| 摘要 |
<p>1514074 Fluid-pressure servomotor systems KRAFTWERK UNION AG 29 April 1976 [30 April 1975] 17569/76 Addition to 1513775 Heading G3P [Also in Division F2] The safety valve in the nuclear reactor installation of the parent Specification is modified by the provision of an auxiliary valve in the closure member 7, Fig. 1, of the valve, whereby the opening of the valve by up to one-half of its fully open cross-section is provided by opening the auxiliary valve. The latter comprises a closure member 24 actuated by a piston 27 slidable in a cylinder 22 formed in the connecting member 8 between the closure member 7 and its actuating piston 10. The spaces above and below the pistons 10, 27 are connected to the main flow path via bores 16, 18, 71 each having a respective restrictor 17, 19, 72. Electromagnetically-actuated valves 35, 43, 44, 45, 52, 53 are operated at various pressures to effect the desired opening or closing of the members 7, 24. Each piston 10, 27 has a respective raised portion 48, 38 on its top surface which, when the piston is moved to the top of its cylinder, co-operates with a seating 49, 37 to seal the cylinder from the lines 41, 42 at line 34. A rod 30 on the piston 27 and a tube 31 on the piston 10 provide means by which magnetically-controllable contacts 58a to e can monitor the respective positions of the closure members 7, 24 and transmit the information electrically to indicating means (not shown). The raised portion 48 at the top of piston 10 is shown in greater detail in Fig. 2, and comprises a resilient annular member 62 when which in its unloaded condition is of substantially frustoconical form but which flattens and co-operates with a pair of concentric seatings 49 when the piston 10 is raised.</p> |
