Abstract: According to one embodiment, an insulation blanket for insulating a structure includes a first facer layer and a second facer layer. A plurality of intermeshed non-woven glass fibers are disposed between the first and second facer layers and a fumed silica insulating powder is also disposed between the first and second facer layers. The fumed silica insulating powder has an average particle size of between about 2 and 20 nanometers. The insulation blanket includes at least one exposed edge having a cauterized face that forms a barrier on the exposed edge to encase the fumed silica insulating powder within the interior of the insulation blanket, which minimizes degradation of the insulating value due to loss or shedding of the fumed silica insulating powder through the exposed edge. The cauterized edge has a depth of cauterized material of between about 0.05 mm and 3 mm.

Abstract: A land based or marine vessel based system for generating power from syngas utilizes a feedstock of waste material acquired from waste dumps, municipalities, and/or ports of call of the marine vessel. The marine vessel or land based system can be retrofitted to be fueled by the waste material. The syngas is used to provide propulsive and/or electrical power for the marine vessel or the land based system. The waste material is not just a feedstock for the syngas but is provided with payment from the ports of call to take the waste material away. The marine vessel also collects garbage floating on the waterway along the voyage between the various ports of call for use as feedstock in the production of syngas. The modular syngas generation system further generates H2 from the syngas. The H2 generated thereby is used to fuel an H2 fuel cell for the generation of electrical power.

Abstract: The present disclosure relates to a cold plasma generating apparatus that can efficiently ignite (initially discharge) cold plasma and easily match common impedance and that is optimized for use in applications related to sterilization because it can uniformly distribute power to multiple plasma sources through a single power supply in a multi-plasma array configuration and increase effective plasma volume, and a multi-cold plasma array apparatus comprising the same.

Abstract: A method for manufacturing a spherical metallic powder blend using a metallic starting material, the method including steps of grinding the metallic starting material to yield an intermediate powder, spheroidizing the intermediate powder to yield a first spherical powder component, and mixing the first spherical powder component with a second spherical powder component, wherein the first spherical powder component and the second spherical powder component have substantially the same chemical composition.

Abstract: Embodiments of arc plasma cutting torches are disclosed. In one embodiment, an eccentric plasma cutting torch includes an upper portion and a lower portion. The lower portion is angled on one side along a length ? which results from continuously smaller cross sections of the lower portion which are biased towards a non-angled side of the torch. As a result, a central axis of an electrode of the torch, used for cutting, is biased by an offset from a central axis of the upper portion towards the non-angled side of the torch. Such an offset allows for a torch tip region of the torch to get closer into otherwise difficult-to-access portions of workpieces for cutting. Furthermore, the overall dimensions of the torch are configured such that cooling elements within the torch dissipate enough heat to keep the torch in a stable operating condition during a cutting operation.

Abstract: A method of forming a golf club head assembly includes aligning a faceplate with a recess of a club head; welding the faceplate to the club head; then, after welding the faceplate, heating the club head and faceplate to at least a solvus temperature of the faceplate for a predetermined amount of time; and then, after heating the club head and faceplate, allowing the club head and faceplate to air cool.

Abstract: A back end of the line (BEOL) fuse structure having a stack of vias. The stacking of vias leads to high aspect ratios making liner and seed coverage inside the vias poorer. The weakness of the liner and seed layers leads to a higher probability of electromigration (EM) failure. The fuse structure addresses failures due to poor liner and seed coverage. Design features permit determining where failures occur, determining the extent of the damaged region after fuse programming and preventing further propagation of the damaged dielectric region.

Abstract: Disclosed herein is a method to produce multiphase composite materials directly from solution precursor droplets by a fast pyrolysis process using a microwave plasma embodiment containing a microwave generating source, a dielectric plasma torch, and a droplet maker. Here, using homogenous solution precursors, droplets are generated with a narrow size distribution, and are injected and introduced into the microwave plasma torch with generally uniform thermal path. The generally uniform thermal path in the torch is achieved by axial injection of droplets into an axisymmetric hot zone with laminar flows. Upon exposing to high temperature within the plasma with controlled residence time, the droplets are pyrolyzed and converted into particles by quenching with a controlled rate of the exhaust gas in a gas chamber. The particles generated have generally uniform sizes and uniform thermal history, and can be used for a variety of applications.

