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


Nominal tank diameter in 5.6.1 API 650

Nominal tank diameter in 5.6.1 API 650

Nominal tank diameter in 5.6.1 API 650

Dear all,
What does the nominal tank diameter in 5.6.1 represent? IS it INSIDE Diameter OR OUTSIDE Diameter of tank?

RE: Nominal tank diameter in 5.6.1 API 650

Usually, the tank diameter will be a rounded number (120 feet or 18 meters or something) and that is the nominal diameter. It may be the ID or OD or at centerline of plates. See Annex L.4 and Section This may be addressed somewhere else, but I'm not seeing it at the moment.

RE: Nominal tank diameter in 5.6.1 API 650

I found out in section that unless otherwise noted it is the centerline diameter of the bottom shell courses plate. But in Annex F, figure F.2, Rc is given as inside radius of tank shell, can we use nominal radius(nominal diameter/2) in this case?

RE: Nominal tank diameter in 5.6.1 API 650

For design it's a meaningless difference between 100' centerline diameter and 100' inside diameter. On a 100' tank with a 1/2" wall the difference is D=100.00' vs D=100.04'. This won't affect ordered thickness, App F required area, etc. I'd use D=100.0' for both cases.

However for detailing and construction it can be important. On the same tank if you detail it for 100' centerline, but build it 100' inside you'll have a 1.5" gap at the final vertical weld.

RE: Nominal tank diameter in 5.6.1 API 650

Thank you, Geoff13.

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


White Paper - The Criticality of the E/E Architecture
Modern vehicles are highly sophisticated systems incorporating electrical, electronic, software and mechanical components. Mechanical systems are giving way to advanced software and electronic devices, driving automakers to innovate and differentiate their vehicles via the electric and electronic (E/E) architecture. As the pace of change accelerates, automotive companies need to evolve their development processes to deliver and maximize the value of these architectures. Download Now
White Paper - Model Based Engineering for Wire Harness Manufacturing
Modern cars, trucks, and other vehicles feature an ever-increasing number of sophisticated electrical and electronic features, placing a larger burden on the wiring harness that enables these new features. As complexity rises, current harness manufacturing methods are struggling to keep pace due to manual data exchanges and the inability to capture tribal knowledge. A model-based wire harness manufacturing engineering flow automates data exchange and captures tribal knowledge through design rules to help harness manufacturers improve harness quality and boost efficiency. Download Now
White Paper - Modeling and Optimizing Wire Harness Costs for Variation Complexity
This paper will focus on the quantification of the complexity related costs in harness variations in order to model them, allowing automated algorithms to optimize for these costs. A number of real world examples will be provided as well. Since no two businesses are alike, it is the aim of this paper to provide the foundational knowledge and methodology so the reader can assess their own business to model how variation complexity costs affect their business. 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