Tube Axial Duct Fan Blower - Direct Drive Model DF HEAVY GAUGE ALL WELDED STEEL CONSTRUCTION. EASILY MOUNTED INTO DUCT. APPLICATION – These direct drive tube axial fan blowers are recommended for duct application in mills, mines, foundries, factories or wherever fumes, dust, smoke, or steam must be removed. Propellers are non-sparking cast aluminum so that unit with explosion proof motor can be used to handle explosive gases. Drum made from heavy gauge steel. Welded construction. Angle iron flanges on each end of drum with eight mounting holes for ease in mounting into duct. Motors – only high quality industrial motors are used. Fans with motors are completely assembled and fan tested at factory before shipping. Motors are available in open drip proof, TEFC (Totally Enclosed, Fan Cooled), and EXP (Explosion Proof).