| 摘要 |
PURPOSE:To prevent the lowering of pressure in pumped water transfer pipe by a method wherein a surge tank is provided on the downstream side of a valve provided in the pumped water transfer pipe and the lowering of pressure in the pipe on the upstream side of the tank is detected before a low pressure wave generating as a result of the stoppage of a pump reaches the point where the surge tank is provided so that the valve is operated by a detected pressure signal. CONSTITUTION:The water from a pump station 1 is supplied to a water tank T through an upstream side pipe 2, a valve 7 and a downstream side pipe 3 and the surge tank 4 is provided adjacent the valve 7 in the pipe 3 through a check valve 5. The valve 7 is operated by an actuator 8 while the latter is controled by a controller 12 which is operative in response to the pressure signals from pressure detectors 9-11. When a pressure drop takes place in the pipe 3 at the position of the pressure detector 9 due to the stoppage of the pump, the controller 12 generates a signal in order to make the pressure in the pipe at the position of the pressure detector 10 offset the pressure drop, to thereby control the opening degree of the valve 7. |
