A liquid cooled electrode for a contact start plasma arc cutting torch is provided. The electrode includes an elongated body defining a longitudinal axis. The elongated body includes a proximal end shaped to matingly engage a torch body of the plasma arc cutting torch and a distal end located substantially opposite of the proximal end along the longitudinal axis. The electrode also includes one or more contact surfaces disposed on an external surface of the distal end of the electrode body between the proximal and distal ends. The one or more contact surfaces are shaped to physically contact a nozzle disposed within the plasma arc cutting torch during a portion of a pilot arc initiation process. The physical contact is configured to support transmission of a pilot arc current between the electrode and the nozzle with a density of at least about 3000 amps per square inch.

A liquid cooled electrode for a contact start plasma arc cutting torch is provided. The electrode includes an elongated body defining a longitudinal axis. The elongated body includes a proximal end shaped to matingly engage a torch body of the plasma arc cutting torch and a distal end located substantially opposite of the proximal end along the longitudinal axis. The electrode also includes one or more contact surfaces disposed on an external surface of the distal end of the electrode body between the proximal and distal ends. The one or more contact surfaces are shaped to physically contact a nozzle disposed within the plasma arc cutting torch during a portion of a pilot arc initiation process. The physical contact is configured to support transmission of a pilot arc current between the electrode and the nozzle with a density of at least about 3000 amps per square inch.

A replacement part unit for a plasma torch includes an electrode, an insulation guide, and a nozzle. The insulation guide includes a hole into which the electrode is inserted. The insulation guide is coupled to the electrode by press-fitting or adhesion. The nozzle includes a hole into which the insulation guide is inserted. The nozzle is coupled to the insulation guide by press-fitting or adhesion.

A replacement part unit for a plasma torch includes an electrode, an insulation guide, and a nozzle. The insulation guide includes a hole into which the electrode is inserted. The insulation guide is coupled to the electrode by press-fitting or adhesion. The nozzle includes a hole into which the insulation guide is inserted. The nozzle is coupled to the insulation guide by press-fitting or adhesion.

Provided is a plasma torch in which a cathode conduit is disposed to be spaced apart from an outer circumferential surface of a cooling conduit, an insulator and an anode conduit are sequentially disposed around the cathode conduit in a closely abutting relation, an electrode element is engagingly coupled to a left end of the cathode conduit, and a nozzle is engagingly coupled to a left end of the anode conduit, and in which the cooling conduit includes one or more small peripheral radial air outlets formed on an outer circumferential surface of a left side end thereof so as to be opened at one sides of the air outlets, and a large central air outlet formed at the center of the left end thereof so that the left end of the cooling conduit is brought into close contact with an inner bottom of the electrode element.

Provided is a plasma torch in which a cathode conduit is disposed to be spaced apart from an outer circumferential surface of a cooling conduit, an insulator and an anode conduit are sequentially disposed around the cathode conduit in a closely abutting relation, an electrode element is engagingly coupled to a left end of the cathode conduit, and a nozzle is engagingly coupled to a left end of the anode conduit, and in which the cooling conduit includes one or more small peripheral radial air outlets formed on an outer circumferential surface of a left side end thereof so as to be opened at one sides of the air outlets, and a large central air outlet formed at the center of the left end thereof so that the left end of the cooling conduit is brought into close contact with an inner bottom of the electrode element.

An inductively coupled plasma source with a simple configuration, has an antenna cooling mechanism capable of reducing costs required for such devices. The plasma source is configured to generate plasma in a vacuum vessel, and includes a frame (antenna fixing frame) provided in a wall of the vacuum vessel and a surface antenna fixed in the frame. Periphery of the antenna is surrounded by the frame, so that heat generated in the antenna flows from the periphery to the frame and further flows from the frame to the vacuum vessel. Thus, the antenna is efficiently cooled. Therefore, a liquid or gas refrigerant is unnecessary, and thus the configuration can be simplified. Furthermore, a temperature control device and a circulation device are unnecessary, so that the cost required for the devices is reduced.

An inductively coupled plasma source with a simple configuration, has an antenna cooling mechanism capable of reducing costs required for such devices. The plasma source is configured to generate plasma in a vacuum vessel, and includes a frame (antenna fixing frame) provided in a wall of the vacuum vessel and a surface antenna fixed in the frame. Periphery of the antenna is surrounded by the frame, so that heat generated in the antenna flows from the periphery to the frame and further flows from the frame to the vacuum vessel. Thus, the antenna is efficiently cooled. Therefore, a liquid or gas refrigerant is unnecessary, and thus the configuration can be simplified. Furthermore, a temperature control device and a circulation device are unnecessary, so that the cost required for the devices is reduced.

A plasma cutting system includes a plasma cutting power supply configured to provide cutting current to a torch. A controllable gas valve regulates at least one of a flow rate and a pressure supplied to the torch. A controller is operatively connected to the power supply to control a current level, and to the gas valve to adjust a valve position. The controller is configured to receive real-time torch position information from a motion control system that controls positioning of the torch. The position information includes torch positions along a first axis and a second axis that is perpendicular to the first axis. The controller is configured to calculate respective derivatives from the torch positions along the first and second axes, and a real-time velocity magnitude of the torch from the respective derivatives, and adjust the current level and the valve position based on the calculated real-time velocity magnitude.

A plasma arc torch includes a cathode extending along an axis of the torch, a pilot arc conductor, and a nozzle body. A first fluid conduit and second fluid conduit extend parallel to the axis of the torch. A first offset fitting includes a first duct coupled to and in fluid communication with the first fluid conduit, and a second duct in fluid communication with the first duct and outwardly radially offset from the first duct and extending away from the first duct in a proximal direction. A second offset fitting includes a third duct coupled to and in fluid communication with the second fluid conduit, and a fourth duct in fluid communication with the third duct and outwardly radially offset from the third duct and extending away from the third duct in the proximal direction. A spring compression plug electrically connects the pilot arc conductor to the nozzle body.