×
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.

# API 650 Chapter 5.12, UPLIFT Loads

## API 650 Chapter 5.12, UPLIFT Loads

(OP)
As per API 650 clause 5.12 tank anchorage, table 5-21a shows uplift load calculation formula including seismic case as (4xMrw/D)-W2(1-0.4Av).

In this W2 is given as dead weight of the shell and roof. since for seismic moment (Mrw) calculation we are including the content weight(liquid weight) inside tank.
but in the uplift load calculation, why we are not considering the W2 as Dead weight of tank + liquid weight?

thanks
senthilb

### RE: API 650 Chapter 5.12, UPLIFT Loads

The sloshing of the liquid in the tank causes uplift on one side of the tank and compression on the other side of the tank.
If the liquid is causing uplift, it can not resist uplift in the same location at the same time.

### RE: API 650 Chapter 5.12, UPLIFT Loads

In order for the liquid weight to resist the uplift the tank bottom must lift off the foundation. This effective liquid weight is calculated in 5.11.2.3 for unanchored tanks.

However, since 5.12 is designing anchor bolts then by definition the bottom can't lift and no liquid weight resists the uplift. Thus no liquid weight is included in W2.

### RE: API 650 Chapter 5.12, UPLIFT Loads

Geoff's answer was better than mine. Use his...

#### 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

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a partâ€™s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. 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!