×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• 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.

# Nominal tank diameter in 5.6.1 API 650

## Nominal tank diameter in 5.6.1 API 650

(OP)
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 5.1.5.3(b). 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

(OP)
I found out in section 5.6.1.1 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

(OP)
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.

#### Resources

eBook - Manufacturing the Cars of Tomorrow
In this ebook, we'll explore how additive manufacturing is going to transform the way cars are made. This includes commentary from thought leaders such as Ford's CTO, Ken Washington, Customer case studies of ways 3D printing is being used today, and a variety of part examples where 3D printing is already impacting how automobiles are made. Download Now
White Paper - Smart Manufacturing for Semiconductor
New technologies and approaches present great opportunities for semiconductor manufacturers to achieve high levels of innovation, yield and improvement. This white paper explores some of these cutting-edge technologies and how they can be applied effectively in the semiconductor industry. Read about how Smart Manufacturing is transforming the semiconductor industry. Download Now
White Paper - Analysis and Simulation in Aircraft Structure Certification
Organizations using simulation and analysis tools effectively see the benefits in their ability to achieve certification faster and with drastically less total cost than those who do not maximize these tools. Read this White Paper to learn about how digital tools such as analysis and simulation help in aircraft structure certification. 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:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!