Flat-Bottom Tank

The double-walled flat-bottom tank from Haase is suitable for the safe storage of chemicals, waste water and other water-polluting liquids.

There are high safety requirements for the storage of water-polluting liquids

According to the provisions of the Water Resources Act (Section 19 WHG), water-polluting liquids may only be used in suitable and approved containers, e.g. stored in a Haase flat-bottom tank. A particular advantage of these tanks made of glass fiber reinforced plastic: They can be assembled on site, so difficult access conditions are not a problem.


  • Wastewater treatment plants
  • Waterworks
  • Utility companies
  • Road maintenance
  • Baths operations
  • Landfills
  • Laboratories
  • Company gas stations
  • Workshops
  • Metalworker
  • Recycling company
  • Hospitals
  • Data centers
  • Hotels / Kitchens
  • Breweries
  • Agricultural holdings
  • and many more: Users from industry, craft and municipalities


  • Sewage
  • Precipitant
  • Diesel fuel
  • Urea / AdBlue

  • Lubricating oils
  • Coolants
  • Refrigerant
  • Firefighting foam
  • Salt brine
  • Food waste
  • Swimming pool water
  • Numerous acids and bases

Further media on request and according to media? list of the German Institute for Building Technology (DIBt), Berlin


  • Safety

    Automatic tightness monitoring in the double-walled flat-bottom tank from Haase – a drip pan is not required.

  • Flexibility

    The large number of diameter-height combinations available makes it possible to use the right tank size for almost every system. The tank offers the greatest possible flexibility with regard to the number, dimensions and arrangement of the connections and fittings.

  • Resistance

    Glass fiber reinforced plastic (GRP) is dimensionally stable, corrosion-free, chemically durable and temperature-stable.

  • On-site assembly

    The Haase flat-bottom tank is supplied in system parts and is only installed at the installation site. An approx. 80 cm wide door is sufficient, for example, to insert a tank with a volume of 40 m³.

  • Delivery times

    A nationwide network of qualified specialist partners ensures short delivery and assembly times.

  • Approved for earthquake zones

    According to approval, Haase flat-bottom tanks may be installed in earthquake zones.


The flat-bottom tank from Haase is constructed with double walls. This means that there is a second tank in the outer tank. The outer and inner tanks are each completely sealed. The control room is located between the walls and is automatically monitored around the clock by a vacuum leak detector.

Double-walled flat-bottom tanks from Haase therefore do not require a sump. Even in water protection areas, it is allowed to put these tanks “just like that” in the room.

Haase's above-ground flat-bottom tanks are double-walled and equipped with a vacuum leak detector.


  • Leak detector
  • Overfill protection
  • Level measurement
  • Connections made of GRP, PVC, KG or metal
  • Foot valves
  • Pipelines between the tanks
  • Tank insulation
  • Container heater
  • Flushing rings
  • Sloping floor
  • Gelcoat
  • Filling cabinets

Do you have any questions?

We will be happy to help you by phone or email.

+49 359 523 550



No installation room is like the other: one is wide and low, the other is narrow and high. One customer needs more storage space, the other less. Haase offers 10 different diameters from 1.03 m to 4.00 m and 9 standard heights between 1.05 m and 3.30 m: This way, every installation room can be optimally used.

