The invention relates to a method for draining water from a tank (22), more particularly a clarification tank, wherein water is optionally drained via a draining apparatus while maintaining a substantially constant liquid level (23).

A minor water leak prevention apparatus for a water inlet valve, in which a float is mounted on a regulation bar and received in a water container. The water container is mounted on a siphon tube. The siphon tube is formed with an air aperture. A counterweight buoyance switch is mounted on the water container. The counterweight buoyance switch has a counterweight water compartment having a lower end forming a water drain hole. The counterweight water compartment has an upper end to which a closure pressing plate is mounted. The closure pressing plate is opposite to the air aperture. The counterweight buoyance switch controls opening/closing of the air aperture. This arrangement allows water ingress through a water inlet valve to be stopped when minor water leakage occurs in a water tank.

The invention relates to a method for draining water from a tank (22), more particularly a clarification tank, wherein water is optionally drained via a draining apparatus while maintaining a substantially constant liquid level (23).

A device for controlling the filling of a cistern in a main reservoir of a toilet flushing system includes a water inlet controlled by a valve. The closing of the valve is controlled by a float that is movable from a high position to a low position. The float is contained in a float housing in the high position. The float housing connects to the main reservoir by at least one siphon having two tubes: a suction tube linked to the float housing; and a discharge tube being linked to the main reservoir and opening into an auxiliary reservoir. There is a control mechanism provided with a mechanism for priming the siphon, wherein shifts between an initial position and an actuated position of the control mechanism result in overpressure or underpressure at the siphon so as to control draining of the float housing.

Disclosed is a minor water leak prevention apparatus for a water inlet valve. A float is mounted on a regulation bar and received in a water container. The water container is mounted on a siphon tube. The siphon tube is formed with an air aperture. A counterweight buoyance switch is mounted on the water container. The counterweight buoyance switch has a counterweight water compartment having a lower end forming a water drain hole. The counterweight water compartment has an upper end to which a closure pressing plate is mounted. The closure pressing plate is opposite to the air aperture. The counterweight buoyance switch controls opening/closing of the air aperture. This arrangement allows water ingress through a water inlet valve to be stopped when minor water leakage occurs in a water tank.