×
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

ASME 1 Vessel
5

ASME 1 Vessel

ASME 1 Vessel

(OP)
During inspections we found that flanges off the vessel were off by 3 degrees. The manufacturer says it is fine. But we do not think so. Is there anything in ASME 1 that states clearly the tolerance or do we have to go off of b31.1.

RE: ASME 1 Vessel

1. A vessel to ASME 1? You mean ASME Section I (which is for power boilers), or sec VIII-1?
2. Which section(s) of the applicable Code have you checked so far that didnt help you find your answer?

RE: ASME 1 Vessel

See Process Industry Practices PIP VEFV 1102.
The manufacturer must show that it is ok.

Regards

RE: ASME 1 Vessel

Quote (r6155)

See Process Industry Practices PIP VEFV 1102.
Thats not the question (regardless if PIP practices could be useful on some cases):

Quote (jayinwww)

Is there anything in ASME 1 that states clearly the tolerance

RE: ASME 1 Vessel

Is that out-of-plumb by 3 degrees? Or rotated about the axis by 3 degrees?
And is this a mating pair of flanges that are both rotated, or a nozzle that needs to bolt to something else that is presumably plum?
It might be informative to calculate stresses in the pipe required to fit things up.

RE: ASME 1 Vessel

2
Nozzles and Attachments Elevation, nozzles and attachments levelness tolerances, etc., etc are not addressed in ASME Code

The Code is not a handbook.

The Code does not fully address tolerances. When dimensions,sizes, or other parameters are not specified with tolerances, the values of these parameters are considered nominal, and allowable tolerances or local variances may be considered acceptable when based on engineering judgment and standard practices as determined by the designer.

Regards

RE: ASME 1 Vessel

3
What tolerances did you specify when you purchased this vessel? Whenever you purchase an ASME Section VIII pressure vessel you have to specify the allowable tolerances for the nozzles. If you didn't specify any tolerances, your nozzles could be off by 30° and the vessel would still meet Code.


-Christine

RE: ASME 1 Vessel

With a responsible manufacturer it is not necessary to specify dimensional tolerances.

Regards

RE: ASME 1 Vessel

ASME PCC-1 "Guidelines for Pressure Boundary Joint Assembly" Appendix E has some guidance for flange alignment tolerances. The BPVC does not contain anything regarding flange alignment as far as I know. In which direction is your flange off by 3 degrees?

    Centerline High/Low: 1/16" max misalignment[/li]
  • Flange Faces Parallel: 1/32" max difference between widest and narrowest gap (no "birdmouthing")
  • Rotational two-hole:1/8" max
  • Excessive spacing/gap: should be self explanatory
I should also note that these guidelines are for joint assembly; it is not necessarily design guidance.

RE: ASME 1 Vessel

This should have been discussed and detailed by both the customer and the fabricator in the purchasing documents!!

Questions like these .... AFTER FABRICATION .... is the direct result of hiring new engineers (because they are cheap) and not having experienced staff available.

Just one question for the OP .... Is this your first pressure vessel ????

MJCronin
Sr. Process Engineer

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! Already a Member? Login


Resources

White Paper - Addressing Tooling and Casting Requirements at the Design Stage
Several of the tooling and casting requirements of a part can be addressed at the design stage. If these requirements are not addressed at the design stage, lot of time is spent in design iteration when the design reaches the die caster. These design issues lead to increase in time and cost of production leading to delay in time to market and reduced profits for the organization. Download Now
White Paper - The Other Side of Design for Assembly
Assembly level constraints need to be satisfied before the design can move downstream. This white paper will go through the various assembly level issues, which need to be tackled by various organizations on a regular basis. Know more about DFMPro, a design for assembly software. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close