Abstract: A sealed tank includes a concrete footing, a steel or concrete shell ring and a sealed and corrosion-resistant dome having a double membrane. There is an inner membrane delimiting, with the surface of the liquid effluent contained in the shell ring, a sealed chamber intended to receive biogas that results from the methane fermentation or from a corrosive environment. An outer membrane envelopes the inner membrane and which, when pressurized, applies a given pressure to the volume of biogas or of corrosive environment contained in the chamber.

Abstract: A device for stabilizing the inclination of an orientable member mobile in rotation relative to a support which is itself mobile. The device includes, the member, a gyroscope the input shaft of which is rotated on itself by an aiming motor having a casing fastened to a cradle coupled in rotation relative to the support by a transmission linkage determining a constant ratio between the relative rotation of the member and the casing relative to the support. The gyroscope includes a precession detector connected to the inclination motor by an automatic control circuit capable of applying at any time to the motor a signal adapted to compensate the precession induced by angular disturbance of the support about the inclination axis.