Liquid level control unit e.g. toilet cistern

摘要

The outlet passage contains a non return valve (34) with aperture connected to the seat (114) and apertures (512) connected to the venting chamber (52A). A further aperture (48) communicates with the outlet passage. A non return valve element (50) closes the seat connecting apertures when the main valve element (51) is in the closed position. It closes the venting chamber connecting apertures (408) when the main valve element is in the open position.