Device for pressurising a lift tank

The device has a gas generator (1) i.e. single or dual-fuel gas generator, operated by combustion of fuel (7) i.e. explosive material, present in a fuel tank (8). Amount of fuel supplied during the combustion depends on pressure present in a buoyancy tank (18) and volume increments to be compensated. Force is exerted on the fuel by a medium (10) i.e. water. An outlet cross-section of the gas generator is adjustable based on pressure predominated in the buoyancy tank. Pressure present in a combustion chamber (1a) of the generator is higher than or equal to pressure in the buoyancy tank.