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

Cable Suspended IFR

Cable Suspended IFR

Cable Suspended IFR


We have a client would like install cable suspended Internal Floating Roof (IFR) for a new tank (diameter=25m).
due to certain reasons, we prefer to use self-supported dome roof without rafter to support the IFR.

I would like to check whether self-support dome roof without rafter strong enough to support the IFR weight due to point load as requested by API650.

What type of calculation shall been used to analysis strength of roof in such a case, by FEA?

Thank for the advice.

RE: Cable Suspended IFR

You can use point loading in FEA or run the analysis by hand. Sometimes people just add a uniform load and do not go into the detail of locating point loads. In this case you might want to look at the local stresses for a single point load. The load will be based on the area supported by each of the cables, the unhjit dead load per the manufacturer and the unit live load per API 650. Per API 650, if the IFR includes automatic drains the live load is 5 psf, if not then it is 12.5 psf. The dead load will vary between 1.25 psf and 2 psf depending on the manufacturer and quality of the IFR. API 650 includes all the load combinations and load factors you need to consider. A 25M IFR will have between about 20 and 40 cables depending on the vendor. Some vendors can easily add additional uniformly spaced cables if it helps.

RE: Cable Suspended IFR

IFR- can you suggest a reference for hand calculating the stress on the roof due to the pointload?

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


eBook - Integrating the Engineering Ecosystem
Aras Innovator provides multiple options for integrating data between systems, depending on the scenario. Utilizing the right approach to meet specific business requirements is vital. These needs range from authoring tools, federating data from various and dissimilar databases, and triggering processes and workflows. Download Now
Research Report - Simulation-Driven Design for SOLIDWORKS Users
In this engineering.com research report, we discuss the rising role of simulation and the paradigm shift commonly called the democratization of simulation. In particular, we focus on how SOLIDWORKS users can take advantage of simulation-driven design through two analysis tools: SOLIDWORKS Simulation and 3DEXPERIENCE WORKS. Download Now
White Paper - Industry 4.0 and the Future of Engineering Education
With industries becoming more automated, more tech-driven and more complex, engineers need to keep their skills and knowledge up to date in order to stay on top of this wave—and to be prepared for the Industry 4.0 future. The University of Cincinnati offers two online Master of Engineering degree programs designed specifically for practicing engineers. Download Now
eBook - The Design Gridlock Manifesto
In this eBook, you’ll learn 6 ways old CAD technology slows your company down and hear how design teams have put those problems to rest. “The Design Gridlock Manifesto” shares first-hand modern CAD experiences from 15 companies around the world. 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