a valve assembly is attached to the spout of a water bottle which is used in liquid dispensing devices common in households and offices . the assembly combines a sleeve - like housing and a valve for preventing water spillage particularly when the bottle is being hoisted and inverted onto the dispensing device . an elongated actuator stem unseats a valve head section from sealing engagement with the housing as the bottle is lowered into the device . the valve assembly is releasably attached to the bottle spout and can be reused repetitively .