Crude oil storage tanks

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The production of petroleum in all of its different states requires different types and sizes of tanks at different stages. Crude oil is the naturally occurring liquid form of petroleum. This is the oil that is then refined into other fuels and oil products that we use on a daily basis all over the world, such as petrol, paraffin and diesel oil. There are some companies that speculatively buy crude oil, and then store it for a time when oil prices go up. Most of the time, the storage of crude oil is temporary. This is because the oil gets moved to other places for further refinement. The tanks are predominantly found above ground. The crude oil storage tanks design must be up to code to ensure that there are no leaks that could potentially cause environmental damage.

In the cases where there is extra oil, that is, more than is needed to cover the needs of the nation, the crude oil is stored under the ground in salt domes. These domes have to be surrounded by rocks that do not allow liquids to pass through them. It would be disastrous to have the crude oil contaminating underground water reserves and so the site is thoroughly vetted beforehand.

Types of crude oil storage tanks

There are a few different types of crude oil storage tanks. To see which type of tank is better suited for a product, you must take the properties of the type of substance that you want to store into consideration. Generally storage tanks can be classified as pressurised storage tanks and atmospheric storage tanks. Pressurised storage tanks are usually used for storing liquids that evaporate. For this reason atmospheric storage tanks are the ones that are best suited for storing crude oil. Atmospheric tanks are operated at or near the pressure found in the atmosphere. Atmospheric storage tanks can be further broken down into open top storage tanks, fixed roof tanks and floating roof storage tanks. Open top tanks are better suited for storing water. The remaining two are widely used to store crude oil, among other oil products. Fixed roof storage tanks are used when the quantities of crude oil are not that much.

Floating roof oil tanks have a cylindrical steel shell. As the name of the tank suggests, this cylindrical steel shell has a floating roof, meaning that it floats on top of the liquid that is in the tank. This is a very interesting concept. When the crude oil levels are low, then the position of the roof will be low as well. When there is more crude oil being stored in the tank, then the level of the roof rises to match the level of the oil.

Floating roof tanks are more ideal for the storage of large quantities of crude oil. Crude oil emits extremely volatile natural gas as well as some air pollutants. The gases collect in the space that is between the roof and the crude oil. The rim seal on the floating roof tank keeps these emissions of highly combustible vapours being released into the environment. These vapours could cause fires and explosions, and so it is good for them to be contained. Depending on the preferences of the owner, it is possible to install mechanisms to capture this vapour so that it is not lost and can be either used at the plant where the crude oil is stored or it can be packaged for sale to interested parties.

The down side of floating roof storage tanks is that they are prone to be affected by the elements. Heavy snow can accumulate on the roof of the tank and cause the roof to be pushed down into the crude oil below. Rain water also has the same effect tank capacity.

Construction of crude oil storage tanks

The construction of storage tanks for crude oil is a process that requires great care. There is no room for leaks in these tanks and they must be rigorously tested before they are put to use. The specifications for these tanks differ from client to client. Many companies that manufacture crude oil storage tanks use carbon steel, which is a type of steel that contains percentages of carbon. Stainless steel is also used, which is a type of steel that contains chromium, which is rust resistant. Carbon steel is cheaper than stainless steel, and so some companies may prefer it as the material that their tanks are made of.

Dimensions and capacity of crude oil storage tanks

Much like every other aspect, crude oil storage tank dimensions really depend on the needs of the client. Some crude oil storage tanks can have a diameter of 30 metres and a height of 10 metres. The bigger oil companies that refine their own oil have large crude oil storage tanks. The crude oil storage tank capacity of a tank that has a diameter of 88 metres and a height of 19.5 metres will be roughly 118 000 cubic metres. Some tanks are so large that they can hold a massive 16 million gallons of crude oil at a time tank size.

In a world where everyone is concerned with keeping the environment clean for future generations to enjoy, it has never been more important to make sure that oil spills are minimised as much as possible. As a result, it is imperative that the tanks that store massive amounts of crude oil be made out of the best materials. The tanks need to be the right size for the amount of oil that they will hold. They also need to have a containment area, or bunding, that has at least the capacity of the tank. Leaks do happen and it is prudent to be prepared for the worst case scenario. Crude oil must be handled safely and securely so that it proceeds to refinement, and we get the various oil products that we get out of it while keeping our world safe.