An arc electric welding head comprising a first contact device housing a first duct for feeding a first electrode and providing electrical contact between a first power source and said first electrode, a second contact device housing a second duct for feeding a second electrode and providing electrical contact between a second power source and said second electrode, said first and second contact devices being electrically insulated from each other, said first and second ducts being parallel.

An arc electric welding head comprising a first contact device housing a first duct for feeding a first electrode and providing electrical contact between a first power source and said first electrode, a second contact device housing a second duct for feeding a second electrode and providing electrical contact between a second power source and said second electrode, said first and second contact devices being electrically insulated from each other, said first and second ducts being parallel.

A method and apparatus for providing welding type power on one of at least two output terminals is disclosed. Input power is received and welding type power is derived and provided by a shared power circuit. The welding type power is provided across a shared terminal and only two process terminals in response to a desired process. The desired process can be set bu user input, feedback, or sensing working connections. The process terminal is selected by selectively opening and closing at least two controllable switches.

A method and apparatus for providing welding type power on one of at least two output terminals is disclosed. Input power is received and welding type power is derived and provided by a shared power circuit. The welding type power is provided across a shared terminal and only two process terminals in response to a desired process. The desired process can be set bu user input, feedback, or sensing working connections. The process terminal is selected by selectively opening and closing at least two controllable switches.

An example conversion apparatus for a welding torch includes: an insulator configured to be mechanically coupled to a first component of a welding torch, to insulate the first component from a first contact tip, and to guide shielding gas through a bore of the insulator, wherein the first component is configured to be in electrical contact with a second contact tip; and a contact tip holder configured to be attached to the welding torch via the insulator, to hold the first contact tip, to conduct welding current to the first contact tip, and to receive the shielding gas from the insulator.

An example conversion apparatus for a welding torch includes: an insulator configured to be mechanically coupled to a first component of a welding torch, to insulate the first component from a first contact tip, and to guide shielding gas through a bore of the insulator, wherein the first component is configured to be in electrical contact with a second contact tip; and a contact tip holder configured to be attached to the welding torch via the insulator, to hold the first contact tip, to conduct welding current to the first contact tip, and to receive the shielding gas from the insulator.

An example wire feeder includes: a frame; a receptacle configured to transfer welding-type current to a welding torch via a torch connector, and to position the torch connector to receive a wire electrode; one or more drive rolls configured to drive the wire electrode to the welding torch, the one or more drive rolls being electrically insulated from the frame, and wherein the wire electrode is electrically insulated from the frame; and a sensor configured to determine at least one of a voltage or an impedance between a first point electrically coupled to the wire electrode and a reference point.

An example wire feeder includes: a frame; a receptacle configured to transfer welding-type current to a welding torch via a torch connector, and to position the torch connector to receive a wire electrode; one or more drive rolls configured to drive the wire electrode to the welding torch, the one or more drive rolls being electrically insulated from the frame, and wherein the wire electrode is electrically insulated from the frame; and a sensor configured to determine at least one of a voltage or an impedance between a first point electrically coupled to the wire electrode and a reference point.

Submerged arc welding torches and systems to resistively preheat electrode wire are disclosed. A disclosed example submerged arc welding torch includes: a first contact tip configured to transfer weld current and preheating current to the wire; a second contact tip configured to conduct the preheating current to the wire; an air-cooled first conductive body portion configured to receive the weld current and to conduct the weld current and the preheating current to the first contact tip; an air-cooled second conductive body portion configured to receive the preheating current and to conduct the preheating current to the second contact tip; and an insulator coupled between the first and second conductive body portions.

Submerged arc welding torches and systems to resistively preheat electrode wire are disclosed. A disclosed example submerged arc welding torch includes: a first contact tip configured to transfer weld current and preheating current to the wire; a second contact tip configured to conduct the preheating current to the wire; an air-cooled first conductive body portion configured to receive the weld current and to conduct the weld current and the preheating current to the first contact tip; an air-cooled second conductive body portion configured to receive the preheating current and to conduct the preheating current to the second contact tip; and an insulator coupled between the first and second conductive body portions.