Comparisons Between Internal Floating Roof Storage Tank And External Floating Storage Tank

When it comes to storing volatile liquids, the choice of storage tanks can significantly impact safety, efficiency, and cost. Two popular options are the internal floating roof storage tank and the external floating storage tank. Understanding the differences between these two types of tanks can help you make an informed decision that best suits your needs. In this article, we will delve into the key aspects of both types of tanks, highlighting their advantages and disadvantages.

Design and Structure

Internal Floating Roof Storage Tank

An internal floating roof storage tank is designed with a floating roof that sits directly on the surface of the stored liquid. This roof rises and falls with the liquid level, minimizing the space between the roof and the liquid. The primary purpose of the internal floating roof is to reduce vapor emissions and prevent the accumulation of flammable vapors. These tanks are often constructed with a stainless steel internal floating roof, which provides durability and resistance to corrosion.

External Floating Storage Tank

In contrast, an external floating storage tank features a floating roof that is exposed to the elements. The roof floats on the liquid's surface, similar to the internal floating roof, but it is not enclosed within the tank. This design allows for easy inspection and maintenance of the roof but can expose the stored liquid to weather conditions, potentially affecting its quality and increasing evaporation losses.

Safety and Environmental Impact

Internal Floating Roof Storage Tank

One of the primary benefits of an internal floating roof storage tank is its ability to significantly reduce vapor emissions. By minimizing the vapor space above the liquid, these tanks help in controlling volatile organic compound (VOC) emissions, which are harmful to both the environment and human health. Additionally, the enclosed design of the internal floating roof provides an extra layer of protection against external contaminants and potential ignition sources.

External Floating Storage Tank

While external floating storage tanks also help in reducing vapor emissions, they are generally less effective than their internal counterparts. The exposed roof can be affected by weather conditions, leading to higher evaporation rates and potential contamination from rainwater or debris. However, the external design allows for easier detection of leaks and other issues, which can be advantageous from a safety perspective.

Maintenance and Durability

Internal Floating Roof Storage Tank

Maintenance of an internal floating roof storage tank can be more challenging due to the enclosed design. Accessing the floating roof for inspection or repairs often requires specialized equipment and procedures. However, the use of a stainless steel internal floating roof can enhance the tank's durability and reduce the frequency of maintenance. Stainless steel is resistant to corrosion and can withstand harsh chemical environments, making it a reliable choice for long-term storage.

External Floating Storage Tank

External floating storage tanks are generally easier to maintain due to the exposed roof design. Inspections and repairs can be conducted without the need for complex procedures, reducing downtime and maintenance costs. However, the exposed roof is more susceptible to wear and tear from environmental factors, which can affect its longevity. Regular maintenance is essential to ensure the tank remains in good condition and continues to function effectively.

Cost Considerations

Internal Floating Roof Storage Tank

The initial cost of an internal floating roof storage tank can be higher due to the complexity of its design and the use of materials like stainless steel for the internal floating roof. However, the long-term benefits of reduced vapor emissions, enhanced safety, and lower maintenance frequency can offset the initial investment. These tanks are often preferred in industries where environmental regulations and safety standards are stringent.

External Floating Storage Tank

External floating storage tanks typically have a lower initial cost compared to internal floating roof tanks. The simpler design and ease of maintenance can result in cost savings, especially for short-term storage needs. However, the potential for higher evaporation losses and increased maintenance requirements should be considered when evaluating the overall cost-effectiveness of these tanks.

Both internal floating roof storage tanks and external floating storage tanks have their unique advantages and disadvantages. The choice between the two depends on various factors, including safety requirements, environmental impact, maintenance considerations, and cost. Internal floating roof storage tanks offer superior vapor control and enhanced safety, making them ideal for industries with strict regulations. On the other hand, external floating storage tanks provide easier maintenance and lower initial costs, which can be beneficial for certain applications. By understanding the key differences between these two types of tanks, you can make an informed decision that aligns with your specific storage needs.