| 摘要 |
PROBLEM TO BE SOLVED: To securely prevent a leakage of a pressure fluid between a back pressure chamber for pressure balance and a valve chamber in both directions in a control valve for bidirectioinal communication. SOLUTION: In this control valve having a valve element 13 which is arranged in a valve chamber 5, is selectively seated in a valve seat part 6 due to the travel in the direction of valve lift to open and close a valve port 7 so as to communicate and shut off a first port 4 and a second port 8, is slidably fitted in a holding bore 17 provided in a valve housing 3 to partition a back pressure chamber 18 on a rear surface side, and is provided with a pressure equalizing passage 19 communicating the back pressure chamber 18 with the second port 8 at all times, a valve stem 24 connected with the valve element 13, and an actuator 25 driving the valve stem 24 in the direction of valve lift, bowl-shaped packings 37, 38 having annular lip parts in contact with inner peripheral faces of each holding bore 17 are mounted in two sections apart in the direction of valve lift of the valve element 13 reversely for each other.
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