| 摘要 |
PROBLEM TO BE SOLVED: To operate an emergency shutoff valve by corresponding to both of detection of excessive flow velocity and a signal from a seismometer. SOLUTION: A rotary valve for attaching a valve element 2 to a valve shaft 5 inside a valve box 3 is provided in a pipe passage P, and an arm 7 with a weight 6 is attached to the valve shaft 5 so as to turn in the vertical direction. The arm 7 is locked by a locking lever 8 capable of swinging in the vertical direction to maintain a valve opening condition by preventing descent of the weight 6. An orifice 10 is provided on the upstream side of the rotary valve to connect pressure introducing pipes 11, 12 with each pipe passage P in front and rear of it. A differential pressure cylinder 20 operating based on its differential pressure is provided to swing the locking lever 8 by advance and retraction of a piston rod 23 of the cylinder 20 and release the locking. A pressure release mechanism 15 by an electromagnetic valve is provided in the pressure introducing pipe 12 on the downstream side of the orifice 10 to release pressure in the pipe by a signal from the seismometer 19. In this differential pressure emergency shutoff valve, it can correspond to even an electric signal from the seismometer 19 by constituting the valve in this way. COPYRIGHT: (C)2006,JPO&NCIPI
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