| 摘要 |
In the case of a drinking-water flow fitting, a backflow preventer (1) and, in addition, a flow-control instrument in a bypass line of smaller flow cross-section are installed in the drinking-water supply line (T), behind a hydraulic pipe disconnector (20) provided therein. In a valve housing (3), which belongs to the flow-control instrument and through which the bypass water can flow, there is displaceably mounted a flow piston (5) which, counter to a restoring force acting on it, allows a proximity switch (4) of an electric circuit, controlling the pipe disconnector, to be actuated by the pressure of the flow water. In order then also to be able to actuate the proximity switch (4) when, in the valve housing (3) of the flow-control instrument, there is no water flow, but simply a drop in the static water pressure, there is displaceably arranged in the valve housing (3), outside the flow piston (5), a pressure piston (6) which monitors the static water pressure prevailing therein and likewise actuates the proximity switch (4) when the water pressure falls beneath a defined level. <IMAGE>
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