| 摘要 |
<p>The apparatus functions for monitoring small leakages in order to activate an alarm in the event that there has been more than a predetermined volume of small leakage through the water taps or other part of the system and to automatically turn off a main valve if flow continues therethrough more than a predetermined time and will allow the main valve to open if the discharge of fluid is temporary stopped. The system includes a main valve having a valve seat and a shunt circuit that bridges the valve seat. The shunt circuit includes a volume flow meter and a shunt valve for blocking fluid flow through the circuit. The main valve opens only when the volume in the shunt path exceeds a predetermined value. The shunt circuit includes a throttle that when fluid flows therethrough, provides a pressure drop in the shunt circuit which results in the main valve diaphragm opening when the shunt circuit predetermined value is exceeded. Control apparatus ascertains the volume of fluid flow through the measuring portion of the shunt circuit and controls the closing the shunt valve.</p> |
