Flushometer valve
Flushometer valve means a valve attached to a pressured water supply pipe and so designed that, when actuated, it opens the line for direct flow into the fixture at a rate and quantity to operate properly the fixture, and then gradually closes to provide trap reseal in the fixture in order to avoid water hammer. The pipe to which this device is connected is in itself of sufficient size that, when opened, will allow the device to deliver water at a sufficient rate of flow for flushing purposes.