GB1533006A - Valve - Google Patents

Abstract

1533006 Valves ISHIKAWAJIMA-HARIMA JUKOGYO KK 30 July 1976 31847/76 Heading F2V An ovoid valve member 3, Fig. 2, is connected with a piston 8 having opposite faces subjected to pressures upstream and downstream of the valve seat 6 so that fluid forces on the valve member are at least partially balanced. The valve is coupled with the piston by a cranked lever 4 of aerofoil section and may be operated by a handwheel 16 or an arm keyed to the pivot 5. A small clearance around the piston 8 allows leakage flow which may be cut-off by a screw 15 when the valve is closed. The valve may also be operated by a further piston (18) Fig. 5 (not shown). In Fig. 11, the valve has a linear movement and is maintained in alignment with its seat by a projection 30 in engagement with a recess 31 in the housing. Actuation is effected by a handwheel 42 and a lever 40, by rack and pinion (43, 44) Fig. 14 (not shown) or by a piston (47) Fig. 15 (not shown). In this embodiment, the screw 15 is replaced by a valve 37 in a balance tube 35. A further embodiment has a valve member with a core 50 connected to a pair of pivoted links 56, 57, the link 56 having its pivot 53 connected to a handle (66) Fig. 17 (not shown). Actuation may alternatively be effected by a fluid-operated diaphragm or by solenoid-operated valves (69) Fig. 20 (not shown) controlling the piston 59. With the duct 63, Fig. 16, closed and a spring load provided on the left-hand side of the piston 59, the valve member 3 opens in response to excess inlet pressure.