| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable inoperative flowing water control and pressure adjusting control that are high in accuracy and stable. <P>SOLUTION: A flowing water detector 10 is provided in the middle of piping, opens a main valve 24 due to reduction of a secondary side pressure to supply pressurized water, and outputs a flowing water detecting signal due to an opening of the main valve 24 by a pressure switch 40. A main valve driving part is provided with a piston 28 that is connected to the main valve 24 and is freely housed in a cylinder chamber 30, controls supply of primary side pressured water for the cylinder chamber 30 to open the main valve 24, and discharges the primary side pressured water from the cylinder chamber 30 to close the main valve 24. A control valve 50, where an inoperative flowing water structure 52 and a pressure adjusting pilot structure 54 are disposed, is disposed in a bypass piping 36 that bypasses a primary side and a secondary side of the main valve 24. When the secondary side pressure is reduced lower than a deadline setting pressure, the inoperative flowing water structure 52 is opened to cause the secondary side pressure to recover. Further, when the secondary side pressure is reduced, the pressure adjusting pilot structure 54 is operated to open the main valve 24. <P>COPYRIGHT: (C)2012,JPO&INPIT |
