GB427726A - Improvements in and relating to flow controllers - Google Patents

Abstract

427,726. Valves. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.-(General Zeolite Co.; 333, West 25th Place, Chicago, U.S.A.) Sept. 18, 1933, No. 25750. [Class 135] A fluid-flow controller in which a loaded control or actuating diaphragm is subject to a pressure differential derived from the main conduit has means for varying the proportion of the desired pressure differential applied to the diaphragm. In the form shown in Fig. 1, the main valve 11 is controlled by a diaphragm 13 carrying a weight 21 tending to open the valve. The conduit above the valve is formed as a Venturi tube 12, the pressure at the full section being applied through a pipe 30 below the diaphragm, while the reduced pressure from the throat is applied through a valve 26 and pipe 29 above the diaphragm. The pipes 29, 30 are joined by a byepass having a constriction 28. The valve 11 is maintained open in a floating condition by a certain difference of pressure across the diaphragm, and its degree of opening may be varied to permit different rates of flow by adjusting the valve 26, thus varying the proportion of the pressure - difference in the Venturi applied to the diaphragm. In a modification, a swingable pipe is arranged to take pressure from the Venturi 12 at different points. In a further form the main pipe is itself of uniform section, and a shiftable conical member is arranged between the points of junction of the pipes 29, 30 with the main pipe. In the arrangement shown in Fig. 6, the main valve 56 is actuated by a bellows 61, controlled by an auxiliary valve 73, itself controlled by the Venturi 51. The interior of the bellows 61 is connected to the outlet and the space around the bellows is connected by pipes 70, 71 through the auxiliary valve 73 to the full inlet pressure at 52. The pipe 70 is also connected to outlet by a constriction 69, so that the pressure in the pipe 70 is determined by the degree of opening of the valve 73. The space above the actuating diaphragm 76 of the valve 73 is connected to the inlet through a fixed constriction 83 and to the Venturi throat 43 through a variable constriction 86 so that the pressure above the diaphragm 76 may be varied substantially between the pressure at 43 and 52. A float-operated valve, not shown, may be incorporated in the pipe 71 and adapted to close, so as to close the main valve 56 when the reservoir being supplied is filled.