A float valve comprising a shut-off lever and a float lever is disclosed. The shut-off lever is supported for pivotal movement about a first axis between a first closed position and a second open position. The float lever is supported for pivotal movement about a second axis between a first closed position and a second open position. The float lever and the shut-off lever include cams which cooperate to transmit closing forces and opening forces between the levers. The valve exhibits a snap closing action whereby seeping is prevented over a substantial range of liquid levels.