| 摘要 |
PURPOSE:To minimize the size of an automatic valve which has a flowing water detective function by providing the valve with both a piston which gives a main valve a motive force for seating and a mechanism which detects flowing water. CONSTITUTION:When a pilot valve 15 is opened in response to actuation of a fire sensor or the like, a pressure in a pressure reducing chamber 30 is reduced so that a main valve 26, a piston 28 and an opening indicator 34 are pushed up by a pressure of a pressurized water at the primary side, namely, a valve is opened, thereby squeezing the pressurized water at the primary side to run to the secondary side. Some of the running pressurized water makes a pressure switch 11 turned ON. When the pressures in the primary chamber 24 and the secondary chamber 25 become approximately equal to each other, the main valve 26 falls and closed and a water supply hole 31 is closed. The pressure switch 11 is therefore turned OFF. |
