Abstract: A method of starting an auto-ignition gas torch includes increasing a flow of oxygen above zero and increasing a flow of fuel gas to a level lower than the flow of oxygen for improved start reliability. In one form, the flow of oxygen is from about two times to about six times higher than the flow of fuel gas.

Abstract: A plasma arc torch is provided that includes a torch head, a pre-flow gas conduit for directing a pre-flow gas through the plasma arc torch, at least one plasma gas conduit for directing a plasma gas through the plasma arc torch, and a gas control device. The pre-flow gas conduit and the plasma gas conduit extend into a proximal end portion of the torch head. The gas control device is disposed proximate the torch head and extends between a distal end portion of the pre-flow gas conduit and a distal end portion of the plasma gas conduit. The gas control device is operatively connected to each of the pre-flow gas conduit and the plasma gas conduit. The gas control device selectively allows one of the pilot gas and the plasma gas to flow through the plasma arc torch.

Abstract: A method of operating a plasma arc torch is provided that includes directing a first portion of gas into a plasma chamber, directing a second portion of the gas to initiate a pilot arc in the plasma chamber, and redirecting the second portion of the gas to form a shield gas flow rather than venting the second portion to atmosphere. A plasma arc torch for this method includes a start cartridge disposed between an electrode and a tip for initiating the pilot arc. The start cartridge defines at least one redirect gas passageway in fluid communication with a shield gas passageway. The second portion of gas is redirected through the at least one redirect gas passageway and into the shield gas passageway.

Abstract: A method of operating a plasma arc torch is provided that includes directing a first portion of gas into a plasma chamber, directing a second portion of the gas to initiate a pilot arc in the plasma chamber, and redirecting the second portion of the gas to form a shield gas flow rather than venting the second portion to atmosphere. A plasma arc torch for this method includes a start cartridge disposed between an electrode and a tip for initiating the pilot arc. The start cartridge defines at least one redirect gas passageway in fluid communication with a shield gas passageway. The second portion of gas is redirected through the at least one redirect gas passageway and into the shield gas passageway.

Abstract: A method of operating a plasma arc torch is provided that includes directing a first portion of gas into a plasma chamber, directing a second portion of the gas to initiate a pilot arc in the plasma chamber, and redirecting the second portion of the gas to form a shield gas flow rather than venting the second portion to atmosphere. A plasma arc torch for this method includes a start cartridge disposed between an electrode and a tip for initiating the pilot arc. The start cartridge defines at least one redirect gas passageway in fluid communication with a shield gas passageway. The second portion of gas is redirected through the at least one redirect gas passageway and into the shield gas passageway.

Abstract: A plasma arc torch is provided that includes a torch head, a pre-flow gas conduit for directing a pre-flow gas through the plasma arc torch, at least one plasma gas conduit for directing a plasma gas through the plasma arc torch, and a gas control device. The pre-flow gas conduit and the plasma gas conduit extend into a proximal end portion of the torch head. The gas control device is disposed proximate the torch head and extends between a distal end portion of the pre-flow gas conduit and a distal end portion of the plasma gas conduit. The gas control device is operatively connected to each of the pre-flow gas conduit and the plasma gas conduit. The gas control device selectively allows one of the pilot gas and the plasma gas to flow through the plasma arc torch.

Abstract: A method of directing a gas flow in a tip of a gas torch includes: directing a flow of gas to an outer passageway of the tip; directing the flow of gas inwardly through at least one intermediate gas passageway; directing the flow of gas to a central gas passageway of the tip; and directing the flow of gas distally through a distal orifice of the tip.

Abstract: A method of directing gas flows in a gas torch includes directing a flow of a first gas and a flow of a second gas to a mixer central gas passageway of a mixer and directing the flow of the mixed first and second gases from the mixer to an axial passageway of a tip. The method further includes directing a flow of a third gas to an outer passageway of the tip, directing the flow of the third gas inwardly through at least one intermediate gas passageway, and then directing the flow of the third gas to a tip central gas passageway of the tip. Finally, the flow of the mixed first and second gases and the flow of the third gas are directed distally through a distal portion of the tip.

Abstract: A tip for use in a gas cutting torch is provided that includes an outer tip portion defining a central cavity and a distal orifice and an inner tip portion disposed within the cavity of the outer tip portion. The inner tip portion defines an outer surface, a central gas passageway in communication with the distal orifice of the outer tip portion, and an least one intermediate gas passageway extending from the outer surface to the central gas passageway for a flow of at least one gas to provide improved cooling to the tip.

Abstract: A tip assembly for use in a gas cutting torch is provided that includes a tip and a mixer. The tip includes a tip central gas passageway and a distal orifice and the mixer includes a proximal end portion and a distal end portion. The distal end portion of the mixer is adapted for connection to the tip and the proximal end portion of the mixer defines a connecting member that removably connects the mixer to a torch head.

Abstract: A method of operating a plasma arc torch is provided that includes directing a first portion of gas into a plasma chamber, directing a second portion of the gas to initiate a pilot arc in the plasma chamber, and redirecting the second portion of the gas to form a shield gas flow rather than venting the second portion to atmosphere. A plasma arc torch for this method includes a start cartridge disposed between an electrode and a tip for initiating the pilot arc. The start cartridge defines at least one redirect gas passageway in fluid communication with a shield gas passageway. The second portion of gas is redirected through the at least one redirect gas passageway and into the shield gas passageway.

Abstract: A method of starting an auto-ignition gas torch includes increasing a flow of oxygen above zero and increasing a flow of fuel gas to a level lower than the flow of oxygen for improved start reliability. In one form, the flow of oxygen is from about two times to about six times higher than the flow of fuel gas.

Abstract: A tip assembly for use in a gas cutting torch is provided that includes a tip and a mixer. The tip includes a tip central gas passageway and a distal orifice and the mixer includes a proximal end portion and a distal end portion. The distal end portion of the mixer is adapted for connection to the tip and the proximal end portion of the mixer defines a connecting member that removably connects the mixer to a torch head.

Abstract: A tip for use in a gas cutting torch is provided that includes an outer tip portion defining a central cavity and a distal orifice and an inner tip portion disposed within the cavity of the outer tip portion. The inner tip portion defines an outer surface, a central gas passageway in communication with the distal orifice of the outer tip portion, and an least one intermediate gas passageway extending from the outer surface to the central gas passageway for a flow of at least one gas to provide improved cooling to the tip.