To raise the probability of shutting off a gas passage when the shut-off state of a shut-off valve is incomplete.
This fluid shut-off device is constituted to give a reshut-off command 69b by a flow existence determining section 51 during shut-off and a reshut-off control section 53 in a shut-off incomplete state so that another shut-off valve 43b not in shut-off operation is driven to shut off when a flow signal 45 is a predetermined quantity Q0 or more after one shut-off valve 43a is driven to shut off. Consequently, even in the shut-off incomplete state due to such causes that seal part foreign matter is interposed to inhibit shut-off of gas, that foreign matter such as dust bites into a movable part to lock, that the movable part or the like is degraded in durability to degrade shut-off ability or that an electric circuit of a driving part is disconnected and short-circuited to inhibit transmission of a normal electric signal to the shut-off valve, the probability of shutting off the gas passage by the shut-off valves 43a, 43b is raised to further enhance the safety of a microcomputer meter.
NAGANUMA NAOTO
Hiroki Naito
Daisuke Nagano
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