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!

*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

Why we are limiting variability of

Why we are limiting variability of

Why we are limiting variability of

Why we are limiting variability of spring with in 25 percent. How does it affect if I choose a variable spring with variability exceeding 25 percent. Thanks in advance

RE: Why we are limiting variability of

Do the math. What happens if you set the difference in hot and cold to say 35%? I doubt if any reasonably designed piping system could handle such variations.

I’m not sure why the default industry was set to 25%, but it must have been chosen at some point by someone, and after that perhaps was accepted as the de facto.

RE: Why we are limiting variability of

That is what I couldn't imagine and seeking explanation. How does it effect the piping system??

RE: Why we are limiting variability of

Spring variability is the difference in loading divided by the operating load (typically (HL-CL)/HL).

As your variability increases, your distance of travel increases, altering the load on the pipe as governed by Hooke's Law (F=-kx). If the component being supported was to be designed for excessive travel using variable spring cans, then it is possible that you end up with a very large localized loading due to the spring becoming significantly compressed/tensioned.

From a practical perspective, constraining variability constrains overall spring movement and likely increases the lifetime of the component. A spring can with a large movement will likely fail sooner than one with a shorter movement when factoring in site conditions like temperature and corrosion.

For systems that have large piping displacements that would otherwise become over-stressed by constraining displacement, like cokers, we've always used constant rate spring hangers.

Michael Hall, PE (TX) PMP - President
Engineering Design Services LLC

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


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