GB698492A - Improvements in or relating to a mixing valve - Google Patents

Abstract

698,492. Thermally-actuated valves. DALE VALVE CO. Aug. 14, 1950, No. 20121/50. Class 135 A thermostatically-controlled mixing valve includes a casing having hot and cold water inlets 12, 11 respectively and an outlet 17 for the mixture. The valve is adjustable so that either hot or cold water may pass directly to the outlet. The casing is formed with hot, cold, and mixture chambers 27, 35, 37 respectively, the flow between which is controlled by a hollow piston 65 coacting at its upper end with a peripherally-apertured disc 41 and at its lower end with an internal flange 36 on the casing. The piston is biased to its lower position by a spring 74, thus cutting off the supply of cold water to the mixing chamber 37, and urged upwards by the movable member 78 of a thermostat 72. The flow of hot water to the chamber 27 is controlled by a check valve 28 having a rubber closure disc 32 and of cold water to the chamber 35 by a similar check valve 22. The casing is closed by end-caps 13, 13<SP>1</SP> housing spring-loaded armatures 15, 15<SP>1</SP> which control the bores in rubber diaphragms 51, 51<SP>1</SP> having bleed holes 61, 61<SP>1</SP> to equalise the pressures on their opposite sides and so bias the diaphragms to seat on removable members 46, 83 having chambers 49, 88 communicating through radial bores 50, 89 with the outlet 17. In operation and assuming it is desired to pass hot water direct to the outlet 17, the electromagnet associated with the armature 15 is energized to open the bore in the diaphragm 51 and relieve the pressure on its upper side, thus unseating the diaphragm and permitting hot water to pass via the member 46 direct to the outlet. To discharge a mixture of hot and cold water, the armature 15<SP>1</SP> is energized to unseat the diaphragm 51<SP>1</SP> and allow the mixture to pass from the chamber 37 and through the member 83 and the passage 19 to the outlet. In this case, the thermostat 72 is set to deliver a mixture of the required temperature.