| 摘要 |
PROBLEM TO BE SOLVED: To provide a preferable accommodation for EVA operation while preventing disturbance from being occurred at a power system after performing a valve test.SOLUTION: A first flow passage 30 for supplying pressure oil to a control oil chamber 21C of a steam valve driving mechanism includes: a second orifice 41; a breaking valve 21 capable of changing-over between a state in which pressure oil is supplied to the control oil chamber 21C and a state in which the supplying is blocked; and a test valve 23 for discharging pressure oil kept in the control oil chamber 21C at the time of valve testing operation. Further, there are provided a second flow passage 31 for supplying pressure oil to the control oil chamber 21C without passing through the second orifice 41 and a quick opening valve 26 capable of changing-over between a state in which the pressure oil is supplied from the second flow passage 31 to the control oil chamber 21C and a state in which its supplying is blocked. A flow rate of oil from the second flow passage 31 to the control oil chamber 21C is set larger than that from the first flow passage 30 to the control oil chamber 21C through the second orifice 41. |
