API650 tank with bottom cone - NDE 2

[MichaelDexter]

Hello All
I am preparing non destructive examination scope for tank designed acc to API 650 with bottom cone. I can't find NDE requiremnents for bottom cone in API 650 and ASME V. Maybe I didn't see it. Do you know where it could be found ?
Thanks in advance

 

[MichaelDexter]

I took NDE requirements from tank shell, from API 650

 

[bimr]

Look into Appendix F NDE Requirements Summary of API 653 Tank Inspection, Repair, Alteration, and Reconstruction

[URL unfurl="true"]https://law.resource.org/pub/us/cfr/ibr/002/api.653.2003.pdf[/url]

 

[LittleInch]

Don't see why section 7.3.3 doesn't apply.

The fact its a cone floor (I assume) doesn't make any difference - it's still a tank bottom.

Is that what you meant?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[JStephen]

If it's a suspended cone bottom, it's not covered by API-650- in that case, stress is similar to a shell, and inspecting similar to a shell would be appropriate.

 

[MichaelDexter]

I wasn't precise. Cone bottom is like for silos - with 30 degree angle from vertical axis (see attachment)

http://files.engineering.com/getfile.aspx?folder=bf9a42a5-08b7-499f-8803-7b34f66e2c9c&file=tank.pdf

Thanks all for help

 

[LittleInch]

Your problem lies in your first post.

This is not an API650 tank, that's why there's nothing in it for a cone floor like that as JStephen says So find out first what code, if any, this is designed to.

If in doubt then do whatever you're doing for the shell.

Is this tank freestanding or resting on the ground?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MichaelDexter]

I have checked, yes, design code for cone bottom isn't API but EN 1993-4-1 (in data sheet). This code was changed to API650 / ASME VIII div. 1. Now all parts of tank are acc. to American Codes - it was reason of change. Shell and roof is acc. to API 650

This tank will stand on foundation slab, above ground

 

[LittleInch]

Sounds like an unholy mess.

so you have part of your tank designed to a code which specifically applies "only to tanks whose entire bottom is uniformly supported..." and basically atmospheric pressure and the bottom section to a pressure vessel code designed for pressures > 15psi.

Glad I'm not signing this off....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[JStephen]

LittleInch- that is not an uncommon situation. "Standard" tank configurations are covered cookbook-style by various standards, anything too oddball just isn't covered and you're on your own.

 

[LittleInch]

Uncommon or not, I personally don't agree with it. Using bits of one code and bits of another is not, IMHO, acceptable. All codes rely on the entire thing being designed to the same standard.

Design the whole thing to some sort of generic structural code, as per the original design - EN 1993-4-1. To try and replace this with parts of something else just so that you try and claim it now complies with American codes is not correct (IMHO). Ifthere isn't an American code that covers it then find another one which does - in this case EN 1993-4-1.

The code noted above is specifically to provide design guidance for the structural design of steel silos. Hence you're not "on your own" in this circumstance.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.