Abstract: There is provided an inductively coupled plasma processing apparatus capable of reducing a RF power loss within a high frequency power supply unit (particularly, a matching unit) and capable of enhancing a plasma generation efficiency. In this inductively coupled plasma processing apparatus, a multiple number of closed-loop secondary circuits 96, 98 independent from each other are formed between a coaxial antenna group 54 and a transformer 68. Further, by varying electrostatic capacitances of variable capacitors 64 and 66, secondary currents I2A and I2B flowing through an inner antenna 58 and an outer antenna 60, respectively, of the coaxial antenna group 54 are independently controlled. Accordingly, it is possible to readily control a plasma density distribution on a semiconductor wafer W in a diametrical direction.

Abstract: A special-purpose plasma arc torch for gouging grooves in a metal workpiece includes an angled nozzle having a bore made up of a first bore portion and a second bore portion that makes an angle of about 15° to about 75° with the first bore portion. The nozzle includes a proximal portion and a distal portion, the proximal portion being adapted for surrounding an electrode assembly when the nozzle is installed in the torch, the distal portion being adapted such that a part of the distal portion extends beyond a front face of an electrode of the torch. The part of the distal portion extending beyond the front face of the electrode has an exterior shape other than cylindrical or conical, and preferably has a non-axisymmetric shape that makes it suitable for fitting within a deep groove in a workpiece.

Abstract: Sealing device (23) for a machine (1) for the plasma treatment of containers (2), comprising at least first and second annular sealing surfaces (24, 25) suitable for cooperating respectively with first and second separate annular zones (13, 15) of the neck (12) of a container (2).

Abstract: A system is provided that includes a torch power unit, wherein the torch power unit includes a motor and a digital device coupled to the motor and configured to control the motor. A method of operation is provided that includes controlling one or more aspects of a torch power unit via a microprocessor, a digital signal processor, or a field programmable gate array, or a combination thereof. In another embodiment, a system is provided that includes a torch power unit that includes a torch, one or more components comprising a generator, a power converter, a compressor, a motor, a wire feeder, or a combination thereof, and a microprocessor configured to control the one or more components.

Abstract: A method of starting a multi-gas plasma arc torch for cutting a workpiece is provided that includes directing a pre-flow gas within the plasma arc torch and switching the pre-flow gas to a plasma gas before a pilot arc is transferred to the workpiece. The plasma gas is supplied initially at a first gas pressure when the pre-flow gas is switched to the plasma gas. The gas pressure is switched to a second gas pressure that is different than the first gas pressure after the pilot arc is transferred. The method provides a smooth transition from the pre-flow gas to the plasma gas and reduces the time delay in replacing the pre-flow gas with the plasma gas in the plasma arc torch, thereby improving cut or marking quality.

Abstract: A method of starting a plasma arc torch is provided that includes directing a pre-flow gas and a start shield gas through the plasma arc torch during generation and transfer of a plasma arc, and switching from the pre-flow gas to a plasma gas, and switching from the start shield gas to a primary shield gas after transfer of the plasma arc to a workpiece. A method of stopping a plasma arc torch is also provided that includes directing a plasma gas and a primary shield gas through the plasma arc torch during steady-state operation, and switching from the primary shield gas to a stop shield gas during ramp down of an operating current.

Abstract: An atmospheric pressure plasma source includes a body including a distal end, a blade extending from the distal end and terminating at a blade edge, a plasma-generating unit, and a plasma outlet communicating with the plasma-generating unit and positioned at the distal end. The plasma outlet is oriented at a downward angle generally toward the blade edge, wherein the plasma outlet provides a plasma path directed generally toward the blade edge. The plasma may be applied to the coating at an interface between the coating and an underlying substrate. While applying the plasma, the blade is moved into contact with the coating at the interface, wherein the blade assists in separating the coating from the substrate while one or more components of the coating react with energetic species of the plasma.

Abstract: A protective shell for surrounding a portion of a body of a handheld plasma torch includes a first and second shell section. The plasma torch body includes a handle, a head extending from the handle and a torch tip extending from the head. The first shell section is structurally independent from an outer surface of the plasma torch body. The second shell section is structurally independent from the outer surface of the plasma torch body and is capable of being secured to the first shell section such that, in combination, the first and second shell sections surround the torch head and provide (i) structural protection to the torch head and (ii) thermal insulation to the torch head, wherein the first and second shell sections are electrically insulated relative to the torch head.

