GB799232A - Improvements in mixing valves for hot and cold fluid - Google Patents

Abstract

799,232. Thermally - actuated valves. ROBERTSHAW FULTON CONTROLS, CO. Dec. 14, 1955 [March 23, 1955], No. 35938/55. Class 135. In a mixing valve for hot and cold fluids, thermally responsive valve means controls the flow of fluid through only one of the inlets. The casing 10, 16, Fig. 2, has hot and cold fluid inlets 12, 14, respectively and an outlet 18. The inlet 12 ends in a wall 26 having two or more orifices 30. One end of a cylindrical valve member 32 is urged by a spring 52 against the wall 26. The other end of the valve member 32 has three inwardly bent fingers 34, Figs. 2 and 4, which engage a thermostatic actuating device 38 carried by a screw 44 adjustably located in a central tubular extension 28 of the wall 26. The casing 10 and the valve member 32 define an annular chamber 48 surrounding the mixing chamber 24. The inlet 14 is connected to the chamber 48 by a throat 50. The orifices 30 cause turbulence and a pressure drop within the chamber 24. In use the hot fluid passes from the inlet 12 into the mixing chamber 24 and when the fusible material in the device 38 expands the valve member 32 is moved to the right, Fig. 2, away from the wall 26, whereupon the cold fluid in the chamber 48 flows radially into the mixing chamber 24. The reduction in temperature of the fluid in the chamber 24 results in contraction of the fusible material and the spring 52 returns the member 32 towards the wall 26. The thermostatically actuated member 38 thus controls the amount of cold fluid entering the mixing chamber 24 and the temperature of the fluid from the outlet 18.