Abstract: A control valve for liquid in stationary tanks, such as toilets humidifiers and the like, of the type housed within a tank, having an inlet orifice for water and an outlet orifice for the same, including a lever which actuates, by means of chain or cable, a sealing plug in said outlet orifice of said tank opening it to empty said tank and which includes a float connected to a rod which actuates a valve member for opening and closing the intake orifice of liquid into the tank, wherein a laminar support structure is connected to said inlet orifice for liquid into said tank a height adjustable bracket projecting from said support structure, a yoke supported on said bracket; a L-shaped elbow member being pivotally supported by its apex on said yoke one of the arms of said elbow member is connected to said rod joined to said float and the other of which arms having its bottom edge rounded in such a manner that when said tank is full it presses, against the bottom face of said yoke supported on said bracket; an ela