×
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

saddle design
4

saddle design

saddle design

(OP)
Dear all,
I have doubt in saddle analysis. I know my question is very silly. But....
Normally horizontal vessel supported on saddle. One is fixed and another one is sliding saddle.
Why both saddle should not be sliding.

RE: saddle design

4
The reason that one end is fixed is for the piping design. In piping design, it is necessary to provide locations where the displacement is zero - directional anchors and guides. This is necessary so that the thermal growth of the piping can be appropriately managed. Having a location of zero thermal expansion in a horizontal vessel is therefore necessary to accurately predict the thermal displacement of nozzles, so that the attached piping doesn't over-stress the nozzles.

If both saddles were sliding, then the thermal displacement of the nozzles would be unknown/indeterminate.

Also, if both were sliding, then the vessel could "walk" over time. If you could imagine that upon first start-up, the left saddle is "fixed" and the right saddles slides, but upon cool-down, the right saddle "sticks" and the left saddle slides. Repeat. When this happens. vessels can translate large enough distances so as to fall off concrete pedestals, etc, causing substantial damage. If the piping is small, then it just gets dragged along for the ride, usually ending up a bent mess. If the piping is large enough, then nozzles could be over-stressed/ripped out.

Make sense?

RE: saddle design

(OP)
Now I clearly understand. Thank you sir.

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