Torch for removing steam generator tubes

A torch assembly for use in a steam generator tube, comprising:

• a base containing a coolant passage for a coolant and an inert gas passage for an inert gas, the base being adapted for connection to a weldhead for supplying electrical power, a coolant and an inert gas to the base;
• a sheath mounted for rotation to the base and defining an elongated conduit space extending from the base, the sheath having an outer diameter which is smaller than an inner diameter of a steam generator tube for receiving the sheath;
• a drive shaft fixed to the base and extending through the sheath for rotation relative to the sheath, the inert gas passage of the base communicating with the conduit space around the drive shaft for conveying inert gas around the drive shaft;
• a gas cap rotatably mounted to an end of the sheath opposite from the base, the gas cap communicating with the conduit space for receiving inert gas from the base and having a radial opening for a torch tip and for discharging inert gas around the torch tip;
• a torch tip fixed to an end of the shaft spaced away from the base and engaged within the gas cap, the tip extending into the radial opening in the gas cap, the base, shaft and tip being electrically connected to each other for conveying electricity from the base to the tip to strike an arc torch at the tip, the gas cap having the opening through which the tip extends for supplying inert gas around an arc struck at the tip, the base, drive shaft, cap and tip being rotatable as a unit for movement inside a tube;
• and
• centering means connected to the sheath and between the sheath and the torch tip, for centering the sheath in a tube to be TIG relaxed by the torch tip.