US Patent 7182096 Self cleaning metering device for diaphragm style flush valve

The self cleaning metering device for a diaphragm of a diaphragm type flush valve comprises a metering cap having a metering orifice therein, a hollow retainer threadedly engaged to the metering cap, the diaphragm being sandwiched therebetween, and a cleaning element comprising a spring coil movably seated within the device, the coil having a first pin centered relative to the metering orifice and extending therethrough and a second pin extending opposite the first pin into and through the hollow retainer, wherein water flowing through the metering device acts to move the coil, and pins thereof, the coil and pins acting to clean debris from the interior of the device upon moving therewithin.