air damper,air volume control (ISO9001/ISO14001) control air volume 1 Media:gas 2 high pressure The introduction of air volume valve ,air damper air damper,air volume control (ISO9001/ISO14001)control air volume1 Media:gas2 high pressure The performance of fireproof valves seriesNumberItemconstruction specfications1The thickness of steel bodyThe length of valve(mm)thickness of steel(mm)flange ...