Abstract: The present invention discloses a valve which utilises an imbalance of flow induced pressure forces to keep the valve open or closed. The valve has an interior cavity (15) into which an opposite and aligned inlet (12) and outlet (13) open. A bulbous body (16) is located within the cavity and is reciprocally mounted on a spindle (17) which passes through the outlet. Movement of the body increases the flow area at one end of the body and decreases the flow area at the other end of the body. In accordance with Bernoulli's theory this changes the pressures acting on the body (16) giving rise to a net force on the body. A cistern inlet valve (111,211) and cistern (19) are also disclosed.