Abstract: A method and a device for generating a plasma jet under atmospheric pressure for the surface treatment of workpieces has a supply line for the plasma-capable medium, and an apparatus for electrically exciting the plasma-capable medium by an electric arc periodically ignited between a cathode and an anode constructed as a nozzle. To achieve a highly effective plasma jet even at relatively low temperatures of the plasma jet, a heating apparatus for preheating the plasma-capable medium is arranged upstream of the apparatus for electrically exciting the plasma-capable medium.

Abstract: Methods for depositing hardfacing material on portions of drill bits comprise providing a vertically oriented plasma transfer arc torch secured to a positioner having controllable movement in a substantially vertical plane. A rolling cutter is secured to a chuck mounted on an articulated arm of a robot. A surface of a tooth of the rolling cutter is positioned in a substantially perpendicular relationship beneath the torch. The torch is oscillated along a substantially horizontal axis. The rolling cutter is moved with the articulated arm of the robot in a plane beneath the oscillating torch. A hardfacing material is deposited on the tooth of the rolling cutter.

Abstract: Methods, devices and systems for laser-supported plasma cutting or plasma welding of a workpiece. In one aspect, a method includes producing a plasma beam which extends in an expansion direction between an electrode and a processing location on the workpiece, the plasma beam having, with respect to a center axis of the plasma beam that extends in the expansion direction, an inner central region and an outer edge region, and supplying laser radiation to the outer edge region of the plasma beam. The laser radiation supplied to the outer edge region extends parallel with the center axis of the plasma beam.

Abstract: Certain embodiments described herein are directed to induction devices comprising an oxidation resistant material. In certain examples, the induction device comprises a coil of wire that is produced from the oxidation resistant material. In some examples, the oxidation resistant induction device can be used to sustain an inductively coupled plasma in a torch.

Abstract: A dual resistance heater for a phase change material region is formed by depositing a resistive material. The heater material is then exposed to an implantation or plasma which increases the resistance of the surface of the heater material relative to the remainder of the heater material. As a result, the portion of the heater material approximate to the phase change material region is a highly effective heater because of its high resistance, but the bulk of the heater material is not as resistive and, thus, does not increase the voltage drop and the current usage of the device.

Abstract: A method of controlling the position of a tilt/tilt style plasma arc torch relative to a workpiece for a bevel cutting operation is provided that includes: calculating a bevel pivot length, wherein the bevel pivot length is a function of a torch height; piercing the workpiece with the plasma arc torch; adjusting a position of the plasma arc torch by at least one linear offset value based on the bevel pivot length; rotating the plasma arc torch about its center of rotation to the desired cutting angle and maintaining a torch center point; and translating the plasma arc along its longitudinal axis to maintain a desired arc voltage between the plasma arc torch and the workpiece.

Abstract: A method of controlling a position of a plasma arc torch relative to a workpiece for a bevel cutting operation is provided that includes: calculating a bevel pivot length, which is a function of a torch height; piercing the workpiece with the plasma arc torch; rotating the plasma arc torch about its center of rotation to a desired cutting angle; translating the plasma arc torch along at least one of X, Y, and Z axes to maintain a torch center point; and translating the plasma arc torch along at least one of the X, Y and Z axes to achieve a resultant displacement along a longitudinal axis of the plasma arc torch to maintain a desired torch height.

Abstract: An electrode for a plasma arc torch includes a generally cylindrical elongated body formed of an electrically conductive material. The elongated body includes a proximal end that connects to a power supply and a distal end that receives an emissive element. The electrode can include a flange that is disposed about a surface relative to the distal end of the elongated body, extends radially from the surface of the elongated body, and is utilized to establish a uniform gas flow distribution of a plasma gas flow about the distal end of the elongated body. The electrode can include a contact element that is in electrical communication with the proximal end of the electrode. The contact element includes seating portion that has an outer width that is greater than the outermost diameter of the electrode body and is configured to position the contact element within the plasma arc torch.

Abstract: An electrode for a plasma arc torch includes a generally cylindrical elongated body formed of an electrically conductive material. The elongated body includes a proximal end that connects to a power supply and a distal end that receives an emissive element. The electrode can include a flange that is disposed about a surface relative to the distal end of the elongated body, extends radially from the surface of the elongated body, and is utilized to establish a uniform gas flow distribution of a plasma gas flow about the distal end of the elongated body. The electrode can include a contact element that is in electrical communication with the proximal end of the electrode. The contact element includes seating portion that has an outer width that is greater than the outermost diameter of the electrode body and is configured to position the contact element within the plasma arc torch.

