| 摘要 |
PROBLEM TO BE SOLVED: To reduce cost, by reducing failure, by quickly confirming operation of a valve element with a simple structure, in a state of not hindering operation of a facility. SOLUTION: A piston rod 7 connected to a piston 8 in a cylinder 6 in one end part of a body main body 5, is faced in the body main body 5. An auxiliary cylinder 11 is installed in the other end part of the body main body 5, and a stopper rod 13 of a stopper piston 12 in this auxiliary cylinder 11 is faced in the body main body 5 so as to be opposed to the piston rod 7. In a full opening state of the valve element 2, a clearance (a) is formed between the piston rod 7 and the stopper rod 13, and when confirming the operation of the valve element 2, when driving the piston 8 in the valve closing direction from a full opening state position of the valve element 2, the piston rod 7 is allowed to abut on the stopper rod 13, and the valve element 2 can be maintained in predetermined desired intermediate opening. COPYRIGHT: (C)2009,JPO&INPIT
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