Design Considerations for Tank Farm Layout

Storage tanks are used extensively across commercial & industrial applications to store oil, gas, fuel, chemical products, and other materials. A tank farm is an area where multiple storage tanks are located together.

These structures look simple on the outside. However, consideration of extremely high safety & environmental standards is a must while designing them. In other words, storage tanks are the impressive feats of engineering.

Read on as through this article, I hope to provide an overview of storage tanks and highlights critical design considerations for the tank farm's equipment layout.

Types of Storage Tanks in Process Plants

Storage tanks are most common in the petroleum industries. The type of containers used in a process plant depends on the product to be stored, the capacity to be utilized, and environmental and ground conditions.

• Cone roof tank: Used to store chemicals, petroleum, petrochemicals, food products & more
• Floating roof tank: Used to store oil and petroleum products in most cases
• Low-temperature storage tank: Used to store liquefied gases
• Horizontal pressure tank: Used to store products that need to be stored at high pressure
• Hortonsphere pressure tank: Used to store products in large capacity under high pressure
• FRP tank: Used to store corrosive fluid
• Underground tank: Used to store drain collection of the plant

Design Considerations for the Tank Farm Layout

Tanks farms, also known as offsite, cover around 75% of the total plot area and can have storage tanks in various shapes and sizes. Safety & economy are the two governing factors that help design tank farms for an industrial plant.

General design considerations for the equipment layout of the tank farm are:

• Client specifications
• Local codes & regulations
• Nearby plant facilities
• Topography
• Type of material to be stored
• Operation & maintenance parameters

The equipment engineering service providers widely use API standards for the design & analysis of storage tanks, pressure vessels, and other equipment.

For instance, API 620 refers to the design of a low-pressure storage tank made with steel and consists of a diameter of more than 300 feet.

Now, let us look at the detailed design considerations for the storage tank farm layout.

• Type of material to be stored in the tanks
• Statutory & safety requirements
• Equipment & supporting facilities
• Piping layout
• Construction material to be used

The material stored in the storage tank can be volatile or require a specific temperature to be stored for the long term. Therefore, the storage tank design often relies on the material being stored.

For instance, floating roof tanks are recommended to store volatile products because when the space between the roof and the liquid is filled with combustible gases, the floating roof protects the liquid from evaporation & contamination. 

Dike Enclosures are Important

For safety measures, all the storage tanks must have dike enclosures. It helps protect nearby properties in the event of accidental leaks or damages.

There are two types of dike; 1) Concrete, and 2) Earthen.

A qualified professional with suitable experience can help choose the right dike according to your industry requirements.

Below are some essential tank farm layout considerations for dike enclosures:

• Storage tanks with 47,700m3 capacity & above must be positioned in a single row, and all the tanks should be arranged in two rows maximum.
• The tank shell and the inside toe of the dike wall must at least have a distance equal to half the height of the storage tank.
• For the petroleum class products, the dike enclosure should have the capacity to consume the whole material of the most massive tank in the specific tank farm.
• If multiple tanks are arranged in a single dike enclosure, an intermediate dike should be laid with a height 450 mm for concrete and 600 mm for earthen.

Piping Layout Considerations

Various factors play a role in finalizing the design of the tank farm piping layout, including:

1. Type of the product to be stored
2. Piping material
3. Type & size of the storage container
4. Tank Settlement
5. Type of the dike

Conclusion

Storage tanks have a wide range of applications. And the plant owners must ensure that adequate safety measures are considered while designing and maintaining the tanks.

A reliable engineering services company can help with the efficient design of the industrial equipment layout of tank farms. With modern tools and technologies, they can help EPC organizations design and install storage tanks, irrespective of their location, project size, and volume.