and 1/2" pipe wall

you would not use that fig for a thread-o-let

just  play it safe and use a coupling and figure uw-16.1(z-1)

RE: ASME Sect. 8 Div.1 thread-o-let and 1/2" pipe wall

Not sure of the groove dimension on the threadolet, but it seems that you might fall more into the domain of UW-16(f)(4) - Fig UW-16.1 sketch (bb)?

jt

RE: ASME Sect. 8 Div.1 thread-o-let and 1/2" pipe wall

I don't believe thread-o-lets are permitted in vessel fabrication since these are not ASME components. They are made to MSS SP-97.

I've only ever seen couplings used for small bore connections as recommended by vesselfab.

RE: ASME Sect. 8 Div.1 thread-o-let and 1/2" pipe wall

(OP)
I was hoping for an outside fillet weld with the thread-o-let- but am guessing that the moment with the thicker plate is the reason they limit the thickness of the vessel.

I have room to weld a coupling in the arrangement shown in UW-16.1 (i) - because my pipe is 8.625 od the curvature makes saddling the branch a real problem.  I am trying to get away from machining an expensive part just to junk it at the end of the review.
 

RE: ASME Sect. 8 Div.1 thread-o-let and 1/2" pipe wall

(OP)
Thanks gents - or ladies whatever the case is.

I will be getting a coupling to do this with.

roadapple

RE: ASME Sect. 8 Div.1 thread-o-let and 1/2" pipe wall

cut a hole in the center of head.  there will not be any machining for curvature.

the opening will be flat.

then stick what ever you want to weld in and use a full penetration weld.

RE: ASME Sect. 8 Div.1 thread-o-let and 1/2" pipe wall

Thread-O-Lets are not banned in Section VIII, but there is no figure in UW-16 that is like a TOL. Also, with the groove built in to the TOL producing a fillet leg is not practical. Use a coupling, and save the TOL for B31.1 work.

The calculations for proving out the weld strength are shown in examples in Section VIII, Appendix L-7, but you will be much happier using the coupling with a standard UW-16 figure.

Your AIA should have advised you on what components to use for the demonstration.

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