×
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

Shrink-Fitting

Shrink-Fitting

Shrink-Fitting

(OP)
I was wondering if I was given the small pipes ID, the large pipes OD and the stress wanted, could I find the thickness of the pipes needed to fit that citeria? Or what equations would i need to combined/use to get what I am being asked for?

RE: Shrink-Fitting


Huh?

RE: Shrink-Fitting

Yes. And you can calculate the temperature needed to do it too.  A thermally expanded segment of pipe placed around a cold pipe would contract radially around the cold pipe.  That contraction produces an external pressure on the cold pipe and an internal pressure on the cooling pipe, which are converted into equivalent radial stresses in both pipes.

The change in circumference of the large pipe would be the circumference at elevated temperature - circumference at normal temperature which must finally be equal to the small pipe's circumference of its OD.

Stretch the larger pipe circumferentially by heating until ID = OD smaller pipe.  The stress developed by the required stretching must be equal to the change in circumference between Large Pipes' ID and the Small Pipe's OD (when both are at normal temperature)

That change in circumference can be set equal to the change in length (in this case circumference) for a given stress of a material with some modulus of elasticity E (Young's modulus), therefore
Stress/Young's_Modulus * L1 =  L2-L1

just substitute the circumferences for the lengths above.

now to get the change in temperature needed,

(S/E) / temperature expansion coefficient = dT

Please check the above for consistancy of units.  I did it very quickly.

http://virtualpipeline.spaces.msn.com

RE: Shrink-Fitting

Note, the above is for large diameter pipe with relatively thin wall thicknesses.  You must use a different stress equation if your large pipe is a "thick walled cylinder".

The small pipe was also assumed to be completely rigid.

http://virtualpipeline.spaces.msn.com

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