| 摘要 |
<p>1506084 Valves SULZER BROS Ltd 26 July 1976 [25 July 1975] 31079/76 Heading F2V A valve has a first closure 21 seating on a second closure 11 and servomotors 13, 23 arranged concentrically for independent operation of the closures, the upper chamber 42 of the servomotor 23 being supplied with and relieved of fluid pressure through a hollow spindle 30, while the lower chamber 45 of the servomotor 23 is connected to the lower chamber 15 of the servomotor 13 through a duct 43. To operate the closures, solenoid-operated valves 66, 57, 59, 61, 62, which may be duplicated to improve reliability, selectively connect the servomotor chambers with the valve inlet 1<SP>1</SP> or an exhaust line 65. The spindle 30 co-operates with position indicators 32, 33, 34 and the valve may be modified so that the duct 1<SP>1</SP> serves as the outlet. The servomotors may be operated by nitrogen from an external pressure source. Specification 1,506,085 is referred to.</p> |
