ELECTRIC ARC WELDING MACHINES; ELECTRIC WELDING MACHINES; [ GAS WELDING MACHINES; LASER WELDING MACHINES; ] PLASMA WELDING MACHINES; GTAW (GAS TUNGSTEN ARC WELDING) WELDING MACHINES; GMAW (GAS METAL ARC WELDING) WELDING MACHINES; PAW (PLASMA ARC WELDING) WELDING MACHINES; DC (DIRECT CURRENT) WELDING MACHINES; AC (ALTERNATING CURRENT) WELDING MACHINES; FCAW (FLUX CORED ARC WELDING) WELDING MACHINES; MAG (METAL ACTIVE GAS) WELDING MACHINES; [ SMAW (SHIELDED METAL ARC WELDING) WELDING MACHINES; RESISTANCE WELDING MACHINES; SPOT WELDING MACHINES; ] FRICTION STIR WELDING MACHINES; [ INDUCTION WELDING MACHINES; ] PARTS OF AND ACCESSORIES FOR THE FOREGOING, NAMELY, WELDING HEADS, WELDING HEADS FOR WELDING OF PIPES, WELDING HEADS FOR WELDING OF TUBING, WELDING HEADS FOR WELDING OF FITTINGS, WELDING HEADS FOR WELDING OF TUBES TO TUBESHEETS, WELDING HEADS FOR WELDING OF PIPES AND PLATES WITH NARROW GAPS BETWEEN PIPES OR PLATES, WELDING HEADS FOR WELDING OF SEAMS BETWEEN FLAT OR CURVED PLATES, WELDING HEADS FOR CLADDING WITH AN ALLOY PIPE OR PLATE SURFACES BY WELDING PROCESS; WELD PUDDLE VIEWING EQUIPMENT, NAMELY, EQUIPMENT THAT INCORPORATES CAMERAS, OPTICS AND OPTICAL FILTERS USED TO OBSERVE AND TRANSMIT TO A RECEIVER IMAGES OF THE MOLTEN METAL PUDDLE THAT IS GENERATED DURING WELDING; WELDING DATA COLLECTION DEVICES, NAMELY, DEVICES THAT MEASURE WELDING PARAMETERS SUCH AS VOLTAGE, AMPERAGE, LINEAR OR CIRCUMFERENTIAL PROGRESS OF THE WELD AND OTHER FUNCTIONS AND RECORD THEM FOR FUTURE USE OR TRANSMIT THEM TO A REMOTE RECIPIENT; WELDING HEAD GUIDE RINGS; WELDING WIRE FEEDERS; WELDING WIRE MANIPULATORS; WELDING MACHINE CONTROL PENDANTS; WELDING MACHINE INTERFACE DEVICES, NAMELY, DEVICES THAT ALLOW A WELDING MACHINE TO COOPERATE WITH A DIFFERENT MACHINE, SUCH AS WITH A ROTATING DEVICE FOR THE PARTS BEING WELDED; TUBE ALIGNMENT GAUGES, NAMELY, GAUGES THAT ARE EMPLOYED TO BRING INTO ALIGNMENT THE ENDS OF TUBES SO THAT WELDING OF THE TUBES ONE TO ANOTHER MAY BE CARRIED OUT; WELD HEAD ALIGNMENT FIXTURES, NAMELY, FIXTURES THAT ARE USED TO POSITION WELD HEADS IN DESIRED RELATIONSHIP TO THE PART BEING WELDED; WELD VIEWING EQUIPMENT, NAMELY, EQUIPMENT THAT INCORPORATES CAMERAS, OPTICS AND OPTICAL FILTERS USED TO OBSERVE AND TRANSMIT TO A RECEIVER IMAGES OF THE WELD ZONE BEFORE WELDING, THE WELD PROCESS DURING WELDING AND THE RESULTING WELD AFTER WELDING, AND PARTS AND ACCESSORIES THEREOF; PIPE CUTTING AND FACING EQUIPMENT, NAMELY, EQUIPMENT INCORPORATING CUTTING TOOLS WHICH ARE EMPLOYED TO CUT APART PIPE SECTIONS OR TO PREPARE THE FACES OF PIPE ENDS FOR WELDING; TUBE CUTTING AND FACING EQUIPMENT, NAMELY, EQUIPMENT INCORPORATING CUTTING TOOLS WHICH ARE EMPLOYED TO CUT APART TUBE SECTIONS OR TO PREPARE THE FACES OF TUBING ENDS FOR WELDING; CONSUMABLE WELDING TORCH PARTS, NAMELY, PARTS OF WELDING TORCHES SUCH AS GAS CUPS THAT DIRECT INERT GAS TOWARDS THE WELD OR TUNGSTEN ELECTRODES THAT EMIT THE WELDING ARC AND WHICH WEAR OUT WITH USE AND THEREFORE ARE "CONSUMED" BUT NOT INCORPORATED INTO THE WELD METAL