Size Chart

Table with the size overview of the Haase flat-bottom tanks

View Table

Tank typeFilling volume [l]Diameter [m]Height [m]
Type S 10: diameter 1.03m
S 10-08 D7501,031,05
S 10-10 D9001,031,25
S 10-11 D1.1001,031,50
S 10-13 D1.2001,031,70
S 10-14 D1.3001,031,85
S 10-16 D1.6001,032,20
S 10-19 D1.8001,032,50
S 10-22 D2.2001,033,00
S 10-24 D2.4001,033,30
Type S 13: diameter 1.30 m
S 13-14 D1.2001,301,05
S 13-16 D1.5001,301,25
S 13-20 D1.8001,301,50
S 13-22 D2.0001,301,70
S 13-24 D2.2001,301,85
S 13-28 D2.6001,302,20
S 13-32 D3.0001,302,50
S 13-36 D3.6001,303,00
S 13-39 D3.9001,303,30
Type S 15: diameter 1.50 m
S 15-18 D1.7001,501,05
S 15-21 D2.0001,501,25
S 15-25 D2.4001,501,50
S 15-28 D2.7001,501,70
S 15-31 D3.0001,501,85
S 15-36 D3.6001,502,20
S 15-42 D4.0001,502,50
S 15-48 D4.8001,503,00
S 15-53 D5.3001,503,30
Type S 17: diameter 1.70 m
S 17-22 D2.1001,701,05
S 17-27 D2.5001,701,25
S 17-33 D3.0001,701,50
S 17-37 D3.5001,701,70
S 17-40 D3.8001,701,85
S 17-48 D4.5001,702,20
S 17-55 D5.1001,702,50
S 17-62 D6.2001,703,00
S 17-68 D6.8001,703,30
Type S 19: diameter 1.92 m
S 19-30 D3.0001,921,05
S 19-34 D3.4001,921,25
S 19-40 D4.0001,921,50
S 19-45 D4.5001,921,70
S 19-50 D4.9001,921,85
S 19-58 D5.8001,922,20
S 19-67 D6.6001,922,50
S 19-79 D7.9001,923,00
S 19-87 D8.7001,923,30
Type S 22: diameter 2.20 m
S 22-37 D3.7002,201,05
S 22-43 D4.3002,201,25
S 22-52 D5.2002,201,50
S 22-59 D5.9002,201,70
S 22-64 D6.4002,201,85
S 22-77 D7.7002,202,20
S 22-87 D8.7002,202,50
S 22-105 D10.5002,203,00
S 22-115 D11.5002,203,30
Type S 25: diameter 2.50 m
S 25-50 D4.7002,501,05
S 25-58 D5.7002,501,25
S 25-70 D6.8002,501,50
S 25-79 D7.7002,501,70
S 25-86 D8.3002,501,85
S 25-100 D10.0002,502,20
S 25-115 D11.4002,502,50
S 25-136 D13.6002,503,00
S 25-149 D14.9002,503,30
Type S 30: diameter 3.00 m
S 30-69 D6.9003,001,05
S 30-82 D8.2003,001,25
S 30-98 D9.8003,001,50
S 30-112 D11.2003,001,70
S 30-122 D12.2003,001,85
S 30-144 D14.4003,002,20
S 30-165 D16.5003,002,50
S 30-197 D19.7003,003,00
S 30-216 D21.6003,003,30
Type S 35: diameter 3.50 m
S 35-94 D9.4003,501,05
S 35-112 D11.2003,501,25
S 35-135 D13.5003,501,50
S 35-153 D15.3003,501,70
S 35-166 D16.6003,501,85
S 35-197 D19.7003,502,20
S 35-224 D22.4003,502,50
S 35-268 D26.9003,503,00
S 35-295 D29.5003,503,30
Type S 40: diameter 4.00 m
S 40-123 D12.3004,001,05
S 40-147 D14.7004,001,25
S 40-176 D17.6004,001,50
S 40-200 D20.0004,001,70
S 40-217 D21.7004,001,85
S 40-258 D25.8004,002,20
S 40-293 D29.3004,002,50
S 40-352 D35.2004,003,00
S 40-387 D38.7004,003,30


Representation of the different sizes of the Haase basement tanks and flat-bottom tanks.


The Haase flat-bottom tanks are characterized by their high chemical and mechanical strength. Because of the material GRP, they are particularly durable, age and weather resistant as well as odor and diffusion tight. Thanks to the low weight, moving the tank is also not a problem.
You can find more information on our GRP material and the various manufacturing processes on the following page.


Do you have any questions, would you like a specific offer or a free and non-binding on-site appointment? Then send us a message using our contact form or call your contact person Mr. Sebastian Eggert directly at +49 35 952 – 355 19.

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