Flat bottom design per API620

[Heyner]

Hi everybody!!

I need to design a flat-bottom tank without counterbalancing weight, per API620. Code states the method shall be a matter of agreement with purchaser.

Do you know any method to do this? it is a 162" diameter and 42' height tank, with internal design pressure of 10 psig. I got reference from an identical tank that has a bottom plate thickness of 1.25".

I don't want to use ASME since tank code must be API620 and checking thickness as per ASME I would need near 2" (flat unstayed plate).

Somebody can help me? even ideas are desired.

Tanks a lot!!!!

Heyner.

 

[LSThill]

HI Heyner (Mechanical)

Flat bottom for pressure vessel
thread794-46942


ETank: Tank design software per API-620, API-650, API-653, UL-142, and API-2000.

http://www.etank.com/

Leonard@thill.biz

http://www.thill.biz

 

[aybee]

you could have a look at Roarkes Stresses , there will be a case in there for a round flat plate with uniform pressure and edge restraint

 

[chicopee]

you can use Grashof formulae listed in Eshbach Hdbk. of Engineering Fundamentals. Use the uniform load w/ edge supported. Be sure to also check center defection provided in this reference since you may want to use that as you designing criterion. Also use appropriate factor of safety such as 5 but not lower than 4.

 

[LSThill]

Hi Heyner (Mechanical)

From-- Structural Engineering Handbook:

Section 23 “STEEL TANKS”

John N. Pirok** and Robert S. Wozniak**
*Chief Structural Engineer and **Design Engineer Chicago Bridge & Iron Company, Oak Brook, Illinois

Edited by Edwin H Gaylord, Jr. Professor of Civil Engineering, Emeritus, university of Illinois, Urbana
Charles N. Gaylord, Professor of Civil Engineering, University of Virginia

Leonard@thill.biz

http://www.thill.biz