| 摘要 |
PROBLEM TO BE SOLVED: To always return a cutoff valve to a complete valve open state without adding new hardware and changing software greatly. SOLUTION: When there is a return command to the valve open state (step S3), and it is determined that lapse time from the time when changing to the valve open state has passed predetermined reference time (Y for step S4), it is instructed that the return operation of the cutoff valve 11b should be repeated for a plurality of times (step S5). As a result, even if a pressure difference influencing the return operation is generated between the upstream and downstream sides of the cutoff valve 11b, the pressure difference is reduced gradually as the return operation is repeated for a plurality of times, and finally the cutoff valve 11b can be returned to a complete valve open state. COPYRIGHT: (C)2005,JPO&NCIPI
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