There are many ways to store liquids and the final choice depends on several main factors. There are tanks available on the market made of: reinforced concrete, steel, polypropylene, polyethylene. However, to transport a 100m3 tank on one pallet for three hundred zlotys and “assemble” it in 30 minutes – it is only possible with the technology of highly durable technical fabrics. Flexible tanks for several decades in the world have been increasing the group of their supporters.
As is usually the case, innovative technologies where logistics and simplicity count, start their way in the army. The first rubberized fabric tanks appeared in the Allied army during World War II, for the purpose of storing fuel in them.
In later years, there was an increase in ideas for their use and the development of the fabrics themselves. Polyester fabrics coated with plastomers (polyurethane and polyvinyl chloride) appeared. For several decades, flexible tanks around the world have been used to store: wine, drinking water, liquid manure, rainwater, mineral fertilizers, fuels and a number of chemicals.
The shape of the flexible reservoir resembles a pillow or a closed bag or balloon. Its shape is formed by a liquid, which is assumed to fill it evenly inside. When filling the tank, its walls rise with the connections. Free-standing “cushions” are usually 1.3 – 1.7 m high.
Flexible tanks can be made of rubber (rubber tanks), but currently in the world they are most often made of special multi-layer fabrics. The inner carrier, mainly responsible for the tear strength, is made of polyester or nylon and a layer of varnishes and plastomers (usually PVC) responsible for UV resistance, tightness and chemical-physical factors. The fabrics are selected depending on the capacity of the tanks and their purpose.
Example of multi-layer technical fabrics (source: www.sioencoating.com)
As with any product, there are a number of “positive and negative” features. Let’s look at the most important ones:
When choosing a flexible tank, it is worth considering all its features. If we plan to invest in the coming years, the several-year (and possibly longer) service life of a flexible tank, combined with its advantages and the lowest storage price per cubic meter, may perfectly match the Investor’s needs.
There are many ideas for the use of flexible tanks, because more and more industries are looking for alternative, reusable and cheaper solutions.
Examples of applications of flexible tanks:
Before we decide to buy a flexible tank, it is worth making sure that the given liquid does not react negatively with the tank jacket. If it is a chemical substance for which we have a safety data sheet – check the recommended packaging and storage in it. If it is a typical liquid (water, fertilizers, oils) – the manufacturer of the tanks usually dedicates products to the most common applications.
Tank material: it is worth comparing the technical parameters of fabrics (manufacturers usually provide: grammage, resistance to tearing or stretching). Note – although the final coating in the tanks compared may be the same, i.e. PVC, the PVC fabric should be dedicated to work in a given chemical environment (there are differences in the production process of PVC fabrics and selected varnishes). If you plan to buy a drinking water tank, ask about the certificates of the tank fabric and components.
Flexible tank manufacturer – it is worth paying attention to the origin of the product, the experience of its manufacturer, but also to the service and technical support it offers.
The growing group of supporters and users of flexible tanks every day proves that it is worth considering, for example, this fluid storage technology. It can be the most economical solution, while ensuring the necessary safety and tightness.
