The term “storage tank” has a remarkably broad definition. While it sounds simple enough, a storage tank will vary from person to person and industry to industry.  Custom fabricated storage tanks can be designed and built to contain organic liquids, non-organic liquids, vapors, or solids. These custom tanks are specifically designed and built with a customer’s need and usage in mind. Industries where storage tanks can be found are typically industries consuming or producing good, liquids, and or vapors. Industries likepetroleum either in producing or manufacturing petroleum, chemical engineering and or manufacturing, and the agriculture industry for bulk storage. Keep reading for a breakdown of storage tank styles and materials to make them.

Types of Tanks

The use of the storage tank and what it will contain will determine the type of tank required.

Spherical Storage Tank Swanton WeldingSpherical storage tanks – Spherical storage tanks are mainly used for storage of high-pressure fluids. The curved shape makes spherical tanks very strong. The even distribution of stresses on the sphere’s surfaces, both internally and externally, generally means that there are no weak points. Spheres however, are much more costly to manufacture than cylindrical vessels.  An advantage of spherical storage vessels is, that they have a smaller surface area per unit volume than any other shape of vessel.

This means, that the quantity of heat transferred from warmer surroundings to the liquid in the sphere.

Cylindrical Storage Stank Swanton Welding

Cylindrical Storage Tanks – Cylinders are widely used for storage due to their being less expensive to produce than spheres. However, cylinders are not as strong as spheres due to the weak point at each end.  Hemispherical or rounded ends being fitted reduce this weakness. If the whole cylinder is manufactured from thicker material than a comparable spherical vessel of similar capacity, storage pressure can be similar to that of a sphere.

Fixed Roof Storage Tank Swanton WeldingFixed Roof Storage Tanks – Fixed-roof tanks are usually the least expensive to construct. They are generally considered the minimum acceptable equipment for storing liquids. A typical fixed-roof tank consists of a cylindrical steel shell with a cone- or dome-shaped roof that is permanently affixed to the tank shell. Storage tanks are usually fully welded and designed for both liquid and vapor. A breather valve is often installed on fixed-roof tanks. This allows the tank to operate at a slight internal pressure or vacuum. This valve prevents the release of vapors during only very small changes in temperature, barometric pressure, or liquid level