Hi,

I did design for diameter 17.8 m & 24.5 m ht tank.If i run the analysis , the output shows

WARNING #169 (General Tank Data)
API-650 Paragraph 5.5.3 warns that for tanks
in excess of 75 ft in height, an elastic analysis
must be used to determine the annular plate thickness.

How i can solve this Error.. which software can we use for elastic analysis?

Thanks

It is not an error; it is rather an warning saying you must perform an elastic analysis for your case.
Having no API 650 guidance to understand the way to develop such calculation, no software considered it.

It is API 650 which stipulates in 5.5.3 that "Beyond this height [i.e. the effective product height of H × G ≤ 23 m (75 ft)] an elastic analysis must be made to determine the annular plate thickness.".

Thanks Mariog,

how to do elastic analysis ,, is there any formula or calculation?

I haven't an answer.

You may take a look to
http://www.eng-tips.com/viewthread.cfm?qid=226281

Guide to Storage Tanks and Equipment By Bob Gardener and Bob Long has an illustrative example of Annular Plate Elastic Analysis. This could be of guidance.

Check out articles on Storage Tanks and Pressure Vessels at www.linuserve.com.
Added new article on Tank foundations and settlement.