×
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

Misalignment of nozzle-to-header joint : any tolerance ?

Misalignment of nozzle-to-header joint : any tolerance ?

Misalignment of nozzle-to-header joint : any tolerance ?

(OP)
Dear all,
Refer to thread292-290132: misalignment of tube to header weld (misalignment of tube to header weld). In this thread it was answered by Metengr that such misplace / misalignment of joint between tube and header is a non-conformance. I fully understand this. Now my question : is there any tolerance on how much the mis-alignment is still considered acceptable ?
For example : I have nozzle to header joint. The nozzle is NPS 4 Sch XXS - grade91, header NPS 8 Sch 160 - grade91. Is misalignment of 8 mm (0.31") still acceptable ?

RE: Misalignment of nozzle-to-header joint : any tolerance ?

abura...

Fabrication tolerances for piping and pressure vessels are not contained within the codes. They are a commercial matter to be resolved between the purchaser and the supplier

For pressure vessel fabrication tolerances, the pressure vessel handbook contains some good information:

http://www.inspection-for-industry.com/pressure-ve...

Engineering companies also develop thier own standards.... I have some older versions.

Also, reportedly, you can also refer the PD 5500 Annex L

http://65.57.255.42/ubbthreads/ubbthreads.php?ubb=...

Hope that this helps.....

Let us know about your final call on this matter....

RE: Misalignment of nozzle-to-header joint : any tolerance ?

Mr New MJCronin's statement is correct "Fabrication tolerances for piping and pressure vessels are not contained within the codes."
However there is a widely accepted "Standard"

The Pipe Fabrication Institute "PFI ES3" Covers Fabrication Tolerances.

Go here for a complete list of all PFI Standards
http://www.pfi-institute.org/products.php

prognosis: Lead or Lag

RE: Misalignment of nozzle-to-header joint : any tolerance ?

(OP)
MJcronin and pennpiper,
I appreciate your advice. I think I need to learn more about this.
As for now, we decided to cut and replace the nozzle with a new one.

RE: Misalignment of nozzle-to-header joint : any tolerance ?

Ive always found the PFI standards a great resource for tools, so to say.
Does anyone know of a (PFI or other) standard for tolerances on VIII-1 vessels, other than whats listed in VIII-1 w/ respect to tolerances?

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