Water meter including variable orifice device

摘要

A fire hydrant water meter having a flow restricting device that creates back pressure to restrict the flow of water through the fire hydrant water meter. The flow restricting device includes a plurality of flexible vanes that combine to define a variable orifice. As the flow of water through the meter increases, the individual flexible vanes move away from each other to expand the size of the flow orifice. The flow restricting device provides a source of back pressure to water flowing through the meter to restrict the flow rate of water and thus protect the metering device contained within the fire hydrant water meter.

主权项

1. A water meter for determining a flow of water, comprising:
a meter maincase defining an inlet for receiving the flow of water and an outlet for discharging the flow of water; a metering device positioned in the maincase between the inlet and the outlet and operable to measure the flow of water through the maincase from the inlet to the outlet; and a flow restricting device positioned between the metering device and the outlet, wherein the flow restricting, device includes a plurality of flexible vanes that define a variable orifice through which the water flows from the metering maincase to the outlet, wherein the flexible vanes are each biased toward a closed position to restrict the size of the variable orifice and create a source of back pressure for the flow of water through the water meter.