Product description:The FN-1B / 2B seam welder are continuous DC welding machines. The FN-1B is for straight seam welding and the FN-2B is for circular seam welding. Keywords: duct connector tube pipe forming making equipment machine manufacturing hvac ductmate flange forming tubeformer ductformer machinery ductconnector laser cutter cutting hvac ducting spiral insulation duct connections roll purlin forming lock forming pittsburgh seamer machine tdc 20 tdc 30 tdf 12.