Height/Diameter ratio for storage tanks 6

[16548613513]

Hi all,

My question is regarding the H/D ratio for the storage tanks. What is the min and max ratio and is there any standart at the API, AWWA or other codes ?

Thanks in advance

 

[JStephen]

There is not any standard or minimum or maximum.
For very large tanks, the product weight should be less than allowable soil bearing, which may limit height.
For very small tanks, it is advantageous to keep the diameter small enough to allow easy hauling if shop-fabricated.
For medium-size tanks, it is advantageous to match height to standard plate widths, so typically, 24', 32', 40', 48' in the US.
For medium-size tanks, approximately H/D = 1 is not uncommon.
High wind areas or high seismic areas will affect the optimum size.
Floating roofs or pressurized tanks may shift the optimum size.

 

[LittleInch]

I don't think you'll see more than 4:1 or 1:4,but no standard or code.

You won't see much higher than about 18m due to wind loads and ground pressure like j Stephen says.

Less than 1000 m3 often higher than diameter, 1 to 4000 1 to 1, more tham 5000 lower than 1 to 1. But this is a very basic guide.

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

 

[3DDave]

Eventually there's an economic limit where the ratio of surface (the metal part) is increasing faster than the volume (what you are paying to store) I recall that as a calculus problem of some sort to find the ratio of the best volume to surface area for a cylinder. If spheres were easier to fab than they are and were easier to support than they are, I expect all storage tanks would be spheres.

The only exceptions are where the section area is limited by some other means - which tank cars on railroads and tanker trailers on highways are, forcing the lengths to increase from the best ratio.

 

[JStephen]

The problem with optimizing the shape is that the cost of roofs, bottoms, and foundations is not the same as the cost of shells.
Long ago, I made up a nice little graph of tank cost per gallon from one end of the spectrum to the other. As expected, it was higher at the ends, but the center part of that graph was pretty flat, too.
I think I've seen tanks built from about H/D = 18.75 to H/D = 1/8.

 

[fel3]

JStephen....

I personally know of one AWWA D-100 water tank in Southern California that has a diameter of 210 ft and a shell height of 32 ft, for H/D = 1/6.6. It was designed in an office I worked in, but before my time there. I was told the reason it wasn't something more like 190 ft dia x 40 ft high (H/D = 1/4.75) was to reduce visual impact.

The largest water tanks I have designed (two of them at this size) are 130 ft dia by 32 ft high (H/D = 1/4.1, or very close to what LittleInch suggested).

============
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[Jay_]

hello,
H/D ratio is very helpful in determining the optimal tank overall weight, but again you should take into consideration a lot of things, such as the location of the tank primarily the design pressure/vacuum.
now for an atmospheric storage tank, it's usually determined by the manufacturer expertise, but i have read a very useful paper online that can help you choose an approximate H/D depending on the capacity of the tank and it takes into consideration the roof structure as well. i can submit it to you if you'd like.
now for a pressure vessel, i advise you to read the Pressure Vessel Handbook by Eugene Megyesy, it discusses this issue.
and if you are the manufacturer don't forget to take into consideration the amount of material excess in the stage of choosing H/D,
greetings.

Detailing is a hobby,

 

[16548613513]

Thanks a lot for everyone

Dear Mr. Jay, Could you please submit the paper that you have mentioned?



Thank you so much