WATER SHUTOFF SYSTEM WITH A FLOW SENSING UNIT HAVING DUAL FLOW PATHS

摘要

A comprehensive water shutoff system is adapted to be connected or associated with a water supply line to a structure. The system comprises a main shutoff valve connected to or in the water supply line and a flow sensing unit for sensing or measuring flow through the supply line. In addition, a controller is operatively connected between the flow sensing unit and the shutoff valve and is operative upon the flow sensing unit sensing one or more predetermined flow conditions, to close the main shutoff valve. Flow sensing unit includes a dual flow path, referred to as a relatively low flow path and a relatively high or main flow path. For relatively low flows being directed through the water supply line, the water flow is directed through the relatively low flow path while the relatively high flow path is closed. In another mode, and in response to the flow rate increasing in the supply line, the relatively high flow path is opened and the water passing through the supply line is directed through this path. In either mode, the flow through the flow sensing unit is sensed and upon certain flow conditions being met (such as uninterrupted flow of water for a selected time period), the controller is operative to close the main shutoff valve.