Patent ID: 7788742

Claim:
A cistern outlet valve assembly, the assembly including: an outlet orifice; a buoyant member with an outlet seal on a first side and a raised housing seal bead on a second side opposite the first side, the raised housing seal bead being integrally formed with the buoyant member; and a valve housing adapted to cover the buoyant member and having a large clearance guide means adapted to guide the movement of the buoyant member from a closed position in which the outlet seal seals against an outlet orifice and an open position in which the housing seal bead seals against a substantially flat annular sealing surface of the valve housing, the sealing surface adjacent to a plurality of protuberances formed on the valve housing and extending in an outward radial direction, each of the protuberances engaging the second side of the buoyant member when the buoyant member is in the open position, wherein when the buoyant member is in the open position any fluid incident on the guide means is prevented from flowing onto the buoyant member by the housing seal bead sealing against the housing and the engagement of the protuberances with the second side of the buoyant member prevent adherence between the buoyant member and the valve housing due to water tension.