A flow responsive valve for a flow metering system comprising a fluid meter having a minimum measuring flow threshold. The valve is shiftable between an open position at flow rates above the minimum measuring flow threshold, and a pressure pulsating position depending on pressure differential over an inlet port and an outlet port of the valve. The pressure pulsating position alters between a closed position essentially prohibiting fluid flow therethrough at flow rates below the minimum measuring flow threshold, and an open position admitting fluid flow into the supply line at a measurable flow rate above the minimum measuring flow threshold.