Abstract: Material treatment is effected in a treatment region by at least two energy sources, such as (i) an atmospheric pressure (AP) plasma and (ii) an ultraviolet (UV) laser directed into the plasma and optionally onto the material being treated. During processing, the material being treated may remain substantially at room temperature. Precursor materials may be dispensed before, and finishing material may be dispensed after treatment. Precursors may be combined in the plasma, allowing for in situ synthesis and dry treatment of the material. Electrodes (e1, e2) for generating the plasma may comprise two spaced-apart rollers which, when rotating, advance the material through a treatment region. Nip rollers adjacent the electrode rollers define a semi-airtight cavity, and may have a metallic outer layer. Loose fibers and fragile membranes may be supported on a carrier membrane, which may be doped. Individual fibers may be processed. Electrostatic deposition may be performed. Topographical changes may be effected.

Abstract: In a method for controlling pulse arc welding where an arc is created between a wire and a base material, a pulse waveform different from the pulse waveform for steady-state welding is outputted when a predetermined time has passed since short-circuit welding control was started at arc start, and after a sufficiently large melt pool is formed, the pulse waveform for the steady-state welding is outputted. This reduces the generation of spatters after an arc is created and until the arc is stabilized.

Abstract: The present disclosure is directed to a system for a surface treatment via plasma generated by a slim and/or flexible electrode and the method thereof. By using the plasma, the surface treatment for an outer wall or an inner wall of a tube can be performed.

Abstract: A system and method for managing power delivered to a processing chamber is described. In one embodiment current is drawn away from the plasma processing chamber while initiating an application of power to the plasma processing chamber during an initial period of time, the amount of current being drawn away decreasing during the initial period of time so as to increase the amount of power applied to the plasma processing chamber during the initial period of time.

Abstract: The present invention provides a multi-mode plasma arc torch that includes a cylindrical vessel having a first end and a second end, a first tangential inlet/outlet connected to or proximate to the first end, a second tangential inlet/outlet connected to or proximate to the second end, an electrode housing connected to the first end of the cylindrical vessel such that a first electrode is (a) aligned with a longitudinal axis of the cylindrical vessel, and (b) extends into the cylindrical vessel, and a hollow electrode nozzle connected to the second end of the cylindrical vessel such that the center line of the hollow electrode nozzle is aligned with the longitudinal axis of the cylindrical vessel. Adjusting a position of the electrode with respect to the hollow electrode causes the multi-mode plasma arc torch to operate in a dead short resistive mode, a submerged arc mode, an electrolysis mode, a glow discharge mode or a plasma arc mode.

Abstract: A process and apparatus for preparing a nanopowder are presented. The process comprises feeding a reactant material into a plasma reactor in which is generated a plasma flow having a temperature sufficiently high to vaporize the material; transporting the vapor with the plasma flow into a quenching zone; injecting a preheated quench gas into the plasma flow in the quenching zone to form a renewable gaseous condensation front; and forming a nanopowder at the interface between the renewable controlled temperature gaseous condensation front and the plasma flow.

Abstract: The invention relates to a device generating a plasma flow comprising an electrically conductive housing, tubular in shape, forming a central channel traversed by a vortex gas, a central electrode arranged coaxially in said channel and an electric power source intended to apply an electric voltage V between the electrode and the housing, characterized in that the mean diameter of the channel formed by the housing decreases progressively from an area situated substantially at the level of the free end of the electrode as far as an end area of said housing, said end area being configured in such a way that the minimum electric voltage Vcmin(0) to be applied in order to develop an electric arc between said electrode and said end area is strictly greater than said voltage V.

Abstract: A system and method for regulating a gas flow of a plasma arc system. The system having a gas regulator that control gas flow from a gas source to the plasma torch system, a pilot input valve to fill a pilot chamber and a pilot dump valve to evacuate the pilot chamber, the pilot chamber mechanically coupled to the gas regulator through a pressure actuator, such that the gas flow pressure through the regulator is controlled using the pressure actuator and based on the pressure in the pilot chamber.

