Apparatus for cooling plasma arc torch nozzles

A method of manufacturing a nozzle for use in a plasma arc torch comprising:

• providing a nozzle body having a hollow interior and a nozzle exit orifice at a distal end, the nozzle body having a cylindrical portion;
• and
• press fitting a nozzle liner into the hollow interior of the nozzle body to (a) align a liner exit orifice with the nozzle exit orifice, and (b) provide contact between a majority of an exterior surface of the cylindrical section of the nozzle liner with an interior surface of the cylindrical portion of the nozzle body to form a thermal contact region that dissipates heat between the nozzle liner and the cylindrical portion of the nozzle body via thermal conduction.

A plasma arc torch comprising:

• a torch body, an electrode mounted in the torch body;
• and
• a nozzle mounted relative to the electrode in the torch body to, at least in part, define a plasma chamber, the nozzle having a nozzle body with a hollow interior, a cylindrical portion, and a nozzle exit orifice at a distal end and a nozzle liner having a hollow interior and a liner orifice aligned with the nozzle exit orifice, the liner having a cylindrical section a majority of which is in contact with an interior surface of the cylindrical portion of the nozzle body to form a thermal contact region that dissipates heat between the nozzle liner and the cylindrical portion of the nozzle body via thermal conduction.

A nozzle for a plasma arc torch comprising:

• a nozzle body having a hollow interior with a nozzle exit orifice at a distal end;
• and
• a nozzle liner having a hollow interior and being disposed in the hollow interior of the nozzle body such that nozzle liner orifice is aligned with the nozzle exit orifice, the nozzle liner having an exterior surface a majority of which is in contact with an interior surface of the nozzle body to form a thermal contact region that dissipates heat between the nozzle liner and the nozzle body via thermal conduction.