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


Part UHX Tube-sheet Stress During Hydrotest

Part UHX Tube-sheet Stress During Hydrotest

Part UHX Tube-sheet Stress During Hydrotest

We are currently fabricating replacement u-tube bundles.

The bundles are Figure UHX-12.1 Configuration D with extended flange, the gaskets either side of the tubesheet are the same configuration and as such no bolt load gets transferred into the tubesheet during normal operation.

The intent is that the new bundles will be hydrotested in the workshop using a test blind directly bolted to the tubesheet. Calculations have been provided to determine the tubesheet bending stress in accordance with UHX-12.5.8 (accounting for both nominated assembly bolt load and hydrotest pressure). This stress is limited to 2*S.

My question is should this stress be limited to 90% of Sy (yield) for hydrotest or should it be limited to 2 * 90% of Sy?

I'm a little confused considering the 2*S limit, primary bending in a flat plate is fairly straight forward as it is limited to S however the bending in the tubesheet is treated differently.

Appreciate any feedback.

RE: Part UHX Tube-sheet Stress During Hydrotest

From a code prospective, there is no limit on stresses during the test condition.

If your client has limits, ask them.

RE: Part UHX Tube-sheet Stress During Hydrotest

Apologies, my initial query was somewhat rushed being late on a Friday.

My query is whether we run a risk of yielding the tubesheet if the stress limit is set to 2 * 90% of Sy?

My understanding is that this is a primary bending stress and therefore I would typically limit this stress to 90% of yield, however, the allowable stress in the ASME formulas limits stress to 2*S so maybe my understanding is incorrect here and infact the stress isn't primary in nature?

I know ASME doesn't set limits on stress in hydrotest however other recognised codes around the world do (90-95% of yield).

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


White Paper - A Guide to 3D Printing Materials
When it comes to using an FDM 3D printer effectively and efficiently, choosing the right material at the right time is essential. This 3D Printing Materials Guide will help give you and your team a basic understanding of some FDM 3D printing polymers and composites, their strengths and weaknesses, and when to use them. 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