... Accessory 1 low resistance,high density, 2 good feature of compression strength. 3 Material FRP,stainless The introduction of ventilation duct ... duct,air conditioning duct.\ Brief introduction Steel materials of ventilation ducts now is the most widely used in conditioning ... Dia)(mm)the wall thickness of duct(mm)flange ventilation duct specificationround ductretangle duct80-3200.50.525*3340-4500 ...