Abstract: A single handle mixing tap includes a tap body within which is a valve mechanism comprising a pair of discs, one of which is rotatable against the other and also movable transversely across the other, whereby fluids to be mixed together from two separate inlets communicating with aligned apertures through the discs can have the ratio of their volumes, as well as their combined volume, varied. The movable disc is coupled by a ball joint arrangement to a rotatable and tiltable handle, whereby the axis of rotation of the disc and the handle through the ball joint during rotation of the disc, and the axis of tilting of the handle relative to the disc at the ball joint during transverse movement of the disc, is such that substantially all forces applied by the handle to the ball joint are radially of said joint rather than along the longitudinal axis of the tap thus relieving friction between the faces of the discs and lowering the operating forces to thereby reduce possible damage to the discs.