The NBS™ system developed by ASTEK creates a low oxygen environment inside the fuel tank as the fuel is used and renders the gases within the tank unignitable.

The system is based on drawing normal atmospheric air through a specially treated and patented hollow fibre gas separation membrane that separates the air into an oxygen rich fraction and an inert nitrogen rich fraction. The nitrogen rich air, which would only contain 11% oxygen instead of the 21% oxygen in normal air, is fed to the fuel tank. As the fuel level drops inside the fuel tank, nitrogen rich air is continually drawn into the tank so as to form a permanent blanket of inert air over the fuel. The system does not store nitrogen on board the vehicle and no pressure vessels are involved.

The lightweight nitrogen blanketing device is derived from a system developed to provide an inert atmosphere inside the fuel tanks of large passenger aircraft.

The membrane units are cylindrical and the housings can be constructed in Aluminium alloy or composite materials such as carbon fibre where unit weight is critical.

The patented membrane system has been designed to produce specific gas mixtures at low pressures and is therefore the safest and most efficient unit available.