System for automatically installing flanges on straight pipe and for operation with bending after welding

The invention discloses a system for automatically installing flanges on a straight pipe and for operation with bending after welding. The system is applied to the field of pipe fitting and flange processing and comprises a tray type storing and feeding unit, a rotary mechanical arm unit, a truss mechanical arm unit and a auxiliary nail welding unit. Multiple groups of flanges are placed on the tray type storing and feeding unit;a rotary mechanical arm clamping jaw, capable of horizontally rotating and vertically moving, of the rotary mechanical arm unit is used for clamping a flange to a flange coding unit for coding; the truss mechanical arm unit is used for clamping the flange placed on the tray type storing and feeding unit or the coded flange on a flange coding machine to an assembling and nail welding unit; and the auxiliary nail welding unit comprises an assembly nail welding supporting mechanism used for supporting the pipe fitting, an assembly nail welding clamping mechanism used for clamping the fla