Abstract: A weldhead for welding small diameter tubing in confined spaces. The weldhead includes a welding body and a separable cartridge. The cartridge has a pair of collet clamps for gripping the two sections of tubing to be joined on either side of the weld joint and for maintaining the tubing in alignment during the welding operation. The weldhead body includes a circular rotor that is notched to fit around the weld joint when the weldhead is inserted into and latched to the cartridge. A tungsten electrode is disposed on the inner circumference of the rotor and is caused to orbit the weld joint by a motor driven gear train. A welding arc is established between the electrode and the tubing and the rotor is then driven so that the electrode orbits the weld joint. Motor speed and welding current are regulated to control the weld puddle size.