Onion Water TankOnion Water Tank

Onion Water Tank - OPENTANK

The OPENTANK onion water tank is in circular shape. It is composed of an inflatable or foam float.

In contrast to the closed flexible tank, this open storage solution allows for quick storage of raw or drinking water by its top opening. Thanks to its fast installation and pumping/filling and its light weight, it can be used in a punctual way. Moreover, it is foldable. Therefore takes up very little space. It is also very easy to clean in case of water pollution by sludge, leaves, sand etc..

This open top water storage tank has been primarily designed for :

  • The storage of raw water dedicated to civil security.  This solution is widely used by firemen to fight forest fires. Helicopters carry bambi buckets that will fill up quickly by dipping them into our open top water storage tanks.  
  • And the storage of drinking water dedicated to humanitarian organizations.

However, this Onion Water Tank can also be used for the storage of industrial effluents or polluted water.

Like our other flexible tanks, it is made of highly resistant PVC coated fabric (1300 gr/m2) and assembled by high frequency welding. This fabric is resistant to any temperature from -30°C to +70°C. 

In the same register, we find the VOLUTEX water retention tank. This is an open top flexible tank dedicated to the storage of all types of solid or liquid elements for a temporary or permanent period.



  • One-off storage
  • Fast pumping/filling


  • Very high resistance coating fabric


  • Foldable and lightweight
  • Fast filling
  • Simple full interior cleaning

Detailed information

  • Material: high resistance 1300 gr/m2 cloth
  • Coating: PVC
  • Technical aspects: high-frequency welding
  • Temperature resistance: -30°C to + 70°C
  • Tailor-made
  • Accessories:
    • One DN50 pipe with direct passage valve and connector + Guillemin system cap, Camlock or others on request
    • One groundsheet

Technical informations

Dimensions (m3) Max. diameter Opening diameter Overall height (mm)
1 1.75 1 600
2 2.20 1.50 750
3 2.55 1.90 850
5 3.05 2.10 1000
10 4.25 3.50 1000
15 5.20 4.70 1000
20 6.05 5.00 1000

You can not find your dimensions

Our design department employs the best project leaders and designers and will be pleased to develop and create a tailor-made product specially for your unique project.


Composition / Advice

Care during use
Avoid any contact with surfaces that are too abrasive or have cutting edges. Never exceed the product’s rated capacity. Refer to the Installation manual.
Maintenance advice
Clean outside parts with clear or soapy water using a soft brush, rince and dry.
Storage advice
Store always in its original box, away from light, humidity and temperature variations.

Standards / regulations

ISO 9001, ISO 140001, ISO 45001


Fact Sheets / Business Guides
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Outlet DN50
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