Double Membrane

The AGROTEL double membrane gas storage facility is designed as an air-inflated roof with integrated gas storage. A combination of technology and operating efficiency ensures robustness, durability and diverse application possibilities for our system.

Double membrane - gas storageDouble membrane - green outside membraneDouble membrane - grey outside membrane


Robustness of the AGROTEL double membrane gas storage facility is due to the design and the respective interaction of the individual components. The double membrane is equipped with a centrifugal fan to withstand the harsh effects of rain, snow or wind, as well as to generate the necessary primary pressure to the gas system. Naturally, the fan can be regulated and is connected with the external membrane. The internal membrane on the edge of the tank is fitted to be gas-tight, separate from the external membrane. It is tailored to be smaller than the external membrane to ensure that a particular air cushion is maintained between the two membranes. On one hand, this guarantees the necessary air-inflated cushion, while on the other hand provides additional insulation. The double membranes made from polyester fabric are synthetic-coated and painted on both sides.

Durability and sealing

Durability of our double membranes is guaranteed due to the supports made out of stainless steel, screw connections and cables. A stainless steel support protruding above the height of the tank wall is situated in the centre of the tank. Arches forming a star shape are projected from this central support out to the tank wall at distances of approx. 0.80m. A net is then laid across the entire expanse of the arched structure to support the internal membrane in the event of insufficient or total lack of gas pressure. This ensures that your precious gas remains in the tank, preventing any loss.


The AGROTEL double membrane gas storage can be applied independently of the material constitution of the tank - regardless of whether the tank is made of concrete, enamel or metal. AGROTEL produces double membrane gas storage facilities featuring diameters of up to 40m. A concrete support already installed on-site – upwards of 30m in diameter would be advantageous - can be integrated into this system.

Taut net - biogas componentsCarrier belts - subconstruction double membraneBiogasplant - schematic drawing

Details at a glance:

  • Membranes made from polyester fabric, synthetic-coated on both sides
  • Painted, extremely flame-resistant B1 as stipulated by DIN 4102
  • Weather-resistant centrifugal pressure blower with pressure regulation
  • Mechanical gas level measuring with GasHmeter
  • Mechanical overpressure and underpressure protection
  • Liquid drum secured directly onto the tank (fermenter)
  • Stainless steel chimney pipe
  • On-site setting of control
  • Standard pressure settings: overpressure 5 mbar, underpressure 2 mbar


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