Why are big water, and fuel tanks cylindrical? Wouldnt it be easier to build them in cubic with straight sides

Question

Wouldnt straight panels be easier to build? What about a more efficient footprint? What about all the waste involved in cutting a round top?

Answer 1

The pressure exerted within the tank cavity is equally distributed amongst all surface areas. The physics in the cylindrical shape actually increase tank strength and rigidity when occupied due to equal opposing force on all sides. This is a natural design to disburse force, similar as to why balloons blow up round and not with angles.

Footprint must be compromised for practicality. When necessary additional height can provide greater volume.

All sheaves and top decks are made with special tooling so there is no more waste than if square or flat. Top decks are placed together in pie shaped segments that adjoin in the center above a ladder that acts as the top deck support. Access to this ladder is provided via a manway or opening large enough for a man or woman to enter the tank.

Great question Dan V, I love talking tank. Ask me about LLI's.

Answer 2

Cylindrical Water Tank

Answer 3

The strength of steel joints depends upon whether they are in compression, tension, or shear. A cylindrical shape with the apllied force inside will be in tension, rather than shear. Generally, all materials have structural properties such that they are strongest in compression, then tension, and least in shear.

When a joint is welded into a sphere or a pipe it is in tension. If the joint is at 90 degrees to each other, it is in shear.

Answer 4

I don't think so

Cylindrical barrels must be more resistant to the liquid pressure than straight ones, and I don't think they are more difficult to build.

The only drawback I see is for storage : place is wasted between cylindrical barrels

Answer 5

it would be alot more expensive, it would have less ability to withstand earthquakes if it had corners, and just about every reason that there aren't any square ones tell you that one piece of flat sheet metal is rolled into a circle and that's easy and welded up and only has one seem. now from the stand point of how many of them there are in the world and how much it would cost to do all the work to change this it would have to have an enormous advantage about the square deal to get on the drawing board and it would be cost prohibitively swept away.

Answer 6

Simple application of materials resistance.
In a cube shape, the most elastic point will be at the center of the face, and the cube would "bubble" in the center of each face, going towards a spherical shape.
In a shpere, ALL points receiving the same force (pressure) are in equilibrium.
A cylinder is similar on its circle: the forces are equal and tensions in the material are equal. Note that the covers are not flat either: they are curved like a part of a sphere: same reason: balance the tensions in the material.

Answer 7

Never arrempt to clean an old metal storage tank, it is being held together with rust, I would suggest that you have it replaced with a plastic one. If your funds are low, DON'T clean it, place old aluminum coke cans with the paint scraped off into the water . The old cans will become the sacrificial anode, and stop further corrosion of the steel. THEY CANNOT REPLATE STEEL BACK INTO THE RUST HOLES, so go for plastic.

Answer 8

Physics was never really my thing, but wouldn't the pressure on the walls of a cylinder be more evenly divided? Like if you fill a flimsy plastic cube full of water, doesn't it bulge outward in a cylinder shape?

Answer 9

Ridgely is correct. For a given amount of material to build with, the cylinder provides the most volume. Do your own calculation. Also, the stress distrubution is pure tension.

Answer 10

It would be easier to build them but it is easier to EMPTY them if they are in a cylinder. If you need to apply air pressure to do so it takes less stress off of the strucure if it is a cylider. Also it is easier to transfer liquid in cylinders.