Abstract: The invention relates to a method and a device for the plasma treatment of metal substrates or insulating substrates (3) running substantially continuously through a vacuum chamber having a treatment zone (2), the plasma being sustained by radiofrequency inductive coupling in the treatment zone (2) by means of an inductor (4) connected to a radiofrequency generator, in which the inductor (4) is protected from any contamination by the material emitted by the surface of the substrates (3) by means of a Faraday cage (7), which is positioned between the plasma and the inductor (4), and in which the Faraday cage (7) is on average electrically biassed positively with respect to the substrates (3) or with respect to a counter-electrode present in the plasma.

Abstract: A method and apparatus for controlling a gas supply to a plasma arc torch uses a proportional control solenoid valve positioned adjacent the torch to manipulate the gas flow to the torch, thereby extending electrode life during arc transfer and shutdown. Swirl ring design can be simplified and gas supply and distribution systems become less complicated. The invention also allows manipulation of shield gas flow to reduce divot formation when making interior cuts. The system can be controlled with a digital signal processor utilizing a feedback loop from a sensor.

Abstract: In order to increase the operable range of a DC plasma torch in an abatement apparatus, the apparatus comprises a power control configured for controlling the power of the plasma torch by selective control of the plasma source gas flow regulator

Abstract: An apparatus for synergistically combining a plasma with a comminution means such as a fluid kinetic energy mill (jet mill), preferably in a single reactor and/or in a single process step is provided by the present invention. Within the apparatus of the invention potential energy is converted into kinetic energy and subsequently into angular momentum by means of wave energy, for comminuting, reacting and separation of feed materials. Methods of use of the apparatus in the practice of various processes are also provided by the present invention.

Abstract: Embodiments of the present invention are related to an electrode for a plasma arc torch, the electrode comprising a generally tubular outer wall, an end wall, and a protrusion. The end wall is joined to a distal end of the outer wall and supports an emissive element in a generally central region. The protrusion extends from the generally central region of the end wall and is configured to connect with an electrode holder by a releasable connection, wherein the protrusion is configured such that at least one coolant passage forms between the protrusion and the electrode holder when the electrode is connected with the electrode holder. In some embodiments, the releasable connection comprises a threaded connection, wherein the protrusion is threaded to releasably connect to a threaded coolant tube of the electrode holder. In other embodiments, at least one coolant passage is defined by the threaded connection.

Abstract: A method and apparatus for processing metal bearing gases involves generating a toroidal plasma in a plasma chamber. A metal bearing gas is introduced into the plasma chamber to react with the toroidal plasma. The interaction between the toroidal plasma and the metal bearing gas produces at least one of a metallic material, a metal oxide material or a metal nitride material.

Abstract: A welding line can be rapidly extracted using three-dimensional CAD data constituted of a large number of line sections containing welding line candidates. The method of choosing a welding line includes: a step (S110) of specifying one face (first face constituting a reference face) from two faces of a member where a welding line is to be formed; a step (S120) of specifying the other face (second face constituting a groove face) from the two faces of the number where a welding line is to be formed; a step (S130) of extracting an edge line; a step (S140) of selecting an edge line zone where welding is possible; a step (S150) of creating welding line information by unifying edge lines where welding is possible; and a step (S160) of correcting welding line information in accordance with the groove shape.

Abstract: A method for oxidizing a combustible material. The method includes introducing a volume of the combustible material into a plasma zone of a gliding electric arc oxidation system. The method also includes introducing a volume of oxidizer into the plasma zone of the gliding electric arc oxidation system. The volume of oxidizer includes a stoichiometrically excessive amount of oxygen. The method also includes generating an electrical discharge between electrodes within the plasma zone of the gliding electric arc oxidation system to oxidize the combustible material.

Abstract: A system for supplying fluids to a plasma arc torch includes a single-gas power supply for regulating electrical power to the torch and for regulating supply of a first fluid to the torch, a flow regulator for regulating supply of a second fluid to the torch, and a first pressure-actuated valve disposed between the flow regulator and the torch. The valve shuts off supply of the second fluid to the torch when the first valve is closed and allows the second fluid to be supplied when the first valve is open. The first valve is opened by pressure of the first fluid supplied to the torch and closed when the first fluid is not supplied to the torch. A second pressure-actuated valve may be provided in the supply line for the first fluid, which is opened by pressure of the second fluid being supplied to the torch.

