GB831469A - Improvements in and relating to a pressure and capacity regulating fluid valve - Google Patents

Abstract

831,469. Fluid-pressure servomotor control-systems; valves. SINGER VALVE CO. Ltd. Jan. 10, 1956, No. 908/56. Class 135. A valve comprises inlet and outlet chambers 15, 16, Fig. 1, separated by a wall 18 in which is threaded a sleeve 32 having a seat 33 for a closure plate 35 with an upstanding stem 36 connected to a control piston 22 or a diaphragm, not shown; a spindle 40 depending from the plate 35 has a ported member 43 at its lower end against which bears a rotatable ported capacity disc 45, the volume between the plate 35 and member 43 forming an expansion chamber 50. Inlet pressure is directed to the control mechanism 23 via a passage 25 whilst the outlet pressure is conduced thereto by a pipe 26, the outlet pressure being adjusted by a head 27 and maintained by the piston 22 which determines the degree of opening of the plate 35 and hence the pressure drop across the seat 33 whilst the capacity ot the valve is regulated by turning the disc 45 relative to the member 43 to adjust the effective size of the passages through which the fluid, for example steam, passes to the outlet chamber 16. Chattering of the plate 35 is eliminated by increasing the distance between the plate and its seat 33 and then rotating the disc 45 to restore the desired outlet pressure and capacity. In a modification, the valve has a sleeve 64, Fig. 4, with the seat end 65 of which co-operates a closure plate 66 connected to a rectangular stem 67 extending upwardly through the sleeve to the control piston, not shown; a number of elongated ports 69. are formed in the sleeve remote from the seat 65 whilst within the sleeve is threaded a capacity disc 72 so that upon turning the stem 67, the disc 72 is threaded up or drawn in the sleeve to vary the effective area of the ports 49. The stem 67 may be rotated by opening the valve and turning the plate 66, or a shaft 84 and fork 78 may be provided to permit this adjustment to be effected from outside the valve. A spring 89 may urge the plate 66 upwardly and a filter screen 91 may be provided. The means for adjusting the capacity plate may also be incorporated in the Fig. 1 embodiment. In another modification, the valve consists of a sleeve 96, Fig. 8, slidable in a ring 103 and having a seat 104 at or near its lower end, in which sleeve is a number of elongated ports 108; the sleeve has the capacity disc 111 threaded therein whilst a square stem 113 fixed to a housing 101 is slidable through the disc 111. A passage 116 serves to equalize fluid pressure on both sides of the disc 111. The closure plate 117 which co-operates with the seat 104 has a hub 118, the upper end of which is connected by radiating arms 120 to the sleeve 96, the lower hub end embodying a slot 123 to enable the plate 117 and sleeve 96 to be rotated ; the hub may extend through the valve casing to enable the disc to be moved from outside the valve. A yoke 130 around the housing 131 is connected to the control piston via a stem 136 and thereby causes the plate 117 to float with the piston. In a further modification, the rectangular capacity disc 154, Fig. 12, is ported and is slidable in slots 166 across the ported face of sleeve end wall 150 to vary the effective area of the passages through both ported members; the disc is moved from outside the valve by a threaded rod.