why all storage tanks & vessels are bullet shaped (cylindrical shell with hemispherical ends)?

Question

storage tanks/vessels used for transporting petroleum or other fluids,storing it etc.

Answer 1

Storage tanks and vessels are pressurized and vary in shapes. Usually if its for petroleum products, its shaped like a bullet or cylinder or sometimes spherical because it distributes pressure more evenly compare to vessels with edges.Pressure vessels used for transport are even more pressurized. And transport vessels especially for LPG have baffles (division) inside for additional stability of liquid when moving.

Answer 2

They aren't. Never-the-less, all are built regarding FUNCTION. The weight

of fluids + motion + inertia etc etc require certain strengths, expansion room,
internal serviceability - cleaning etc- and other variables according to the intended use. Thus cylindrical shapes fill the bill for many requirements
BETTER and c h e a p e r [# welds etc]. ALSO, the market is competitive:
thus if you were selling tanks, you would want to sell your tank design to
as many end users as possible and beat the competitor who made a different shaped tank for each use. Your custom tanks would have a higher price.
Picture the lateral pressure and thus force at the widest part of a gasoline
hauling semi-trailer taking a fairly sharp curve at 55mph. Compare the same truck with a rectangular tank of the same height make the same curve at
the same speed. The liquid would shift [but with a flat outer wall] and the cg
[center of gravity] could actually be higher with that tank, thus giving a stability favor to the cylindrical tank. You don't have to be an engineer to grasp the concepts of product standardization, production standardization, nor accessability for maintenance, nor tipover, etc etc etc hope this helps

Answer 3

#1 The ratio of volume by surface area is high in case of a cylinder. The highest is for a sphere. But there are problems in manufacturing and transporting spherical vessels. Low surface area means lesser material cost in manufacturing these bullet shaped vessels.
#2 Because of its shape there are fewer stress concentration points in bullet shaped vessels.
#3 Lesser welded joints. In case of a rectangular container all the sheets would have to be welded. In a bullet shaped vessel there are just two welded joints where the hemisphere connect to the cylinder.

Answer 4

Point your ears!

This is definately an engineering question. You will find on here many questions wondering what configuration produces the most area.

All knowledgeable people will say a circle, and thus for volume a cylinder.

The answer to your question is found in the cheapest available volume(area) per perimeter length.

For material, the circle is the way to go and governs most applications from a soda can to an oil or water storage structure.

Answer 5

The sphere is the best pressure vessle available, but transportation restraints limit the diameter, so the compromise of the cylinder with spherical end caps is used.

Answer 6

It helps spread the pressure of the contents over the inside surface better.