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


HDPE conduit and cable thermal expansion issues

HDPE conduit and cable thermal expansion issues

HDPE conduit and cable thermal expansion issues

I'm looking at an application where some power and fiber optic cables are installed in HDPE conduit. Total length and ambient temperature fluctuation is such that the conduit will expand and contract by up to +/- 5m (15 ft). The cables inside will expand and contract at a much lower rate.

I'm looking for some references/advice on how this can be handled. The obvious thing to do is to leave some slack so that the cables can get pulled in and out of the conduit as the length changes. Some other issues arise though. The power cable has a splice which won't be able to handle as much tension as the rest of the cable. I'm not sure how to determine the tension in the cable when the conduit expands. The fiber will see compressive loads when the temperature drops possibly kinking it inside the conduit etc.

Has anyone done/seen anything like this done?

Any advice would be appreciated.

RE: HDPE conduit and cable thermal expansion issues

I would be more worried about the movement relative to the ground or anchor points. Once that is taken care of the cables will probably be okay. HDPE is not a stiff material so the restraining forces would not be high. Restraint in one direction will show as movement in the other directions (i.e, radial). The same conditions exist between copper conductors and wire insulation.

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!


3D Scanning in the Automotive Industry
With over 100 years of production history, the automotive industry has been at the forefront of manufacturing technology since its inception. Whether the transformative technology of the day was the assembly line, the integration of robotics into the manufacturing process, or the switch from steel to aluminum frame chasses, the automotive industry has consistently implemented advanced technology into its manufacturing and production workflow to improve manufacturing and product performance. Today, the same is true. Download Now
Green light on lidar: Developing low cost systems for autonomous vehicles
Lidar has been around for quite some time, but to date, it’s been custom—and expensive. Right now, there isn’t a clear-cut solution that’s suitable for all applications, such as lidar in autonomous vehicles. As they explore options, optical and mechanical engineers are forced to make choices and tradeoffs during the design process. 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