A center pipe is used in a plasma torch including a base portion and an electrode to supply cooling water into the electrode. The center pipe includes a pipe body and a contact piece. The pipe body has a tube-like shape with a cooling water channel therein. The pipe body is electrically conductive and configured to be electrically connected to an external power source via the base portion. The contact piece is arranged radially outside the pipe body at an intermediate position between a base end surface and a tip end surface of the pipe body. The contact piece is electrically conductive and energizes the electrode through contact with an internal circumferential surface of the electrode. The base end surface is disposed outside the electrode when the center pipe is inserted into the electrode. The pipe body is configured to be electrically connected to the electrode via the contact piece.

The present invention relates to a method and device for CO.sub.2 plasma cutting of a work piece, using a plasma cutting torch, wherein an arc is generated between the cutting head and the work piece, and a shielding gas is provided around the arc, characterized in that the shielding gas comprises CO.sub.2-snow or a mixture containing CO.sub.2-snow.

In one aspect, nozzles for arc torches are described herein comprising refractory coatings for increasing nozzle operational lifetimes via resistance to weld splatter and the associated accumulation of molten metal deposits. In one aspect, a nozzle for an arc torch comprises a first body including a central bore and an exterior surface. A coating is adhered to the exterior surface by thermal spray, physical vapor deposition (PVD), or chemical vapor deposition (CVD), the coating comprising a refractory layer including one or more metallic elements selected from the group consisting of aluminum, silicon and metallic elements of Groups IIIB-VIIIB of the Periodic Table and one or more non-metallic elements selected from Groups IIIA, IVA, VA, and VIA of the Periodic Table.

The present invention relates to techniques for absorbing and dissipating heat from a cutting torch during a plasma cutting process/operation, including a piercing stage. In accordance with at least one embodiment of the present invention, an outer shield club with a deflector ring absorbs and dissipates heat from a cutting torch including consumable components disposed therein. The shield club surrounds and protects the outermost consumable (e.g., nozzle/tip, shield, etc.) and dissipates heat from the plasma cutting operation. In some implementations, a flow of cooling water flows between and cools the outermost consumable and the shield club.

The invention features a replaceable cartridge for a plasma arc torch. The cartridge includes a cartridge body having a first section and a second section. The first and second sections are joined at an interface to form a substantially hollow chamber. The interface provides a coupling force that secures the first and second sections together. The cartridge also includes an arc constricting member located in the second section; an electrode included within the substantially hollow chamber; and a contact start spring element affixed to the electrode. The spring element imparts a separating force that biases the electrode toward at least one of the first section or the second section of the body. The separating force has a magnitude that is less than a magnitude of the coupling force.

A nozzle for a liquid cooled plasma arc cutting torch is provided. The nozzle includes a hollow nozzle body and a nozzle jacket disposed about an external surface of the nozzle body. The jacket defines (i) a length along the central longitudinal axis and (ii) a diameter of a distal tip of the jacket at the distal region of the nozzle, where the length is greater than about 1.5 inches and a ratio of the length to the diameter is greater than about 1.4. The nozzle also includes a coolant inlet and a coolant outlet defined between the nozzle body and nozzle jacket at the proximal region of the nozzle. The nozzle further includes a plurality of coolant channels cooperatively defined between the nozzle body and the nozzle jacket. The plurality of coolant channels extend axially between the proximal region and the distal region of the nozzle.

An adapter for a plasma arc torch comprising a torch body is provided. The adapter includes a body defining a longitudinal axis between a proximal end and a distal end and at least one protruding portion extending from the proximal end of the body. The at least one protruding portion is configured to be inserted into a cavity of the torch body to physically engage a switch inside of the cavity. The engagement of the switch is adapted to indicate installation of a consumable component in the plasma arc torch.

A plasma nozzle (120) having a nozzle body and a liner material (123) arranged within the nozzle body. The liner material (123) has a higher melting temperature than the nozzle body and includes one of a Tungsten alloy having a cross-sectional thickness (C) significantly greater than 0.25 mm, Molybdenum, Silver and Iridium.

The invention relates to an electrode for an especially gas-cooled plasma torch, in particular plasma cutting torch, the electrode comprising: an elongated electrode body with an open end and a closed end, the ends defining a longitudinal axis L, and an emission insert in the closed end, a cavity extending in the electrode body from the open end of the electrode body towards the closed end, the cavity fluidically communicating with the outer face of the electrode body which is radial with regard to the longitudinal axis, via at least one opening in its wall or in the front solid portion of the closed end. The invention further relates to a system consisting of said electrode and cooling tube, to a gas conducting unit, a plasma torch comprising same, a method for conducting gas in a plasma torch and a method for operating the plasma torch.

A method for conducting gas in a gas-cooled plasma torch wherein the plasma torch has a plasma torch body which holds an electrode with an open end and a closed end. A cavity extends from the open end in the direction of the closed end, and which, with a spacing in an axial direction, holds a nozzle by means of a nozzle holder. The nozzle has a central opening with an upstream inlet end, into which the electrode projects, and with an outlet end with a nozzle bore and is surrounded by a nozzle cap and/or a nozzle protection cap. The plasma torch body has an opening for a gas feeder, which opening is fluidically connected to a cooling tube which projects into the open end of the electrode.