Pulse valve sealing is provided by diaphragms. There are 1 diaphragm in 3/4 "and 1" sizes, and generally 2 diaphragms in sizes 11/2 "and above. In time, the diaphragm is deformed by the impact of impacts. Deformed diaphragms are replaced with new ones. Longer life (3.5 million on-off)
