ASME Flat Bottom Tank

[clp]

Having trouble designing the bottom thickness for an ASME, ground supported flat bottom tank/.1 psi/ambient temp/120" dia/304SS material. Customer specifically wants ASME, not API tank. When I use the typical ASME equation for flat plates I get a thickness of 1.5". Is there a way to account for the ground-support in order to thin down the bottom plate and still conform with the ASME code?

clp

 

[deanc]

Apples and oranges. Inform your Cust. of the cost and try for a API design.

 

[prex]

No you can't.
And if, as I suspect, your 0.1 psi pressure is a liquid head, you have an atmospheric tank, and is really an oddity to design it per ASME VIII: by the way this would also include weld details, inspection, pressure test, etc.

prex

http://www.xcalcs.com

Online tools for structural design

 

[Heyner]

I had a similar trouble with a gas boot, 10 psi and 13.5ft dia, 40ftheight.

Finally, it was designed as per API standard 620. It has a torispherical head and 1.25"thk flat bottom, including anchor bolts. Great! ain't it? shell thk was ab 3/8". Many of these boots have been constructed, same details...

 

[JoeTank]

Hey prex... 0.1 psi is only about 3 inches of water column. Sounds like a gas pressure to me.

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com

 

[JoeTank]

Heyner,
Why was the bottom so thick? If the tank was anchored to a foundation I would have expected a much thinner tank bottom.

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com

 

[GenB]

I get less than .188" on
.1 PSI AND 120" dia, where and how did you get to 1.5" t.?
I really like to know.
The calc depends and changes according to the attachment desin, if you use a good attaching weld design you are okay. IF THE TANK HOLDS LIQUID, do not forget head prssure that must be added to the design pressure, it can add up considerable.
E.R.