Sloan flush valves, referred to as "Flushometers" by the company, are designed to connect directly to the water supply line and release a predetermined amount of water with each flush. The flushing process is automated by the flush valve, releasing the preset flushing water and then automatically closing the water supply line. Two distinct types of Sloan flush valves exist: diaphragm flush valves and piston flush valves. Though each of these valve types functions in a similar manner, the design of the flush valves and the materials used in their construction differs.
Diaphragm Flush Valves
Diaphragm flush valves consist of two chambers that are connected by a single bypass hole. A flexible rubber diaphragm sits between the chambers, preventing leaks and ensuring that the Flushometer is ready to be used at all times. When flushed, the change in pressure between the two chambers causes the diaphragm to be lifted from its position so that water can pass through the valve. A small portion of water also passes over the top of the diaphragm, weighing it down so that it settles back into position once the appropriate amount of water for the flush has passed through.
Piston Flush Valves
As with diaphragm flush valves, piston flush valves consist of two chambers that are connected by a bypass hole. A piston Flushometer features a moulded cup that serves to keep the bypass closed. When flushed, the change in pressure that occurs lifts the cup in much the same manner as the diaphragm is lifted in diaphragm flush valves; this allows water to pass through from the water supply line in order to flush the toilet, water cabinet or urinal. As water passes through, a small portion of water is also moved across the top of the cup in order to move it back into position once the flush has been completed.
Sloan flush valves also contain a vacuum breaker component that is designed to prevent backflow and contamination of the water source on the other end of the water supply line. Backflow is caused by a vacuum being created within the line after flushing; by using the vacuum breaker component to stop this suction, any backflow will revert to flowing normally and will not be able to reach the water source.