Abstract: The present invention relates to a system and method for automated or “robotic” application of hardfacing to the surface of a steel-toothed cutter of a rock bit. In particular, the system incorporates a grounded adapter plate and chuck mounted to a robotic arm for grasping and manipulating a rock bit cutter beneath an electrical or photonic energy welding source, such as a plasma arc welding torch manipulated by a positioner. In this configuration, the torch is positioned substantially vertically and oscillated along a horizontal axis as the cutter is manipulated relative along a target path for the distribution of hardfacing. Moving the cutter beneath the torch allows more areas of more teeth to be overlayed, and allows superior placement for operational feedback, such as automatic positioning and parameter correction. In the preferred embodiment, sensors provide data to the control system for identification, positioning, welding program selection, and welding program correction.

Abstract: A plasma spray gun comprises a nozzle, an upstream powder injector, and a downstream powder injector. The upstream powder injector is disposed outside the nozzle and axially adjacent a nozzle outlet. The downstream powder injector is disposed axially downstream of the first upstream powder injector. The downstream powder injector is operative in a first coating mode, and the upstream powder injector is operative in a second coating mode.

Abstract: An electrode for a plasma arc torch is provided by the teachings of the present disclosure. In one form, the electrode includes a conductive body, a plurality of deformed emissive inserts, and a dimple. In one form, the plurality of emissive inserts are concentrically nested about the centerline of the conductive body, and the dimple is positioned concentrically about a centerline of the conductive body. The plurality of emissive inserts and the dimple increase the life of the electrode.

Abstract: The invention relates to a method for cleaning a contact tube (20) of a welding torch (10), via which contact tube a welding wire (13) is supplied with electrical energy, said welding wire being moved towards the welding torch (10) by a wire reel (14) or a welding drum via a wire feeder (11), as well as to a welding plant (1) and a contact tube (20) for the welding torch (10) of such a welding plant (1). In order to prolong the service life of a contact tube (20) of a welding torch (10), the invention provides that the welding wire (13) is at least once moved backwards in the direction of the wire reel (4) or wire drum until the end (27) of the welding wire (13) lies at least within the length (36) of the contact tube (20), and that the welding wire (13) will subsequently again be moved forwards, in particular moved backwards into its starting position.

Abstract: A method is disclosed for adjusting the composition of plasmas used in plasma doping, plasma deposition and plasma etching techniques. The disclosed method enables the plasma composition to be controlled by modifying the energy distribution of the electrons present in the plasma. Energetic electrons are produced in the plasma by accelerating electrons in the plasma using very fast voltage pulses. The pulses are long enough to influence the electrons, but too fast to affect the ions significantly. Collisions between the energetic electrons and the constituents of the plasma result in changes in the plasma composition. The plasma composition can then be optimized to meet the requirements of the specific process being used. This can entail changing the ratio of ion species in the plasma, changing the ratio of ionization to dissociation, or changing the excited state population of the plasma.

Abstract: A method and apparatus for processing metal bearing gases involves generating a toroidal plasma in a plasma chamber. A metal bearing gas is introduced into the plasma chamber to react with the toroidal plasma. The interaction between the toroidal plasma and the metal bearing gas produces at least one of a metallic material, a metal oxide material or a metal nitride material.

Abstract: A plasma arc torch is provided that includes a wear stop designed to detect wear of an electrode and prevent the use of the electrode once the electrode has experienced a certain amount of wear. Either the electrode or the nozzle is movable with respect to the main torch body, and the movable component defines a projection. The wear stop is positioned a predetermined distance from a nozzle of the torch, such that prior to experiencing an excessive amount of wear, the electrode is able to contact the nozzle and initiate a pilot arc for starting a torch operation. Once the length of the electrode becomes shorter than a predetermined length due to wear, the projection of the electrode engages the wear stop, and the wear stop prevents the electrode from contacting the nozzle. In this way, an electrode that is excessively worn cannot be used in subsequent torch operations.

Abstract: An improved plasma torch and method of starting the torch are provided. The torch may comprise a main torch body with an electrode assembly coupled to a piston therein. The piston and electrode assembly are moveable between a starting position whereby the electrode assembly contacts a nozzle, and an operating position whereby the electrode assembly does not contact the nozzle. The piston is moveable by directing fluid, which may comprise coolant, through the plasma torch either in a first direction which biases the piston to the starting position, or in an opposite second direction which biases the piston so as to retract the electrode assembly to the operating position. A reversing valve or reversible pump may be used to control the direction of the flow of the fluid. Thereby, the coolant supply may be used to both cool the torch and control the starting and operation of the torch.