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 Ingenieurbüro Imhof GmbH · Otto Hahn Str. 12 · 63165 Mühlheim/Main - Germany / Allemagne
 Tel./ Phone / Téléphone: +49 6108 / 6 09 99 · E-Mail:

External Floating Roof

Integrated Double Seals


  • High sealing efficiency
  • Exceptional centring of floating roof by using spring elements with progressive increasing compression forces
  • Safe application even with very wide rim gap variations
  • Small height above pontoon required. No loss of tank capacity

Imhof Tanktechnik - IM-GLS2, IM-GLW2, IM-GHS2 und IM-GHW2 integrierte Doppeldichtung IM-GLS2 für externe Schwimmdächer IM-GLS2  IM-GLW2**    IM-GHS2          IM-GHW2**

Imhof Tanktechnik - IM-GKSS2B integrierte Doppeldichtung IM-GKSS2B für externe Schwimmdächer

(**) These seals are equipped with a water-absorbent contact element to the tank wall, and are designed for water-free storage for all "white" storage products.

Shoe type seals, type "GL" are designed for floating roofs type CBI or Graver or similar.

Shoe type seals, type "GH" are designed for floating roofs type Wiggins or similar.

Usually, all metal parts are supplied in stainless steel. All sealing curtains are antistatic on both sides, and compatible with the storage products and the atmospheric conditions.

Integrated double seals can be equipped with additional weather shields, if required.


Separate Secondary or Tertiary Seals

Typical seals for refined ("white") storage products

(**) These seals are equipped with a water-absorbent contact element and are used for water-free storage
of "white" products.

Typical seals for crude oil tanks

Der letter "C" stands for Compression-Plate-type seals.


Threefold Seals

Basically, each existing floating roof sealing systems can be upgraded to a threefold sealing system.

Here it is advisable to start with an integrated double seal. In this case the third seal only need the height of a former separate secondary seal.

In case of tanks for “white” storage products (refined products) the third seal shall be equipped with a water- absorbent contact element, draining all rain from inner tank walls.

As from 2006 IMHOF has upgraded numerous primary and secondary systems into threefold sealing systems.

Furthermore we supplied threefold sealing systems for a number of gasoline tank farms in Switzerland, equipped with free ventilated fixed roof tanks and internal floating covers.
The advantage for the customer was to avoid costly installations for vapor balancing and vapor recovery systems to meet stringent rules of the Swiss health system.

Typical threefold seal for refined ("white") products

The water absobent third seal completely (98%) removes rainwater films from the inner tank wall and drains the water onto the floating roof deck.

Typical threefold seal for crude oil tank


© Ingenieurbüro Imhof GmbH • Otto-Hahn-Str. 12 • 63165 Mühlheim/Germany • Tel. +49 6108 / 60 999 •