Patent ID: 8167215

Claim:
A thermostatic mixing valve having a valve body and respective inlets for connection to supplies of hot and cold water and an outlet for temperature controlled water, a valve member movable between hot and cold seats to vary the relative proportions of hot and cold water supplied to a mixing chamber, said valve member being spaced from an inner surface of said valve body, a thermostat supporting said valve member and responsive to temperature of water in said mixing chamber for controlling movement of said valve member in accordance with adjustable selection of the outlet water temperature, a seal between said valve member and said inner surface of said valve body, a flow guide located within said mixing chamber and spaced from an inner surface of said valve body, a return spring mounted between said valve body and said flow guide which biases said flow guide against said thermostat for biasing said thermostat and said valve member towards said cold seat, said return spring comprising a wave spring having a longitudinal axis and opposing ends, wherein the wave spring reduces resistance to lateral displacement of the ends for respectively maintaining seals between the hot and cold seats and promoting an even flow of water across the hot and cold seats when the ends of the wave spring are offset relative to the longitudinal axis.