Patent ID: 7299814
Filing Date: 2007-11-27
Classification: F17D,G01M,Y10T

Abstract:
1. For use in a building having a water supply pipe through which water is supplied to this building, water flowing in a first forward direction through the water supply pipe when water is being used in the building, the direction opposite to the first forward direction being a second backflow direction, an apparatus for selectively interrupting the flow of water through the water supply pipe comprising: at least one flow sensor for detecting flow of water at least in the first of the first and second directions, the sensor providing a water flow output indicating signal corresponding to the direction of water flow; a flow monitoring circuit coupled to the at least one flow sensor so as to receive the water flow output indicating signal, the flow monitoring circuit being adapted to provide a valve close signal in the event water flow in at least the first direction exceeds a first forward flow threshold; and in the event water flow is in the second backflow direction is equal to or exceeds a second backflow threshold; wherein the first forward flow threshold is greater than the second backflow threshold; and a valve coupled to the flow monitoring circuit and adapted to interrupt the flow of water through the water supply pipe in response to the valve close signal.