... ventilation ducts.(2) Air volume regulating valves have folio-type blades and sequential-opened blades, used as regulating valves ... performance.Our air valves include pneumatic air valves, wide-type air valves, mechanical air valves, direct blow air valve ... Flexible operation, low noise, small leak amount (airtight-type leak amount <0.5%), wide working temperature range, reliable structure, safety and ...