The difference between flexitank and ISO tank : Everything you need to know

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In the world of liquid transportation, there are various methods and containers used to move bulk liquids efficiently. Two prominent options are Flexitanks and ISO Tanks, each with its own set of advantages and disadvantages. This article aims to provide you with an in-depth comparison of Flexitanks and ISO Tanks, focusing on their differences, uses, and environmental implications.

What is a Flexitank?

A Flexitank, short for “flexible tank,” is a single-use, flexible, and collapsible bladder designed to carry non-hazardous liquid cargo. These tanks are made from multiple layers of polyethylene or polypropylene and are installed inside a standard 20-foot shipping container. Flexitanks come in various capacities, ranging from 16,000 to 26,000 liters, making them suitable for transporting a wide range of liquid products, from food-grade liquids to non-hazardous chemicals.

Advantages of Flexitanks:

1. Cost-Effective: Flexitanks are more economical than ISO Tanks due to their lower initial investment costs and reduced cleaning and maintenance expenses.

2. Versatility: They can transport a variety of liquid cargos, including oils, wines, fruit juices, and industrial chemicals.

3. Easy Installation: Setting up a Flexitank is a straightforward process, and it doesn’t require specialized equipment or manpower.

4. Single-Use: Flexitanks are disposable, eliminating the need for return logistics, cleaning, and maintenance.

5. Space Efficiency: Flexitanks maximize the use of available container space, as they expand to fit the container’s dimensions.

What is an ISO Tank?

An ISO Tank, or intermodal tank, is a steel tank container built to ISO standards. These tanks come in various sizes, including 20-foot and 40-foot containers, and are used to transport both hazardous and non-hazardous liquids. ISO Tanks are designed to withstand rugged handling and harsh environmental conditions, making them suitable for long-distance transportation.

Advantages of ISO Tanks:

1. Durability: ISO Tanks are built to last, with a strong steel frame capable of withstanding rough handling and extreme conditions.

2. Reusability: ISO Tanks are designed for multiple uses, reducing the overall cost per trip as they can be refilled and transported again.

3. Cargo Safety: ISO Tanks provide secure containment for hazardous liquids, reducing the risk of spills and leaks during transportation.

4. Environmentally Friendly: The reusability of ISO Tanks minimizes waste and reduces the environmental impact.

Differences Between Flexitanks and ISO Tanks

1. Material and Design:

The primary distinction between Flexitanks and ISO Tanks is the material and design. Flexitanks are single-use, flexible bladders made from polyethylene or polypropylene, while ISO Tanks are rigid containers constructed from steel. ISO Tanks are reusable, whereas Flexitanks are intended for one-time use.

2. Liquid Compatibility:

ISO Tanks are suitable for both hazardous and non-hazardous liquids, thanks to their robust construction and safety features. Flexitanks, on the other hand, are typically designed for non-hazardous liquids and are not recommended for hazardous cargo.

3. Transportation Costs:

Flexitanks have a clear advantage when it comes to transportation costs. They are more cost-effective to use initially and incur lower cleaning and maintenance expenses. ISO Tanks require more significant initial investment and ongoing maintenance, including cleaning and repair.

4. Environmental Impact:

ISO Tanks are more environmentally friendly in the long run due to their reusability. They reduce the amount of waste generated, making them a sustainable option. Flexitanks, being single-use, contribute to higher waste generation.

5. Capacity:

ISO Tanks come in various sizes, making them suitable for different cargo capacities. Flexitanks, on the other hand, have fixed capacities, which may limit their suitability for certain cargo quantities.

6. Installation and Handling:

Flexitanks are easy to install, requiring minimal equipment and expertise. ISO Tanks, due to their size and weight, require specialized equipment for handling and transportation.

7. Safety and Containment:

ISO Tanks offer better safety and containment for hazardous liquids due to their steel construction. Flexitanks may not be the ideal choice for such cargo due to their flexibility.

Uses of Flexitanks and ISO Tanks

Flexitanks and ISO Tanks serve different purposes, and their suitability depends on the type of liquid cargo and specific transportation needs.

Flexitank Uses:

1. Food and Beverages: Flexitanks are commonly used to transport food-grade liquids such as vegetable oils, fruit juices, and wines.

2. Non-Hazardous Chemicals: They are suitable for non-hazardous industrial chemicals that don’t require the safety features of ISO Tanks.

3. Agriculture: Flexitanks can carry liquid fertilizers and crop protection products.

ISO Tank Uses:

1. Hazardous Chemicals: ISO Tanks are designed to safely transport hazardous chemicals, including flammable and corrosive substances.

2. Bulk Liquids: They are used for the efficient transportation of large quantities of non-hazardous liquids, such as water, fuel, and industrial chemicals.

3. Pharmaceuticals: ISO Tanks can be used to transport pharmaceutical products, ensuring product integrity and safety.


In the choice between Flexitanks and ISO Tanks, there is no one-size-fits-all answer. The decision depends on the specific requirements of your liquid cargo transportation. Flexitanks are cost-effective, easy to use, and versatile for non-hazardous liquids, while ISO Tanks offer durability, reusability, and enhanced safety for both hazardous and non-hazardous cargo.

Environmental considerations also play a significant role in this decision. If sustainability is a top priority, ISO Tanks, with their reusability, can be the more eco-friendly option.

Ultimately, whether you opt for Flexitanks or ISO Tanks, it’s essential to weigh the advantages and disadvantages in the context of your cargo, budget, and environmental values. By understanding the key differences between these two liquid transportation methods, you can make an informed choice that best suits your needs.

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